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UNITED STATES PACIFIC FLEET AND PACIFIC OCEAN AREAS 25' 30' 35' 55' I52°O" • 40' TRUK • • • FIELD SURVEY ULALU.S of DUBLONIS PARAM IS. ETEN IS i / TARIK IS / .FEFAN JAPANESE DEFENSES •. L CAFALI AA BEGUETS IS on 10" MESEGON IS
5" TRUK KUOP ATOLL 7°0' KEY MAP 55 I52°O 5 PART ONE-THE REPORT
CINCPAC-CINCPOA BULLETIN NO. 34 6 15 MARCH 1946 Eforofu Kaikyo fu Sluma
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.rfilrhongR !*«> C . \ AfMun&ma V Arnjmka 3 Tg.S.-lataa ./.ll'.l SEA K unnuyii I)j am Is BAJNDA SKA , ^7 V r.Van Dumoi. TIMOA SJM/cm NAME RANK ORGANIZATION REPRESENTINq HEADQUARTERS, FLEET MARINE FORCE, PACIFIC WEINTRAUB, Daniel J. Captain, USN PHIBSPAC PHIBSPAC C/O FLEET POST OFFICE, SAN FRANCISCO. GUTHRIE, James T. Lt.. USC & GS PHIBSPAC PHIBSPAC HELANDER, Melvin Lt (jg), USNR INTERPRON 2 COMMARIANAS Confidential 1 March, 1946 ZIRKELBACH, Harry W. Ensign, USNR MEIU 4 MEIU 4 From : Officer in Charge, Japanese Defense Study Group. (4) Signal Communications. To : The Commander in Chief, Pacific Fleet and Pacific Ocean Areas, ORGANIZATION REPRESENTING Via : The Commanding General, Fleet Marine Force, Pacific, NAME RANK POPE, Albert L. Captain, USMC Hdqts, FMF PAC FMF,PAC Subject: TRUK, transmittal of Japanese defense study of. CLARK, John A. Lt (Jg), USNR JICPOA JICPOA HURLBUT, Franklin C. Ensign, USNR COMMARIANAS COMMARIANAS References: (a) CinCPOA dispatch 162329 of November, 1945. EVANS, William A. Rad. Elec. NOB, GUAM COMMARIANAS (b) CinCPO- - A dispatch 220315 of November, 1945. (c) CinCPOA dispatch 270316 of November, 1945, (5) Strategic and Tactical Subjects;(History; Order of Battle; Panoramic-Photographic Terrain Study; Tactical Dispositions; 00 1* Upon completing its survey of CHICHI JIMA the Japanese Defense Infantry Weapons Dispositions; Medical and Sanitary Condi Study Group proceeded to TRUK on board the USS Castle Rock (AVP 35) in accordance < with references (a), (b), and (c). The Group was organized as set forth below tions). to carry out its mission of reporting on the Japanese defenses on TRUK, Avail o able intelligence material was studied enroute. NAME RANK ORGANIZATION REPRESENTING z GOWER, Elmer B. Major, USA Hdqts, AFMIDPAC AFMIDPAC 2. The Study Group was organized as follows: MALLON, James R. Captain, USMCR 3rd MarDiv FMF,PAC KJ Ensign, USNR JICPOA JICPOA (a) Supervisory group. SHEEHAN, Richard G. NAME RANK ORGANIZATION REPRESENTING (6) Aviation, Z NAME RANK ORGANIZATION REPRESENTING DAVIS, Leonard L. Brig. Gen.,USA 2273d AAC (Hawaii) AFMIDPAC MARSHALL, St.Julien R. Colonel, USMC Hdqts, FMF,PAC FMF,PAC PETERS, James M. Commander, USN COMAIRPAC COMAIRPAC CO REEVE, Parker M. Colonel, USA Oahu Engr. Ser. AFMIDPAC WEINTRAUB, Daniel J. Captain, USN PHIBSPAC PHIBSPAC 3. The Study Group arrived at TRUK on 13 December, 1945 and commenced Z COMAIRPAC COMAIRPAC PETERS, James M. Commander, USN a study of the Japanese defenses Immediately. The desired data was collected by _J •RIDGE, Thomas L. Lt.Col., USMC 3rd MarDiv FMF,PAC 23 December, 1945 and the Study Group departed. co MEDINNIS, Charles L. P. Lt.Col., USA Oahu Ord. Ser. AFMIDPAC POPE, Albert L. Captain, USMC Hdqts, FMF,PAC FMF,PAC UI PORTH, Alfred M. 1st Lt., USMCR Hdqts, FMF,PAC FMF,PAC Z •Assembly and Publication of Report. ST. JUKEEN R. MARE o (b) For the purpose of collecting information and preparation of Cblonel, USMC as the final report the Study Group was divided into sections with the senior officer in charge of each section, HEADQUARTERS (l) Engineer. (Fortifications, Installations, Roads, Rail FLEET MARINE FORCE, PACIFIC roads, Bridges, Explosives, Demolitions) C/O FLEET POST OFFICE, SAN FRANCISCO. NAME RANK ORGANIZATION REPRESENTING Confidential 2 March, 1946. REEVE, Parker M, Colonel, USA Oahu Engr, Ser. AFMIDPAC JAMES, David E. Captain, USA 2805th Engr.Gen.Sr.Bn. AFMIDPAC JAEDTKE, Gilbert H, Lt (jg), USNR 5th Naval Cons. Brig. COMMARIANAS 1st Endorsement on ltr fr OinC, Japanese Z HIROKI, Howard K. 2nd Lt., USA Hdqts, MIDPAC AFMIDPAC Defense Study Group to CINCPAC-CINCPOA, NAHLIK, Sylvester R. Carpenter, USNR 5th Naval Cons. Brig. COMMARIANAS o dtd 1 March, 1946. CO UJ (2) Artillery and Ordnance. (CD,AA, and DP Guns: Tanks, and From : The Commanding General, Z CO Vehicles) To : ui The Commander in Chief, Pacific Fleet and Pacific Ocean Areas. NAME RANK ORGANIZATION REPRESENTING Subject: TRUK, transmittal of Japanese defense study of. CO MEDINNIS, Charles L. P. Lt.Col. USA Oahu Ord. Ser. AFMIDPAC 1. UI DORR, William R. Lt.Col. USMC Hdqte, FMF,PAC FMF,PAC Forwarded, HARRISON, Edward P. Lt.Col. USA Oahu Ord. Ser. AFMIDPAC Z MENDENHALL, George E. Lt (Jg) USNR JICPOA JICPOA WYCOFF, DeWltt D. 2nd Lt. USMCR 3rd MarDiv FMF,PAC (3) Beaches and Hydrography; Naval Vessels and Installations. ROY S. GEIGER LC". G ..1L£D AT 3 YEfcR INTERVALS; Lu^.^rtcSlHED ASTfcR 12 YEABS. DOD DIB 5200.10 UNITED STATES PACIFIC FLEET AND PACIFIC OCEAN AREAS NAVY HEADQUARTERS OF THE COMMANDER IN CHIEF 20 CNO TLR/Jrf 2 BuAir 2 BuMed CONFIDENTIAL 2 BuOrd Z 2 BuShlps 15 March 1946 - Serial ADM-150802 2 BuDocke 2 The Hydrographer Navy Dept From: Commander in Chief, U. S. Pacific Fleet and Pacific Ocean 5 ComdtANSCol Wash D C Areas* 5 ComdtNavWarCollege Newport R I 00 To: Distribution List. 2 ComPhlbTraPac FPO San Diego Calif 2 COTCPac FPO San Diego Calif < Subject: CINCPAC-CINCPOA Bulletin No. 3-46, JAPANESE DEFENSES ON 2 CONavResLab Bellevue D C TRUK ATOLL, CAROLINE ISLANDS. 2 USNLO RadiationResearchLabMIT Cambridge Mass o 2 USNLORadloLabHarvardU Cambridge Mass a. Enclosure: (A) Subject Bulletin. 2 USNLOOSRD Wash D C 5 CINCPAC Z 1. Subject report, forwarded herewith, need not be reported 5 ComAirPac and when no longer of value should be destroyed. No report of destruction 2 ComBatCruPac is necessary. 2 ComDe sPac 5 CominPac z 2 ComServPac 2 ComPhibsPac 2 AdComPhlb sPac Q L. E. PETERSEN, 2 Com5thFleet By direction. 2 Com7thFleet Z 2 OinCSUPRADPAC DISTRIBUTION LIST 2 ComNavJap CO 2 Chief NavTecJap UJ Copies ARMY 2 SNO USSBS Z 2 PhotoIntelCenter Anacostia D C 2 COInterpronONE _j 10 ComGenAAF War Dept For: AC/AS Intelligence 2 COInterpronTWO o 10 ComGenAGF Army War College Wash D C 2 DivPacDivBuDocks Navy 128 (PH) 5 ComGenASF War Dept 5 ComMarJ anas 14 Chief MIS War Dept 2 Chiefof Engrs War Dept MARINE CORPS 2 ChiefofOrd War Dept 4 ChiefSigOff War Dept 4 ComdtMarCorps Incl: Arlington Hall Station Arlington Va 3 ComGenFMFPAC 2 ChiefChemicalWarfare War Dept 2 C omGe nAirFMFPAC 2 SurgeonGeneral War Dept 2 ComGenlllPhibCorpe 5 ComdtCom&StaffSch Ft Leavenworth Kan 5 ComdtMarCorpsSchsMarBks Quantico Va 2 ComdtFASch Ft Sill Ofcla 2 ea. ComGenMarDiv z 2 COOrdBDCAberdeenProvingGround Aberdeen Md 2 ComGenTraCom FMF o 2 ComdtlnfantrySchool Ft Benning Ga 3 DlrofAviation MARCORPS CO 10 SCAP 10 AT COM TRUK UJ CO 5 ClnCAFPAC APO 500 Z 2 ComGenPACUSA APO 925 Ul 2 ComGenUSAFIK APO 235 u. 2 ComGenUSAFCTO APO 879 NY UJ 2 ComGenEIGHT APO 343 a 10 ComGenMIDPAC APO 958 Ul 2 The EngrMIDPAC APO 958 CO 2 C030thEngrBaseTopoBn APO 957 Ul Z 2 C064thEngrTopoBn APO 246 2 CO AGF APO 246 2 CO AGF APO' 247 2 ComGenWesPacBasCom APO 244 TABLE OF CONTENTS TITLE PAGE NO TITLE PAGE NO. GEOGRAPHY 1 Army Communications 101 SUMMARY 6 Radio 101 Radio Countermeasures 103 A SHORT HISTORY OF THE MILITARY DEVELOPMENT OF TRUK 8 Radio Intelligence 103 Radio Direction Finders 103 JAPANESE ORDER OF BATTLE, TRUK ISLANDS 9 Wire; Telephone 103 Radar 103 PANORAMIC PHOTOGRAPHIC TERRAIN STUDY 12 Power Equipment 103 Visual 103 ARTILLERY AND "ORDNANCE 22 Pigeons 103 Codes and Ciphers 103 Sources of Information 22 Air-Ground Communications 103 Development of the Defenses 22 Meteorlogical Stations 103 Equipment Available 22 Supply and Repair 103 Artillery Tactical Control 22 Artillery Fire Control 22 NAVAL ACTIVITIES 107 Artillery - General Remarks 23 Artillery Positions On Barrier Reef Islands 23 General 107 c Description of Individual Batteries 23 Mine Warfare 116 Maintenance and Repair Facilities 34 Defense of the North and South Passes 118 o. Total Quantities of Fire Control Items 36 Details on Minefields in TRUK Atoll 123 Total Quantities of Vehicles 38 Obstacles 124 Z Total Quantities of Weapons and Ammunition 38 Vessels 125 Navy Ships and Boats 125 ENGINEERING 46 Naval Communications 126 i Hydrographic Information 126 Z Military Engineering 46 Conditions of the Sinking of Submarine 1-169 127 The Attack on TRUK by the British Task Force 127 Engineer and Construction Troops 46 > Organization of the Ground 46 BEACHES 128 Q Fortifications 48 Z Obstacle Construction Types 52 General 129 Searchlights 58 Beach No. 1 129 Mines, Mine Warfare, Booby Traps, Explosives and Demolitions 58 Beach No. 2 129 Camouflage 58 Beach No. 3 130 Chemical Warfare 58 Beach No. 4 131 z Field Utilities 62 Beach No. 5 131 Beach No. 6 132 o General Construction 63 Beach No. 7 133 Beach No. 8 133 < Roads, Trails, and Railroads 67 Beach No. 9 134 Wharves and Docks 67 Beach No. 3.0 134 Bridges and Causeways 67 Beach No. 11 136 Installations 70 Beach No. 12 136 Underground Installations in General 82 Beach No. 13 137 Fixed or Permanent Utilities 82 Beach No. 14 137 SIGNAL COMMUNICATIONS 86 AVIATION 138 General 86 General 138 Z Navy Communications 86 Construction of Air Facilities 138 Disposition of Aircraft 138 o Radio 86 UJ Destruction of Japanese Air Power at TRUK 139 CO Radio Countermeasures 92 Z Radio Intelligence 92 MEDICAL & SANITARY CONDITIONS 143 m Radio Direction Finding 92 u. UJ Wire 92 Introduction Radar 94 143 General 143 a Summary 98 Ul Medical 143 CO Power Equipment 100 144 Ul VIsual 100 Sanitary Conditions Z Pigeons 100 145 Codes and Ciphers 100 APPENDIX I Air-Ground Communications 100 Meteorlogical Stations 100 APPENDIX II Supply and Repair 100 150 APPENDIX III HI TABLE OF CONTENTS LIST OF FIGURES IN PART ONE FIGURE NO. TITLE PAGE NO, 1 TRUK ATOLL 4 o PART TWO 2 CAROLINE - MARIANAS AREA 5 o 3 PANORAMIC PHOTOGRAPHIC STATIONS 12 4 ARTILLERY & SEARCHLIGHT POSITIONS (TOL) 42 5 ARTILLERY & SEARCHLIGHT POSITIONS (FEFAN) 43 6 ARTILLERY & SEARCHLIGHT POSITIONS (UDOT & EOT) 43 I 7 ARTILLERY & SEARCHLIGHT POSITIONS (UMAN) 43 .LIST 8 ARTILLERY & SEARCHLIGHT POSITIONS (DUBLON & ETEN) 44 OF ENCLOSURES 9 ARTILLERY & SEARCHLIGHT POSITIONS (PARAM) 45 2 10 ARTILLERY & SEARCHLIGHT POSITIONS (MOEN) 45 11 15 CM GUN POSITION (N. TOL) 53 m (A) ENEMY DEFENSIVE INSTALLATIONS, TROOF DISPOSITIONS, AND FACILITIES, DUBLON 12 155 MM COAST DEFENSE BATTERY (UMAN) 53 13 14 CM GUN BATTERY (S. UMAN) 54 ISLAND, SCALE 1:12,500, CONFIDENTIAL. 14 ANTI-AIRCRAFT BATTERY EMPLACEMENT (FEFAN) 54 (B) ENEMY DEFENSIVE INSTALLATIONS, TROOP DISPOSITIONS, AND FACILITIES, MOEN 15 ARMY DIVISIONAL COMMAND POST (DUBLON) 55 z 16 3D INFANTRY BATTALION COMMAND POST, 69TH REGT.,(DUBLON) 55 I— ISLAND, SCALE 1:25,000, CONFIDENTIAL. MT. UBAN, 341ST BATTALION COMMAND POST (FEFAN) 56 UI 17 (C) ENEMY DEFENSIVE INSTALLATIONS, TROOP DISPOSITIONS ,AND FACILITIES, FEFAN 18 NAVAL BATTLE COMMAND POST CAVES (DUBLON) 56 19 ANTI-TANK OBSTACLE 56 ISLAND, SCALE 1:25,000, CONFIDENTIAL. 20 GAS PROOF SHELTER (DUBLON) 59 (D) ENEMY DEFENSIVE INSTALLATIONS, TROOP DISPOSITIONS, AND FACILITIES, PARAM, 21 LOCATION OF PIERS (TRUK ATOLL) 65 22 DUBLON ISLAND SUBMARINE BASE 65 , o UDOT AND EOT ISLANDS, SCALES 1:12,500 AND 1:25,000, CONFIDENTIAL. 23 4TH ShIP REPAIR DEPT. (DUBLON) 66 (E) ENEMY DEFENSIVE INSTALLATIONS, TROOP DISPOSITIONS, AND FACILITIES, ETEN 24 4TH COMMUNICATION UNIT TRANSMITTING STATION 68 Z 25 NANKO DOCK OR CHARE AREA 68 AND UMAN ISLANDS, SCALE 1:12,500, CONFIDENTIAL. 26A FUEL OIL TANK FARM & OIL SUPPLY PIERS 68 (F) ENEMY DEFENSIVE INSTALLATIONS, TROOP DISPOSITIONS, AND FACILITIES, NORTH 26B DUBLON ISLAND SEAPLANE BASE 72 27 SUPPLY WAREHOUSE AREA 73 V TOL ISLAND, SCALE 1:25,000, CONFIDENTIAL. 28 COMMUNICATION UNIT RECEIVING STATION 73 (G) ENEMY DEFENSIVE INSTALLATIONS, TROOP DISPOSITIONS, AND FACILITIES, WEST 29 4TH NAVAL HOSPITAL (DUBLON) 74 z 30 104TH AIR FORCE ARSENAL 75 TOL AND SOUTH TOL, SCALE 1:25,000, CONFIDENTIAL. 31 AIRFIELD NO. 1 (MOEN) 75 CO (H) ENEMY DEFENSIVE INSTALLATIONS, TROOP DISPOSITIONS, AND FACILITIES, TRUK 32 AIRFIELD NO. 2 4 SEAPLANE BASE 75 BARRIER REEF, SCALE 1:250,000 CONFIDENTIAL. 33 ETEN ISLAND AIRFIELD AND FACILITIES 80 Z 34 PARAM AIRFIELD 81 (I) LOCATION OF GROUND PHOTOGRAPHS, TRUK ATOLL, SCALE 1:96,585, CONFIDENTIAL. 35 UMAN ISLAND RADIO STATION 81 _J 36 DUBLON ISLAND WATER DISTRIBUTION SYSTEM 83 CO (J) H. 0. CHART 6046, REPRINTED. 37 MOEN ISLAND WATER DISTRIBUTION SYSTEM 83 UI 38 POWER DISTRIBUTION SYSTEM (DUBLON) 84 Z 39 POWER DISTRIBUTION SYSTEM (MOEN) 85 40 PACIFIC AREA RADIO SYSTEM (NAVY) 91 o 41 COMMUNICATIONS: SUBMARINE CABLE, BURIED CABLE, AND AERIAL CABLE 93 42 NAVY TELEPHONE SYSTEM (DUBLON) 93 43 RADAR COVERAGE DIAGRAM 99 44 PACIFIC AREA RADIO SYSTEM (ARMY) 104 45 ARMY TELEPHONE SYSTEM (DUBLON) 105 46 DEFENSIVE COMMUNICATIONS SYSTEM (DUBLON) 106 COMMENT ON T.HE NUMBERING OF PHOTOGRAPHS 47 MATSUSHIMA BRANCH (4TH REPAIR DEPT.) 114 48 IMPROVISED TORPEDO BOAT 114 Individual photographs, the first of which appears on page 20, are sequentially 49 ANTI-TORPEDO NET FOR BATTLESHIPS 115 numbered to facilitate reference thereto in the written body of the report. 50 1 MAN TORPEDO ATTACK BASE 115 Immediately f 01 lowing th'e sequential number is the "PM" number in par.ent he s is , 51 1 MAN TORPEDO (SIDE VIEW) 115 z i.e., Picture No. 1 (PM 572), which indicates the basic number of a picture in 52 MINEFIELDS, SUNKEN SHIPS AND BUOY OBSTACLES (TRUK) 117 o APPENDIX III /Ground Photographic Reference Data) and on the map ent it led 53 TYPICAL SMALL MINE LOCATIONS 118 CO "LOCATION OF GROUND PHOTOGRAPHS" in PART TWO. This procedure was adopted in UI 54 TYPE 2 - UNDERWATER MAGNETIC DETECTOR 118 CO order to maintain a cross-reference between the 451 photographs appear ing in 55 DIAGRAM OF INTERIOR OF GUARD STATION (UMAN) 119 Z this publicat i on and the total of 575 photographs that were taken and are listed 56 SUSPENDED TYPE MODEL 1 HYDROPHONE (UMAN) 119 UI in APPENDIX III and on the map entitled "LOCATION OF GROUND PHOTOGRAPHS" in 57 DIAGRAM OF CONTROLLED TYPE 92 MINES IN NORTH PASS 122 PART TWO. It should be noted that the photographs contained in the panoramic 58 BUOYS USED TO OBSTRUCT SMALL CRAFT (DUBLON) 124 strips have no sequential numbers since the individual photographs contained- 59 STEEL RAIL UNDERWATER OBSTACLES AND COCONUT LOG OBSTACLES 124 UI therein are" not referred to in the written body of the raPort. Aerial Photo- 60 LOCATION, OF LANDING BEACHES (TRUK ATOLL) 128 CO graphs are given separate numbers, i.e.. Air. Photo No. 1, and appear only in 61 129 UI the sections entitled "BEACHES" and "AVIATION"- See APPENDIX III for the lo- PROFILE OF BEACH NO. 1 (DUBLON) Z 62 PROFILE OF BEACH NO. 2 (DUBLON) 130 cation of all photographic negat ives in the event copies of phot ographs are 63 PROFILE OF BEACH NO. 3 (DUBLON) 130 desired. 64 PROFILE OF BEACH NO. 4 (DUBLON) 131 65 PROFILE OF BEACH NO. 5 4 6 (ETEN) 132 66 PROFILE OF BEACH NO. 7 (MOEN) 133 67 PROFILE OF BEACH NO. 8 (MOEN) 133 68 PROFILE OF BEACH NO, 9 (MOEN) 134 69 PROFILE OF BEACH NO. 10 MOEN) 134 70 PROFILE OF BEACH NO. 12 ;FALA-BEGUETS) 137 71 PROFILE OF BEACH NO. 13 ,ULALU) 137 iv "0 o O o o m o o > H Z X o m O > CO H O > o > -I XJ -n O > o H 2 (OH — m H (/) o o o > >• I— Z Z > O H O Z -n > m > o r en 2 o o H 0 o o z m H CO c ^ r > O o O m o 1 z 2 m — or r n- m CO I—' • O o o o o m m -P ro •P \ CL /> JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1946. JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 19467 t t-J o o m o o CO Z H O I O m O m > > o > —l r- > 09 XI -n x> 3} -> cz > O — > m H 2 o z z o O H O "n > m > TO CO 2 O O H o o -n O Z m> H i- o o o m o 2 rn — or ro r n- m O o o m o m > CJ1 -P ro -P nil m o r c o CD 5 O o m rn Xt O n > Z H Xt C O I H O m — -H o m > o r -n X> X) > O co > — H H CO o o > I" > O H r> "n > > CO 2 o 0 o O Z m H r > O c O o o 1 z 2 ra in — | m r o ro o m -n 3: O O o o O en -P ro 4= £ CO JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1946. JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1946 GEOGRAPHY i i r 135* 1 1 r 140*^ 150* J 1 155* 1 1 1 I606 1 1 1 'ASUNCION TRUK ATOLL, Equivalent English-Japanese place names. I 0 AGRIHAN Name on Chart Japanese Name •o ' PAGAN eALAMAGAM TRUK ATOLL (Islands) TORAKKU SHOTO X KJ 'GUGUAN MOEN HARU SHIMA ac DUBLON NATSU SHIMA ANATAHAN ;SARAGAN FEFAN AKI SHIMA " * MEDINILLA UMAN FUYU JIMA 15' ETEN TAKE JIMA cSAIPAN UDOT GETSUYO TO TINIAN EOT MAE SHIMA -0 " ROTA FALA-BEGUETS KAYO TO m TOL SUIYO TO GUAM PATA (NW part TOL) MOKUYO TO Z POLLE (SW part TOL) KINYO TO »— ONAMUE KOYO TO ui ULALU NICHIYO TO OENIWETOK KUOP ATOLL .... KUNTO SHOTO ID TARIK HOSHI SHIMA ea TSIS USU SHIMA ULITHI PARAM KAEIDE SHIMA o •-UJELANG OTTA I. OTA SHIMA a. * YAP MASU SHIMA KJ •GAFERUT NAM HISTORY. On 2 September, 1945, the surrender of all Japanese controlled islands under Modern fire control devices were almost non-existent. There were only four the TRUK headquarters was accepted. Prior to November, 1940, TRUK was used chiefly AAA directors, few range or height finders and no fire control radar. AAA not as an anchorage for the 4th Fleet (organized November, 1939)• Little effort was equipped otherwise used an improvised forward area sight. Seacoast artillery re made to garrison the establishment before January, 1944. At TRUK in June, 1945, lied on registration markers and buoys at known ranges. There were 20 search there were 24,061 Navy personnel and 14,299 Army personnel. lights controlled by various gun battery commanders with little central supervision from the Navy CP on DUBLON. The Japanese were engaged in continuous offensive accion from December, 1941, t'o February, 1944. After the American task force raid at the latter date, the main Ammunition storage was in the battery position cave or in a nearby revetment, force of the Japanese fleet left TRUK and the naval base was, thereafter, to stand and ready boxes were generally Installed at gun positions. alone. After the loss of the MARIANAS in June-July, 1944, reinforcement of TRUK became impossible. Intrabattery tactical communication was primarily by telephone supplemented by buzzer and speaking tube systems. Interbattery communication was principally "** The almost complete isolation of TRUK necessitated the adoption of a defensive by telephone and radio supplemented by runners and carrier pigeons. organization to repel any invasion by American forces. The Japanese Army and Navy exercised a joint command and TRUK was divided into five defense districts. Where Maintenance and repair facilities, until the bombing of 30 April, 1944, were LU possible, installations were concentrated on the main Islands and in most cases lo capable of making very extensive repairs including 5th echelon at the Naval Air cated in caves or bomb-proof structures. In June, 1945, the Japanese reached the force Construction Department and Garrison shops. The bombing reduced these fac height of their defensive power. ilities to roughly 10 to 20 percent of their former effectiveness. The TRUK garrison lacked adequate quantities of planes, artillery, ammunition ENGINEERING. o and construction materials, but in spit of this they stated that they were satis fied with their overall situation. They apparently felt their lack of equipment The Japanese on TRUK, as elsewhere, were trying to conduct a major war with Z could be countered by the "Bushldo" spirit. inadequate military materiel. To this fundamental error they added an unbalanced sense of proportion which gave all-out backing to naval projects regardless of u DEFENSE PLAN, their, strategical or tactical value. For example, age old necessities such as roads were neglected, while heavy weapons were moved over seemingly impassable The Japanese defense plan of TRUK called for a strong defense of MOEN, DUBLON, terrain into caves. FEFAN and UMAN, with units for observation and delaying actions stationed on the other islands within the lagoon and on the barrier reef. Observations revealed .that Organization of the ground, fortifications, and workmanship were generally the distribution of men and materiel was carried out in accordance with this plan. excellent, though often lack of attention to routine details such as ventilation, However, the skill with which the organization of the ground and construction work drainage and personnel safety was apparent. The over-all accomplishment of the CO was carried out depended solely on the ability of individual commanding officers; Japanese was but fair in all sorts of fortifications including obstacles, mine Q apparently the high command allowed considerable latitude for the initiative of warfare, explosives and demolitions. Camouflage in the tropical terrain was ex- Z all subordinate echelons. cellent to superior, though it would be interesting to time the gun crew going into action against a land target where there were a dozen sturdy banana stalks in CO The guiding principle in defense was to annihilate assaulting forces at the the field of fire of th*ir piece less than 61 from the muzzle. beach. This was virtually dictated by the relatively small land masses involved. LU Plans were drawn up to provide for mutual support among the islands by means of Z In offensive chemical warfare the Japanese could do nothing but lay down a amphibious reserves, and it was highly probable that unless all defending forces few small smoke screens. Defensively they were only fairly well prepared with o had been pinned down by simultaneous assaults at each island, an assault force gas masks, collective protectors and properly designed ventilation. Their last- might have found itself under attack on the flank or rear by Japanese troops ar ditch Installations were located at elevations where it would be very difficult to riving by landing craft from nearby islands. Special emphasis was placed on achieve lethal concentrations of gafe, and to deliver flame. training in night maneuvers for counter-attack, including the use of landing craft and tanks, in order to eliminate or contain any airborne attackers who might Roads, trails and bridges were poor to fair in construction. Traffic circu land within the defense lines. lation was Inadequate due to poor drainage, narrow widths and ungraded road metal. The roads oarrying the least traffic were the best and appeared to be the oldest, A superficial Inspection of the positions and dispositions throughout TRUK indicating that whatever merit the roads did have was of prewar vintage and not a leads to the conclusion that the Japanese had not entirely abandoned the idea of characteristic of wartime construction. retaining mobility in order to go underground. It is probable, however, that this was because they had too little equipment, material and supplies, too few people, Utilities, including water supply, power and light, fire fighting, and preven and too little time to complete their underground installations before the end of tion, sanitation and refuse disposal were inadequate. Engineer supply was very poor Z hostilities. both in respect to materials furnished and facilities for their receipt, storage and issue. o ARTILLERY AND ORDNANCE. CO Engineer ana construction troops were inadequate in all three essentials: UJ TRUK was protected by numerous but relatively light artillery pieces. The staff, trained manpower and equipment. The engineers and "pioneers" lacked the CO inventory lists 101 Army guns (75 to 105mm.) in 86 battery positions; 85 naval wea tools and equipment that should have differentiated them from other combat troops. Z pons (75 to 200mm.) in 36 battery positions; and 302 automatic weapons (13 to 25mm.). The naval construction forces were more numerous and better equipped than the eng Ammunition in varying quantities was on hand for each type of weapon. ineers or "pioneers" but were too few for the Navy's needs alone. Following our air raids of February, 1944, the defensive plan was changed. CO NAVAL ACTIVITIES. UJ Heavy artillery was withdrawn from reef positions and relocated on the principal Z inner islands; except for AAA and a few other batteries, most artillery was em- When the primary mission of TRUK changed to the defense, naval units impro placed in caves or in cut and cover type emplacements. This program had been cur vised weapons, such as the one-man controlled torpedo, and the torpedo-carrying tailed by lack of time and materials. Only two batteries could fire effectively landing craft. The mine-fields in the passes and inside the reef, and small model beyond the reef. Most of the heavy artillery was for minefield and inshore defense. beach mines had previously been the main protection against invasion. General tactical control of artillery was exercised at 4th Fleet and 31st Naval shore establishments were never extensive without drydocking facilities Army Command Posts on DUBLON, but in the final defense plan each island commander for large ships and with few repair facilities. Larger ships were refueled from controlled his own units. Artillery on the various islands was capable of mutual tankers in the harbor, or by oil barges from an oil pier on DUBLON. support. SUMMARY o o X KJ OC BEACHES, Suitable sites for landing ships were rare. All the large islands lay inside dry batteries, and all of their telephones were local-battery, their most acute the barrier reef and are fringed by wide reefs and mangrove swamps, backed by steep shortage was dry batteries. They were also short of spare parts and radio tubes. LU hills and mountains. Sand beaches were rarely found on the larger islands and those The Army communication system was not capable of efficient operation at the end existing were usually inaccessible to landing ships due to reefs. Dispersal areas of hostilities. on the whole were restricted by swampy, hilly, or wooded ground, and movement of vehicular traffic was difficult. Our bombing and shelling of TRUK had destroyed or damaged most of the instal lations above ground with the exception of the radars, which were practically un O Th smaller islands were also surrounded by fringing reefs and occasional man damaged. Virtually all Important installations had been moved underground prior grove gv- vth, but generally had sandy beaches and a low, sandy, wooded interior. to our attacks, so little serious damage to the overall efficiency of the system a. resulted. Z Attempts were made to approach possible beaches in a Japanese landing craft "DAIHATSU", but normally the craft grounded on passing over the fringing reef. AVIATION. Average depth of water- over the reef was 2.5 feet. TRUK was originally a major staging base to the SOLOMONS, RABAUL, the MARSH SIGNAL COMMUNICATIONS. ALLS and GILBERTS and was well defended by air, but in the carrier strikes of Feb z ruary and April, 1944, such damage was done that the base never recovered. Each TRUK was primarily a naval installation and as such the major part of the sig- raid destroyed nearly all aircraft on hand at the time, and all air facilities nal communications was operated and controlled by the Navy. Army communications were severely damaged and much material destroyed. Plans for expanding air facil- CO were limited to tactical use in the atoll inner defense. ities were given up since they were hard pressed in repairing what was left. After the capture of the MARIANAS, American planes methodically destroyed practically all a Long range and internal administrative communications operated efficiently, facilities above ground, and the Japanese found it difficult to keep even runways but control of subordinate units during tactical operations was not evident in the operational. z existing signal plan. CO Finally nothing operated from TRUK but a few planes for reconnaissance of LU The communication equipment was, in general, of fairly good construction and ULITHI and the MARIANAS, and the base could have been nothing but a staging point reasonably efficient, although the general design was somewhat out of date. No even if aircraft had been available. z moisture proofing or fungus-proofing was apparent in any of the equipment, and the MEDICAL. Japanese claimed considerable failures due to moisture. o OC TRUK had fairly good search radar protection, but the equipment was out of date The Army and Navy at TRUK maintained separate medical facilities. Each had a ' No fire control or searchlight control radars were installed, and the search radars base hospital on DUBLON with branch hospitals on the larger islands, and sickbays could give little more than the general direction of targets. or dispensaries located near military activities scattered throughout the islands. The isolation of TRUK since June-July, 1944, had caused shortages of most com Supplies were, in general, adequate; X-ray film and carbasone was available munication supplies. However, the Navy system could have operated for several in limited quantities. There were sufficient medical officers and corpsmen, but the hospitals were dirty, crowded and unsanitary by American standards. months with little loss of efficiency and considerably longer without being ser Zi iously hampered. Their main shortages were, battery acid, dry batteries and radio OC spare parts, (especially tubes). The most prevalent diseases were malnutrition, beri-beri, tuberculosis, amoe bic dysentery, paratyphoid A, ,and WEIL1s disease; dengue was sporadic, occasionally z Army communications were hardest hit by isolation because they depended ex- reaching epidemic heights. No malaria, typhus or cholera were evident. 1 o tensively on supplies furnished by the Navy. The Navy s shortage of materials and CO the lack of close cooperation between the services further aggravated the sit- Sanitation control was noted by its absence. There was little central super- UJ uation. Since most of the Army radio equipment was small portable sets employing vision of sewage and waste disposal, fly and rat control, individual water supply, CO or prevention of spread of intestinal diseases. Z CO Ul Z A SHORT HISTORY OF THE MILITARY DEVELOPMENT OF TRUK ATOLL On 28 August, 1945, a message was dropped by plane on one of the main islands TRUK was divided into five defense districts—MOEN, DUBLON, FEFAN, UMAN, and of the TRUK Atoll and was followed at 0700, 30 August, 1945, by the arrival of the the Western defense district with Headquarters on TOL Island. The Japanese placed USS STACK (DD) and USS OSMUS (DE). The STACK carried Brig. Oen. L. D. HERMLE, USMC, the stress on the first four of these which were known as the "Season Islands". and a party of 12 officers which informed Rear Admiral SUMIKAWA, Chief of Staff of The Navy was to take charge of surface and air defense, the stress in the case of the 4th Fleet, and five other Japanese officers of the requirements preliminary to the former being placed on the area inside the atoll. By agreement between the surrender. This party also handed the Japanese a copy of the Articles of Surrender 31st Army and the 4th Fleet, the senior officer on each island was named as the which were to be signed at a later date. over-all commander. 2 Aboard the USS PORTLAND on 2 September, 1945, Vice Admiral George D. MURRAY, DEFENSE DISTRICTS ARMY COMMANDERS NAVY COMMANDERS USN, Commander MARIANAS, accepted the surrender of all Japanese controlled islands under the TRUK Headquarters from Lt. G-en. Shunzaburo MUG-IKURA, Vice Admiral DUBLON (ETEN) Col.Tameichi SHIBANO Rear Admiral Hiroshi KOJIMA Chuichi HARA, and Mr. AIHIRA, a representative of the South Seas Government sta MOEN (FALO) Col.Keizo HAYASHIDA Capt. Yoshimitsu IMAZATO tioned at TRUK. UMAN Maj.Kyuichi KONDO Rear Admiral Tomotaro MIURA FEFAN Maj.Hldeakl MORI Capt. Furuya YOSHIRO Lt. Gen. MUGIKURA, who had assumed command of the 52nd Division in November, PARAM MaJ.Eiji SHIBATA Capt. Furuya YOSHIRO Z 1941, was ranking officer and was appointed commander of the 31st Army on 20 Jan Western(Hq.on S.TOL) Maj.Gen.Kanenobu IJUIN Rear Admiral Hiroshi KOZIMA LU uary, 1945, Vice Admiral Chuichi HARA, Commander-in-Chief of the 4th Fleet, came S.TOL Maj.Jisaku YOSHIDA to TRUK on 23 February, 1944. The headquarters of the 31st Army and the 4th Fleet N.TOL Capt.Shigekl MORI were both on DUBLON. W.TOL MaJ.Jofuku SAKAMOTO =3 UDOT Capt.Kaneori FUKUTOME According to Japanese sources little effort was made to garrison TRUK before January, 1944, and at the height of its power in June, 1945, the Japanese Navy had The Army units on TRUK—the 52nd Division, the 9th Independent Engineer Reg o 24,061 men and the Army 14,299 men stationed there. The Army and Navy forces were iment and the 51st Independent Mixed Brigade—had the mission of defending TRUK fiL based as follows: against the Anglo-American forces by joint action with the 4th Fleet and air forces. They emphasized the following: anti-tank warfare, well-mined waters and beach ob Z stacles, strong and persistent delaying actions, strong positions among rocky PERSONNEL DUBLON ETEN MOEN FEFAN PARAM UMAN UDOT TOL cliffs, and steps to make TRUK self-sufficient in food. Army 3,242 2,962 2,914 365 873 748 3,150 2= Navy 4,485 462 578 2,572 827 1,417 1,025 6,220 The Japanese did not place great reliance on airplanes because of the great attrition rate and the impossibility of getting more from JAPAN after their com The remainder was scattered throughout the lesser islands- munication lines were cut off. Their plan was to use those planes which were al ready on TRUK until such time as enemy attacks should make it more feasible to The 4th Fleet Headquarters was established at TRUK on 10 November, 1943. The remove them, in which case they would be based at PONAPE, NAMOI and ENDERBY. co 31st Army Headquarters was organized on 20 January, 1945. The establishment or Q arrival of other Naval and Army units was as follows: In July, 1944, the mounted guns on some of the small islets of the reefs were Z removed to the main islands inside the atoll for the following reasons: (1), to NAVAL UNITS DATE ARMY UNITS DATE place the batteries in caves, rather than in the open so as to gain more protec tion from bombardment and bomblngj (2), to lay stress on the attack of ships which 4th Office of Admin. might manage to get inside the atoll, and to gain mutual support between batteries; and Supply. 15Dec40 52nd Dlv. Hq. 4Jan44 (3), to protect the main islands as long as possible. z 4th Munitions Dept. 15Dec40 69th Inf. Regt. 4Jan44 4th Construction Dept. Dec40 Signal Unit 4Jan44 Wire was strung between buoys on the surface at W.MOEN and N.DUBLON. This was o 41st Naval Guard Force Nov40 Field Hospital 4Jan44 done in front of possible landing points and the aim was to forestall any landing 43rd Naval Guard Force Dec44 Tank Unit 18Feb44 attempt. < 47th Naval Guard Force Transportation Unit 18Feb44 48th Naval Guard Force to Ordnance Serv. Unit 18Feb44 The Japanese expected no great help from their anti-aircraft guns as they were 49th Naval Guard Force May45 Intendance Serv. Unit 18Feb44 all short of ammunition. After the loss of the MARIANAS in June and July, 1944, O 4th Harbor Department 25Aug41 150th Inf. Regt. 18Feb44 reinforcement of TRUK became impossible, save by submarine, and the garrison went 104th Naval Air Depot May42 9th Ind. Eng. Regt. 16Apr44 on short rations. 4th Naval Hospital 21Aug42 2nd & 8th Det.reorg. as after 17th Air Corps Dec41 51st 1MB. 16Apr44 The Army and Navy exercised a Joint Command—and the Japanese stated that there 11th Ind. Mixed Regt. 18Sep44 was no serious difference of opinion between the Army and the Navy or between in dividuals—but when land action started, the Supreme Commander was to be Lt. Gen. The 17th Naval Air Corps and various other units, which arrived from 1942 to MUGIKURA. z 1944 when the Japanese air arm was virtually inoperative, were combined to form o the EAST CAROLINE Air Unit. In addition to the 9,895 natives scattered over the larger islands of TRUK, CO LU there were 793 natives of NAURU, brought to TRUK by the Japanese; 1,590 Japanese CO Prior to 15 November, 1940, (the date of the organization of the 4th Defense civilians; 6 Germans; 7 Spaniards; and 1 Swede. They were forbidden to approach Z Unit on DUBLON) TRUK was used chiefly as an anchorage for the 4th Fleet which had any defense installation. The natives were impressed into semi-slavery and were LU been organized in November, 1939. The 4th Defense Unit was originally a part of used mostly for roadwork. LU the 5th Base Unit having headquarters on SAIPAN, and lt had about 850 personnel. LU O However, in November, 1942, the Defense Unit became the 41st Naval Guard Force, The following information on the natives and the history of the Japanese LU and was still in existence at the end of the war. military activity on TRUK was gathered from an interview with a priest who came to CO TRUK in 1927. Some of his statements do not agree with those made by the Japan After December, 1941, there was a period of continuous offensive action and ese. TRUK was used principally as a fleet base—the fleet being engaged in attacks in the SOLOMONS and MARSHALLS areas. As the advance of the Americans in the SOLO The missionaires came to TRUK in 1911 and were followed by the Spanish mis MONS became more and more successful, TRUK was used as a staging area for airplanes sionaries in 1920. During the war there were about a dozen missionaries scattered which were to be transshipped into a more active area. After the American task force throughout the TRUK Islands and six sisters lived on FEFAN. These sisters, how raid of 17-18 February, 1944, the main force of the Japanese fleet left TRUK. There ever, left in September, 1942, and were thought by the priest to have gone to PO after, TRUK was to stand alone. NAPE, followed by two of the brothers. A SHORT HISTORY (CON'T) JAPANESE ORDER OF BATTLE Z UI The priest stated that when he first came to TRUK the only Japanese present TOTAL STRENGTH. were civilians. The Navy started fortifications in 1931 and 1932 and the Army in j the latter part of 1942 and 1943 by which time, the priest estimated about 10,000 OFFICERS ENLISTED CIVILIAN PERSONNEL TOTAL had arrived. By 1940, the natives and missionaries were made to stop all com o munication with the outer world. ARMY 741 13,558 14,299 I According to the priest, the first island on which the Japanese concentrated NAVY 419 9,422 14,220 24,061 their attention was ETEN. They told the natives that they were merely fixing up the islands for fishing purposes. Then followed in turn, DUBLON, FEFAN, and UMAN. TOTALS 1,160 22,980 14,220 38,360 MOEN was one of the last Islands to receive the attention of the.Japanese, but according to the priest, when the Japanese did get around to MOEN, they made rapid progress. ARMY UNITS ON TRUK. DATE OF The lighthouse on the east tip of MOEN was erected in 1937, the priest said, UNIT LOCATION OFF. W.O. TOTAL CODE NAME NCO EM ARRIVAL ro and the airfields were built in 1939. It was in 1940 that the main force of the 31st Army Hq# DUBLON 31 3 43 51 128 SONAE 7920 20Jan45 Japanese Navy came to TRUK, and the Army arrived in 1943. 52nd Div.Hq. DUBLON 37 10 100 151 298 KASHIWA 4650 4Jan44 z 69th Inf.Regt. DUBLON 124 32 717 1,821 2,694 a 4654 4Jan44 Coincident with the expansion of the military installations at TRUK, in 1940 (-2 Bn, the Japanese stopped all communication between the missionaries and their homes. 2nd Bn Henceforth, TRUK"was to be isolated. Until 1940, the missionaries had been free on UMAN) CO to go from island to Island as they pleased. About the latter part of 1940, how 150th Inf.Regt. MOEN 109 29 828 1,170 2,136 « 4656 18Feb44 ever, they were restricted to one island. Tank Unit TOL 4 2 39 58 103 * 4672 18Feb44 < Signal Unit DUBLON 8 1 52 180 241 * 4662 4Jan44 o Japan's successive reverses in the Pacific, i.e., TARAWA, KWAJALEIN, SAIPAN, 9th Ind.Eng.Regt . DUBLON 15 4 145 319 483 M 4812 16Apr44 GUAM, etc., resulted in an emphasis being placed on AT warfare at TRUK. Strong Transportation DUBLON 3 1 30 71 105 " 4673 18Feb44 Z and persistent delaying actions were to be the order of the day, Instead of the Unit previous tactics of counter-attacking enemy beachheads. Another lesson driven Over-sea Trans- DUBLON 32 6 353 741 1,132 * 4674 llMar44 home by the previous defeats was the necessity for constructing strong positions port Unit MOEN among rocky cliffs in order to be able to withstand artillery bombardments. Be Ordnance Serv. DUBLON 3 2 34 20 59 " 4664 18Feb44 cause of the severance of supply lineo (with the loss of SAIPAN) steps were taken Unit to make TRUK self-sufficient. To this end, all land was put under cultivation, and Intendance Serv. MOEN 15 4 36 62 117 " 4675 18Feb44 z sweet potatoes became the food staple. Unit FEFAN DUBLON The Army at TRUK felt that it could repel an American attack for a very long TOL period, assuming that ten American divisions were brought against it. The Navy Field Hospital MOEN 51 4 176 418 649 " 4676 4Jan44 Q was not so optimistic, feeling that three months would be the time during which it DUBLON Z could hold out. All resolved to die in their places in order to inflict as many UMAN casualties upon the enemy and gain as much time as possible. It does not appear FEFAN that the Japanese ever felt that they could permanently hold TRUK. TOL 51st Ind.Mixed UDOT 244 63 1,695 2,786 4,788 SONAE 17564 24Mar44 Although the TRUK garrison lacked adequate quantities of planes, anti-aircraft Brig. TOL 16Apr44 and heavy artillery, ammunition, fortress-construction units, and materials for FEFAN such construction, they stated that they were well satisfied with their overall PARAM o situation—apparently feeling that the lack in material could be countered by the 11th Ind.Mixed FEFAN 65 24 420 857 1,366 " 17585 18Sep44 spirit and determination of all the men. The morale of the Japanese on TRUK was, Regt. DUBLON 19Jan45 at all times, very high, it was stated. The TRUK garrison received information concerning the activities of the UNITED TOTALS 741 185 4,668 8,705 14,299 STATES forces from the Imperial Headquarters. However, it appears that the com plete story of Japanese Naval reverses was not forthcoming from TOKYO. Any in formation received from TOKYO was considered to be reliable. Such news as the The 31st Army was organized at TRUK. Japanese on TRUK received from UNITED STATES broadcasts was not wholly ignored— neither was it believed. The Japanese did not place too much credence in these The 2nd Detachment arrived on 24 March, 1944 and the 8th Detachment arrived broadcasts, as they considered them to be propaganda. Such information was "Put on 16 April, 1944. These units were reorganized as the 51st Independent Mixed Brigade. z aside for reference". o c/> The Japanese on TRUK correctly estimated that the U. S. forces would attack ui SAIPAN and IWO JIMA. It appears that at no time did they anticipate TRUK would be CO the subject of the next all-out assault. However, at such times as they were under The 51st Independent Mixed Brigade was disposed as follows: Z attack by out task-forces, they seemingly felt that this was the forerunner of the 336th Ind. Bn. -\ 337th Ind. Bn. - UDOT ui invasion attempt. After SAIPAN, they assumed correctly that the weight of U. S. 338th Ind. Bn. y TOL 339th Ind. Bn. -•>__,_.„ power would fall to the northwest. But they did not know whether FORMOSA, OKINAWA, lst Art. Unit ( 2nd Art. Unit -)FEFAN the CHINA Coast or a combination of the three would be the precursor of the attack 51st 1MB Hq. J 340th Ind. Bn. - FEFAN & PARAM. on JAPAN. Realization that TRUK had been by-passed came when OKINAWA was attacked, and it was thought that JAPAN proper would be next. UI Z After August, 1944, no ships were able to get to TRUK from the Japanese home The Headquarters and the 1st Battalion of the 11th Independent Mixed Regiment land, and the garrison was completely isolated, save for sporadic visits by sub was on FEFAN; the 3rd Battalion was on DUBLON. marines. JAPANESE ORDER OF BATTLE STRENGTH AND DISPOSITION OF ARMY FORCES ON TRUK (INCLUDING MEDICAL PERSONNEL). STRENGTH AND DISPOSITION OF NAVY FORCES ON TRUK. ISLAND OFFICERS W.O. NCO ENLISTED MEN TOTAL CIVILIAN GRAND MOEN 146 29 735 2,052 2,962 UNIT OFF Wt0. NCO EM TOTAL PERSONNEL TOTAL FEFAN 116 38 625 2,135 2,914 I DUBLON 227 43 697 2,275 3,242 DUBLON ISLAND: cc PARAM 20 6 127 212 365 4th Fleet Hq. 25 3 104 69 201 5 206 UMAN 36 10 174 653 873 Judge Advocate 2 2 4 8 12 UDOT 28 10 181 529 748 1st Pers. Repl. Dept. 2 5 2 9 9 ULALU 3 0 10 27 40 41st Guard Police 44 19 567 475 1,105 102 1,207 PATA 9 2 49 156 216 4th Comm. Unit 20 2 169 153 344 2 346 N. TOL 41 11 237 538 827 4th Harbor Dept, 4 27 18 49 30 79 S. TOL 81 14 327 911 1,333 TRUK Transport Unit 2 1 6 3 12 46 58 POLLE 35 15 221 503 774 E.CAROLINES Naval Air Unit 9 2 114 110 235 5 240 227th Const. Bn. 4 4 z ARMY MEDICAL PERSONNEL. 4th Naval Stores Dept. 16 4 50 38 108 280 388 MOEN 29 6 85 193 313 4th Naval Const. Unit 8 14 14 36 461 497 DUBLON 45 8 92 193 338 4th Naval Civil Eng.Dept. 7 3 17 8 35 974 1,009 FEFAN 17 1 38 103 159 4th Naval Hospital 11 1 23 42 77 38 115 UMAN 4 0 8 25 37 4th Naval Office of Supply 2 2 4 46 50 CQ UDOT 4 0 10 29 43 and Administration TOL 26 1 47 129 203 104th Naval Air Depot 3 1 3 7 14 190 204 O POLLE 2 0 5 15 22 4th Meteorological Unit 1 8 5 14 31 45 CL KJ PARAM 2 0 2 13 17 10th FPO Unit 16 16 z TOTALS 129 16 287 700 KJ NOTE: The T/0 as presented above was obtained from the Japanese Forces TOTALS 156 36 1,111 944 a, 247 2,238 4,485 0 at TRUK and no attempt has been made to verify its accuracy. NAVY UNITS ON TRUK. ETEN ISLAND: z CIV. GRAND CODE DATE OF 41st Naval Guard Force 3 1 37 79 120 120 UNIT OFF W.O. NCO EM TOTAL PERS. TOTAL NAME ARRIVAL E.CAROLINES Air Unit 4 4 74 88 170 2 i72 4th Fleet Hq. 28 7 129 76 240 22 262 U 87 10Nov43 4th Naval Civil Eng.Dept. 1 3 4 166 170 CO 4th Fleet Judge Advocate 2 2 4 8 12 u 87 10Nov43 TOTALS 114 167 294 168 462 Q Dept. Z 1st Pers.Repl.Dept, 2 5 2 9 9 u 225 Dec42 41st Naval Guard Force 61 29 885 795 1,770 155 1,925 u 44 15Nov40 CO 43rd Naval Guard Force 28 13 499 521 1,061 14 1,075 u 504 lDec44 TONELIK ISLAND: 47th Naval Guard Force 44 5 546 908 1,503 8 1,511 603 20Mar45 Ul u 41st Naval Guard Force 23 41 66 66 Z 48th Naval Guard Force 31 13 412 769 1,225 1 1,226 u 624 !May45 49th Naval Guard Force 21 9 300 294 624 2 626 625 lMay45 —i u NORTHEAST ISLAND; 4th Comm. Unit 24 5 246 228 503 31 534 u 17 14Jan41 418t Naval Guard Force 3 3 6 6 o 4th Harbor Duty Dept. 11 1 122 78 212 158 370 u 88 25Aug41 TRUK Naval Transp.Dept. 11 2 46 28 87 612 699 u 119 Jul42 MOR ISLAND: E.CAROLINES Naval Air 50 35 1,03 3 864 1,982 23 2,005 u 453-27 DUBLON 4th Fleet Hq. 1 1 3 5 Unit u 453-53 ETEN 41st Naval Guard Force 7 5 12 u 453-22 2 PARAM -21 Jul44 TOTALS 15 11 26 227th Const.Bn. 7 9 4 20 864 884 u 389 Mar44 4th Naval Hospital 24 1 43 104 172 96 268 u 169 21Aug42 4th Naval Office of 2 2 4 46 50 u 59 15Dec40 ELI KANIBU ISLAND; Admin. & Supply 41st Naval Guard Force 4 2 6 6 104th Naval Air Depot 9 2 13 17 41 737 778 u 135 May42 Z 4th Meteorological Unit 2 17 10 29 64 93 u 6"3 Uun41 SALAT ISLAND: o 10th FPO Unit 37 37 u 0 0 Jan41 41st Naval Guard Force 8 2 10 10 CO 4th Const. & Repair 12 24 18 54 826 880 4th Const. Dept. u 60 Dec40 OTTA ISLAND: Z 4th Repair Dept. u 96 lDec41 41st Naval Guard Force 2 4 6 6 ui 4th Munition Dept. u 62 15Dec40 85th Submarine Baae u 14 6 15May42 FALEU ISLAND: 4th Naval Stores Dept. 30 8 100 58 196 1,223 1,419 41st Naval Guard Force 10 20 31 31 4th Naval Civ.Eng.Dept. 20 15 53 17 105 9,293 9,398 CO TOTALS 419 145 4,486 4,791 9,841 14,220 24,061 FALO ISLAND: UJ 47th Naval Guard Force 16 3 20 20 The 43rd, 47th, 48th and 49th Naval Guard Forces were all formed on TRUK. Z FALAS ISLAND: The 4th Naval Base was established at TRUK in August, 1941. Until May, 1944, 41st Naval Guard Force 5 5 5 the 4th Fleet Headquarters commanded the 4th Naval Base; the 4th Naval Base, in turn, commanded TRUK. When the 4th Naval Base was disbanded, in May, 1944, the FANUELA ISLAND; 4th Fleet Headquarters directly commanded TRUK. 41st Naval Guard Force 5 5 5 10 JAPANESE ORDER OF BATTLE -\ i—i CIVILIAN GRAND CIVILIAN GRAND UNIT OFF W.O. NCO EM TOTAL PERSONNEL TOTAL UNIT OFF W.O. NCO EM TOTAL PERSONNEL TOTAL MOEN ISLAND: TOL ISLAND: PATA. POLLE: o 47th Naval Guard Force 43 5 530 905 1,483 8 1,491 4th Fleet Hq. 1 1 1 4th Comm. Unit 2 32 27 61 14 75 4th Naval Guard Force 1 2 61 38 102 2 104 I 4th Naval Harbor Duty Unit 1 13 13 27 27 54 43rd Naval Guard Force 22 11 397 404 834 14 848 E.CAROLINES Naval Air Unit 30 23 664 464 1,181 15 1,196 TRUK Transport Unit 9 1 40 25 75 566 641 4th Naval Stores Dept. 2 1 11 14 99 113 E.CAROLINES Naval Air Group 2 24 27 53 53 16 2,145 2,161 227th Const. Bn. 7 9 4 20 860 880 4th Naval Civil Eng. Dept. 3 3 8 2 in 4th Naval Hospital 4 4 18 26 21 47 4th Naval Stores Dept, 4 3 20 2 29 410 439 104th Naval Air Depot 6 1 10 10 27 547 574 4th Civil Eng. Dept, 5 5 12 2 24 2,889 2, 913 10th FPO Unit 7 7 4th Naval Const. Unit 2 2 1 5 220 225 4th Naval Hospital 4 16 26 28 54 TOTALS 90 34 1,272 1 ,439 2,835 2,883 5,718 6 CO 4th Meteorological Unit 1 9 5 15 33 48 10th FPO Unit 14 14 z BUET ISLAND: TOTALS 58 22 580 524 1.184 5,036 6,22 0 41st Naval Guard Force 4 1 5 5 ULALU ISLAND: 4th Comm. Unit 1 2 23 27 53 15 68 4th Civil Eng. Dept. 227 227 FEFAN ISLAND: TOTALS 1 2 23 27 53 242 295 CQ 4th Fleet Hq. 2 3 19 1 25 10 35 < 41st Naval Guard Force 3 3 51 82 139 139 UDOT ISLAND: 48th Naval Guard Force 18 11 264 437 730 1 731 4th Fleet Hq. 5 5 10 5 15 o 4th Harbor Duty Unit 11 11 43rd Naval Guard Force 3 2 40 28 73 73 CL. E.CAROLINES Naval Air Group 31 50 81 81 48th Naval Guard Force 4 35 77 116 116 z 4th Naval Stores Dept. 5 11 17 33 174 207 4th Naval Stores Dept. 1 3 4 21 25 4th Naval Construction 2 8 3 13 145 158 4th Civil Eng. Dept. 2 1 3 1 7 789 796 4th Civil Eng. Dept. 1 4 2 9 1,169 1,178 TOTALS 10 3 86 111 210 815 1,02 5 < 4th Naval Hospital 3 6 15 24 8 32 TOTALS 35 18 394 607 1,054 1,518 2,572 FALA-BEGUETS.ISLAND: &. 4th Naval Stores Dept. 2 4 1 7 239 246 z PARAM ISLAND: EOT ISLAND: CO 48th Naval Guard Force 9 2 113 255 379 379 41st Naval Guard Force 1 1 24 25 Q E CAROLINES Naval Air Group 5 5 103 116 229 1 230 43rd Naval Guard Force 3 58 82 143 143 Z 4th Civil Eng. Dept, 1 2 1 4 214 218 TOTALS 3 58 83 144 24 168 TOTALS co 15 7 218 372 612 215 827 OLLAN ISLAND: 43rd Naval Guard Force. 2 4 6 6 Ul Z TSIS ISLAND: YAWATA ISLAND: E.CAROLINES Naval Air Group 11 3 14 14 43rd Naval Guard Force. 2 3 5 5 o 4th Civil Eng. Det>t. 125 125 < TOTALS 11 3 14 125 139 SUB-TOTALS FOR ABOVE 410 141 4,349 4,72 9 9,629 14,150 23, 779 SHIP-BASED PERSONNEL NAME: 41st NAVAL GUARD UNIT: O Light Mine Layer #3 3 1 41 10 55 55 Special Mineswpr##5 2 2 30 13 47 47 TARIK ISLAND: Fuyo Maru #2 1 10 9 20 1 21 4th Civil Eng. Dept, 7 7 Hosai Maru #2 1 6 6 13 1 14 Kosei Maru 1 10 4 15 2 17 Hozan Maru 7 7 z Yamato Maru #5 1 1 7 8 o TOTALS 7 4 98 42 151 18 169 UJ CO 4th NAVAL HARBOR DUTY: Z UMAN ISLAND: Futakami, FEFAN 2 37 18 57 57 UJ 49th Naval Guard Force 21 9 300 294 624 2 626 Tug #3, FEFAN 1 1 13 14 LU 4th Comm. Unit 1 1 22 21 45 45 Manshu Maru, DUBLON 11 11 UJ 5 43 27 75 113 Dai shin Maru, DUBLON 7 4th Harbor Duty Unit 38 7 UJ E.CAROLINES Naval Air Group 1 12 6 19 19 Kotobuki Maru, DUBLON 1 2 3 5 8 CO UJ 4th Civil Eng. Dept, 1 4 1 6 588 594 Yachiyo Maru, MOEN 10 10 4th Naval Hospital 2 4 13 19 1 20 Shinzo, Maru, MOEN 6 6 Z TOTALS 29 12 385 362 788 629 1,417 TOTALS 2 39 20 61 52 113 SUBTOTALS 9 4 137 62 212 70 282 ELIKANIBU ISLAND: 4th Naval Stores Dept, 1 1 1 GRAND - TOTALS 419 145 4,486 4,79 1 9,841 14,220 24, 061 ii A PANORAMIC PHOTOGRAPHIC TERRAIN STUDY ng~the planning stage of this report, prior to the arrival of the Study below. Each photograph, within the panoramic strips, is numbered and is represented Group at TRUK, the decision was made to supplement the written report by the maximum on the map by a numbered ray from the lettered panoramic station, thereby enabling use of photography, thereby visually presenting the exlstant conditions and subjects the reader to rapidly and accurately visualize the area covered by each photograph. of Interest. In addition to the treatment of specific subjects by this means, the decision was made that a series of panoramic photographic strips from critical ele- Panoramic strips from Stations "C", "D", "E","F" , and "I" each have 360° cov vations should be prepared to facilitate the presentation of the terrain and asso- erage. The panoramic strips from Stations "A", "B "G". "H«, and "J" have 185°, ciated features. 120°, 270°, 300°, and 170° coverage, respectively, due to obstructed views. Panoramic strips were photographed on various Islands as indicated: three on The numbers of the individual photographs contained In the panoramic strips are MOEN, three on DUBLON, two on FEFAN, one on UMAN, and one on PARAM. These are pre- preceeded by an abbreviation, "PMM, which Indicates the basic number of a picture sented on the following pages. In order to assist the reader in orienting the pan- whether on the Outline Map (Figure 3 - PANORAMIC PHOTOGRAPHIC STATIONS), In APPENDIX X oramic strips and individual pictures contained therein, a map (Figure No. 3), lo- III (Ground Photographic Reference Data), or on the map entitled "LOCATION OF GROUND cating the camera stations from which the panoramic strips were taken, is presented PHOTOGRAPHS" in PART TWO. Sea "COMMENT Oil THE NUMBERING OF PHOTOGRAPHS" on page iv. 116,117 115 365 363 366 MAN IS. DUBLON IS. ETEN IS. 367 FALO IS o 361 z 368 [STATION V 135 51 134 a CO z CO 275,276 274 372 o 371 272 o *: oc I— TSIS IS. Z o CO LU CO z 433 434 EASTERN ISLANDS OF TRUK ATOLL CO ELEVATIONS LU 435 STATION — ELEVATION Z MAP REFERENCE - H.O. CHART NO. 6048 "A" A'SfVf APPPDY ) "B" — — 45O'(APPROXJ SCALE |: 55,600 M C"— — 754' "D" — 85 31 "EM —- — 3901 — 1184' 441 V — 958' V — 2361 II. II 1 440 439 TAR K IS. 1 —— 899 880* FIGURE NO. 3-PANORAMIC PHOTOGRAPHIC STATIONS 7°20'N v— A PANORAMIC PHOTOGRAPHIC TERRAIN STUDY TIP OF FALO ISLAND OUTER REEF LIGHTHOUSE RAD 10 STATION HILL 810 SOUTH RIDGE OF HILL 1200 I 1 K .4, o a. Z PM 293 PM 292 PM 291 PM 290 PM 289 £ Z v-/ PANORAMIC PHOTOGRAPHIC STRIP FROM STATION "A" MOEN ISLAND CO Q Z CO LU Z _ i HILL 1200 ANCHORAGE MANGROVE SWAMP H LL 700 (STATION "C") HQS. , I S.COM.(21ST.MAR) rCAUSEWAY o o z o en LU CO z LU Z PM PM 285 PM 286 PM 287 PM 288 PANORAMIC PHOTOGRAPHIC STRIP FRQM STATION "B'VMOEN ISLAND n^Jr WWL 13 A PANORAMIC PHOTOGRAPHIC TERRAIN STUDY C.G.QUARTERS, TRUK ATOLL FEFAN ISLAND PARAM ISLAND FLOATING CRANE HQS. , CAUSEWAY LIGHTHOUSE H ILL 800 SMALL BOAT PIER N.C.B. CAMP i HILL 1200 o o I 5 m CO Z O3 o Q_ z : z PM 278 PM 279 v . PM 268 & 281 PM 269 PM 270 CO 4I M Q PANORAMIC PHOTOGRAPHIC STRIP f ROM STATION C MOEN ISLAND CONTINUED z o OUTER REEF ROAD ACROSS CAUSEWAY HILL 390 (STATION "E") SIGNAL LIGHT (STATION"F") FEFAN ISLAND on RAD 10 STATION Z o (/> CO Z Z a. < / \ 137 PM 138 PM 139 PM 1U0 PM 141 PM 143 PANORAMIC PHOTOGRAPHIC STRIP FROM STATION UD"DUBLON ISLAND CONTINUED 14 A PANORAMIC PHOTOGRAPHIC TERRAIN STUDY IE OL ISLAND U.S.N. ANCHORAGE L.S.T. LANDINGS AIRFIELD UNDER CONSTRUCTION FOR U.S.N. FALO ISLAND o a. Z PM 271 PM 272 PM 273 PM 274 PM 275 PM 276 PM 277 Z CONTINUED PANORAMIC PHOTOGRAPHIC STRIP FROM STATION "C" MOEN ISLAND Q Z CO LU Z —i o MT.N ISHIKI .(STATION "I"),FEFAN ISLAND UDOT ISLAND ANCHORAGE SEAPLANE BASE HILL 1200t M0.EN ISLAND RADIO STATION PARAM ISLAND TOL ISLAND HILL 800.MOEN ISLAND oz en LU CO Z UJ CO LU Z PM 143 | PM 142 PM 133 PM 134 PM 135 PM 136 CONTINUED PANORAMIC PHOTOGRAPHIC STRIP FROM STATION MD" MOEN ISLAND 15 A PANORAMIC PHOTOGRAPHIC TERRAIN STUDY UMAN ISLAND EATON ISLAND FEFAN ISLAND (AIR FIELD ) FUEL PIER o I en Z Z PM 116 & 117 PM 118 PM 119 PM 120 PM 121 PM 122 z PM 115 m to U Q PANORAMIC PHOTOGRAPHIC STRIP FROM STATION E" DUBLON ISLAND CONTINUED Z z - I o ETEN ISLAND (AIRFIELD) UMAN ISLAND FEFAN ISLAND MT.NISHIKI (STATION "I") TOL ISLAND _ . a: SEAPLANE BASE AMMUNITION, TORPEDO STORAGE FLOATING DRY DOCK \ o z O CO ui to zu.1 Q U£ CO PM 153 PANORAMIC PHOTOGRAPHIC STRIP FROM STATION "F* DUBLON ISLAND CONTINUED 16 ^•1 A PANORAMIC PHOTOGRAPHIC TERRAIN STUDY. f SEAPLANE BASE SIGNAL LIGHT (STATION "F") SIGNAL TOWER (STATION "D") MOEN ISLAND LIGHTHOUSE (MOEN ISLAND) FEFAN ISLAND \ HOSPITAL ARMY RADIO STATION PM 122 PM 123 I PM 110 PM 111 PM 112 PiV, 113 PM 114 PM 115 CONTINUED PANORAMIC PHOTOGRAPHIC STRIP FROM STATION "EMDUBLON ISLAND ANTI-TANK BARRIERS SEAPLANE BASE MOEN ISLAND SIGNAL TOWER (STATION " D " ) NE. POINT OF DUBLON ISLAND SE. POINT OF DUBLCN ISLAND ANCHORAGE RADIO STATION LIGHTHOUSE OUTER REEF HILL 390 (STATION "E") PM 155 PM 154 PM PM 145 PM 146 PM 147 CONTINUED PANORAMIC PHOTOGRAPHIC STRIP FROM STATION MF" DUBLON ISLAND A PANORAMIC PHOTOGRAPHIC TERRAIN STUDY W FEFAN ISLAND RADIO STATION MOEN ISLAND STATION "F ,DUBLON ISLAND OUTER REEF t TEN ISLAND z o CL z PM 369 PM 36 1 j PM 362 PM 363 PM 364 z z PANORAMIC PHOTOGRAPHIC STRIP FROM STATION "G" UMAN ISLAND CONTINUED UJ z - J o STATION "D"t DUBLQN ISLAND STATION "F".DUBLON ISLAND FEFAN ISLAND TSIS ISLAND as < O z O CO UJ in UJ z PM 433 PM 434 PM 435 PM 436 i ta- PANORAMIC PHOTOGRAPHIC STRIP FROM STATION *H" PARAM ISLAND CONTINUED 18 A PANORAMIC PHOTOGRAPHIC TERRAIN STUDY SMALL BOAT DOCK FANEU ISLAND OUTER REEF ISLANDS o T— I m Z H LU _J -I O o. Z PM 364 PM 365 PM 366 PM 367 PM 368 Z CONTINUED CO PANORAMIC PHOTOGRAPHIC STRIP FROM STATION "6" UMAN ISLAND Q Z CO o SMALL BOAT DOCI K ITA R IK ISLAND PARAM AIRFIELD TOL ISLANrD E IOL ISLAND UDOT ISLAND OS Z o CO tu CO z CO Z PM 437 PM 439 PM 440 PM PM 442 CONTINUED PANORAMIC PHOTOGRAPHIC STRIP FROM STATION "H" PARAM ISLAND 19 A PANORAMIC PHOTOGRAPHIC TERRAIN STUDY UMAN SLAND MT. UBUN TSIS ISLAND TAR I K ISLAND TOL ISLAND UDOT ISLAND PARAM ISLAND z o OL z PM 375 PM 376 PM 377 PM 378 PM 379 PM 380 PM 381 z Z PANORAMIC PHOTOGRAPHIC STRIP FROM STATION "P FEFAN ISLAND CONTINUED CO UJ z —I o Picture No. i (PM 572) DUBLON: Seen from point i£ mile offshore, true-south. Part of MOEN may be seen in the left backqround. z o (/I CO UJ Picture Mo. 2 (PM 571) UMAN: Depicted from position i£ Z mtle offshore to the south. Mt. URORAS is shown in the center of the photograph. JACK STAFF-AV.R 35 For Information regarding the system used in the numbering of individual photographs, of which the above individual photographs (Nos. 1 & 2) are the first to appear in this report out of a total of 351, see "COM MENT ON THE NUMBERING OF PHOTOGRAPHS'1 on page iv. A PANORAMIC PHOTOGRAPHIC TERRAIN STUDY ? 'Iff / H MT.SANREI ANCH0RA6E SEAPLANE BASE MOEN ISLAND LIGHTHOUSE STATION "D t DUBLON ISLAND SEAPLANE BASE ETEN ISLAND A/F FLOATING DRY DOCK STATION "F" / OUTER REEF z PM 37U KJ PM 369 & 381 PM 370 PM 37 1 PM 37 2 PM 373 z CO Q Z CONTINUED PANORAMIC PHOTOGRAPHIC STRIP FROM STATION "P FEFAN ISLAND to SIGNAL TOWER.DUBLON IS..(STATION "D") SEAPLANE BASE ETEN IS.AIRFIELD OUTER REEF UMAN ISLAND MT. ARASHI TSIS ISLAND O FLOATING DRY DOCK STATION "F" (SIGNAL LIGHT) z o CO UJ CO Z CO UJ Z PM 387 PM 386 PM 385 PM 384 PM 383 PM 382 PANORAMIC PHOTOGRAPHIC STRIP FROM STATION M J" FEFAN ISLAND 21 ARTILLERY AND ORDNANCE Final Defense Location CO o The Information appearing herein was obtained from sources as follows: En W Conferences with Japanese Army and Navy Staff Officers. CO Copies of defense plans furnished by the Japanese. B •H W X Actual reconnaissance with Japanese authorities covering all of the M PQ principal Islands within the TRUK Atoll and the reef islands at NORTH and SOUTH O 22 ARTILLERY AND ORDNANCE Wi *w ARTILLERY - GENERAL REMARKS. At all batteries personnel were quartered in barracks or shacks made of scrap lumber and galvanized sheet metal. These huts varied in size allowing in most cases The long range artillery defense of TRUK was weak. Batteries capable of firing accomodation of squads and in a few cases accomodation of 150 men. These in addition 11 effectively beyond the reef line were limited to one turreted 4-gun 20cm. (8 ) bat to galleys, mess halls, and officers quarters, were located in camouflaged defiladed o tery located on DUBLON, and to one turreted 3-gun 155mm. (611) battery located on areas adjacent to the gun positions. During bombing attacks personnel lived in the UMAN. The remaining heavy artillery, all of 15cm. or less, was capable only of caves and tunnels of the gun positions* o mine field and inshore defense. I The entire searchlight defense of TRUK employed only 20 searchlights. Only Ammunition was stored in the emplacement near each gun with exoeption of one 4 of these lights employed control stations and no searchlights employed radar or two batteries on TOL and the 12.7cm AA battery on DUBLON. At these excepted oc control* The majority of the searchlights were available for use by both anti positions ammunition was stored both in metal ready boxes placed in niches of the aircraft and seacoast artillery. Little attempt was made to control searchlights cave or revetment near the gun and in well constructed dumps for reserve ammunition. tactically from the Naval CP on DUBLON, tactical control usually resting with the In almost all caves and tunnels temperatures were moderate and stable. However, the battery commander of the nearest gun battery. In general, the searchlight defense atmosphere was quite humid and in many cases water dripped from the walls and was of TRUK was exceptionally weak. not well drained from the emplacement. Generally, ammunition storage facilities Although our air action had effected practically complete destruction of above- were very poor. ground naval and air installations, no damage was sustained by turreted or other heavy artillery in open emplacements, excepting one anti-aircraft gun battery on Intra-battery tactical communication systems consisted principally of telephone ETEN consisting of two 12.7cm. twin mounts which were destroyed. circuits employing sound powered or battery powered telephones. Phones were installed at guns, directors, range or height finders, OP1s and CP's in the AA batteries and Naval bombardment by the British for two days, about 27 June 1945, resulted at guns, range finders, OP's and CP1s in the coast defense and field artillery gun in no damage to heavy artillery. positions. At many of the battery positions the telephone circuits were paralleled with voice tube8 and buzzer systems. The communlcation listed in description of ARTILLERY POSITIONS ON BARRIER REEF ISLANDS. Individual batteries refers to intra-battery type. Artillery and searchlights located on the reef islands were moved after Communication between gun batteries and the island artillery tactical commanders, O February 1944, to cave positions on the principal islands Inside the reef. both Army and Navy, was by means of telephone and radio principally and augmented a. Artillery and searchlights had been emplaced as follows: by runner and pigeon. Little emphasis was placed on maintaining this communication. z In the following table, position numbers refer to Figures 4 through 10 (artillery and searchlight positions). The letter prefix denotes the island in accordance with GUNS FIELD SEARCHLIGHTS the following code; M-MOEN, D-DUBLON, F-FEFAN, U-UMAN, E-EOT, UD-UDOT, P-PARAM, ISLANDS NUMBER SIZE OF FIRE NUMBER SIZE T-TOL. TONELIK 2 in turret 14cm. 270° to 90° T 1 90 cm. Z Northeast 2 15cm. 360°, except for small — — area blanked by palm CO tree8. O MOB 2 15cm. Water area outside 1 90cm. reef. Z SALAT 2 15cm. Water area outside 1 75cm. -I reef. CO OTTA 2 15cm. Water area outside 1 75cm. LU reef. Z FALEU 2 15cm. 360° 1 90cm. -i FALASIT 2 15cm. __ K B ELI KANIBU 2 15cm. __ o YAWATA 2 15cm. — — — a: Direct fire telescopic sights were employed with all weapons. At TONELIK and FALEU Islands 2.5 meter range finders were employed and at approximately one half of the other islands 1.5 meter range finders were employed. The Navy controlled all batteries located on the reef islands and communication was maintained between DUBIXJN and all islands by use of underwater telephone and telegraph cable and radio. Positions were of the open type with log and sand parapets. Gun pedestals were bolted to reinforced concrete platforms. Z The searchlights were employed primarily for illumination of sea borne targets o and secondarily as pick up lights for illumination of aircraft. The lights were CO 1 UJ emplaoed on small towers approximately 6 high. The lights at TONELIK and FALEU CO were equipped with sound locators and comparators, and were tactically controlled by searchlight officers; all other lights employed hand control only and were z LU tactically controlled by the battery commanders of the island gun battery. No u. attempt was made to control the searchlights from the Navy CP on DUBLON. LU a DESCRIPTION OF INDIVIDUAL BATTERIES. LU CO Maximum and minimum effective ranges were obtained for the Navy weapons by LU questioning the Japanese battery and battalion commanders and from maps (believed z to be quite accurate) submitted by the Jap Navy Headquarters Staff; those for the Army were obtained from Army sources similar to the above Navy sources and also from knowledge of the characteristics of the weapon (characteristics obtained from CINCPAC - CINCPOA Bulletin No. 152-45, 1 July 1945). Limiting angles of fields of fire were obtained for practically all of the Navy emplacements and about 40# of the Army emplacements by actual measurement and for the remaining Picture Mo. 3 (PM 486) FORMER 14cm GUM EMPLACEMENT, emplacements from the maps submitted by the Japanese* FALEU ISLAMD (Reef). 23 ARTILLERY AND ORDNANCE o Weapons o M-l 1 75mm.Mtn.Gun, A Cave* Direct Fire. 8,000 No M-16 1 8cm.Armstrong A Open revetment. Direct; Fire* 8,000 No T.94 900 type Gun. M-2 1 75mm.Mtn.Gun, A Cave. Direct Fire. 8,000 No M-17 1 75mm.Mtn.Gun, A Cave w/palm log Direct Fire sights; Yes T.94 T.94 embr. Elev. no communication. M-3 1 75mm.Mtn*Gun, A 3 caves con Direct Fire. 8,000 No -15° to / 40°. z T.94 nected. 900 M-18 2 75mm.Mtn.Gun, A Cut type revet- Direct Fire sights; Yes (8,000)NE T.94 LU ment. no communication. _J (1,300) M-19 1 8cm.CD.Gun,3rd A Palm log cut & Direct Fire sights; Yes 16 & 17 _J (8,000)SE yr. type. cover type cave no communication. ( 700) w/concrete embr. OQ M-4 1 15cm.,40 cal. N Cave w/gravel Direct Fire;tele 10,900 Yes Elev.-2oto/5°. Armstrong Gun. filled 55 gal. scopic sights; 1,200 M-20 1 12cm.CD.Gun,3rd N Concrete cut & Direct Fire sights; 16,500 Yes 11 & 12 O (Some instruc drum embr.Elev.-telephone & voice yr. type* cover w/concrete no communication. 900 tion plates on 4° to / 20°. tube. embr* Elev* a. gun in Spanish). -7° to / 28°. Z M-5 1 15cm.,45 cal. N Cave w/gravel Direct Fire;tele 15,400 Yes M-21 4 20cm.,40 cal* N Turrets in open Azimuth & eleva 19,800 Yes 4 thru Vickers(B*L.G. filled 55 gal. scopic sights; RF 1,200 Armstrong Tur revetments*Elev. tion telescopes on 1,540 10, & G Mk H) Gun. drum embr.Elev for use of guns at ret type Gun -5° to / 28°. each side of gun; #40 -7° to / 18°. positions No.M-5 & removed from Jap 4.5m.RF;oil gears M-6,also,which are cruisers IWAMI, were on each gun, all connected by IWATE,NISSIN,' to move it in ele telephone. KASUGA. vation & azimuth; M-6 1 15cm.,45 cal* N Concrete cover- Direct Fire;tele 15,400 Yes telephone & voice Vickers Gun. ed & lined(cut &scopic sights;tele 1,200 tube. o fill type).Elev.phone & voice M-22 1 15cm.,40 cal* N Cave w/concrete Direct Fire sights; 10,900 Yes -7° to / 18°. tubes. Naval Gun* embr. Elev* no communication* 900 z M-7 1 75mm.Mtn*Gun, A Cave. Direct Fire. 8,000 No -4° to / 10°. T.94 300 M-23 2 15cm.,45 cal* N Cave. Elev. Direct Fire sight; 15,400 Yes 13,14,15 M-8 1 75mm.Mtn.Gun, A Cave. Direct Fire. 8,000 No Naval Guns* -2° to / 20°. 1.5m.RF; voice 1,100 z T.94 660 tube. M-9 1 75mm.Mtn.Gun, A Cave. Direct Fire. 8,000 No M-24 1 15cm.,40 cal* N Cave.Elev.-2 ° Direct Fire sights; 12,000 Yes T.94 400 Naval Guns. to/20°. Another 4*5m.RF;no oom 1,000 o 2 14cm.,50 cal* N Caves w/con Direct Fire;tele 18,700 Yes gun of this type muni cat ion. OS 3rd yr.turret crete embrs* scopic sights; < 1,000 on hand& was to KJ type gun* 3.5m.BF in CP be have been em tween guns;tele placed. phone & voice M-25 5 12cm.DP.Guns, N Open revetment. None other than Yes tube s• 10th yr.type. Elev. ? to /750 , Btry.Comdr. spot M-ll 4 75mm.AA guns, N Earth revet Direct Fire;3.5m, Yes Used forAAfire. ting with 8cm.bin T.88 ment Army guns HF;telephones. oculars & calling fired by Navy directions to the personnel. guns by voice M-12 1 75mm.Mtn.Gun, A Cave* Direct Fire. 8,000 No tubes;guns have T.94 Z 450 open type speed o M-13 1 75mm.Mtn*Gun, A Cave w/palm log Direct Fire sights Yes ring sights. A Dir T.41 embr. Elev. with known refer ector & HF.never UJ -10° to / 40°. ence points In arrived from Japan. en field of fire; no M-26 1 75mm.Mtn.Gun, A Cave. Direct Fire. Z communication. 8,000 No ui T.94 800 u. M-14 1 75mm.Mtn*Gun, A Cavo w/palm log Direct Fire sights; Yes M-27 1 75mm.Mtn.Gun, A Cave w/concrete Direct Fire only; 5,000 Yes UJ T.41 embr. Elev. no communication. T.94 embr. Elev. telephone instal 300 O -15° to / 40°. -5° to / 2° led. LU U-15 1 75mm.Mtn*Gun, A Cave w/concrete Direct Fire sights to Yes 18 M-28 4 12cm.DP.Guns, N Guns revetted Speed ring sights Yes LU T.94 & steel embr. & lm.RF; no comm. T.10 AA positions 50 only;complete tele Z Elev .-15°t o/40°. yds.apart on phone system in- Alternate posi steel sled bases^talled;Btry.QP.5O tion in a cave Elev./3°to/75°. yds N.of center of 50 yds.W.to give Btry.-had B.C*tel field of fire escope; hand wrench 295° to 20°* fuze cutter. 24 o ••• 5 so o •• ft «•> •• ««• o «» 0 • 3 3 *c o 1 • to "3 ft] CO CD <« e o • to .* CD : ^ I * 10 O 10 • to I »o 10 -u Co so en en D C*5 CD a*. t3 -fe. o CD CD o o »* en o 1 - o «• 3 5*! * © O O to t> a »o 10 CD Co so CD JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1946 ARTILLERY AND ORDNANCE CQ oj Weapon8 Weapons ©M © c 0) o +3 M-29 2 12cm.DP,Guns, N Guns,revetted Speed ring sights Yes D-4 3 75mm.AA Gun, A Each gun in sep- Direct Fire;3m.RF. Yes T.10 AA positions 20 only;no telephones T.88 arate cave; at W.gun;known ref- yds apart;steel installed;Section mounts tipped erence points;Bn. sled bases-no Chief stood between forward to per- island CP.was at concrete.Elev. guns & shouted;hand mit lower angle this position,tel- 0° to / 75°. wrench fuze putter. of fli*e. Elev. ephone comm. M-30 1 75mm.Mtn.G-un, A Cave w/2 embrs. Direct Fire;lm.RF. 5,000 Yes -10°to/5°.Cave CQ T.41 15 yds.apart; in S.cave opening; 300 connected E.& < gun could be no communication central guns. moved to either installed;runner D-5 1 75mm.Mtn.Gun, A Cave w/cane Direct Fire;lm.RF. Yes o opening. Elev. only. T.94 embr.and steel at CPjtelephone to a. -5° to / 10°. doors;cave con- CP. M-31 2 75mm,Mtn,Gun, A Connecting caves Direct Fire; com- 5,000 Yes nected to CP. T.94 w/embrs.20 yds. munication by run- 300 10m.W.of gun. apart & CP .be ner. Elev.-3°W6°. tween the embrs D-6 2 75mm.AA Gun, A Newly completed Direct Fire;lm.RF. Yes Elev.-5°to/10°. T.88 cave connecting at S. gun. M-32 1 75mm.Mtn.Gun, A Cave. Elev.-3° Direct Fire;no 5,000 Yes guns;guns 20m. z T.94 to / 10°. telephone instal- 300 apart;cave en led. trance 70m.dis- M-33 1 75mm.Mtn.Gun, A Cave• Direct Fire. 8,000 No tance on rever T.94 se slope of hill; electric lights \NDS . installed.Elev. D-1 1 75mm.Mtn.Gun, A Cave w/concrete Direct Fire;tele —5° to -/5° erabr;3/8B steel phone to OP. Yes D-7 1 75mm.Mtn.Gun, A Yes ISL / T.41 Cave. Elev*. Direct Fire;lm.HF. door covering T.94 -3° to / 10°. & known reference embr. Elev. points in field of ^^ .IN E -5° to / 13°. fire;telephone to D-2 1 12cm.CD.Gun, N Concrete lined Direct Fire;tele- 19,800 OP. O Yes 3rd yr.type caves;1 gun on scopic sights; 3,000 D-8 1 75mm.Mtn.Gun, A Cut & fill-con- Direct Fire;lm.RFv Yes (1914)fitted each side of speaking tube, T.94 crete w/earth telephone to OP. •» w/shield. hill connected cover-2 concrete _j by caves; cave -j embrs.firing entrance on S. ports in em 0 side of hill. placements: Elev. 1 12cm.CD.Gun, Cave also con -3° to / 3 6 . 11th yr.type nected to OP.on D-9 2 75mm.Mtn.Gun, A Cave connected Direct Fire;lm.RF. Yes (1922). N.side of hill. T.94 by tunnel to OP.on hill between Elev.-6° to/30°. position D-7. positions D-7 & D-9; D-3 2 105mm.How.,T.91 A Open cave in Direct Fire;lm.RF. 11,000 Yes Elev.-5°to/3°. telephone to OP. Z (1931). cliff;guns could at W. gun;0P.in D-lo 1 75mm.Mtn.Gun, A Concrete lined Direct Fire. Yes o be moved to ob- separate cave;tel T.41 cave w/concrete CO tain max.elev., ephone to OP. embr. Elev. U l (45°);cave con -5° to / 5°. CO nected guns. D-ll 1 8cm.,40 cal.CD. A Cave. Direct Fire;tele Z s 4,000 Yes 21 Ul Elev.-3 to/9° in Gun,Armstrong phone to Bn. CP. 200 u. cave. Ul T.,fixed mount. Q D-12 1 75mm.Mtn.Gun, A Cave. Direct Fire;tele- Yes U l T.94-Gun not phone to Btry.CP. CO emplaced. Ul Z 26 t-. «• O O\ o o M >o r> 3 -ex O e o o a* a*. CT3 M O 5*: « warn • c to o o » o o o 10 •JO 10 (0 Co o o (=1 en 3 C*l CD CD CO O M a oo o VJI 3 I "T3 • »0 CD a*. o Us. CD N) JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1946 ARTILLERY AND ORDNANCE CO o Weapons •d Weapons a o •H fc o O O 28 Picture No. 24 (PM 511) RANGE FINDER, STEREOSCOPIC , 4.5m, Picture No. 22 (PM 512) 127mm AA GUN, TYPE 89: AA Picture No. 23 (PM 5°9) DIRECTOR, TYPE Used in 95; TYPE 94: Used m 12.7cm AA battery on DUBLON. Pipe m lower battery on DOBLON. Position D-14. 12.7cm AA battery on DUBLON. Posit ton D-14 f ore ground continues up through Range Finder pedestal and also to position near Director for fire commands, Position D-14. o z z • - Ok z CO o Picture No. 25 (PM 510) 12.7cm AA GUN COMMAND POST: Picture No. 26 (PM 408) TYPICAL FIELD OF FIRE: 75*» field Picture No. 27 (PM 108) 12.7cm AA GUN, TYPE 89: AA O DUBLON. Lower foreground is entranee to Personnel gun, tyPe 38. Position F-14. battery on DUBLON. Pos it 1 on D-14. quarters. Reserve ammunition dump located m cave beneath quarters. Pos it ion D-14. z o CO Ul CO Z Ul u. Ul Q Ul CO Ul Z Picture No. 28 (PM 409) GUN POSITION IN CAVE 12cm, Picture No. 29 (PM 417) 8cm, D.P.. 10th YR TYPE GUN: Picture No. 30 (PM 402) 12cm, D.P. 10th YR TYPE GUN, 3rd yr type gun, position F-10. In c oncrete AA position F-6. Posit 1 on F-9. 29 ARTILLERY AND ORDNANCE y &••• ESS fli >> co •d 1946 . Weapons •z, i CD M • Weapons $. JL >•*—' CJ CD CD o r'i > s v 30 o <* 01 -3 a*. Si. C3 o I 4. O o "3 o •* 10 %*••• ">i o o I • o JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1946; ARTILLERY AND ORDNANCE Weaoons Wearons Nav y Nav y 1 (Yds ) (Yds ) 1 • o r o r itio n be r 194 6 Inspecte d Effectiv e Max.-Min . Numbe r Range s Arm y No , Piotur e Inspecte d Type. i Effectiv e Range s Max.-Min . No * (Positio n iNumbe r Piotur e IC H Emplacement I Fire Control • Numbe r Arm y Emplacement F Type, i Fire Control i Li. —- P-1 5 12cm.,45 cal,, N Cut type revet- T.2 Director & dir- Ye 8 49 T-14 2 15cm.,40 cal* N Cave* Direct Fire tele- 12,100 No DP.Gun,10th ments lined w/ ect fire sights; Gun8.Stabili- scopic sightBjl-^m. 1,500 in yr. type. palm logs. 2m.RF w/altitude mento Arm- coincidence RF* convertor;data strong Puzzuoli, transmission sys 1-15 1 75mm.Mtn.Gun, A Cave* Direct Fire* 7,600 No 1 tem; powered by 2 T.94 330 en 3kw,generators;tel T-16 1 76mm.Mtn*Gun, A Cave* Direct Fire* 2,300 No Z ephone & voice T.41 660 t— tube comm. T-17 1 75mm.Mtn.Gun, A Cave* Direct Fire* 3,300 No UJ • P-2 1 12cm.,45 cal., N Cave-lined w/ Locally manufac 10,900 Yes 47 T.41 190 _i DP.Gun,10th corrugated sheet tured direct fire 2,200 T-18 1 75mm.Mtn.Gun, A Cave* Direct Fire* 2,500 No yr. type. metal. Elev. sights;no comm. T.41 165 00 -4° to /15°. T-19 1 75mm.Mtn,Gun, A Cave, Direct Fire* 2,200 No < P-3 3 75mm.AA Gun, N Open revetment. Direct Fire sights; Yes T.41 165 O T.88 2m.RF;telephones. T-20 1 75mm.Mtn.Gun, A Cave, Direct Fire, 2,600 No a. P-4 2 75mm.Mtn.Gun, A Open emplace Direct Fire, 8,000 No T.41 165 T.94 ment (caves pro 200 T-21 1 75mm.Mtn.Gun, A Cave, Direct Fire* 2,100 No Mm posed); field of T.41 770 % fire to N.by T-22 4 15cm,,40 cal* N Caves w/concrete Direct Fire:tele 10,900 Yes swinging 1 gun Gune.Stabili Ac rook embrs. scopic eights*3m. 2,000 around. mento Ana- Elev*-4°to/17° • coincidence RF;tel P-5 1 75mm.Mtn.Gun, A Cave(on Tarik Direct Fire, 6,000 No strong Puzzuoli ephone & buazer. * z T.41 I.) P-6 1 75mm.AA Gun, N Open revetment Direct Fire, No T.88 to fire AA. a T-1 1 12cm.DP.Gun, N Cave, Direct Fire, 13,200 No z 10th yr.type. 1,000 < T-2 1 75mm,Mtn*Gun, A Cave, Direct Fire* 2,180 No ir# T.94 330 LU T-3 1 75mm.Mtn.Gun, A Cave, Direct Fire. 2,180 Z T.94 435 _ i Connecting caves r\ T-4 3 15cm.,40 cal, N Direct Fire;tele 14,300 Yes \j WrUnSP nri , QuuaDj.ll •*- j-t V> O 1 w/concrete & scopic sights; 3m, 2,500 ••m mento,Armstrong rock embrs'tun coincidence RF; Puzzuoli,elec nel to CP.Eiev, telephone,voice tric firing cir^ -4° to /L7°* tube & buzzer. i on i ^ -i ^% T-5 1 75mm.Mtn.Gun, A Cave connecting Direct Fire. 2,180 No U T.41 w/alternate po 330 sition. Alternate Pos 550 T-6 1 75mm.Mtn.Gun, A Cave. Direct Fire. 2,180 No T.41 200 T-7 1 75mm.Mtn.Gun, A Cave, Direct Fire* 3,000 No z T.41 440 oCO 111 T-8 1 75mm.Mtn.Gun, A Cave, Direct Fire* 1,600 No UJ T.94 330 to T-9 1 75mm.Mtn.Gun, A Cave connecting Direct Fire* 7,600 No zUJ W I a T.94 w/alternate po- 870 UJ sition. O T-10 1 75mm.Mtn.Gun, A Cave connecting Direct Fire* 7,600 No UJ T.94 w/alternate po 1,950 CO sition. UJ T-11 1 75mm.Mtn.Gun, A Cave, Direct Fire, 7,600 No T.94 1,100 7c5nm V*~n Gun C A VP _ Nn T-12 1-J» A vll cw U C -Lie. DjUUU JNO WLWm < T.41* 440 T-13 1 75mm,Mtn,Gun, A Cave, Direct Fire. 7,600 No Picture Mo. do (PM 333) PARTIAL VIEW OF FIELD OF FIRE T.94 330 2ocu GUM r. MOEM: Position M-ai. 1 32 C5 •*> ^ co o « •»-!«•> O •• • "S 3 -^ l» a • • ^ » . — -u to ••OH •• a o 0 *— a «• ^ •» o 1 n K u ^ • 10 f o -^^^^m^tmattti C. en on >-. J •-a CO o «* C5 O I • o CD C5 >•. I CD O - ts O U) a io 'JV 3 3 o o CD CO CO JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1946 ARTILLERY AND ORDNANCE MAINTENANCE AND REPAIR FACILITIES. Picture No. In general, maintenance and repair facilities according to our standards did 1 - Universal grinder, 8" swing X 24" between centers, Br^wn & not exist in the Japanese Army at *his installation. Apparently no maintenance Sharpe No. lu. X organization existed as such. The using units performed their own first and 1 - Radial Drill, 48w radius X 48" vertical olearance, Minoura & 66 limited second echelon maintenance. Early in the war, third echelon assemblies Co., Ltd., individual motor drive. were shipped to JAPAN and new or rebuilt assemblies were shipped to TRUK. Later 1 - Shaper, vertical (or Keyway cutter) 26M dla table, 14" 61 in the war, the ^my depended on the Navy for such higher echelon maintenance as stroke, Kubooho, Tokyo, Individual motor drive. was required and which could be performed by the Navy shops. 1 - Pipe threader, i-3/8" diameter capacity, equipped with bolt thread fly cutters only, Landis Machinery Co., Waynesboro, Up to 30 April 1944, when its shops were bombed out, the Navy had very Pa., belt drive. adequately manned and equipped repair facilities which were capable of malting very 1 - Lathe, 14" swing X 48" between centers, heavy duty, turret 60 extensive repairs on a wide varlbwy of materiel. type tool holder. J.F.K. Mfg., Osaka, individual motor drive. 2 - Lathe, 16" swing X 28" between centers, gap bed, Japanese 62 z In addition, prior to January, 1944, three Japanese repair ships - a part of manufacture, belt drive. the Grand Fleet - assisted island personnel in the maintenance of materiel. 1 - Lathe, 16" swing X 48" between centers, with taper attaoh UJ ment, Amerioan Tool Works Co., Cincinnati, Ohio. Navy Yard A map showing the extent of the Navy maintenance facilities before and after No. 9-77, Purchased 1931, Cost $3,161. _i the bombing of 30 April 1944, ana subsequent shops constructed, is included as a 1 - Boring Machine, horizontal, 51" spindle head to support bear- 63 CQ part of the Engineer's Annex to this report. ing, the Fairbanks Co., Navy Yard No. 9-5, purchased 1909, cost $1,125. Following the bombing of 30 April 1944, shop equipment which was still service- 1 - Turret lathe, 22" swing X 72" between centers, gap bed, the 64 o able, or could be made so, was in most cases moved underground. The principal Rahn Larmon Co., Cincinnati, Ohio, Navy Yard No. 340B-8, underground machine shop is indicated on the above-mentioned annex. The floor is purchased 1921. Property of the U. S. Army, P4299.448C, No. z rock-dirt and very wet, requiring a pump to control the water level in the shop. 124 Ordnance Department, belt drive, Due to the extremely damp conditions, all machine and hand tools are In a very poor 1 - Planer, open side, bed 28" X 120", Petrick and Harvey Machine 65 state of preservation. Co., belt drive. 1 - Drill press, sensitive type, 12" swing, floor type. The blacksmith shop consisted of a small open shed. 2 - Lathe, 6fl swing X 12" between centers, bench type, precision, Z with turret attachment, not installed to operate motor drive. The foundry was reduced to one medium-sized oil-fired cupula (see picture No. 1 - Punch and shear, Yamokawa Press Mfg. Co., Individual motor 66 67) from which small xron castings could be produced. It was found at approximately drive. its original position. 1 - Sheer, gate, 51 capacity 3/8" stock. 68 CO Q 1 - Hammer, individual motor drive. 69 The welding shop, while in its original position, was damaged. Due to the 1 - Furnace, heat treating, 18" wide X 24" deep X 12" high. Z lack of proper welding rod, soft iron wire cut to proper length and dipped In an 1 - Forge, anvil, blacksmith vioe, hand tools. asbestos paste was used. The gasoline-driven direct-current machines were still CO in operation. Acetylene welding was stopped with the destruction of the oxygen The 104th Alrforce Arsenal (Navy), prior to 17 February, 1944, was laid out and acetylene plants. as indicated in the plan included as a part of the Engineer's annex to this report. At the time indicated, it was destroyed by bombing. At present, the power-plant Partial destruction of the carpenter shop reduced the production of pattern- building is standing. Machines in the shops were destroyed and have been removed. making and carpentry to a hand operati-on. The only indication of the machine tools is the "Wooden Shop" (Carpenter Shop). o The following machinery is in that location but is unserviceable: The above shops each had well-equipped tool rooms with an adequate supply of micrometers (both inside and outside), verniers, scales, calipers, electric drills, 2 - bandsaw 36" taps and dies, planes, chisels, carpentry and blacksmith tools. 1 - Joiner 1-14" planer Following is a list of the principal machine tools with which the above shops 1-18" planer are now equipped and which were in operating condition: 1 - 16" swing X 36" between centers, lathe 1 - Circular saw and Joiner Picture No. 1 - Shaper (Asano-Jyuko) 16" stroke, 16" horizontal and 14W ver- 57 tical travel table. Individual motor drive. z 1 - Lathe, 16" swing X 48" between centers, Monarch Machine Tool The 4th Construction Department Repair Shop (Civil Engineering Department of o Co. Navy Yard Number 9-104, Back geared, individual motor the Japanese Navy) has a machine and repair shop which was evidently used for the CO drive. repair of its equipment and for such manufacture as was required. The machine tools UJ l! fl CO 1 - Lathe, 16 swing X 60 between centers, quick change gears, and other equipment were in good condition but of very old manufacture (possibly Z individual drive, taper attachment, South Bend. before 1900)• The machine shop was powered by a single cylinder horizontal YANMAN 1 - Lathe, 8I! swing X 24" between centers, Japanese manufacture, Diesel Engine, all machines being driven from overhead pulleys and line shafts. WSK-3, back geared, taper attachment, turret type tool Shop equipment included the following: holder, Individual motor drive. 3 - Lathe, 8H swing X 26" between centers, precision type, com- 58 CO plete with collet set, Japanese manufacture, individual motor 1 - Lathe, 18" X 96", gap bed, turret type tool holder, back geared. LU drive. 1 - Lathe, 18" X 30", gap bed, turret type tool holder, back geared. Z 2 - Drill press, 22" swing, floor type, movable table, Individual 59 1 - Lathe, 16" X 30", gap bed, turret type tool holder, back geared. 1 - Drill press, 22" swing -Tloor type, hand feed. motor drive, power feed, Minoura & Co., Ltd. W 1 - Universal Milling Machine, The Kempsmlth Mfg. Co., Milwaukee, 1 - Milling machine, table 7 X 29", with dividing head. Wisconsin., Navy Yard No. 9-78, year purchased 1921, cost 1 - Shaper, 18" stroke, with vice. Si.793. individual motor drive. 1 - Grinder, pedestal type, 10" wheels. PiTr VV 34 afei. z Picture No. 50 (PM 25) i.oookv GENERATOR l.yoohp DIESEL Picture No. 51 (PM 26) 74kw GENERATOR g-ohp DIESEL Picture No. 52 (PM 39) 6$kva(ac) - 65ku>(dc) GENERATOR ENGINE ENGINE. lQohp diestl engine. o z a z UJ Z o ac Pictur.* ^o . 53 (PM40) iookva(ac) GENERATOR: 150HP Picture No. 54 W 35) UNDERGROUND MACHINE SHOP: View Picture No. 55 (PM 36) UNDERGROUND MACHINE SHOP: View die set engine (unserviceable). from e nt ranc e. from inside the shop. Z o in UJ Z Picture No. 56 (PM 30) RADIAL DRILL: 48" radius X 48" Picture No. 57 (PM 27) SHAPER: (Ansano Jyuko 16" Picture No. 58 (PM 28) LATHE: 8" sum? X 26" vert ical c Learance, indiv idua I motor drive, Mtnoura and stroke, table travel 16" horizontal X 14" vertical, centers, precision type, comtlete- with col Co., ltd. indiv idua I motor drive. individual motor drive. $E ^A ftTi 35 ARTILLERY AND ORDNANCE A email blacksmith shop, with two forges and two anvils, located adjacent to TOTAL QUANTITIES OF FIRE CONTROL ITEMS. the machine shop is presently used to store kafir corn. One of the lathes listed above was equipped with attachments for threshing, and there was a grist mill for The following inventory was compiled by the Japanese and is believed to be grinding this corn. quite complete and accurate. The inventories do not include such items as binoculars end compasses which were used by the Japanese Naval Air Unit on TRUK. A two-stall garage-type shop was used to repair Construction Department vehicles, air compressors, bicycles, etc. A saw-mill was operated to make rough lumber for construction purposes. A 2 1 m 4 diameter band-saw mounted with a cradle for passing and handling the logs, was driven by a diesel engine. Navy Fire Control Items: The above installations were equipped with limited hand tools, such as: Quantity Item Picture Number micrometers, calipers, verniers, scales, blacksmith and mechanic's hand tools. 2 Type 94, 4.5m Range Finder. 24 The 41st Garrison Machine Shop and Warehouse had evidently been a small 1 Type 93, 4.5m Range Finder. combination shop for general repairs and maintenance. It had some permanent equip 1 BU Type, 4.5m DP Range Finder. ment installed as follows: 1 BU Type, 3.5m Range Finder. 1 BU Type, 2.5m Range Finder. CQ 1 - Lathe, 18" X 36", quick change gears, heavy duty, Jap manufacture 2 Waterproof, 3.5m light Range Finder. similar to a modern South Bend Lathe, taper attachment, of very modern 5 Range Finders. o type, individual motor drive. Picture No. 71. 2 Range change. 1 - Grinder, pedestal type, 12" wheels. 2 Type 13 Range Clocks. a. 1 - Drill press, 22" swing, floor type, hand and power feed. 1 15cm binoculars. Z 1 - Saw, band, 36" diameter wheels (woodworking) Individual motor drive. 57 12cm binoculars. 1 - Circular saw, 12" diameter blade, tilt top, table type, with complete set 22 12cm high angle binoculars. dado heads (woodworking) individual motor drive. 3 12cm observation glasses. 1 - Planer, 16" blades (woodworking) individual motor drive. 2 12cm binoculars, Type 97 waterproof. 1 - Sharpener for woodworking band saws. 42 8cm binoculars. z 1 - Lathe, 16" X 40" (woodworking) individual motor drive. 31 8cm high angle binoculars. 1 - Bla.cksmithing outfit complete with forge, anvil, shear, vices and hand 10 6cm high angle binoculars. tools. 8 Model 3 observation glasses. to 1 - Furnace (in ground) oil-fired for producing iron castings. 1 66cm range finder. Q 3cm binoculars, high angle. In addition, the shop was equipped for both acetylene and arc welding. A 1 22 Prismatic binoculars, Model I. Z complete supply of hand tools for use with the above machine tools was on hand. 1 10 power prismatic binoculars. 7 power prismatic binoculars. to Evidently a number of machine tools was received from JAPAN which it was 461 thought best not to install for operation. These were stored in caves and recently 19 6 power prismatic binoculars. LU 33 Wall clock, weekly wind, luminous. Z had been moved to this shop for storage. These machines of very recent manufacture and very modern design are listed as follows: 48 Wall clock, dally wind, luminous. _ i 11 Wall clock, weekly wind. 38 Wall clock, daily wind. 1 - Lathe, 18" X 48" between centers, heavy duty type, quick change gears, o 45 Wall clock. < (similar to Reed-Prentice), individual motor driven. 25 Stop watch, model 1-B. 1 - Lathe, 18" X 30" between centers, heavy duty type, quick change gears, 3 Stop watch, model 3. (similar to Reed-Prentice), Individual motor drive. 170 Stop watch. 1 - Shaper, 20" stroke, with vice, (similar to Cincinnati) Individual motor 7 Ordinary binoculars. drive. Picture No. 72. 1 - Circular saw 12" blade, tilt top table type complete with dado heads, Army Fire Control Items: individual motor drive. 1 - Drill press 22" swing, power and hand feed floor type, individual motor 1 Type 96 Searchlight Instrument. drive. 595 13th yr type Binoculars. 3 - Welders, electric, AC transformer type. 43 Type 89 Binoculars. z 603 Type 93 Binoculars. o It is felt that prior to the bombing of 30 April 1944, the maintenance and 13 Type 37 Artillery glasses. en repair facilities of TRUK were such that very extensive repairs, including fifth Ul 38 Type 93 Artillery glasses. to echelon, were possible and had been accomplished. Probably the most serious 83 Type 93 50cm observation glasses. handicap was the difficulty encountered with procurement of supplies from supply 30 Type 93 Field range finder. Z bases In JAPAN due to the distance to be traveled. This lack of supply became more LU 2 serious as our attacks reduced the tonnage of Japanese shipjjing of manufactured and 8th yr type Heavy range finder. raw materials which was getting through to TRUK. After the bombing of 30 April 1944, 1 Type 89 AA binoculars. the maintenance facilities were curtailed to a large extent, until they were re 17 7 power periscope binoculars. LU located and re-established as indicated in the above paragraphs. However, they were 1 8cm binoculars. to 1 LU never able to approach the capabilities which were formerly enjoyed. It is felt 12cm binoculars. Z that their facilities are roughly 10 to 20 per cent of what they previously had 1 12cm high angle binocular range finder. been. By observation and conversation with Japanese officers, it is concluded that 15 Type 98 Light ground fire control instrument. maintenance was practically at a standstill due to the lack of fundamental supplies. Little or no stock of major items, assemblies, sub-assemblies or raw materials existed at the cessation of the war. /M 36 •© o I m Z Picture No. 59 (PM 29) DRILL PRESS: 22" swm? , floor Picture No. 60 (PM 32J LATHE: 14" su m ? X 48" between Picture No. 61 (PM 31) VERTICAL SHAPER: (on keyway type, ntoi/aHe table, individual motor drive, power feed centers, heavy duty turret type tool holder, m d ividua I cutter.) 26" dta. table X 14" stroke, tniiv idud I motor Mmotira and Co., ltd. motor drive, J.F.K. Mfg.. OSAKA. drive, Kubocho, Tokyo. o a. z z a z o Picture No. 62 (PM 33) LATHE: * 6 " swing X 28" between Picture No. 63 (PM 34) BORING MACHINE: horizontal, 51" Picture No. 64 (PM 3J) TURRET LATHE: 22" swtnf X 72 " between centers, gap bed, Japanese manufacture, bel't drive. spindle head to support beannf. The Fairbanks Co., Navy centers, gap bed. The Rahn Larmon Co. , Cincinnati, Ohio, Navy o Yard No. 9-5, purehased igog. Cost $1,125. Yard No. 340B-8. purchased 1921 , Property of U.S.Army P4299. 448C, No. 124 Ordnance Department. Z o to to Z LU CO LU Z a Picture No. 65 (PM 38) PLANER: Open side, bed 28" X Picture ,1,0. 66 (PM 42) PUSCh AND SHEAR: Inlivilual motor Picture No. 67 (PM 41) COPULA: Oil S civ y repair shop 120", belt drive, Petnck and Harvey Machine Co. drive, Yanojawa Press Mfg. Co. , old fiavy repair area. area. 37 ARTILLERY AND ORDNANCE Quantity o Item TOTAL QUANTITIES OF WEAPONS AND AMMUNITION. I 3 Gunner's slide rule. The following Inventory was complied by the Japanese and is believed to be 2 Calculating boards. quite complete and accurate insofar as weapons are concerned. The ammunition 1 Type 98 Fire calculating board. inventory is of unknown accuracy since all ammunition had been dumped at sea prior 1 Type Mark I Plotting board. to the arrival of the Study Group. These inventories do not include bombs and bomb 1 Type Mark II Plotting board. fuzes, aircraft machine guns nor the ammunition for these guns which were used by 5 Goniometer. the Jap Air Unit on TRUK, nor the ammunition stored at TRUK for the Imperial Fleet. 4 Protractor. 1 Trajectory and wind plotting board. Navy Ordnance Equipment: 8 Stop watch. AMMUNITION 13 Portable thermometer. QUANTITY TYPE CALIBER WEAPON (ROUNDS) PICTURE NO. z 2 Type 93 Height finder. 752 Type 98 Night compass. 4 Safety 45 20cm Gun 946 Ul 3 Type 1 Plane altitude measuring instrument. 3 3rd yr. 60 15,5cm Gun 773 3 Type 2 Plane altitude measuring instrument. 13 Safety 40 15cm Gun 3,103 9 Type 97 Rifle type stereoscopic sight. 4 Safety 45 15cm Gun 3,706 15 Type 97 Stereoscopic sight. 4 41 40 15cm Gun < 5 Type 98 Target range finder. 0 14cm Gun 3,855 15 Gun sight direction block. 7 3rd yr. 50 12cm Gun 2,780 O 1 Clinometer. 3 41 40 12cm Gun 262 2 Clinometer spectacles. 2 89 40 12.7cm Multiple Mount 2,908 CD 4 Mil slide rule. DP Gun 7,337 AA 29 10th yr. 45 12cm AA Gun 1,957 AA TOTAL QUANTITIES OF VEHICLES (NO TACTICAL VEHICLES WERE FOUND ON TRUKK 609 CD 3 3rd yr. 40 8cm AA Gun 2,122 AA KJ The following inventory was compiled by the Japanese. Two Inventories were 1 5th yr. Short 8cm AA Gun 132 submitted, one showing total quantities at TRUK, the other showing quantities on 9 7cm AA Gun 3,237 z each island. Discrepancies exist in comparing the two. The following is believed 23 3 8cm Mortars 3,957 therefore to be only fairly complete and accurate. 2 1 47mm Mobile Gun 272 2 94 37mm Anti-Tank Gun 1,984 Q Navy Vehicles; 1 2 30mm MG, fixed 1,700 Z 1 2 20mm MG Quantity Vehicle 91 99 MK 1 20mm MG 47,207 73 96 25mm Multiple Mount MG 196 Trucks. 23 96 25mm Single Mount MG 472,835 34 Personnel carriers. 3 93 13mm Multiple Mount MG 15 Fire trucks. 89 93 13ram Single Mount MG 265,064 13 Motorcycles with side cars 1 Hotchkiss 13mm Quad. Mount MG o (believed to be motor tricycles). 140 92 7.7mm Single Mount MG 1 Sidecar (with motorcycle). 28 92 7.7mm Flex, Mount MG 1,137,094 7 Machine gun carts. 1 Lewis 7.7mm MG 11 Tractors. 8 Model 1 7.7mm Flex. MG 1 Three-wheeled fire cart. 31 92 Heavy MG 272,928 5 Trucks equipped with crane. Light MG 11 177 99 Fuel oil trucks. 1 3rd yr. MG 51,100 2 Ambulances. Light MG 2 15 96 Air charging truck (torpedoes). 3 11 Light MG 5 Ditchers. 1 Sprinkler truck. 6,567 2 Trucks for transporting torpedoes. 99 Rifle 1,369,197 1 1,214 38 Rifle 1,120,401 Z Oxygen generating truck. 9 W 1 Searchlight truck. 27 I Rifle o 4 Water supply trucks. 325 14 Pistol 189,443 45 Army Pistol # (/> Army Vehicles; 56 BE Automatic Pistol 85 Very Pistol Z 25 Quantity Vehicle 10 100 Flame Throwers UI 7 Large Model Flame Throwers 78 75 Trucks. 26 Locally Manuf. Bomb Rocket Launchers 20, 82 3 Type 96 Trailer car. 11 57 Bomb Rocket Launchers UJ 1 Ambulance. for land use. Z 7 Passenger car. 100 89 Heavy Grenade Dischargers 7,064 3 Type 95 wheel drive passenger car, 211 100 Grenade Launcher 1 Light repair truck. 2 95 AA MG for land use. 94 Type 39 Trucks. 1 2 AA MG for land use. 38 1 Pic 3 3 P 3 C_ p o P ft] ft] 3 so «•»• o 3 .. p R n ^^^Mi >.. •*• 1 w^ P r> co^ c^ iHVJR*^»w m—~i ••• C BPI^^rT' ' i p mm. 3 *•• C3 3 f» mi Co i tt• 3 ft 3 *: o p. PU R O V o «• «tttm^ «•»• o Co ft 2 1 3 U. M mm IC ^HHIB* _^J • p . -fe. ^ / P. c uo - K Ji- i^iH o HBB^H •* ^ I " ^ P ^ ° R- ft • 1 ^B ' Vw^ iBB^i ^^^^^^B^M HH- B • *• c 3 -&. .• » «>• p o ~J rn« 1 ft /m h 7 m^ («.„ R-N _ 1 Co r - fO -fl^B Co a- « • 3 "^ C~< • to • [• fe ^^B, 3 2k ^ H o o p^p^p^pj Jr'fi*. "' co t*3 "^>- «*• ,* - ;*-. „ »». . .^H • - ^ p^p^p^v 1 m i • m m ^^HH^ o Tt1 / «•. p^p^p^^ "•O O • • ^^^^f-• «"i P ft] '^H •«• • • 3 • I-H R- P / CO "o 3 -• 2 k 1 • .... b ^^ 1 C t so 1 ': 1 di^MU MCO KOi 1• ^ _ _>> C« 3 1 i I % m jtA^k^k^BiHI o 3^1 ft ^^| ^^WMw^WMWMWMWMWMWMM O C3 3 1 p I P | 2ZON 1 3 ^0 1 ill 2ft so * A ml • CO a • « — 3 f 1 <* 2 k c • r mw ^H| ^ HPBPi n 1 o *»- T* - 1 ^•1 o ft o O J^J" -^ t— • *•> I f 1 ^ se: 1 CO ft) l «• a- ft] • i.. ..^iiiiiiiiiiiiiiiiiiiifl P R 31 ^-" 3 M CO ^ »» o *1 f « M 3 o ft R 1 1 _ O 3 ** IBJIBJIBJ R o o c> « • • ^ r^> HHHHJ ft] A -. Co 2 k c -\ p^p^pH ^^^r so -^ 3 mw i 2 k CO ft rimm ' ' 1H3 c-2 I = f o u • ' M ,; na 1 l * a _1_ ia • p H m C ' fl ? \ i 1 ^^BBH^RRI Co o t ! o o j^^^B •4BMMMH R ^_ CO • PL ri- ' "^ ""IB* St; lijjj • VkW' L^^^B ~^ ft 2 k 1 <=> , P. ii * ^ i\ • • • • •-i 1 ft] A .. 111 ' my • mm I *' P 10 I 3 SO I P 1 l-l ft) o 3 P CO 3 mmWm\ C CO 1 ^ j - M CO 1 o }• H ^^ .' 9 3 10 l o o o 1 s. IBPP 1 ^ j T* 1 » • i •CSr " ** ^^ - » 1 Co 1 i ° • A f ft I j H 7 P * ?"^^ & 1 3 ^BE ji^Bn^* ' ^^s^. ift c M • i 1 ft "tt- a- 1 R 1 I • 1 R. ••pwpp nI Co a- • 1 ft o ft « "O CO o" ^ \ pjppjpj - t «* ft] [ CO 3 . J so o r ft c+ [ 1 •-i 3 <* 1 -mrnt "fr^B ft n ii^iH t— CO • w.ft^HB9 3 so o ^ r Uf«HJ 3 1 Ifl =«: 3 O 1 P T> ??? 2^-4 1 •• k :' ^ ^^^^^flr * So t-O 3 ^ 2 k ft "^ o • ^ _ O R. p 11 vi^i^i^Bf ^^^fl ~ l^^^^^^^^l ^^^*f mmm\ ° a p. -fc. UO • • 10 10 ^ 1 3 V*. co 3 1 P if m go W 1 °^ .gaft 3 2^ If ••-»• o R O3 % • CO° C ft] 1 1 o -"Ml 'A o m • u Co "^ ; S5 X wWF ft" o ft] 1 —•' * CO if•i O ft P 1 t—I Iv BW B^^B 4^MH l^^^^^^^^l 1 i; a * ftj ^: 1 ^^^ R 2k • ^H P I H I 55 o o r.c ft) O 1^1 ^ ^ll^^^^^l 2 k i CO KL 1 ft • o *t> Sc; WBgkM -j^r—•— I mt^^Wt' j If ^^^^^^^^^^fl Co 1 HI JIHA O ••! 1 o ft] •pi MM 'a 1 3 " w JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1946 ARTILLERY AND ORDNANCE The Navy had the following additional explosives on hand: Army Ordnance Equipment; (Continued) AMMUNITION X EXPLOSIVE OR ROUNDS TYPE QUANTITY TYPE CALIBER WEAPON (ROUNDS) PICTURE NO, 20 15cm How. (4th yr) 12 3rd yr. 81mm Mortar 4,680 (also 6,000 Type 97 Automatic Gun, HE shells for type 99) 6 Type 92 Infantry Gun 15 97 90mm Mortar 5,557 1,042 Sound Shells 23 97 20mm Automatic Gun 57,646 (also 40 Experimental Sound Sphere for auto cannon) 61 Type 90 Booster Charges 42 92 70mm Infantry Gun 21,003 109 Type 91 Smoke Shells 81 94 37mm Anti-Tank Gun 40,568 61 Type 89 Smoke Shells Mod. 1 37 1 47mm Anti-Tank Gun 17,590 z 660 Signal Shells 41 94 75mm Mountain Gun 77,516 t— 48 Torpedo Firing Charges 34 41 75mm Mountain Gun 10,727 Ul 243 Signal Lights (flares) 9 98 37mm Anti-Tank Gun 6,334 210 Slow Fuzes 18 99 81mm Small Mortar 4,680 (also 152 Smoke Shells for type 3) CQ 25 Signal Rockets 3 98 20mm Automatic Cannon 57,646 (also < 20 Launching Charges for auto gun) 921,769 All types of Fuzes 3 38 75mra Improved Field Gun o 48,033 All types of Primers 2 95 75miu Field Gun 3,031 a. 11,133 Types 91 and 96 Booster Charge Cylinders 6 91 105mm I'^witzer 3,067 6,133 All types of Booster Charges 7 Armstrong 8 cm 8cm 40 cal. Gun 3,341 11,000 Ordinary Primers 8 88 75mm AA Gun 2,306 14,500 Electric Primers 46 93 Flame Thrower 1,500 kg. Type 88 Explosive Charge 27 100 Flame Thrower 5,474 Cartridges 208 MK 2 Demolition Hooks 954 Land Demolition Charges The Army had the following additional explosives on hand: 644 m. Land Fuze 590 m. Safety Fuze Type #6 Land Explosive Charges en 84 QUANTITY TYPE DESCRIPTION a Army Ordnance Equipment: 1,272 91 Hand Grenade For hand throwing z AMMUNITION 63,900 97 Hand Grenade and grenade dischargers QUANTITY TYPE CALIBER WEAPON (ROUNDS) PICTURE NO TI CO 63,763 99 and Grenade and launchers. 7,045 94 Small Smoke Candle ui 421 38th yr. 6.5mm Infantry Rifle 2,585 94 Large Smoke Candle 66 38th yr. 6.5mm Cavalry Rifle 660,125 2,945 94 Floating Smoke Candle z 11,699 99 7.7mm Short Rifle 3,887,222 2,677 99 Self-projecting Smoke Candle (also for L.MG) 211 94 Training Smoke Candle o 100 26th yr. 8mm Pistol 4,819 1,392 Experimental Smoke Grenade as 811 14th yr. 8mm Pistol 2,155 Incendiary Grenade 243 94 8mm Pistol 41,718 2,458 Frangible Incendiary Grenade 159 Various 6.35 to Pistol 3,038 43 60 Kilo For Bomb-throwing Mortar 7.65mm 2,147 97 Yellow Explosive Block 21 10th yr. 50mm Grenade Discharger 15 97 Yellow Explosive Stick 1,110 89 50mm Grenade Discharger Listed In 7,120 93 Anti-Tank Mine 1,192 100 Rifle Grenade Launcher next paragraph 5,657 Anti-Personnel Mine =3 475 2 Grenade Discharger 382 99 Bangalore Torpedo as 4 7cm Barrage Mortar 26 767 Yardstick Mine 3 11th yr. 6.5mm Light MG 3,887,222 401 1 Kg Demolition Can z 50 96 6.5mm Light MG (also for rifles) 411 Kg Fine grained Powder o 739 99 7.7mm Light MG 134,244 240 Explosive Can CO 376 92 7.7mm Heavy MG UI 807 Improved Land Mine CO 388 92 7.7mm Heavy MG AA 6,000 Kg Dynamite Z 5 92 7.7ram Machine Gun 4,485,489 247 Kg Karitto Powder 8 92 7.7mm Fixed Machine Gun Mark 1 Incendiary Powder 19 140 LJJ 92 7.7mm Flexible MG 2,220 Meters Primacord a 18 97 13mm Mobile Heavy MG 4,292 10th yr Signal Shell 5 93 13mm Single Mount MG U l 10,069 1,778 100 Flare CO 58 97 81mm Mortar 31,583 UJ 2,449 Hand-launched Molotov Cocktail z 40 u ~ 3 « ••v <, ' -i CO 3 O 3 - N n S3 Co tl 1 3 W «•» r. P. U. « *- P. C •XJ- V. O n» Cc o ^ ^ O » - >T< >Jl w c< uo =0 o CD a* o o a- 3 * 3 <>3 « - > o O S3 «. O 3 -o O »- «> P O C3 a 3 O « a R- «/^ ( ^ <«••• t—j *» -< t~- v; 3 • « -O t» R 3 «» • 3 "^ P. O a « e «• 3 •«• I O 5 0D 3 Co P K. 3 10 • . 3 ^> • iB 3 A» 3 C) CO o •* en ~^3 3 S3 » Ci /•-,rr .3 * : so Si. o o ^ CO so v. JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1946.' * o X L 1/ Z T-6 UJ T-3 CO >T-7 \ < ( % J o i; \J ..rv T-8 i> Z / ^ N+^ i .11'"* !i Q Z TOL ISLAND '//-*% UJ ^..; ^ Z f o *%#,. \ \ O I % T-IO Z o Ul CO T-ll Z Ul u. tu vT-13 V O UJ en UJ r-i7 Z •"/« T-15 / / w 0J 'N FIGURE NO. 4 AND SEARCHLIGHT POSITIONS 10WING FIELDS OF FIRE y SEARCHLIGHT ^C ARMY ARTILLERY AND FIELD OF FIRE xZZ. NAVY ARTILLERY AND FIELD OF FIRE 4 2 URE NO. 7 ISLAND I a: z I— LU CQ o Q. z z z CO UJ Z _i o FIGURE NO. 6 UDOT and EOT ISLANDS z o CO UJ CO Z UJ CO UJ Z a. ALL SCALES = r.25,000 ARTILLERY AND SEARCHLIGHT POSITIONS SHOWING FIELDS OF FIRE SEARCHLIGHT ARMY ARTILLERY AND FIELD OF FIRE NAVY ARTILLERY AND FIELD OF FIRE OBSTRUCTION IN FIELD OF FIRE mm i 43 I GARRISON CO o CL U Z v 0 Z CO Z < DUBLON ISLAND to DUBLOW TOW o a: 7 WT Z EAPLANE BASE ETEN^iSLAND o CO UJ CO at CO FIGURE N0.8 - ARTILLERY AND SEARCHLIGHT POSITIONS SHOWING FIELDS OF FIRE -1:25,000 SEARCHLIGHT o C ARMY ARTILLERY AND FIELD OF FIRE wm& cc: NAVY ARTILLERY AND FIELD OF FIRE OBSTRUCTION IN FIELD OF FIRE 44 JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1946 MILITARY ENGINEERING ENGINEER AND CONSTRUCTION TROOPS. TABLE A-l (Cont.) o The staff engineer of the Japanese 52nd Division was Major Satoichl TANABE, 227TH CONSTRUCTION CORPS ORGANIZATION whose duties were to advise, coordinate and supervise fortification work performed by infantry units vithln the division. No Army engineer troops existed at TRUK H as far as numerical designations were concerned. However there was evidence that u H +3 bD oS P^1 some individuals and units had received engineer training before.departure from O O O JAPAN. One officer interrogated on UMAN stated that he was the engineer officer CD •H •H CSO 0 H After the loss of the MARIANAS and the consequent cutting-off of incoming H H pl y -p bD ctf supplies, the Japanese plans for the defense of TRUK called for a long term, pro o o o §' rS CD W •H •H 0 H tracted resistance* The defense aimed at: minimizing damage from our air attacks -P co CD •H H 4-3 • 5s O by use of the terrain and protective shelters; annihilating our Invading force at si a.: o u CD •H the beaches; and maintaining the defense as long as possible. Defensive positions o O bD CD {50 46 z t— UJ Picture Mo. 86 (PM 104) 97mm GUN PILLBOX, MORTBEAST BEACH, Picture Mo. 87 (PM 105) HEAVY MACHIME GUM PILLBOX, EAST BEACH, Picturt Mo. 88 (PM 106) 97mm GUM PILLBOX. EAST BEACH, DUBLOM, DCBLOM: Mote view through embrasures showing grazing field DUBLON: Walls of this pillbox were 5' thick. Note figure. Closeup of embrasure. Mote earth and rock cover on roof and of fire along shore line. Dirt and earth cover caves on roof Major S. TAMABE, Staff Engine*-, Japanese *>2nd Div., for com natural camouflage. of Pillbox removed at time Picture was taken. paring size. Rock cover has been removed from roof. o a. Q- z CO Q Z CO o °icturo. Mo. 89 (PM 266) HEAVY MACHINE GUN PILLBOX ON BEACH Picture No. go (PM 152) 37mm AT GUN PILLBOX, SOUTH BEACH,UMAN: Picture No. 91 (PM 126) EMBRASURE 47mm GUN PILLBOX, 4TH FLEET AT MOEN AIRFIELD MO. 1: Note double embrasure and pr.oximity Interior, view. Note double embrasure and limited headroom. CR0SS.R0AD, DUBLON: The baffled or stepped embrasure was to to water's edge. Earth cover and camouflage have been re- Water and mud on floor show poor drainage . Note also reduce the number of small arms ricochets e lane m e into the moved. -oof support. Grass blocked field of grazing fire. emp lac erne nt. Z o CO UJ CO z CO UJ z Picture No. 92 (PM 405) 12cm GUN, MT. MISHIKI, FEFAN: Typical Picture No. 99 (PM 443) 12cm AA GUN IN CAVE, PARAM: Originally Picture. No. 94 (PM no) 14cm NAVAL GUM CAVE EMPLACEMENT; UMAN naval artillery cave emplacement. Entrance to position is by gun was part of 6-gun battery with AA mission, later emplaced One of a pair of CD gun c ove ring SOUTH Pass. Gun originally tunnel to rear. Rock wall at front affords some protect ion to fire on surface craft north of PARAM. Note use of steel on a ship. Half drums c ontamed growing native vegetation to from snail arms fire but also limits depression of gun. rails and sheet metal for roof re mf crement and protection. camouflage position. 47 MILITARY ENGINEERING I OS Z o a. z Picture Mo. 95 (PM 337) 14cm GUM, UMAM: Mo. 2 ?«n of 2 -fun Picture Mo. 96 (PM 331) 14cm GUM CAVE EMPLACEMEMT, YUKOKA, Picture Mo. 97 (PM 4 83)'iacm AA GUM IM CAVE EMPLACEMEMT, UDOT: battery covering SOUTH Pass Mote use of re in/ ore mg steel UMAM: Mote rear of tur.r.et, breech (covered) an d typical rock This weapon i s the only large art 1 llery weapon located on UDOT t o Prevent caving or spallm ? fr^m muzzle blast. strata. Close inspection will reveal a horizontal "dyke" Mission: t o fire on surface craft t o the north. Trees pro u about 1 ' thick just be low ce i ling line. videi camouflage fo r Position but were removab It b y filling. Z o Plans called for each island to be self sufficient defensively. However, naif way up the slope* Caves and dugouts provided cover for nearly every weapon. z mutually supporting artillery fires were planned between adjacent islands. A part A large number of small air raid shelters were found scattered throughout the area. of each island1s forces was to be held out specifically as a mobile reserve for Battalion officers stated that even with these many shelters, some 20 men were island-to-island amphibious movement and counterattack* Indications are that the killed there as a result of US bombing. Extensive communication trenches in ex — Japanese would have made a concerted effort to defend strongly only the four "Season cellent condition linked positions on the lower slope. In the rocky areas near UJ Islands" but the general plan recognized also the importance of movement of forces to the summit, tunnels connected the cave positions. Some of the machine guns were z meet any possible landing. placed so as to fire from caves on low flying aircraft only. No anti-aircraft - I artillery was located in the immediate vicinity but batteries on adjacent islands o No general distinctions were noted in the organization of the ground in com could provide ack-ack support. Unit officers stated also that, seventy knee-mor paring the defenses of DUBLON, MOEN, UMAN, and FEFAN. Weapons were placed to pro tars were available in the MT. KONGO area in addition to those weapons shown on the vide a concentration of fire from divisional weapons on all possible landing beach weapons disposition map. es. Beaoh pillboxes provided bands of interlacing grazing fire, usually in two directions from each along the beach. These beach positions provided also the FORTIFICATIONS. - I automatic weapons coverage for the inshore minefields and for Inshore and beach ob- O stacles. In general, observation from the beach positions was adequate for the wea Permanent: Lt Col YAMAMOTO, Chief of Staff, Japanese 52nd Division, stated pons emplaced. Concealment was achieved by natural growth, transplanted as neces there were no permanent fortifications when his unit arrived at TRUK in January, 5: sary, and the use of wire screens garnished with natural materials. As one pro- 1944. An extensive fortification program was started then with the construction XL gressed inland, the difficult terrain offered many problems to weapons placement. of pillboxes and blockhouses on the seashore as first priority. For concrete con ac The Japanese recognized the dead spaces in fields of fire of automatic weapons and struction they used a 1:2:4 mix with beach sand and crusher-run basalt rock. Steel also their limited fields of view in the abundant tropical growths. In most in- reinforcing bars 20 mm in diameter were placed 25 cm apart in the conventional z stances they attempted to cover these defiladed areas by rifle and mortar fire. In right angled grid* Typical pillboxes found on the beaches are shown in Picture o comparison with the Japanese defenses found on CHICHI JIMA, TRUK defenses had less Nos. 86, 87, 88, 89, and 90* Picture No. 91 shows an ant1-ricochet type embrasure CO fortification of inland areas, less excavation work and less connecting of positions. noted at several emplacements. The idea was to reduce the number of email arms UJ Wooden platforms were constructed for OPs atop the principal mountain peaks but their ricochets glancing into the emplacement. Some pillboxes were constructed so near complete lack of cover and concealment would have limited their use considerably as the water, or so low in it, that seepage or flow through the embrasures flooded soon as hostile planes and surface craft approached within effective ranges. the interiors. Eventually the lack of cement halted concrete construction* At the time of the inspection several stockpiles of reinforcing steel remained at The primary missions of the 250 men placed on the reef islands were obser various locations on several islands* vation and the construction of dummy positions. Their communications were by under- CO water cable and radio to the main islands. Nearly all of the larger naval artillery pieces, except anti-aircraft batteries, UJ were placed in caves or dugouts typical examples of which are shown In Picture Nos. On the whole, organization of the ground for the defense of airfields followed 92, 93, 94, 95, 96, 97, and 101. Figures 11 and 13 show details of typical con z accepted US doctrine. At the typical MOEN No. 1 Field and the adjacent MT. KONGO nected cave emplacements. Picture Nos. 98 and 105 show an exception to the usual hill mass, the defense force consisted of about 500 Army personnel and 300 Naval emplacement in that this weapon was located only 50* from the seashore on LIGHTHOUSE personnel of a special navy landing party. The Naval unit provided grazing MG fire Hill, MOEN. Typical accessories, such as observation posts and ammunition storage over the airfield, its dispersal areas, and over the beaches adjacent to the field. facilities, for artillery pieces located in caves are shown in Picture Nos. 99, 100, Army 47mm. auto-cannon in pillboxes covered possible road approaches and, in two 102, and 104. places, alternate positions were noted. Two platoons were held in reserve in caves 48 Picture No. 98 (PM 261) 12cm GUN EMPLACEMENT, LIGHTHOUSE HILL Picture No. 99 (PM 333) OP, 14cm GUN BATTERY, UMAN: Note Picture No. 100 (PM 332) RANGE FINDER, 14cm GUN BATTERY, UMAN, MOEN: Mission: to Provide supporting fire on troops assault' figure of G-eneral DAVIS for size. C ommun ic at i on was by tele- Range finder in operating position with canvas cover in place in? DUBLOh. Note angle embrasure and rear exit. Re xnf or.ced phone and voice tubes (1 to left, 9 to right) to the gun Cave provided cover while m storage Position. Retraction by concrete roof, 2 thick, catuouf lagei with native grass. posit 1ons. hand propelled cart on small railway track. o a. u Z u Z V to Q Z CO o Picture No. 101 (PM 336) 14cm GUN(U-8), UMAN: No. 2 gun of Picture No. 102 (PM 444) ENTRANCE, 12cm GUN EMPLACEMENT, PARAM: Picture No. 103 (PM 446) 6" ARMSTRONG CD BATTERY, P4LLE O s-gun battery. Note rear of turret and use of steel rein- Note coconut log shoring an.' use of steel railway rails as roof Timber magazine in niche off tunnel c onnect ing pieces- forcing r.ods and mesh to prevent caving and wooden shield to beams. Entrance gives access to tunnel to gun position shown prevent spalls falling from overhead during firing. in picture no. 93. Z O CO UJ CO Z UJ a Ui CO Picture No. 10 4 (PM 33^) AMMUNITION STORAGE, 14cm GUN BATTERY, Picture No . 105 (PM 262) ENTRANCE TO 12cm GUN EMPLACEMENT, Picture Vo. 106 (PM 447) 6" ARMSTRONG CD GUN BATTERY, POLLE: UMAN: Typical cave storage posit 1 on. Powder cans emptied LIGHTHOUSE HILL. MOEN: Note coconut log roof support, shallow Inclined shaft leading from tunnel connecting pieces and mag- under surrender terms. earth overhead cover, and dr y masonry sidewall revetment. azines. To right of man's feet there wa s a sump for collecting seepage to be delivered by hose, center, to lower. Levels.:" 49 Picture tfo. 107 (P# 258-/ 20cm CO GM, MOEM: One of four sim Picture No. 108 (PM 259) 20cm CD GUN, MOEN: No. 2 gu n of th e Picture No. lo g (PM 257; OP, 20cm CD BATTERY, LIGHTHOUSE HILL, CO ilar heavy crusier turrets and puns in open pit emplacements battery. Note odd shape of t h 1 s turret. Earth embankment MOEN: Note steel pipe column supporting roof, sod and earth Turret of 1" armor plate protected pun crew and a portion of hiies base of turret. roof cover, and banana trees for camouflage. Entrance was by o the ammunit 1 on. either of two tunnels from manholes about 5 yds away. a. Z Z CO Q Z en LU z o Picture No. 110 (PM 260) AMMUNITION STORAGE, 20cm CD BATTERY, Picture No. 111 (PM 345) AMMUNITION STORAGE, Picture No. 112 (PM 35°> OP, l^m m BATTERY, UMAN: This MOEN: Note concrete construction, st-iel doors, and earth BATTERY, UMAN: Note heavy concrete arched roof, re shelter housed th e battery's BC scope. Steel anqle col- cover on roof and ends. cessed doorway, elevated deck, and earth cover. umns support 14" thick concrete roof. Entrance by cov ered Pas sage way from rear. z O CO LU CO Z LU CO LU Z Picjurje #*vr.ir$r 7tt'M 344) l^^mm CD GUN EMPLACEMENT, UMAN Picture No . 114 (PM 346) AMMUNITION STORAGE, l^^mm BATTERY. Picture No . 115 (t> M 151) RANiit. PlNUbK, 155mm BATTERY, UMAS: i« j " /•"• V Tylpiaal open pit Emplacement of q-gun battery. Shore- UMAN: Interio r of installation shown m Picture No . 111 . Note rock and earth wall a round open pi t emplacement. Tracks Tirffc; t-«. bac k? round. Excellen t handcraft shown in timber, storag e shelving at lead to nearby cave shelter for range finder. Mound in back right . Note overhead electric lighting. ground i s observa t to n post shown m Picture No . 112 . z Picture No. 116 (PM 401) 6-GUN, 12cm AA BATTERY, FEFAN: 2 Picturfi No. ny (PM 402) 12cm AA GUN, FEFAN: Gun mounted Picture No. 118 (PM 404) AIR RAID SHELTER, 12cm AA BAT of the 6 guns are distinguished easily; cleared area shows on t rune at e d cone-shaped steel foundation pedestal 1 met e r TERY, FEFAN: Timbers for support ing roof appeared to CD emplacement locations. Individuals are standing over com high. Underground shelter directly behind e lev at ing gear. be of msuf f i c lent strength and Poorly selected. Note munications room. rock and earth ov e r he ad cover. o CL. z z CO Q Z _» CO o Pic ture No. ng (PM 480) BTRY CONTROL, 12cm AA, EOT: Type Picture No. 120 (PM 63) ENTRANCE DIVISION BATTLE CP, Picture No. 121 (PM 265) LIGHT MG PILLBOX ON BEACH, MOEN 2 f ire director (foreground); open pit (observer); remote DUBLON: Note inter 1 or baffle wall and steel door. A/F NO. 1: Pillbox c onst ruct i on of cemented stones over controls for 150cm searchlight (bac kground); BC 's post filled drums. Roof reinforcement of steel angle members. and scope (left bac kground). Deterioration indicates poor construction. z o CO UJ CO Z CO UJ Z Picture No. 122 (PM 61) CG's AIR RAID SHELTER, 52ND DIV- Picture No. 123 (PM 62) DIVISION BATTLE CP, DUBLON: Picture No. 124 (PM 481) 12cm AA GUN, EOT: All 4 guns of ISION BATTLE CP, DUBLON: Photo shows the niche where the Interior view. Debris marks end of uncomp letei tunnel this battery were emplaced m open pits with concrete re- General reclined during air raids. Excavation m solid Form nails imbedded in ceiling a definite overhead vetted walls. Vails had numerous shelves for "ready" rock approximately 20 meters underground. hazard. ammunit 1 on. 51 1 V. MILITARY ENGINEERING o o I a: CO z o Z /"tcture tfo. 125 C P/f 355; tf£/17}' #G PILLBOX, UMAN: Picture No. 126(PM 357,1 OBSTACLE, SOUTH BEACH, UMAN: This Picture No. 127 (PM 3q6) INTERIOR OF AIR RAID SHELTER, MT. Q. overhead coconut log roof support a t entrance and log wa II (appr ox 5 ' 101 de and 3 ' above water) was to obstruct NISHIKI, FEFAN: Note notched timber construction and en blast barrier protecting entrance. This j ort1f1catt on landing of "alligator" type craft. ifa 11 covered by enfi- trance in backg round. Except1ona I ly heavy timbers used to z had heavy cover of earth and stone. lading small arms fire from two directions. support sleeping mats. CO Q Z co Typical of the coastal defense gun emplacements found at TRUK are those for Figure 16 shows the plan of a battalion command post near the summit of MT. the 4-gun battery of 20cm. pieces on LIGHTHOUSE Hill, Picture Nos. 107, 108, 109, FUOUKANAN, DUBLON. Again the excavation was in solid rock with thick overhead 110, and the 3-gun, 155mm. battery, south UMAN, Figure 12 shown also in Picture protection. Figure 17 shows a battalion command post found on MT. UBUN, FEFAN. Nos. Ill, 112, 113, 114, and 115. Field Fortifications: In general no unusual field fortifications were found o Figure 14 shows a 6-gun, 12cm., AA battery located on MT. NISHIKI, FEFAN. at TRUK. Many of the coconut log and earth emplacements and shelters were de This battery position was landscaped very neatly and gave the over-all appearance stroyed after the surrender and prior to arrival of the Study Group. Picture Nos. of a public park. Picture Nos. 116, 117, and 118 are of the same battery. A sim 121, 125, and 127 are typical examples. Infantry units constructed their own ilar 4-gun, 12cm. AA battery located on EOT is shown in Picture Nos. 119, and 124. fortifications from local materials and, generally, by hand labor. Picture No. 129 of the interior of a 47mm. AT gun emplacement at the 4th Fleet Road crossing, Figure 15 depicts the permanent type battle CP of the Japanese 52nd Division DUBLON, shows where a portion of the roof has collapsed by reason of the rotting O on DUBLON. Picture Nos. 120, 122, and 123 are of this same installation. It was of the coconut logs used to shore it. Entrenchments noted were of good design. used during the periods of actual US air and British naval attacks only. In gen No revetment work was needed to prevent cave-ins on the two communication trenches eral the tunnel is 10 meters underground in solid rock with an arched concrete observed. roof. Living quarters for the commanding general ana his staff are provided in the shelter and storage and communication facilities in rooms off the main tunnel. OBSTACLE CONSTRUCTION TYPES. (For locations see Maps in PART TWO.) Overhead electric lighting provided illumination. One hundred men labored daily z for six months to construct this CP. No inshore obstacles were observed, they were removed shortly after the sur O render, but It was reported that various steel rail anti-tank and anti-boc?.t ob to Figure 18 shovrs the Navy battle command post at the summit of MT, TOLOMEN, stacles had been emplaced. These obstacles were not completed when hostilities UJ DUBLON. The parallel tunnels have exits on both sides of MT. TOLOMEN. The en- ceased. CO trances are roughly 20 meters underground with overhead cover of solid rock in- Z creasingly thicker as one proceeds towards the center of the mountain. Work was The only type of beach obstacle observed was a rock wall, anti-personnel and started in July, 1944, and completed in July, 1945. Some 31,000 man hours of anti-walli£ator"~, approximately 51 high and 81 wide at the base. Picture No. 126 labor were required to excavate the 2,100 cubic meters of solid rock. For this shows an example of tills type obstacle. Pillboxes were placed so as to cover with UJ excavation of a 380 cfm-lOO# compressor, belt driven by a vertical diesel engine, CO enfilade machine gun fire both faces of the wall. LU was located 100• down the slope. The air was piped uphill to three rock drills at the worksite. About 6,300 kilograms of dynamite were required for blasting the No anti-personnel or anti-tank mines were found inland and it was reported that Z rock. Spoil was carted by hand from the tunnel in small cars or wagona on indus there had been none there. However various anti-tank obstacles, located to take trial railway track. Extensive communication facilities were provided in the in $ maximum advantage of the terrain, such as walls and trenches, were found. Figure stallation. The reported capacity of the two tunnels was 600 men. The use of 19, and Picture No. 128 show an anti-tank wall constructed of earth and faced with power tools when available to speed construction is typical of all naval forti rock-filled oil drums across a low flat area near DUBLON Town. fication work at TRUK. 52 FIGURE NO.II 15 CM GUN POSITIONS,NORTH SECTION OF TOL ISLAND "E" o 3T0N WATER TANKS I 'i * o I O < GENERATOR \ 25KVA I GUN'S AMMUNITION FIELD OF FIRE 160* DUMP MAX RANGE- 3000 M. FIRE CONTROL AMMUNITION*1 DUMP o CO TYPE 41- 15 CM. GUN 120* z MAX. RANGE- 13,600 METERS FIELD OF FIRE-45* 25MMx2 SEE DETAIL MAX. RANGE-3000 M NO. I o FIELD OF FIRE-135 \ SEARCHLIGHT l3MMxl SIZE-90 CM MAX. RANGE-2500 M. MODEL-TYPE-96 RESERVE FIELD OF FIRE-135" AMMUNITION DUMP SEE DETAIL NO. 2 Q. RANGE FINDER TYPE 14 3.50 M. z G PROTECTIVE CO CAVE FOR RANGE FINDER 3RD YEARl MODEL Q 15 CM.GUN 140' Z FIRE CONTROL CENTER TYPE 41-15 CM GUN TYPE 96,110 CM z SEARCH LIGHT CAVE FOR SEARCH LIGHT 7.7 MM x I 25 MM D.P. GUN O MAX.RANGE-2004 M FIELD OF FIRE'14 SEARCHLIGHT < KJ A FIRE CONTROL RESERVE •0- RANGE FINDER AMMO DUMP - ~ HMG -— LMG O GENERATOR l3MMxl 270° FIELD OF FIRE 160 3 FIGURE NO 12 CAVE z ENTRANCE 155MM COAST DEFENSE BATTERY o 7.7MMxl ^ CO 230° FIELD OF FIRE 120' UMAN ISLAND z LU MAIN AMMUNITION1 DUMP ' A SECONDARY ^MUNITION DUMP FRONTAGE 25 M. FRONTAGE 0.8 M LU DEPTH 3.0 M DEPTH 6.4 M CO LU HEIGHT 2.0M HEIGHT 1.8 M THICKNESS THICKNESS z OF CONCRETE 0.8 M OF CONCRETE 0.3M EARTH MOUND 2.0 M EARTH MOUND 1.0 M GUN'S INDIVIDUAL AMMO. FIRE CONTROL CENTER DUMP "C" "D" FRONTAGE 3.0M FRONTAGE 2.3 M DEPTH I.OM DEPTH 3.3 M HEIGHT I.7 M HEIGHT I.6M THICKNESS THICKNESS 0.3M OFCONCRETE 0.2 M OF CONCRETE EARTH MOUND 0.5 M EARTH MOUND 2.0M GENERATOR CHAMBER "E" ROOF 5M THICK FRONTAGE 2.8M HEIGHT 1.6 M THICKNESS OF DEPTH 8.8 M 3.0 M SECTION- CC ROOF 53 ^ I V. "•; '..SB FIGURE NO. I4-(FEFAN ISL) 5TON WATER COOLING ANTI-AIRCRAFT BATTERY EMPLACENTS TANKS O ANTI-AIRCRAFT GUN MACHINE GUN (13mm) VENTILATION OPENING V777\ BURIED BUILDINGJUNNEL 25 KVA GENERATORS 90 CM SEARCHLIGHT z SEARCHLIGHT UJ # CQ O OL Z u Z AMMUNITION STORAGE CO Z - i CO UJ Z FIGURE NO. 13 14 CM GUN BATTERY-(SOUTH) PART OF UMAN ISLAND) SHALLOW DRAIN DRAINAGE DITCH x — TELEPHONE LINE Y— VOICE TUBE z o CO UJ CO UJ a UJ CO UJ AMMUNITION z STORAGE :« li" ' j» »•' / - *, ;TI , ^ *! J . ^ SWITCHBOARD PLANNING AND r OPERATION o I STAFF ROOM COMMUNICATIONS I6MM-25CM C.TOC 0 = I2MM — 25CM C.TOC O WATER TROUGH Z CROSS SECTION A-A CO Q FIGURE NO. 15- ARMY Z DIVISIONAL COMMAND POST (DUBLON ISLAND) z o BATTALION COMMANDING OFFICER Z o CO Ui CO Z UJ FIGURE NO. 16 Q UJ CO 3RD INFANTRY BATTALION COMMAND UJ Z POST (69THREGIMENT)-DUBL0N ISL NOTE : LIVING CAPACITY 100 MEN-WOODEN PLATFORMS FOR SLEEPING. ALL DIMENSIONS IN METERS 55 NOTE-® TO ® IS 35 METERS o o X NOTE-DOTTED LINES INDICATE PROPOSED PLAN OF CONSTRUCTING ROOMS.END •o OF THE WAR DISMISSED ALL PLANS. m FIGURE NO. 17 34IST BN. C. P. CO MT. UBAN-FEFAN ISLAND o ELEVATION 550 FT a. Z Z u CO a z FIGURE N0.I8 NAVAL BATTLE C.P CAVES, DUBLON SCALE-HOOO o FIELD KITCHEN '' —25MM MACHINE GUN 1.5 M 280 M. ^GENERATOR ROOM BATTE FUEL ST OS. ONS COMMliN I CATION^ Z ARSENA o CO UJ OPERATIONS a STAFF RM. CO CHIEF OF STAFF Z UJ Q UJ CO UJ Z FOOD STORAGE FOOT TRAIL 280 M. FIGURE NO. 19 ELEVATION OF TYPICAL ANTI-TANK OBSTACLE TUNNEL ENTRANCE 880' NOT TO SCALE ij ^\ 56 mm Picture No. 128 (PM 103) AJT WALL, DUBLON: In a low area Picture No. 129 (PM 125) 47 GUN EMPLACEMENT, 4 TH FLEET Picture No. 130 (PM 348) 155mm CD GUN, UMAN: Picture taken at approx. 100 yds m length, 8' across at top and 20' at CR. DUBLON: Showing caving of overhead when coconut logs 25 yds. shows ab undant natural camouflage growth on rev etment base. Slope graded to 1 on 1 on opposite side of earth used as shoring rotted away. around gun. On direct observation, green gun barrel and green f \ lied drums. and-black mottled turret blended well into green bac kground. o a. Z Z CO a z _ i CO O Picture So. 131 (PM 449) 90cm SEARCHLIGHT, TOL: Typical Picture No. 132 (PM 256) 150cm SEARCHLIGHT SHELTER, LIGHT Picture No. 133 (PM 558) NORTH PASS, fONELIK 90cm o hand car movement from cave shelter to operating position HOUSE HILL, MOEN: Searchlight was moved to operating po Search light shot out by US strafing fire. Note track fitting flush with concrete floor also voice sition shown m Picture No. 135 by handcar on narrow gauge tubes and telephone on cave walls. track. H ot e concrete roof and rock sidewa I I facing. z o CO UJ to Z CO UJ Z Picture No. 134 (PM 997; 75cm SEARCHLIGHT, MT. NISH1KI, Picture No. 195 (PM 255) 150cm SEARCHLIGHT, LIGHTHOUzb Picture No. 136 (PM 445) 150cm SEARCHLIGHT, PARAM: FEFAN: Platform forms roof of personnel shelter directly HILL, MOEN: This searchlight was located at the 20cm placement of coconut logs housed searchlight which u.as beneath and of the same size. Note exce I lent hanicraft m CD battery. Light was retractable into cave shown m remotely controlled f r om position c^o yds au;ay. Steel platform rail construe11 on. Picture No. 112- Note seashore m background. rails support camouflage net. 57 Picture No. 137 (PM 334) RANGE FINDER, 14cm BATTERY, UMAN: Picture No. i 3 8 (PM 353) EXTERIOR VIEni 37mm AT GUN PILLBOX, Picture No. 239 (PM 239J SEAPLANE BASE, MOEN: Showing one of 00 Natural camouflage. Abundant grovth of vines from vertical UMAN: Close inspect 1 on reveals embrasure indicated by mar- several cars mount ing painted earth filled boxes surmounted by < cliff concealed cave mou+h. Vines were pushed aside easily ginal arrows. Excellent natural camouflage. See Picture gas drums sprouting natural camouflage. Cars could be rolled o to Permit instrument to be rolled into ope rat ing position. No. go for interior view. across cave entrance on industrial railway track. a. Z SEARCHLIGHTS. z MINES. MINE WARFARE. BOOBY TRAPS. EXPLOSIVES AND DEMOLITIONS. The only army searchlight unit on TRUK was the 4th Battery, 25th AA Unit. Inshore and beach mine fields are shown on Maps in PART TWO. Mines have been Five Type 93, 150cm, searchlights were utilized, four of them were emplaced in CO removed in accordance with surrender instructions. No inland mines were noted. open pits on DUBLON and one on FALO. For location of these searchlights see (See Obstacles) a Artillery Disposition Map, Power for searchlights was furnished by truck mounted generators. One Type 90, sound detector, was used in conjunction with the search- The usual dynamite explosives were used while stocks lasted. After exhaustion z lights. of the normal types, explosive charges from aerial bombs were used to continue CO blasting work in connection with fortifications and quarries. (See Picture No, 163 LU Table A-2 shows the type and number of Navy searchlights at TRUK, Picture for preparation of improvised charges for quarrying). Indications are that dyna- Z Nos. 131, 132, 133, 134, and 135 show typical searchlight emplacements. The Artil- mite and dynamite caps were often poor and faulty. Very probably this was due to lery Disposition Map shows the location of the naval searchlights on the various damp storage. o islands, CAMOUFLAGE. TABLE A-2 No attempt was made to conceal the larger permanent service Installations, Inventory of Searchlights on TRUK (Nav.v) Army or Navy, by camouflage. Field units utilized terrain, natural materials, and Island camouflage nets for concealment. The general policy was to cover the tops of pill Battery Type Diameter(in cm.) Number boxes with earth and sod as shown in Picture No. 138. Picture No. 130 shows a 155cm, gun at 25 yds. Entrances to positions were hidden by planting trees, usual MOEN 7cm, AA 96 110 2 MOEN ly banana, and by hanging camouflage nets. Communication trenches and barracks 12cm. AA 96(w/truck 150 1 roofs were covered with coconut palm fronds. Some disruptive painting was noted w/o controller) MOEN around embrasures. The Japanese said they planned to use logs In the construction 12cm, AA Su 75 1 of dummy gun positions along the beaches but had not done so by the cessation of z MOEN 20cm. CD Tsulbi 150 1 hostilities. In the event of attack it was planned to use the limited supply of DUBLON 12.7cm. AA 92 150 1 chemical smoke (See Army Ammunition Inventory) to draw fire to unimportant areas O FEFAN 12cm, AA 96(w/truck 150 1 and to cover local counterattacks. Picture No. 137 shows natural camouflage of CO & controller) the entrance to a tunnel containing the range finder for the 14cm. guns on UMAN. LU FEFAN 8cm, AA 75 1 CO Su See Picture No. 139 for ambitious scheme for concealing an entrance to a cave used UMAN 15.5cm. CD 96 110 1 as a hangar. z UMAN 14cm. CD 92 90 1 S. TOL 15cm. CD 92 90 1 CHEMICAL WARFARE. N. TOL 15cm, CD 92 90 1 CO POLLE 15cm. CD 96 110 1 The Japanese insisted they had no plans or equipment for offensive chemical UJ FALO 96(w/truck) 150 1 warfare. Z TONELIK Su 90 1 12cm. AA 96(w/con 150 1 EOT In defensive chemical warfare they emphasized the use of Individual equipment troller) such as gas masks and gas clothing. Only one gas proof shelter was completed 7cm. AA 96(w/con 150 1 PARAM though four others were in process of construction. Figure 20 shows detailed plans troller) for the one shelter they finished. The active purifying chemical was copra char 7cm. AA 92(w/ 110 1 PARAM coal. Tables*A-3, and A-4 show chemical warfare equipment on hand at the end of troller) the war. PARAM 12cm. AA Su 110 1 PARAM 12cm. AA 92 150 1 58 « CD -I o CD > o rn> o 5 T CD I.IOM. \ O O o o mTAI I r^ CO O > m g -n r~ C>O > CHE L O H o m -n A xo o-n oil 2o , m c/> JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1 »£ V MILITARY ENGINEERING CO z CQ O z Picture yo. 140 ff# 406; J/4rffJ? COLLECT Picture No. 141 (PM 398) 2$kva GENERATOR, Picture No. 142 (PM 403) COMMUNICATION Picture No. 143 (PM 482) 4Okva GENERATOR z ION, FEFAN: Example of the effort the FEFAN: This diesel driven generator fur CENTER SHELTER, 6-GUN AA BATTERY, FEFAN: EOT: This iiesel driven generat or fur Japanese made to collect all available nished power for one T^cm searchlight Underground room contained intrabattery nished power for one 150cm searchlight, u water. Small metal troughs colLectei and appears to be the standard power telephone switchboard, data transmission one fire director and data transmission CO the seepage from the tunnel interior unit at TRUK for this searchlight. equipment, and radio for communication system for four 12cm AA Guns. Switch Q and carried it to a concrete storage to DUBLON. Ladders lead through 24" board m background. Z tank in tunnel floor. concrete. - I CO o O Z o CO LU CO Z CO UJ Z Picture No. 144 (PM 33SJ TYPICAL LATRINE Picture No. 145 (PM 339J INTERIOR OF Picture No. 146 (PM 340) TYPICAL LATRINE Picture No. 147 (PM 342) PERMANENT TYPE UMAN: Latrine cons1sted of two simple URINAL, UMAN: Interior of latrine shown UMAN: Note complete lack of screening. LATRINE, UMAN: This latrine was used frame structures, one housing the urinal m Ptctur". No. 144. Wooden trough em China "squatter" for e xc r.eme nt was pro by enlisted men of the 155mm gun battery and the other for fecal matter (Picture ptied into a metal trough which ran vided with loose fitting wooden cover located on South UMAN. Note smooth con- No. 146). Small wooden box was for dis downhiI I for 6' where the und 1 luted (barely discernible leaning against far c ret o. finish on urinal at right. Doors infectant used to wash hands after urin urine spilled over the open ground. wall). at left led to individual box seats ating. over a pit. 60 ; 4 Picture No. 148 (PM i 99) WATER STORAGE TANKS, MT. NISHIKI, Picture No. 149 (PM 484) TROOP SHELTER, UDOT: Structure con Picture No. 1^0 (PM 452) NAVY GUN CREW BARRACKS, NORTH TOL, FEFAN: These two tanks for collecting rainwater had a stcr sisted of simple wooden framing with thatched grass s idewaI Is Barrac ks for 140 men. This area had not been disturbed by age capacity of «> tons each. Tanks had sheet-metal linings and c orrugated sheet metal roof. Note overhead shelves for US bombing. and roofs. storing clothing and equipment . Reported occupancy 10 men. o a. Z 3 z CO Q Z CO LJJ z Picture No. 151 (Pm 14?) TROOP SHELTER, 155mm BATTERY, UMAN: Picture No. 252 (PM 450) GENERATOR CAVE. CD BATTERY, NORTH Picture No. 159 (PM 451) GENERATOR CAVE, CD BATTERY, NORTH Note grass floor sleeping mats, mosquit0 nets, electric TOL: Prime mover, and generat or. right; suitchboard, center; TOL: Gene rat ing unit m f ore ground and cooling water tanks o I tght ing, and, a rarity, glass windows. workbench, left. beyond. I— z o CO Ul CO Z LU LU LU Q LU CO LU z Picture No. 1^4 (PM 394) 8cm AA GUN EMPLACEMENT, MT. NISHIKI, Picture No. 155 (PM 407) 13mm MG CAVE POSITION, MT. UBUN, Picture No. 1^6 (PM 149) 150cm SEARCHLIGHT, 155m* CD BATTERY, FEFAN: Note "ready" ammunition concrete shelf >n revetment. FEFAN: Weapon's mission was to fire on seashore t 1 r g <> t s on UMAN: Se arc h light was used to 1 I lummatt targets for CD guns East FEFAN beach from cave position at 550' elevation. and to aid ships in entering SOUTH Pass at night. Shelter and track are in background, M n n <**•*"> "1 Tff 61 MILITARY ENGINEERING o ^* o TABLE A-5 TABLE A-4 I . Lj.st of Army Chemical Warfare Materiel List of Navy Chemical Warfare Materiel Equipment: ARTICLE UNIT QUANTITY ARTICLE UNIT QUANTITY NOTE Gas Masks Each 11,071 Containers and Fittings Small sound alarm Item 40 for Gas Masks Kit 79 Portable sound alarm Item 210 Light Gas Clothing Each 2,064 Simple meteorological Set 18 A number of hygrothermographs are Gas Clothing Each 161 Z apparatus broken. Gas Detector Each 90 Type 95 decontamination Can 450 A large amount is deliquescent; Gas Covers Each 9,941 LU powder round numbers are given. Mk-3 Decontamination Kit Kit 159 Mk-4 Decontamination Kit Kit 395 =3 Mk-5 Decontamination Kit Kit 100 0Q Type 98 Unit Gas Mask Set 40 Oxygen Gas Masks Each 5 Testing Machine, Mk 1 Oxygen Generator Each 20 o and Mk 2 for personnel Air Filter Each 7 Gas Masks for personnel Item 15,617 u Canisters (for exchange) Item 487 Type 96 Complete Gas Set 1,105 z Protective Clothing FIELD UTILITIES. Type 96 Light Gas Set 14,481 Protective Clothing Except where dispersed Army units had rainwater cisterns, springs, or shallow Gas-Protective Shoe Set 150 wells, water supply was primarily a Navy function. (See General Construction). Z Cover (A) Rainwater was collected by means of systems of troughs, gutters and pipes from Gas-Protective Shoe Set 420 nearly every roofed building, hut, and shack. Normal precipitation in this area Cover (B) is sufficient to supply small isolated groups but inadequate for such concentrated CO Substitute Gas- Set 1,935 Since most of these have deter- installations as the"battle CPs on MT. TOLOMEN, DUBLON. There, water supply would o Protective Clothing iorated and cannot be used, only have become a serious problem In the event that hostile troops held the surrounding Z the reserves are shown. lowlands. The caves were too near the relatively small peak or summit to tap sub- Gas-Protective Coat Set 47 terranean basins or flows. By collecting rainwater, the Japanese reduced consider ably their need for filtering and purifying equipment. Boiling was prescribed as CO Observation Eye-Glasses Set 896 Anti-dim Plate Set 410 the approved standard method for purifying water for drinking. The army had 472 Repair Kit for Gas- Set 10 cases of amoebic dysentary in 1944 and 266 cases in 1945. In view of the widespread Protective Clothing use of night soil for fertilizing, these cases should not be attributed exclusively to impure drinking water. Picture No. 148 shows two typical 5 ton capacity rain o water storage tanks at an anti-aircraft battery on MT. NISHIKI, FEFAN. Picture No. Unit Gas Medicine Set 49 140 shows collection of water dripping from the interior of a cave on FEFAN. The Pannier Japanese claimed that US bombings interfered with their search for additional water Medical Unit Gas Pannier Set 2 sources and with their further exploitation of those they had. Hospital Gas Medical Set 7 Pannier The main installations were dependent upon a central source of electrical o Gas Medical Treatment Kit A Set 31 power. Smaller units, such as anti-aircraft troops, had standard 17.5, 25, and I— Gas Medical Treatment Kit B Set 32 40kva dlesel engine driven generators. Picture Nos. 141 and 143 show typical equip- Gas Medical Treatment Kit C Set 208 ment. In nearly all cases these generators were in unprotected frame buildings lo- Mark 1 First Aid Kit Set 102 cated near searchlights. Some truck mounted generators were available for use with Mark 2 First Aid Kit Set 287 searchlights. Gas First Aid Kit Set 29 z Gas Masks for wounded Item 38 In general, there were no enforced sanitation or refuse disposal regulations. o Personnel decontamination Item 18,000 Individuals relieved themselves wherever they pleased. Flies were everywhere in CO LU Pouch abundance and especially near latrines. Picture Nos. 144, 145, and 146 show a CO Decontamination Pouch Item About Since their use has been discon- latrine used by naval officers of the 155mm. gun battery on south UMAN. The most Z 25,000 tinued it is difficult to give elaborate field latrine found was that for the 155mm. gun crews on UMAN. (See Picture UJ accurate figures* No. 147). Fecal matter from oil drum type latrines was used freely as "night soil" u. or fertilizer and any remainder was buried. UJ A Medical prescription Item 550 a B Medical prescription Item 2,300 Hi Eye lotion Item Housing for dispersed units and small groups was, by our standards, highly CO 1,100 UJ Nose lotion Item 1,100 unsatisfactory. Overcrowded shacks of salvaged materials with twigs and branches Z Chlorine suction tube Item 500 for flooring were standard. No screening was observed on any of the islands. Some mosquito bars were noted however. Picture Nos. 149 and 150 show some of the better type of shelters observed. This table gives the total of all chemical warfare material for the various Army units at TRUK. Usually the shelters for signal communications facilities were rooms off the This table is based on reports for July, 1945. Because of bombing, depreciation, main tunnel In a cave. Picture No. 142 shows a signal communication center room etc., the present totals will be somewhat different. for AA battery. 62 l o < * o I oc 2 m Picture No. 157 (PM 93) DUBLON: One of the two -'<-cu yl carry- Picture Ho. 158 (PM 102) DUBLON: Typical rock crusher Picture No. 159 (PM 234) MOEN: View of rock crushing plant alls never used because no tractors arrived. They sit where showing diesel engine Prime mover, left, and crusher, right CD they were unloaded. All tires were "salvaged" with knives for use otherwise. z o z z UJ o _l oc Picture No. 162 (PM 237) MOEN: "Out" end of crushing plant Picture No. 160 (PM 235J MOEN: 45 HP diesel engine prime Picture No. 161 (PM 2^6) MOEN: Rock Crusher of plant shown shown m Picture No. 159. Crushed rock is chuted into cars o mover of plant shown in Picture No. i Z o CO UJ CO z CO Ul z Picture No. 163 (PM 238) MOEN: This blasting cartridge fac- Picture No. 164 (PM 72) DUBLON: One of the 50 HP gasoline Picture No. 165 (PM 82) 4TH SHIP REPAIR BASE, DUBLON: tory was operat ing within 75 yds of the crusher shown in Pic- engine driven narrow gauge locomotives used as prime movers Mobile unit for shtpside^ repairs; a 100-ton barge with ture No. 1 f) g. Soldiers are shown Pulverizing and sacking the for hauling rock, supplies, etc. 40 HP compressor and 45kw generator for arc welding. picric acid explosive. 63 GENERAL CONSTRUCTION ROADS. TRAIL3. AND RAILROADS. railway ears. The capacity of each crusher was approximately 2 cubic meters per nour. All quarry drilling was done by hand, A typical rock crusher installation Roads: All roads on the islands of TRUK were found to be narrow (91 to 10' is shcv.'fi in Picture Nos, 159, 160, 161, and 162. wide) and were constructed, reportedly, mainly of a 6" to 10" layer of poorly graded machine crushed volcanic rock (basalt) with a clay-soil binder. Our obser lifter the Japanese exhausted their supply of dynamite, they drew picric acid o vations corroborated the report. In general, all roads followed the natural con- explosive fillers from aerial bombs, crushed it by hand (See Picture No.163), pour o tour of the ground; cuts or fills being used only where unavoidable, as sidehill ed hap-hazzard quantities into homemade paper sacks and used the variable car bench-sections on steep slopes. Meager attention was paid to drainage in the east tridges thus formed for blasting in their quarries, caves and tunnels. I ern islands of the atoll. The more sparsely peopled western islands had fairly well drained roads, where there were any roads at all. The Seaplane Base and a few of Trails: Military installations, in the islands1 hills, as lookout posts, gun the streets in DUBLON Town on DUBLON Island were paved with concrete but this was positions, air raid shelters and, later, barracks areas, were accessible by well but a small fraction of the total road mileage. secluded primitive trails, taking full advantage of natural cover and concealment. Trails were simple paths following easy ground contours. The steeper grades were The equipment used for road construction consisted of rock crushers (See Picture overcome by means of crude stepd dug into the rocky earth. No. 158), trucks, hand carts, and hand tools. No graders, dozers or motor-patrols were to be found anywhere on TRUK, Two 6 cu. yd, carryalls (See Picture No, 157) Railroads: Narrow gauge railroads were used extensively for moving rock and were in the Transport Department1a storage yard east of DUBLON Town but the Jap spoil from quarries and tunnels or caves. Numbers of 3 cu, yd. tipple cars were m anese claimed they never used them because they had no tractors. The crushers were used. Initially, these cars were drawn in trains of 12 by 50 HP gasoline loco Z hand fed from narrov? gauge railway cars loaded at the quarries and pushed by hand motives, (See Picture No. 164), After the loss of the locomotives to US bombings, to crushers. Crushers were elevated with chutes to trucks or other narrow gauge hand power prevailed but advantage was taken of gravity grades for loaded cars wherever possible. O a. z Q Z to o a: Picture No. 166 (PM 70) SUBMARINE BASE, DUBLON: Interior Picture No. 167 (PM 71) SUBMARINE BASE, DUBLON: Interior Picture No. 168 (PM 66) SUBMARINE BASE, DUBLOS: Torpedo of cxygen generating equipment cave showing distilling tank, of oxygen generating equipment cave showing purifier tanks loading pier. Note narrow gauge railway, 2&-ton stiff- left, ani receiver tank, right. Note shoring of corrugated left, and c ompre ss or, right. leg derrick and floating Irydock (background, right). O sheet iron canopy protecting equipment from seepage. I — Z o 1 0 LLJ 00 z Q UJ UJ Z Picture tfo. 169 ft* tj)•'• S&BMAR flg ^ Hand op- Picture No. 170 (PM 68) SUBMARINE BASE, DUBLON: Torpedo Picture No. 171 (PM 64) SUBMARINE BASE, DUBLOS: North e rated winches fof«2£-ton s t i f f-.lkg* ie rr 1 c handling loading pier. Note 2^-ton stiff-leg derrick for hand- f JLC e of North Pier . t orpedoes. [• -1 \- ,, ling torpedoes. Only two lighters could be berthed here •rVt^1 ' ft. at a time. 64 x KJ ^ > ACID STORAGE ^ 300 Ton WATER TANK DISPENSARY TORPEDO ADJUST BATTERY CHARGING ING BUILDING EQPT for ELECTRIC O TORPEDOS Q- TORPEDO EXPORT PIER z 5 Ton CRANE Q_ z SUB REPAIR PARTS D STORAGE AREA TORPEDO a 1 |OXYGEN • WARHEAD z GENERATORS STORAGE FUSE 300 Ton WATER TANK STORAGE BARRACKS AREA MACHINE SHOP' o a: FOOD STORAGE o TORPEDOS WARHEAD STORAGE AREA Z o MACHINE SHOP J I SUPPLY CAVES / WARHEAD STORAGE FIGURE N0.22- POLICEMANS STATION DUBLON ISLAND SUBMARINE BASE |CD| AIR RAID SHELTER WATER TANKS NAKAMURA BATTERY ANTI -TANK OBSTACLES SHIRAHAMA WATER SERVICE .TORPEDO STORAGE CAVES EARTH MOUND-BARRICADE ORE FLEET. NORTH\(~~~^ i /TAKAO MARU / \ ^-UDOT TORPEDO 30 0 30 60 90 120 150 180 210 240 \ \ /URIKAI SHIP REPAIR, t V^FUJI MARU J \JI>\ CHARE\DUBLON \ SOUTH ^ r j TOL/ EBISO-MARU YASAI ^CHUZAI TRANSPORT HOZAN-MARlfl—< NETON -T ^X V-AMACHIYAN PAF AIR GROUP WATA\AIR DEPOT CHURCH J) \\? FUKASON SEAPLANE BASE / \J> JUHO BATTERY Y/~ V ^-^ HOZAN FIGURE NO.21 LOCATIONS OF PIERS (TRUK ATOLL) BATTERY 65 100 a 65 KVA / v GENERATORSX/" 1 ! ! DISPENSA TORPEDO ORDNANCE S REPAIR SHOP 45 KVA GENERATO Oe GAS 4TH SHIP REPAIR OFFICE TELEPH0N • J E REPAIR SHOP /^ARPENTER SHOP / \y\STORE 300 T MARIN RAILVi^Y FIGURE N0.23 (NOT COMPLETED) 4TH SHIP REPAIR DEPARTMENT FLOATING DRY DOCK DUBLON ISLAND,TRUK ATOLL LENGTH - 117 M CAROLINE ISLANDS BREADTH-16.7 M HT. OF SIDE WALL 9.2 M DISPLACEMENT IN LIGHT CONDITION 2027 T 0 10 20 30 40 BO 60 70 10 90 •=•=• SCALE IN METERS 66 GENERAL CONSTRUCTION \r •: fc WHARVES AND DOCKS. BRIDGES AND CAUSEWAYS. •o Bridges: Simple stringer bridges of timber construction and limited span, 101 Information on wharves and docks is found in Table A-5. All facilities were o capable of accommodating small craft only (5-ton lighters and 10-ton sampans). to 12', spanned drainage ditches and tidal openings through causeways. There was no storage on the wharves. Cargo was unloaded directly into trucks or X carts and removed to warehouses or open storage. Causeways: A 600' causeway, 2' above high tide, of rock and earth fill con struction crossed the shallow bay indenting the east shore of DUBLON. The exposed There was no evidence of dredged docks. Apparently, the wharves (jetties, faces were protected by rip-rap walls. Another causeway crossed the swampy re-en piers, quays, landing stages) were built out to where the water was deep enough trant on the northeastern shore of MOEN. for small craft and no attempt was made to berth large vessels alongside them. See Figure 21. o Z LL> CQ TABLE A-5 TABLE A-5 (Cont'd.) o a. NUMBER OF CAN IT CARGO NUMBER OF CAN IT CARGO v DEPTH LIGHTERS CARRY HANDLING DEPTH LIGHTERS CARRY HANDLING Z NAME OF WHARF ALONGSIDE ACCOM- MOTOR EQUIP- TYPE OF NAME OF WHARF ALONGSIDE ACCOM- MOTOR EQUIP- TYPE OF OR PIER (METERS) MODATED VEHICLES? MENT CONSTRUCTION OR PIER (KST2RS) MODATED VEHICLES? MENT CONSTRUCTION DUBLON UDOT w z KOHATSU 2.5 4 Yes 12 concrete slab on ro YASAI JETTY 1.5 1 No Piled Rock. TRANSPORT JETTY 3.5 3 Yes 2 - 3-ton Earth fill with wood en CHUZAI JETTY 1.5 2 No Piled Rock. stiff leg URIKAI 1.0 1 Yes Piled Rock. CO derricks Q CHARE 4.0 4 Yes Concrete slab on rock TOL Z fill. AIR DEPOT 2.0 2 Yes 1 - 10-ton Concrete slab on rock HMACHIYAN 4.0 1 No Piled Rock. CO crane fill. FUKASON 2.5 1 No Piled Rock. UI NAICAI 4.0 1 Yes Concrete face around JUHO 3.0 1 No Piled Rock. Z rock fill. HOZAM 2.0 2 No Piled Rock, wood end. SEAPLANE BASE 1.7 1 Yes Concrete on rock. ORE 3.0 1 No Concrete slab. o SHIP REPAIR 6.5 4 Yes Heavy timber. BATTERY 2.5 1 Yes Concrete slab. TORPEDO PIER 1.5 1 Yes 2-1-ton stiff- Rock fill and concrete NET ON 3.0 1 No Piled Rock. leg derrick wall. £31SU MARU 1.5 1 Yes Piled Rock. KJ GARRISON 4.6 2 Yes Iron plate over timber, FUJI MARU 1.2 1 No Piled Rock. bents and deck. TAKAO MARU 0.8 1 No Piled Rock. FLEET 4.0 4 Yes Rock fill wood end. ULALU MOEN COMMUNICATION JETTY 1.5 1 No Piled Rock. NO. 2 BASE JETTY 2.0 2 Yes Heavy timber. 3 NAKAMURA oc 1.5 3 Yes Heavy timber. ETEN H KAMENKO 2.0 2 Piled rock. Yes Z BATTERY 1.5 1 No Concrete slab on rock TAKESHIMA 4.0 3 Yes Concrete slab on rock fill. fill. o SHIRAHAMA 1.5 1 Yes Rock fill. CO POLICEMAN'S STA. 4.0 1 Yes Rock fill. UMAN UI WATER SERVICE CO 5.0 5 Yes Water dis- Concrete slab on rock Z charge fill. BATTERY JETTY 2.0 2 Yes Concrete slab on rock UI fill. u. FEFAN SCHOOL 2.1 1 Yes Rock fill. UI RADIO 3.0 1 No Wood. a WATA JETTY 3.0 4 Yes Concrete slab on rock UI fill. CO KATSUO PARAM UI 2.0 1 Yes Narrow gauge Piled rock. Z track AIR GROUP JETTY 3.0 1 Yes Timber. SABOTA 2.0 1 No Light wood. KUKKU 1.0 1 (too narrow) Roc kfill. CHURCH 0.6 None (too narrow) Roc kfill. 67 -V FUEL OIL TANK FARM AND OIL SUPPLY PIERS .NOT TO SCALE NOTE I OPERATION OF TANK FARM CEASED APRIL 1944, DUE TO EXTENSIVE DAMAGE FROM BOMBING 2 IO>UNDERGROUND OIL LINE 3 EARTH OYKES AROUND ALL TANKS 4. ALL TANKS RIVETED, STEEL PLATE CONSTRUCTION FIGURE NO. 26A o z < a. Z CO Q NANKO DOCK z CHARE A°REA, DUBLON INSTALLATIONS OF 4TH MUNITION DEPT 30 JUNE .943 ©SUPPLY OFFICE - 4th MUNITION DEPT o ©OFFICE-NANKO SUlSAN CO en @REFRIGERATOR BUILDING ©SUPPLY STORES ©BARRACKS FIGURE NO. Z5 t— Z o 32 72 to OIL-TANK uu to (CONCRETE) Z 54 63 45M MAST WARE HOUSE GENERATING ROOM (RICE) (60 KVA) Z o 351 TRANSMITTING ROOM NO 2 4th COMMUNICATION UNIT TRANSMITTING STATION DUBLON IS, TRUK ATOLL, CAROLINE ISLANDS 194 NOTES I.NOT TO SCALE ? ALL BUILDINGS WOOD CONSTRUCTION BARRACKS TRANSMITTING ROOM 3 BUILDING AREAS INDICATED IN SO METERS TOILET • 45 M MAST COOKING HOUSE '0 36 FIGURE NO 24 BATHING ROOM 68 • K C5t •O O 3 •• C ft W. O ~ re « -», * 3 E O «*ft.• ft e :% "> 3 O - • o 3 * O <= ft O ft «* Ol •< W O 10 CO Co <• ft. a *• ft 3 t: 3 ^^ ^ !^ ft «• «*•• ^ Co cc •^ 3- VJO e o v_ r~ 3 > - ft c: -* re re ft. C3 "-K o *i a e oo a- o n <* 3 r ~- 9 w. <*• v; ft. a- «* c*j ft. «•• o <* -Q *tj -«- co e Dt» ^ ft C * - T -O- »3 re o 3 • CO V <* Co B CO 3 2.. U . rt- Co •s a t *• r ft — re. re O Cr; t- •«• ~O CO «~ o 3 ^ •* e - 3 <* 1 r~ ft o <^ ^ ft ~ ^ <* 3 »• O »• -1 3 U. O «> (T> t+ <* C e n t c 3 C t • ft ft ft ''Q ^ to e* *\ » O O *••» 1 c *; o «— O • 3 O 3 ft re o o O O ^J ^.3 5 J) re r— *• »• 3 ^J 3 ft p- 3 •»• o ~ co *>. ns O at; ft JO - 3- Co m 5 ~ Co 3 O 3 tc; O - a t CO 3 2* O ^0 B It ^ CO C*} I Co Co (^ Co «• « Co ~ 3 O 10 <* ft O O W ». t 1 3 «* ^ ft. o r o -^ • ft «- oo 3 " ^ CO 3 M 3 W. CO JO 00 o **; o •-, I *T3 c-t- O S3 «> 33 co ~o O 2>. 3 ^ y 0 •-( 1 33 3 CO re Si. 00 ft «* C5 o Co ft Co Co ft t CO ^; 3 O Oi JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1946.' GENERAL CONSTRUCTION •o o I Z Picture No. 181 (PM 86) NANKO DOCK AREA, DUBLON: View inland Picture So. 182 (PM H4) NANKO DOCK AREA, DUBLON: Rock Pictur.e No. 183 (PM 85) NANKO DOCK AREA, DUBLON: View showing dry rtorage Left, and cold storage, center and right. filled pier shown was major supply receiving facility from pier, showing slip, foreground, and poorly con Z Photo shows 1/9 of former msta LLat ion whirb remained oper at TRUK. structed timber wharf, middleground, for smaller craft, able after US bombing. INSTALLATIONS. The 45, 65, and lOOkva generators were removed from their respec Z tive base site buildings and Installed in caves in the adjacent hillside. A typ DUBLON; ical underground installation is shown in Picture Nos. 172 and 173. Submarine Base-The submarine base layout is shown in Figure 22. It was Two small sawmills were operated by the base personnel cutting 24" z equipped fully to provide supplies, munitions and extensive repairs to a sizeable imported hard wood logs and local soft wood breadfruit trees. submarine force* Base working crews were quartered in two-story frame barracks with additional housing facilities for four submarine crews* Both compressed air The 300-ton marine railway, 36* wide, 250' long, built on a 1 to 15 to and electric torpedoes were adjusted here at the rate of 18 to 36 man-days per tor slope of 41 thick concrete slabs, was never completed. (See Picture Nos. 174 and pedo. Torpedoes were stored then in a frame building surrounded by an earth revet 176). ment. Complete machine shops were established in typical frame buildings. After the initial US bombings caused serious loss of equipment, all remaining shops, A floating drydock, 117 meters in length and 18*7 meters in breadth, o storage and working areas were removed to and installed in an extensive cave system lay inshore at the base and was reported to have been used for docking destroyers, nearby. Work in the caves was hampered by adverse working conditions, dampness, submarine and small craft* The dock could be sunk 4*8 meters below normal dis ac standing water, and foul air, Equipment for generating oxygen and storing it in placement* (See Picture Nos* 177, 178, 179, and 180)* cylinders Is shown in Picture Nos. 166 and 167. Torpedoes were transported by nar row gauge rail cars from cave storage to submarine base pier (See Picture No. 168) 4th Communications Unit Transmitting Station-The layout of this stacion and there loaded aboard lighters by a 2^-ton stiff-leg derrick. The pier and fac- is shown in Figure 24* All buildings were of frame construction* The two-story O ilities are shown in Picture Nos. 169 and 170. The floating drydock of the adjacent barracks were set on concrete piers* After US bombing began these facilities were ship repair base was used for major submarine repairs also. Picture No. 171 shows salvaged and crude open barracks built for them in the adjacent wooded areas* $h north pier of the submarine base. 1 3 N, The two power plant buildings with concrete decks, 4 high sill walls a: 4th Ship Repair Base-This base was equipped to make minor repairs to all and wooden superstructures were totally destroyed by US bombing* The Japanese had »— ships and major repairs and adjustments to vessels up to and including the destroy- anticipated severe bombing attacks and had removed all machinery and transmitting Z er and submarine classes. The base was operated by 1,000 workers of all required equipment to a prepared underground site and so suffered little interruption to o skills, trades and crafts. All structures, Including one-story barracks, shops and their signal communications. warehouses, were of wood construction on concrete decks or sill walls. Only the UJ two-otory barracks had wood decks on concrete piers elevated for dryness. All ship The ruins of the former transmitting rooms showed evidence of hand CO repairs were accomplished while vessels were anchored in the lagoon. This required rubbed finish on the Interior of the concrete walls as well as on the interior Z the use of many tugs, barges, cranes and lighters. Two 100-ton barges, one equipped wood trim. Glass sash had been provided* with a 40 HP compressor and a 45kw generator for electric welding machines shown in Picture No. 165, the other a deck barge used for transporting heavy loads (as gun tur Three steel 45-meter masts set in concrete foundations supported the rets), were available. A 30-ton self-propelled floating crane was used in con- antennae. en Junction with the drydock which lacked crane facilities of its own. The other com- The newly prepared underground site Included a power house, two UJ ponent parts of the base are shown in Figure 23. The principal items were: transmitting caves and provided only the bare essentials. The entrance to one of Z the transmitting caves is shown in Picture No. 184. A substantial machine shop was reported to have been equipped fully with 20 engine lathes, several heavy duty drill presses, moulding and punching The power house sheltering the 65 and 60kva generators was of heav equipment, milling machines, shapers, oxygen generating equipment and all pertinent ily reinforced concrete construction with 18" walls, 36" roof slab, and concrete hand tools. After US bombing attacks, about one fourth of this equipment was sal deck. The entire building was oovered with earth and sodded. No ventilation was vaged and installed in a nearby cut-and-cover shelter which provided the usual ex provided and the air inside was hot and smelled of grease. The two cut-and-cover tremely poor working conditions. (See Picture No. 172). Lathe operators and mach transmitting shelters, of reinforced concrete construction and of horseshoe cross inists stood on duck boards to keep out of the standing water. The atmosphere was section, were 601 long, 12* wide, 81 high and had walls 12" thick. A 12" X 12" stale and damp in spite of the ventilation ducts or pipes to the air above. combination ventilation duct and escape hatch made these units quite habitable. 70 «• o re «+ p -^ o «* t • o o CO ** O O 3 - P C5 rV Co CO •* o <* o •- C Q3 E o -o «— ** I O R C rt 3 "^ O —^ ft. -t 3 tj Co •"•• ft. <* O o re o to p re to co cv Co •^ Co P K^ P 3 o 3 cn P "1 !*- SO •^ re ik P C Co C5 O- o- C*j re. M t "-J C C3 3 O 3a. rt fit;o «- 3 ^. t 3 S«> ft. * re co ft p •«. re •»< * P o- ft. v; » Co P 3 o »• t 10 c o o <* R -< p re «* O O 3 ^ • c co "^ Co e oo 3 5 L Co 3 re «• re «• t c re 3 «+ cr "-», C o o «> e 73- 1 R re -^ re 3 p c> lo C ft.» ^ • s- o «> 3 CD 6 -O 3 3 O ft. o- co O C Co C 3 <» Co r— O co £«; B O c O - Co «• 3 C3 «- "a ft.- »-c "> 1 Co - 3 3 a* o- T^ o ( HSCj ft. re J.1 JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1946 JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1946.( TO BRANCH OFFICES RADIO EQUIPMENT MOVED TO CAVE I—I OFFICERS SINGLE _ WAREHOUSE MAST L J wMAIN MAST COMMANDAN w OFFICERS i 1 QUARTER I SINGLE MAST I i CIVIL RADIO STATION N£L6L— L_J • MAIN MAST GENERATOR I i I OFFICE RECEIVING ROOM BARRACKS FIGURE NO. 28 I N02 i NO.3 _] COMMUNICATION. UNIT i RECEIVING STAT BARRACKS (DUBLON ISLAND) l 11 1 i—i HEADQUARTERS OFFICE II i NOTE: DASHED BUILDINGS DESTROYED COOK" BATHTOILET DRAWING NOT TO SCALE HOUSE i J SHELTER NO. I SHELTE R NO. 2 WORKER'S BARRACKS TO SEAPLANE_BASE 7,000 ton OIL STORAGE TANKS WAREHOUSES FIGURE NO. 27 BARRACKS SUPPLY WAREHOUSE AREA WAREHOUSES (4th MUNITION DEPOT) CD FACTORY 10 0 10 20 30 40 50 60 70 80 SCALE IN METERS 73 *. s>, w\ BACILLUS RESEARCH ROOM! STORE WC O ROOM o TUBERCULOS WATER o WARD I DISEASE WARD WATER OFFICER S AREA in WATER we O o WATER DISEASE WARD n z MEDICAL I— UJ WARD W C ca < o BATH STORAGE a. HOUSE FOOD STORE BOILER o o CO ICE STOREHOUSE a z CO STORAGE UJ XRAY Z SURGICAL ROON WARD OFFICERS o WC OPERATING ROOM WC WC STORAGE ADMINISTRATIONS PHARMACY ID DENTISTRY^ a: i— STORAGE Z T o OFFICER'S ROOM CO UJ CO Z Ul u. UJ FIGURE NO.29 a 4TH NAVAL HOSPITAL UJ CO GARAGE STORAGE UJ (DUBLON ISLAND) Z %,?y ta ^-J DUBLON FIGURE NO. 31 LZTZI GALLEY nmfm AIRFIELD NO.I(MOEN ISLAND) 200 400 600 800 BARRACKS OIL TANKS ETEN =1 [ ] BARR/ DISPENSARY COAL BOMB WELDING SHOP I I PROPOSED EXTENSION STOREHOUSE OIL GARAGE |J TORE TANK u BOMB STORAGE CARPENTER PLANE SHOP HANGER ORDNANCE • OIL z SHOP H- STORE LU OIL STORAGE I I REPAIR PARTS REPAIR _l • LZH _l WELDING PARTS ORDNANCE CQ PLANE REPAIR • o PROPELLER AERO AERO-GAUGE a. SH0 P CONTROL MACHINE REPAIR (ZH BARRA TOWER REPAIR z en Q Z FIGURE N0.30 10 TON CRANE 104TH AIR FORCE ARSENAL (NAVY) CO LU DRAWING-NO SCALE Z O FIGURE N0.32 AIRFIELD N0.2AND SEAPLANE BASE LEGEND SAME AS FIG.3I 200100 0 200 400 600 z --ZZZ : CONCRETE PAVING o CO 20 — ——• GRAVEL PAVING LU CO Z ui LU LU a LU / CO UNDERGROUND HANGER-I PLANE LU CAPACITY z ALL DIMENSIONS IN METERS 75 GENERAL CONSTRUCTION I z O Q. Picture JVo. 299 (PM 101) 4TH FLEET NAVY HOSPITAL Picture No. 1g4 (PM 98) 4TH FLEET NAVY HOSPITAL, Picture No. IQ5 (PM 100) 4TH FLEET NAVY HOSPITAL z DUBLOff: Interior of Pharmacy. DUBLON: Interior of Surgical Ward. DUBLON: Interior of Dental Clinic. z NANKO Dock Area-This area was operated formerly by the South Sea Devel Supply Warehouse Area and 4th Munition Depot-consisted of 29 corrugated opment Company and comprised their entire supply storage area for the sustenance iron roofed frame buildings seV on concrete foundations. Supplies were brought of the civilian Inhabitants of TRUK. The area was taken over by the Japanese mil- to these warehouses from SOUTH or KOKATSO Jetty, Transport Jetty and NANKO Pier Q Z itary and utilized, as shown In Figure 25, as one of their main receiving and stor- by truck. The warehouses were used for the storage of supplies for ships, such age areas for the military forces. The area Included: a frame headquarters, many as munitions, food, fuel, clothing and repair parts for small arms. When in full one and two-story frame barracks on concrete piers and frame warehouses, some on operation, 1,200 men and officers were required to work this area. See Figure 27. concrete decks and others on concrete piers, but both well elevated. The refri 1 geration plant consisted of three cold storage units, each unit 30' X 30* X lo . The Harbor Department-located on the southeast part of the island near Three 75 HP diesel engines furnished power for the belt driven ammonia compressors. DUBLON Town, contained approximately 22 wooden buildings, warehouses, repair shop The cold storage buildings were of frame construction with 4 inches of sheet cork and barracks. The department was responsible for all placing, upkeep and repair insulation between wall studs and ceiling rafters closed in with 1 inch sheathing of channel buoys, mooring buoys, lighted buoys, anchors, chains and other harbor o and a stucco exterior finish. (See Picture No. 181) facilities for all ships and boats for the entire TRUK Atoll. Even though this site was one of the. major receiving points at TRUK,* its The 4th Transport Department-was a unit of approximately 600 men (steve wharf facilities were very meager with respect t& lighter capacity and to the expe 1 dores) for loading and unloading all ships. There being no docking facilities for ditious handling of cargo. A rock filled pier, Picture No. 182, 50 wide extended larger ships, all supplies and equipment had to be lightered. Their operations out to 10' of water while the north side of this pier formed a slip where small covered the NANKO docks, TRANSPORT Jetty and SOUTH or KOHATSO Jetty. Their equip o craft drawing 101 might enter and tie up at a small, poorly constructed timber pier 1 ment consisted of approximately 40 trucks, 50 to 60 two-wheel carts, 50 sampans and approximately 50' long by 15 wide. (See Picture No. 183), one stiff-leg derrick. Sampans repair was accomplished here on a hand-operated marine railway capable of raising up to 150-ton vessels. Three or four vessels of Seaplane Base-This base, the layout of which is shown in Figure 26-B, 30 to 40 tons could be handled simultaneously. consisted of two-story wooden barracks and facilities for base operating personnel, z 2 steel hangars for operational maintenance but without repair shops for planes, The Army Hospital-with a capacity of 300 patients, comprised the former o and reinforced concrete air raid shelters of horseshoe section well dispersed for civilian hospital which was taken over by the Army, three public school buildings the 800 workers and flight personnel. Two seaplane ramps of pre-cast concrete slab used as wards, and added frame buildings. The school buildings were concrete and construction below lower low water and monlithic above were 65 • wide and extended (/> 1 stucco with concrete decks and corrugated iron roofs, no screened windows or doors. UJ out into the water for 160 on a 1 : 12 elope. Ramp No. 2 is shown in Picture No. The Surgery, located in the old civilian hospital had white tile deck, poorly fin CO 185, A 3" concrete apron paved the area between ramps and hangars. Aviation gas ished. Latrines were of the open pit type not removed from the ward buildings. z oline was stored in two-650 gallon underground tanks and distributed by a 10 HP Drainage was by open ditch. The water supply system consisted of two hand-dug wells diesel engine driven pump of 50-tons per hour capacity. Bomb storage areas were 24* deep and two rain water reservoirs of 30 and 20 tons capacity respectively. located in caves dug into the rock of the adjacent hills. The entire waterfront Hand-operated pumps were used on the wells and a gravity system from the reservoirs. was protected by a rock wall without mortar binder. The heavy reinforced concrete CO Except for those borrowed from the Navy, there were no ambulances to transoort Army UJ building used as the control tower is shown in Picture No. 186. sick or injured* z Fuel and Storage Tank Farm-The fuel oil storage area, located on the The 4th Communication Unit Receiving Station-southern peninsula, DUBLON, south side of DUBLON, consisted of four 10,000-ton and one 7,000-ton heavy oil contained three barracks for enlisted men, three buildings for officers, a receiv tanks, of which four were above ground, surrounded by earth dyke (Picture No. 190), ing room, generator house, battery house, civil radio station building, office and while the other was set into an excavation in the adjacent hillside. Plans were 1 sick bay. There were three steel towers and three wooden towers. All buildings made to pour 3 of reinforced concrete over the top of this tank but the work was were of wooden construction with the exception of the receiving room and generator never started. Two oil pipe-lines, lo" and 12" in diameter, extended from the tanks house. After US bombings started, the receiving equipment and the generators not to the pump house and thence to the Oil Pier. The pump house was a concrete struc destroyed were moved to caves in the adjacent hillside. There were two caves, each ture housing one 200-metric ton per hour heavy oil pump and one 85 HP diesel engine. 120 meters long, approximately 60 meters apart, connected by a tunnel. Each cave Two of the tanks are standing, but are damaged badly by bombing and strafing fire. had two decks, the lower decks being used as the receiving room, office, generator One has been repaired and is being used now to store approximately 100 tons. For room, battery room and storage for accessories, and top decks for living quarters additional details see Figure 26-A. and food storage. See Figure 28. 76 X KJ z Picture No. 196 (PM go) 104TB AIRFORCE ARSENAL, DUBLON. Picture Ho. J97 (PM 263J AIRFIELD NO. 1, MOEN: Crushing Picture No. ig8 (PM 264) AIRFIELD NO. 1, MOEN: Rock quarry 13 Showing 10-ton hammerhead crane and pier. Plant. Since US occupatton, American trucks, loader and showing shelf along which tipple cars on narrow gauge track CO supervision has been added. No Japanese crushing plant carried rock to crushing plant. Since US occupat 1 on, Amer- m TRUK had screening mac hintry or bins. ican trucks, dozers and power shovel have been added. z z to O z CO o o Picture No. IQQ (PM 248) BRANCH HOSPITAL (NAVY), MOEf*. Picture No. 200 (PM 249) BRANCH HOSPITAL (NAVY), MOEN. Picture Vo. 201 (PM 241) SEAPLANE BASE, MOEN: Interior Typical ward. Interior of typical ward. of Hangar Cave (in use as dump for orinance items group ed fir disposal under surrender te.rms). The 4th Fleet Navy Hospital-northern peninsula, DUBLON, had facilities Ration Storage-Food supplies were stored in an area next to the Seaplane to care for 850 patients in 5 wards and 24 other buildings. The buildings were of Base. All buildings were of crude frame construction, some with dirt and some with Z wooden construction with logs for studding, rafters, and floor Joists and rough wooden decks. After US bombings, a 1 food was removed from this area to caves on O sawed boards for iecking. Roofs of all structures were of corrugated Iron. No DUBLON and other islands. Much food being destroyed by the air raids, an acute CO screening was ussd on any of the buildings. A charcoal-fired boiler furnished LU food shortage ensued and part of the 4th Construction Department was put to plant- CO steam for sterilizing and hot water for bathing. A steam line ran over-head from ing of rice and sweet potatoes. the boiler room to the operating room. (See Picture Nos. 187 and 188). Water was Z supplied from 12 concrete reservoirs of 50-ton capacity each. (See Picture No. 189) The 104th Air Force Arsenal (Navy), located on the south shore of DUBLON, All water lines were run underground. No flush type latrines were present, all was used for the general repair of planes at the seaplane base and from other is being the open pit type. Electricity was supplied by a generator located at the lands* The roads through this area were of concrete with concrete gutters. Build 4th Construction Department. There was no separate circuit or power source for ings were of wooden construction with the exception of the power house and oxygen CO the X-ray clinic. TSee Picture No. 191). Two eleotrio refrigerators and one ice manufacturing plant, still standing, which were of heavy concrete construction. UJ box were used for medical supplies. The hospital had a small ice house also. Oxygen was manufactured here for use in high altitude flying. The approximate Z Other facilities included a modern dental clinic, pharmacy, medical research lab output of the equipment was reported to be 15 cubic meters per hour. There was a and three medical warehouses. (See Picture Nos. 192, 193, and 195). SUJ .leal, concrete and stone pier, 10 meters X 60 meters, with a fixed lo-ton hammerheRd infectious, medical and tubercular patients were segregated. See Figure 29 and crane. (See Picture No. 196). The dock at this pier was from lfc to 3 meters in Picture No. 194. depth. Water was supplied to the arsenal from six 50-ton and one 100-ton concrete rainwater reservoirs by underground pipelines to various installations. Electric The Ammunition Storage Area-located near the NANKO Area, was used for the power was furnished by two 50kva generators. All power lines to the main buili storage of all types of ammunition for island distribution. Except for two well ings were run underground. A complement of 850 men operated this entire area and constructed concrete buildings, all structures were of wood. After the first US furnished plane repair crews as needed from time to time on other islands. They air raids, ammunition was moved to caves and some was distributed to other islands wer« housed in two-story frame barracks. See Figure 30. because of lack of sufficient manpower to dig all the caves required on DUBLON. A small pier SO1 X 1601 was used for unloading ammunition from lighters to trucks. The buildings were protected by dirt revetments from 101 to 141 in height. 77 GENERAL CONSTRUCTION en Z o Picture No. 202 (PM 243) SEAPLANE BASE, MOEN: Entrance Picture Ho. 203 (PM 240) SEAPLANE BASE, MOEM: Hangar Picture No. 204 (PM 242) SEAPLANE BASE, MOEN: Interior a. to aviation supply cave. cave for two seaplanes with wings folded. Mote track of aviation supply cave. Japanese Officer m Charge for plane dolly. Naval Const ruetion stated cave was intended for bomb Z storage. Z CO Q Z CO o O Z Picture No. 205 (PM 246) SEAPLANE BASE, MOEN: Diesel Picture No. 206 (PM 245) SEAPLANE BASE, MOEN: Another Picture No. 207 (PM 244) SEAPLANE BASE, MOEN: Oxygen driven generat or unit in oxygen gene rat 1 on cave; in- view, subject same as Picture No. 207. generat ing equipment m cave. Installation inc omplete o stallation never completed. and never placed m operat i on. CO UJ CO Z MOEN; (See Picture Nos. 202 and 204)* One cave, JLOO1 long by 251 wide and 12* high, was CO used to house two planes by folding back their wings* (See Picture Nos* 201 and UJ Airfield No* 1-located on the northwest side of the island, (Figure 31), 203)* The Japanese were in process of setting up an oxygen plant in another cave Z was 200* vide and 3,900* long and paved with 2&N to 5" of concrete* No hangars here when the war ended* (See Picture Nos 205, 206, and 207). The construction were built at this base, all planes were kept in revetments* There were no storage of the base was started In February, 1943• facilities except the caves in the adjacent hill* Rock for the paving was obtained from the East Hock Quarry where there are 3 small crushers reportedly capable of The MOEN Radio Station-located in the easterly part of the island, was an output of approximately 6 tons each per day* (See Picture Nos* 197 and 198)• operated by the 5th Detachment of the 4th Communication Unit. The building 3251 X 90', was of heavily reinforced concrete construction, 31 heavily reinforced con Airfield No* 2 and Seaplane Base-1301 wide and 3,250* long, was surfaced crete roof, double deck, supported by 18" X 18" concrete pilasters. All doors with from 2&* to 4" of sand and cement* Figure 32* The runway was built level, and windows were protected by double £" sheet metal. Radio equipment, two 50kva without crown* There were two concrete seaplane ramps, each approximately 651 X generators, personnel, supplies and miscellaneous equipment were housed in this 160', of pre-cast concrete blocks below lower low water, monolithic above. Planes building. One 40-ton fuel oil tank and one 30-ton water tank for rainwater were were drawn ashore on dolly8 by a power operated winch* One steel hangar, 120' X located on south side of tnis building. One 40kva generator was housed in a con 120', was used for plane repairs and planes were kept in dirt revetments* Numer crete building approximately 20' east of main building. There were- three 1301 ous caves in the adjacent hill were used for the sto^^a/re of ammunition and supplies. steel antennae towers* 78 Picture No. 208 (PM 501J ETEN AIRFIELD: Supply caves m hill- Picture Ho. 209 (PM 494) ETEN AIRFIELD: Administration and Pictur.e No. 210 (PM 499) ETEN AIRFIELD: Air Unit Bead- side adjacent to airstrip. Terracing of hillside occurred when Communicat1ons Building showing US bomb damage t 0 Eas* Wing. quarters Building damaged by US bombing. hill was shaved down by hand to make the strip. In general, strafing fire did not Penetrate heavy steel platt shutters backed by "I" beams. o Q- z z CO Q Z CO O < Picture No. 211 (PM 49^) ETEN AiKflELD: Administration Picture No. 212 ifM 497) HTEN AIRFIELD: Little damaged Picture No. 213 (PM 498) ETEN AIRFIELD: Remforced o and Communications Building detail showing US bomb dam- reinforced concrete personnel shelter shown to give concrete Personnel shelter demolished by sliding into age . standard of c ompans on with picture of one of those the crater formed by very near miss. demolished. Z o 10 LU CO Z CO LU z Picture No. 214 (PM 504) ETEN AIRFIELD: Interior of Power Picture No. 215 (PM ^06) ETEN AIRFIELD: Interior of Power Picture No. 216 (PM 505/ ETE N A IRFIE LD : ~ Int e r 1 or of Power Plant Plant where, reportedly, a US dud bomb penet rat ed concrete Plant where alleged US dud bomb, having penetrated roof, pen- showing underside of roof slab where US bomb is alleged t o have roof. No operational damage to Power Plant. etrated balcony deck also and went on to crater ma m floor. hit and exploded.] It was a near miss on the Power Plant that No ope rat 1 on aL dama? e to Power Plant . put it out of operation by fragments and blast effect. 79 GENERAL CONSTRUCTION NO. DESCRIPTION 1 RADIO RECEIVING STATION 2 POWER PLANT 3 HEADQUARTERS 4 GASOLINE STORE HOUSE 5 GASOLINE STORE HOUSE 6 CONTROL TOWER 7 FORGE SHOP FIGURE NO. 33 e WOOD SHOP 9 FOOD STORE HOUSE 10 SUPPLIES II GARAGE ETEN ISLAND AIRFIELD 12 ETON SHRINE X 13 SICK BAY 14 ROCK CRUSHER AND FACILITIES IS ALL OTHER BUILDINGS SHOWN WITHOUT DESCRIPTION ARE RELATIVE TO HOUSING S ITS FACILITYS 20 40 60 80 100 SCALE IN METERS DIMENSIONS GIVEN IN METERS ASPHALT, CEMENT- AIRSTRIPS a TAXIWAY AREAS CONCRETE - AIRSTRIP a TAXIWAY AREAS ROCK, EARTH-COMPACTED TAXIWAYS en o z t— LU CO < o a. \j Z * CO a z I.IOOM • CO LU Z o STEM; Lighting-Tlils airfield was reported by the Japanese to have been the only one at TRUK equipped with runway lights for night operation. The airstrip-was the best constructed at TRUK and had sustained the heav iest damage of all. The layout of the 1,000 by 80-meter strip and its accessories Aids to navigation-Radio compass and air-ground radio were in use for is shown in Figure 33, Construction on the strip began in August of 1941. Mater landing planes but no homing devices had been installed. Weather information was ial from the central hill of the island was deposited within a rubble masonry sea obtained from the meteorological station in DUBLON and from weather flights origin wall forming the three seaward boundaries of the field. The subgrade was reported ating or terminating on the field. to consist of 8" to 10" of rock crushed locally, spread and compacted over the rock- ID and-earth fill taken from the hill. The finished surface of the strip was l£w of OC Repairs-Only minor plane and engine repairs were handled by the shops and I— asphaltic concrete originally but several large bomb craters had been filled and facilities on ETEN. Maintenance and minor repair operations were reported to have Z surfaced over with concrete 5" thick, made with Portland cement. Many other been carried on in the two 1001 X 1001 steel hangars, on the service aprons, and craters had been filled only. The elevation of the finished grade was approximate- 1 while planes were parked in revetments. Major repairs were handled by skilled o ly 5 above high tide. For drainage the strip was pitched slightly toward the sea. mechanics, dispatched from 104th Air Arsenal on DUBLON or the plane was sent to the CO This field was reported to have been completed the latter part of 1943. LU Arsenal for repair. Small armament repair facilities were available at ETEN but CO major armament work was done on DUBLON. For major overhaul or reconditioning, Z A loop taxiway-reportedly to be of concrete but nev=r completed, was found planes were returned to the Empire. to be nothing but a poorly drained, narrow and rutted road encircling the island and connecting the asphalt paved repair apron on the south with the north end of the Aviation gasoline storage-was the original purpose of the heavily rein strip. forced concrete buildings #4 and #5 in Figure No, 33. As US bombings threatened LU CO 1 these structures, the aviation gas was removed to an underground concrete vault LU Seventy-four earth revetments-8 high, were provided for the 217 planes of horseshoe cross section 50* wide, 25 • high and 60' long. Bombs were stored in Z stationed at the base. These were dispersed along the hillside adjacent to" the an identical vault nearby. Both of these vaults were well drained, and had their air-strip and off the taxi loop but always up against the protection of the hill- 451 X 551 X 6" thick floor slabs elevated 31 above the concrete footings. These a. side. It was reported that planes had been parked, unprotected, in the south ser and other miscellaneous storage caves are shown in Picture No. 208. Bomb damage vice apron and along the shoulder between the sea and the runway. to the power plant Is shown in Picture Nos. 214, 215, and 216. The control tower-was located on the second deck of the heavily reinforced The quarters and faclllties-for the 1,200 personnel stationed at ETEN concrete administration and radio communications building. (See Picture Nos. 209 were scattered throughout the island as shown on the layout. Barracks and miscel and 211), This building had been caved in by bomb hits in the center but the north laneous buildings were all of frame construction. and south wings were usable. 80 o 5 DESTROYED MASTS I o o 2 9 ABANDONED MASTS TRANSMITTING • STATION TRANSMITTER O BLDG. O W.T. 30 O WATER TANK i=n° 2 40 T. CONCRETE WASH HOUSE COMMISSARY O O 150 K.V.A. BLDG o Q. 6 PRESENT MASTS z 60 K.V.A.GENERATOR W.T. 200T. BLDG. (CONCRET < a. Z AIR RAIDSHELT (50 PERS.) In FIGURE NO.35 a z TRUK ATOLL UMAN ISLAND RADIO STATION INSTALLATIONS REMOVED FROM _ / ORIGINAL POSITION TO PRESENT * SITE.AFTER AIR RAIDS 10 10 20 30 4 0 50 o TRANSMITTEI SCALE IN METERS BLDG. O z o CO UJ CO Z LU Q FIGURE N0.34 iu CO LU PARAM AIRFIELD Z Q. | 1 CONCRETE PAVED I | AIRSTRIPS TAXIWAYS. H H ROCK-EARTH FILLED 1 --T J AIRSTRIP a TAXIWAYS / . 40 0 40 80 120 SCALE IN METERS 1ST EXTENSION 6OM J2NDEXTJ ROCK FILLED ARE> FOR PROPOSED EXTENSIONS I8OO M. 81 GENERAL CONSTRUCTION UMAN; few calls for repairs, Bombs and fuel were stored in caves in the hillside near o the air strip* -*• o The Radio Station-built in 1942, located on the north tip of UMAN com prised six frame buildings: transmitter house, generator house, warehouse, barracks There were three frame barracks for officers and five for enlisted men. I and commissary, and 3 concrete water tanks, 240-ton, 200-ton and 30-ton. The an Rations and supplies were stored in caves. There were no other construction items tennae towers were lashed timber poles, approximately 60' to 75• in height. Power of interest on this island, ac was supplied by two 150kva and one 25kva diesel engine driven generators. Operation of the station occupied approximately 600 men of the 4th Naval (signal) Communica UNDERGROUND INSTALLATIONS IN GENERAL. 2 tions Corps. There were also about 400 men from the 4th Naval Construction Depart in ment engaged in digging caves and trenches, in road building, and on general con When US air attacks became imminent early in 1944, the Japanese began moving struction. See Figure 35. their essential installations underground. This move included generators, machine shops, plane hangars, ammunition, rations and general stores. It entailed the There were few other installations on UMAN. Medical facilities consist construction of air raid shelters for all. Wherever practicable these caves were ed of a 300-bed Navy hospital in crude wood and log buildings. The Army hospital dug with the aid of compressed drills. Narrow gauge tracks were advanced into the Z with the same type of structures was capable of handling 100 patients. Medical drifts as digging progressed, the rock loaded by hand into 3 cubic yard tipple cars equipment for both Army and Navy was very limited. and disposed of usually to good advantage. In many instances the spoil was used for UJ land reclamation along waterfronts areas. More frequently than not the sound rock FEFAN; formation obviated timber shoring. 3 m 4th Naval Stores Department-FEFAN was used mainly for the storage of am The Japanese had no mechanical equipment for ventilation but promoted natural munition, food and small arms for the supply of the fleet and other TRUK islands. gravity air flow through the larger caves by varying the elevations of the mul Shortly before US bombing started, most of the ammunition and supplies were moved tiple openings. Caves without this ventilation were always damp, stuffy, foul and, o from DUBLON to FEFAN. All storage operations were handled by approximately 250 men in the case of generator caves, hot, and greasy smelling. Meager attention was a. from the FEFAN branch of the 4th Naval Stores Department. given to drainage; standing water was prevalent, and in caves not used for several months, considerable pumping or bailing would be necessary to make them usable again. Z The ammunition magazines were 201 X 401 wood buildings; good by American construction standards. All studding, rafters, trussing, floor and ceiling joists Caves for ammunition storage were all intended to be lined with approximately were of S4S fir, while floors, walls and ceilings were of 5/8" X 6M T&G white pine. I1 of concrete but this program was far from completion because of the lack of con Each building was set on an elevated concrete foundation. The exteriors, both sides struction equipment and materials, principally cement. The 3 bomb and ammunition and roofs, were covered with corrugated metal. Surrounding each building was an caves on ETEN were among those completed, and showed good design and workmanship. z earth revetment, 101 to 141 in height. These buildings were erected in 1943. There In these magazines the Japanese had incorporated an elevated 6" concrete slab on were also many caves used for ammunition storage. Approximately 500 men on FEFAN monolithic concrete piers for dryness. A peripheral gutter in the base slab drain CO from the 4th Naval Construction Department were engaged in building roads, piers, ed away all seepage. O gun emplacements, caves and on general construction. Stone for crushing was very limited and much of the aggregate had to be brought in from other islands. All z concrete mixing had to be done by hand. In consequence there is little concrete work on the island. There had been four 12" rock crushers on the island but when FIXED OR PERMANENT UTILITIES. - I the stone was found to be of such limited quantity they were moved to other islands. CO UJ Electricity was supplied from one 5kva and one 15kva generator. Water Supply - DUBLON: On DUBLON there were two principal sources of water Z supply. The RARA Source located at the middle of the western shore consisted of Two field hospitals, one Army and one Navy, both with only very limited four concrete dams confining mountain streams. The water passed on by gravity o equipment and facilities, were located on the island. All hospital buildings were flow to a concrete settling tank, then through rapid san filter beds in reinforced OS of very crude construction, being native homes that had been taken over by the concrete tanks to a concrete purification basin for chlorination. The water was Japanese. then pumped up to a distributing reservoir where it flowed by gravity through underground pipes to the installations shown in Figure 26, The amount of water at PARAM: this source was reported to have reached a maximum of 1,800 cubic meters per day with a minimum of 460 cubic meters during dry spells. Because of the poor condition o The runway-on PARAM (Figure 34), as completed in 1943, was 1,200 meters of the filters and the exhausting of the supply of chlorine, all drinking water was long by 40 meters wide. During the period February to April, 1944, it was extended supposed to be boiled. The Japanese had been unable to renew the filter sand. Tests to 1,400 meters and widened to 60.meters. Another extension was made between Nov reported by the Japanese on the RARA Source are: ember, 1944, and March, 1945, to 1,600 meters in length by 100 meters in width. The original strip was paved with 3" to 4" of concrete but the extensions were of Test Before Treatment After Treatment crushed rock and earth well packed by rolling. The concrete mixers, 5 rollers, 5 z rock crushers, numerous hand carts, 10 trucks, small narrow gauge railway C£.rs and External Appearance Colorless (For most part) Colorless but slight o various hand tools were used in the construction of the strip and taxiways. Drain but slight trace of color traces of white CO age was very poor. The greater portion of the strip was only 6" to 10" above high UJ matter CO tide. Fifty torpedo planes had been based at this airfield. Taste Normal Normal Z Reaction PH 6.6 7,2 Five taxiways-leading from the runway to fifteen revetments, were paved Ammonia None detected None detected UJ with approximately 2§" of concrete. One taxiway was of rock and sand. All were Nitrous Acid None detected None detected O built up approximately 12" over a swamp area. Amount of MG in 1 liter UJ (a) Organic 6.1 5.58 CO The diapersal area-comprised fifteen revetments of earth and stone, 61 (b) Chlorinated 15,7 UJ 1 13.8 Z to 10 in height, each capable of accommodating a small type plane. Nitric Acid None detected Large traces Sulphuric Acid None detected None detected There were no towers-beacons or lighting equipment for the runway and no Lime None detected None detected airground radio communication. Weather information was received from the weather Bacilli Count 232 184 station on DUBLON, "B" Coli None detected Decision Suitable for All repairs-to planes were made in the open. There were no hangars or drinking when even small shops. It was reported that all Dianes had been new and there had been boiled 82 00 CO JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1V46". FIGURE NO. 3 8 POWER DISTRIBUTION SYSTEM DUBLON IS. z Picture No. 217 (PM 73J DUBLON: Remains of i,oookva diese I driven generator, located between SUBMARINE BASE and SHIP REPAIR BASE, the largest such unit found in TRUK. Building beyond housed 4>jkva generator still in running condition. o a. 4IST. GARRISON V BICy*%t Z FORCE x v Z to a z o , ' COAST OEFENSE eg BATTERY ij— ISKVA.XI KV X „ X 4TH FLEET COMMUNICATIONS^ *' ' NOTE: Z O 5 KVAr Xi en LU POWER OF UNIT (ONE UNIT) NOTOFUNITS to Z LEGEND HIGH TENSION UNDERGROUND LINE HIGH TENSION OVERHEAD LINE _0W ENSION UNDERGROUND LINE _0W TENSION OV ERHEAD LINE Z =>OLE TRANSFORMER POWER S ATION FIGURE N039 POWER DISTRIBUTION SYSTEM MOEN ISLAND ). 2 a SEAPLANE BASE 84 GENERAL CONSTRUCTION The NECHIYAPPU source located In the geographical center of the Island was collected, Power and Light; The power plant installations and power distribution systems treated and distributed as was the RARA Supply. The maximum dally supply of water for DUBLON and MOEN are shown in Figure 38, and Figure 39, respectively. The re was reported to have been 600 cubic meters with a minumum daily supply of 187 cubic mains of a l,000kva generator located between the Submarine Base and Ship Repair meter8. The distribution is shown in Fig. 36. Tests reported on this source by the Base on DUBLON are shown in Picture No. 217. Japanese revealed analysis and quality as follows: Generator plants on all other islands were all local to the various installations with no central power stations or feeder systems. The capacity of these local units were covered in discussions of the individual installations. Test Before Treatment After Treatment There were only three Instances where the Japanese had installed generators in External appearance Clear and transparent Colorless and clear structures of the heavily reinforced concrete type, the radio station on MOEN, the but traces of floating airfield on ETEN and the 104th Air Arsenal Plane Repair Base on DUBLON. All other z matter. original power plant structures were frame buildings with concrete decks. Taste Normal Normal Reaction PH 7.2 7.3 After the initial US bombing attack, all generators on all islands were removed Ammonia None detected None detected to unimproved caves. Meager attention was paid to ventilation and drainage of these Nitrous Acid None detected None detected underground sites and they were universally dark, poorly lighted, and carried hot Amount of MG in 1 litre air smelling of grease and exhaust from the running engines. (a) Organic 5.2 4.68 (b) Chlorinated 16.3 13.7 Fire Prevention and Fire Fighting; DUBLON had the only organized and coordinated o Nitric Acid None detected None detected fire fighting system. There were five fire stations located at: The 4th Harbor De Sulphuric Acid None detected None detected partment, 4th Munition Depot, Seaplane Base, 4th Ship Repair Depot, and the 41st z Lime None detected None detected Naval Guard Force. Each of these stations had telephone communications and fire Bacilli Count 214 263 fighting equipment consisting of two or three 1,300 gal. water trucks, and small "B" Coli None detected three-wheel motorcycle type 300 gal. per hour pumpers. (See Picture No. 218). Decision Suitable for drink ing when boiled The 4th Naval Hospital on DUBLON had standard hand extinguishers of both the u foamite and carbon dioxide type scattered among the various buildings but there was Z MOENi The principal source of water (Fig. 37) was In the hills north of the no evidence that this had been-»a standard provision at other installations. water supply Jetty on the south coast of MOEN. The water was impounded by two dams, filtered and treated exactly as in the DUBLON systems and then piped to ships via In conclusion it seems that the Japanese relied on the old bucket brigade pro- Q the Water Pier. The maximum available daily at the source was 800 cubic meters cedure from reservoir to fire in fighting the bulk of their fires. They claimed to Z dropping at times to a minumum of 200 cubic meters. Tests reported on this source have no men skilled or trained in fire fighting but all worked on the "volunteer revealed analysis and quality of water as follows: system". to Test Before Treatment After Treatment External appearance Coldness but slight Colorless but amount of white float- slight traces of O Ing matter white matter Taste Normal Normal Reaction PH 6.4 7.8 Ammonia None detected None detected Nitrous Acid None detected None detected Amount of MG in 1 litre o (a) Organic Large amount Slight amount (b) Chlorinated 12.0 10.5 Nitric Acid None detected None detected Sulphuric Acid None detected None detected Lime None detected Slight amount Baccilla Count 480 130 Z "B" Coli None detected None detected Decision o Boll for drinking No danger in drink CO ing LU co The Japanese operated 3 water supply ships of 150-ton, 100-ton, and 100-ton capaci Z ties, respectively, carrying water from PONAPE to TRUK to supplement the water supply to ships at TRUK. Other Islands: Water for all oth3r islands of TRUK came from one or both of CO two sources: rainwater (drained from roofs into various containers up to 50-ton re LU inforced concrete reservoirs, scattered throughout the island bivouac areas and z installations) and dug shallow wells (the deepest being 6 meters). Water from both of these sources was used without filtering and was supposed to be boiled always for drinking. The rainwater was used principally for drinking and the other for bathing. Occasionally the Japanese would develop a spring. (See Picture No. 140). Picture *o. ?i8 (PM gi) DUBLON: Fire Fi?htm? Equipment Typical three wheel pumper unit se If prope I lei, ^oo gallons per hour. 85 SIGNAL COMMUNICATIONS GENERAL DISTRIBUTION OF NAVAL COMMUNICATION PERSONNEL. Source of Information: The information contained in this report was obtained Main Unit Subordinate Sections Officers WO Enlisted o by inspection of installations, interrogation of personnel and reports submitted by Units the Japanese. Generally, the Japanese were very cooperative and as far as could be X ascertained were quite truthful. However, in many cases, key personnel were not available due to repatriation, etc., and information had to be obtained from personnel EAST CAROLINES HQ 60 who were not fully conversant with the subject. It was not possible to accurately AIR GROUP. PARAM check every detail of the Japanese reports, but most of the information was checked Detachment. 8 and found to be correct with the exception of minor unintentional errors in trans ETEN lation, etc. Detachment. DUBLON Detachment. 15 to Z History of Communications: The communication installations at TRUK represent 43rd NAVAL GUARD HQ 14 the results of a long program of defensive installations beginning with the Japanese FORCE. POLLE Radar occupation of the atoll. Extensive underground construction had been carried on and OP. over a long period of time and had apparently reached a virtual state of completion. 150mm Gun Pos. The necessity for moving installations previously operated above ground, to under N. TOL. ground locations, had been anticipated and in most cases was easily accomplished with 150mm Gun Pos. no particular loss of efficiency. Considerable damage to most surface construction S. TOL. 0 had been Inflicted by our air and naval bombardment, but the communication system 120mm Gun Pos. o as a whole was not seriously affected. Prior to the surrender of the Japanese, the EOT. Navy and Army forces on TRUK had been instructed to destroy all secret documents. Torpedo Bomber flu This was accomplished with very few exceptions. Unit. UDOT. Z YAWATA OP. 0 OLLAN OP. a S. part ? Is. Relationship of Army and Navv: Due to the distinct separation between the Navy OP. Z and Army activities on TRUK, it is considered necessary to separate this report into Army and Navy categories. There were virtually no Joint communication activities 47th NAVAL GUARD HQ and little evidence of cooperation between the two. The Navy definitely dominated FORCE. the communications picture and had by far the most elaborate Installations. MOEN Radar & OP. to 7cm AA Gun Posi Q tion^ Z 120mm Gun Posi tion. co NAVY COMMUNICATIONS. 12cm Gun Position. ui FALO SL Pos. Z General: The Navy communication system on TRUK consisted of that which was necessary to serve a Fleet Headquarters, a Naval Base and the tactical defense of the atoll. These installations altogether were quite elaborate and apparently were 48th NAVAL GUARD HQ 10 o reasonably efficient. The equipment however, was of rather antiquated design and FORCE. 80mm AA Gun Pos. construction. Even the equipment of fairly recent manufacture was, by our standards, 15cm Gun Pos. < somewhat obsolete. 15cm Gun Pos. 200mm Gun Pos. Organization: The following table of organization represents the distribution PARAM 27cm of personnel at the cessation of hostilities: AA Gun DISTRIBUTION OF NAVAL COMMUNICATION PERSONNEL. 49th NAVAL GUARD HQ 12 FORCE. UMAN SL Pos, Main Unit Subordinate Sections Officers WO Enlisted East 14cm Gun Units z Position. 4th FLEET HQ. West 14cm Gun o Fleet Comm. 0. Position, CO Section. 1 0 6 North 15cm Gun LU Radio Section 2 0 23 Position. CO Code Section. 4 1 20 Z NO. 4 COMM. UNIT. HQ Radio Section. Ill Radio: UJ Code Section. 40 O CHARE General - The principal radio transmitting and receiving installations CO Xmitter Sta . Xmitter Section. 1 0 16 were located on DUBLON, MOEN and UMAN. The installations on the various islands UJ MOEN will be discussed separately. The attached diagrams indicate the circuits in oper Z Xmitter Sta . Xmitter Section. 1 0 16 ation at the end of hostilities. UMAN Xmitter Sta . Xmitter Section. 1 1 14 DUBLON - The main Navy installations on DUBLON consisted of a main trans ULALU D/F Section mitting station, the Naval Receiving Station, and a seaplane base transmitting sta D/F Sta. Control Section. tion. The stations are discussed Individually below: 88 SIGNAL COMMUNICATIONS tSSIFIEb Main Navy Receiving Station - This was the radio receiving center for the 46 Type 92, All-wave receiver, 20-20,000 kcs. entire atoll. From this station all major transmitters on DUBLON, MOEN and UMAN 1 Diesel Generator, AC., 40 Kva. could be keyed by direct lines, or by radio. It was located in an extensive 1 Diesel Generator, AC., 25 Kva. connecting tunnel system, dug into the side of a mountain. There were three exits 2 Diesel Generator, DC., 220V, 5KW, o to the tunnel system; one on the east slope of the mountain, one on the northwest 2 Gasoline Generator, AC., 6 KW. slope, and the main entrance to the north. The construction and location of this 2 Gasoline Generator, AC, 1.5KW, I tunnel system made it virtually immune to serious damage from bombardment. However, KJ the tunnels ran straight into the mountain in each case and were very vulnerable The Type 95 and Type TM transmitters were intended for emergency communications. a: to flame-thrower, demolition and small-arms attacks from the ground. This station The Type 2, medium-wave transmitters were for emergency radio-keying of the trans was previously located in a building between the radio towers. The building had mitters at the DUBLON, MOEN and UMAN transmitting stations. The large number of been completely destroyed by our bombing attacks, but virtually all equipment had Type 92 receivers was due to a policy of installing a new receiver each .time a been moved underground prior to the destruction of the building. According to the set became inoperative. All of the 46 receivers were actually installed, but the Japanese the necessity for moving underground had been anticipated and was started Japanese claimed that not more than ten were ever in use at one time. The 40kva when we began bombing RABAUL in April, 1944. The move was completed by June, 1944. and 25kva generators were intended to supply power in case of failure of the main The following equipment was installed in the station: DUBLON power station (from which power was normally obtained by underground cable). The 5 KW., DC generators were normally employed to furnish power for the receivers, 2 Type 95, Mark 3, Short-wave transmitters. 3750-20,000 kcs., 1 KW. however, power units were available- that would enable the receivers to operate from 4 Type TM, Portable short-wave transmitters. 3750-12,000 kcs., AC if necessary. 250 watts. 7 Type 2, Mark 5, Medium-wave transmitters. 1200-4000 kcs., 200 watts. o z Z \J co Q Z o Picture No. 219 (PM 59) NORTH (MAIN) ENTRANCE TO MAIN Picture No. 220 (PM 60) NORTHWEST ENTRANCE TO MAIN NAVY Picture No. 221 (PM 58) EAST ENTRANCE TO MAIN NAVY o NAVY RECEIVING STATION: DUBLON. RECEIVING STATION: DUBLON. RECEIVING STATION: DUBLON. Z o co LU CO Z CO LU Z Picture No. 222 (PM 57) INTERIOR OF MAIN NAVY RECEIVING Picture No. 223 (PM 56) INTERIOR OF MAIN NAVY RECEIVING Picture No. 224 (PM 542) ANTENHA TOWERS: Site of old STATION: DUBLON (Looking toward mam entrance). STATION: DUBLON. Navy Rece iv ins* station - DUBLON. 87 SIGNAL COMMUNICATIONS Navy Transmitting Station - This station consisted of two concrete bomb 1 Type 92, all-wave receiver, 20-20,000 kcs. shelters, located approximately 50 yards apart. Their construction was such that damage could result only from direct hits by heavy shells or bombs, but their spacing 1 Diesel driven 25 KW, 220 V, DC Generator. was such that one would not be damaged by a direct hit on the other. The Japanese The main power for these two stations was supplied by one 65kva and one 60kva o referred to these installations as Transmitting Stations No. 2 and 3, but to all 3 - phase, 220V., diesel-driven AC generators located in an underground power house intents they actually composed one station. The following equipment was Installed near the stations. These generators were operated alternately. The 25 kw DC gen X u in these shelters: erator in station No. 3 was used as power for the Type 92 transmitter. All of the oc transmitters were keyed from the DUBLON Receiving Station by means of underground Station No. 2 keying lines, or in emergency by radio. 3 Type 95, Mark 3, short-wave transmitters, 3750-20,000 kcs, 1 KW. 2 Type 95, Mark 4, short-wave transmitters, 3750-18,000 kcs, 500 Watts. Seaplane Base Transmitting Station - This station was located in an under 2 Type 95, Mark 5, short-wave transmitters, 3750-18,000 kcs, 250 Watts. ground shelter about 500 yards from the Navy Transmitting Station. The shelter was 1 Type 2, Mark 5, medium-wave transmitter, 1200-4000 kcs, 200 Watts. well underground and virtually immune to serious damage from bombardment. The 2 Type 92 all-wave receivers, 20-20,000 kcs. following equipment was installed in the station: 3 Type 95, Mark 3, Transmitters. 3 Type 95, Mark 4, Transmitters. Station No. 2 Type 92, Mark 3, Modification 1 transmitters. 3 Type 95, Mark 3, transmitters. "see above) 2 Type 95, Mark 4, transmitters. ii • All of the transmitters (with the exception of the Type 92) were capable of 1 Type 92, Mark 3, long-wave transmitter, 150-500 kcs., 1 KW. voice operation by means of modulator units. O Q. z KJ Z CO Q Z CO o oc O Picture No. 225 (PM 52) THREE TYPE 95. MK 3, MODIFICATION Picture No. 226 (PM 51) INTERIOR OF DUBLON TRANS. STATION Picture No. 227 (PM 49) TRANSMITTER INSTALLATIONS Tu/o 1. TRANSMITTERS: DUBLON Trans. Station No. 2. NO. 2: Showing type 2, Mark 5, Moiif. 1, Transmitter, Type 95, Mk 4, DUBLON Transmitt in? Station No. 2 : >• juipment and type 92, Moiif. 2, monitor receivers. z o CO LU CO Z CO LU Z Picture No. 228 (PM 5 Picture No. 229 (PM 54) MOTOR - GENERATOR INSTALLATIONS NO. 3. Picture No. 230 (PM 55°) ENTRANCE TO NAVY SEAPLANE BASE DUBLON Trans. Station No. 3. TRANSMITTING STATION: DUBLON. 88 SIGNAL COMMUNICATIONS Seaplane Base Receiving Station - This station was located In a building The transmitters were keyed: frbtt 'the;maln rJtiei vindication by means of submarine at the Seaplane Base and had been completely destroyed by bombing. The following and underground cable, with radio keying as an emergency measure. The following equipment was found stored In an armory at the seaplane base: equipment was located in the building: 4 Type 3, Mark 6, Model 4, Airborne search radars (allegedly 2 Type 97, Mark 2, Model 1, Modification 1, short-wave transmitters. Installed on 3-place Zero float planes). 2 Type 95, Mark 3, short-wave transmitters. 2 Type 2, Mark 5, Modification 1, Middle frequency aircraft 1 Type 95, Mark 4, short-wave transmitter. transmitters. 1 Type 95, modification voice amplifier. 2 TM mobile transmitters, Modification 3. 1 Type 97, modulator. 2 TM mobile transmitters, Modification 2. 2 Type TM, modification 3, short-wave transmitters. 12 Type 1, Mark 3, Aircraft Direction finder receivers, 1 Type 98, Mark 2, Model 2 transmitter. 1 Type 92, Mark 3, Modification 1, transmitter. 1 Type 1, Mark 2, Model 2 voice transmitter. MOENi - The main Navy radio installations on MOEN were the naval transmitting 3 Type 92, modification 4 { special receivers, with Type 99 keying unit. station and the Seaplane Base Receiving Station. 1 Diesel-driven, 250kva, AC generator. 1 Diesel-driven, 40kva, AC generator. z MOEN Navy Transmitting Station - This station was located in a reinforced concrete building (shown on map). While not bomb-proof, the building was well This station was essentially a part of the main Naval radio system, and although constructed, and although it had been subjected to bombing and strafing attacks, keying of most of the transmitters was accomplished from DUBLON, it is believed that as well ae naval bombardment (British), the structure was not seriously damaged. the voice transmitters were remote controlled from the MOEN Seaplane Base Receiving Station. o o. KJ z z CO Q Z < -I CO O oc Picture No. 231 (PM 549) INTERIOR NAVY SEAPLANE BASE Picture No. 232 (PM 548) NAVY SEAPH.NE BASE TRANSMITTING Picture No. 233 (PM 55) SEAPLINE BASE ARMORY INTERIOR o TRANSMITTING STATION: DUBLON. STATION: DUBLON. VIEW: Used as radio & radar storeroom - DUBLON. Z O CO UJ CO Z CO UJ Z Picture No. 234 (PM 192) FRONT VIEW: MOEN Trans. Station Picture No. 235 (PM 191) TWO TYPE 97. MK 2, MODEL 1 Picture No. 236 (PM 189) NORTHWEST WING:*' MOEN Trans TRANSMITTERS: MOEN Trans. Station. me Station. 89 SIGNAL COMMUNICATIONS MOEN Seaplane Base Receiving Station - This station was installed in a UMAN: The only major naval radio Installation on UMAN was the radio trans tunnel extending straight through a promontory on the west slope of Mt. TEROKEN, mitting station. It was located in a cave dug into the north face of Mt# URORAS. Although referred to by the Japanese as the "Naval Seaplane Base Receiving Station11 The transmitters were keyed from the DUBLON Receiving Station by means of keying it is believed that it served land-based naval air activities as well. There was lines (submarine and underground cable) with radio keying as an emergency measure no seaplane base transmitting station which could be identified as such, but it in case of line failure. The following equipment was installed at this station: is believed that the voice transmitters located at the MOEN Transmitting Station were employed for air communications, and were controlled from the Seaplane Base 2 Type 99, Mark 2, short-wave, transmitters. Receiving Station or from either of the airfield8. The following equipment was 3 Type 95, Mark 3, modification 1, short-wave transmitters. Installed or stored in the tunnel: 1 Experimental Type 2, Mark 5, modification 1, middle wave transmitter. 1 Type 95, Mark 4, short-wave transmitter (CW only). 2 Type TM mobile short-wave transmitters. 3 Type TM, modification 3, mobile radio transmitters'. 4 Type 92 special receivers. 6 Type 2, Mark 3, modification 1, aircraft transmitter and 2 Diesel-driven 150kva AO generators. receivers (stored). 1 Diesel-driven 25kva AC generator. 26 Type 92, Mark 4, all-wave receivers, (normally operated 9). 2 Type 92, modification 2, monitor receivers. The transmitting a&tennas for this station were located on the north point of the island. Antenna J-Sads offears O«pp«r wire extended from slits in* the wall of This installation was relatively immune to damage from bombardment, but was the cave and ran on knob insulators approximately 300 yards to the antennae. vulnerable to ground attack by flame-throwers and demolitions. o a. Z u Z a z o < Picture No. 23S (PM 163) OPERATING POSITIONS (LOOKING VEST): Seaplane Base Receiving Station MOEN. Picture No. 237 (PM 165) WEST ENTRANCE: Seaplane Base Picture No. 239 (PM 162) EAST ENTRANCE: Seaplane Base Receiving Station MOEN. Rece iv ing Station MOEN. Z o CO LU CO Z CO 305) INTERIOR OF UMAN TRANS. STATION. Picture No. 241 (PM 3°3) TYPE 95 TRANSMITTERS & RECTI- Pxcture No. 242 (PM 306) TYPE 99 KEYING UNIT: Attached FIERS: UMAN Trans. Station. to Type Q2 Receiver - UMAN Trans Station. 90 SIGNAL COMMUNICATIONS o o •«• Tokyi I OH 2 Wake in PaganO Wotje PACIFIC AREA RADIO SYSTEM (NAVY) (COMMUNICATIONS NET) z FREQUENCY OPERATION PERIOD POWER CALL SIGNS Maleolap v— UJ TOKYO Transmitter: 5585 kc (night) en 16755 kc (day) TRUK Transmitter Continuously TRUK - 5kw (TOKYO) NIMINE < 5125 kc (night) (TRUK) NASOKE 17630 kc (day) o a. TOKYO Transmission #1 u 4175, 8350 kc (night) Z 8350. 12525, 16700 kc (day) TOKYO Transmission #2 39,4630, 9260 kc (night) Continuously Unknown (TOKYO) NIMINE 39,9260. 13890, 18520 LamotrelO" kc (day) TOKYO Regular Trans a mission 3995 kc, 7990 kc z (night) 7990. 12935, 18155 kc UJ (day) Z Enderby M _j 3795 kc (night) TRUK Continuously TRUK - 15kw (TRUK) KO SEMO (WOLEAI) (Puluwat) 6625 kc (day) Others when Other s - NI"SOHI (ROTA) HInREMI o necessary 1 kw-1.5 kw (PONAPE) ROnYAHA (ENDERBY) HO"RIYA oc (PAGAN) FUMSEI (MORTLOCK) NUWKOTSU (LAMOTREK) Palau MUWCHIN. 3860 kc (night) TRUK Continuously TRUK - 1.5 - (TRUK) KO"SEMO (WAKE) 9720 kc (day) Others when 3 kw; Others NOnWANI (WOTJE) HO"INA t)Mortlock necessary 1 kw-1.5 kw. (OCEAN) FUnIMU (RABAUL) IMMISU (JALUIT) SHIMHOSU (MILI) TE"SOME (KUSAIE) Rabaul Z CHIWYOU (PALAU) NAMMIKE (MALEOLAP) NIMSAMI (NAURU) M o SHI KORU. CO LU 4282.5 kc (night) Beginning of TRUK-1.5 kw (TRUK) KO"SEMO CO 8565 kc (day) every hour Z ui a UI CO FIGURE NO. 40 UJ Z PACIFIC AREA RADIO SYSTEM (NAVY) 91 o Picture No. 243 (PM 308) ENTRANCE TO UMAN TRANSMITTING Picture No. 244 (PM 309) ANTENNA VENTS IN SIDE OF CAVE, Picture No. 245 (PM 310) TRANSMITTING ANTENNA INSTAL STATION. UMAN Trins. Station. LATIONS: UMAN Trars. Station. Other Islands; In addition to the main radio installations described above, questioning, and the communication officers professed to know nothing of radio o the Navy maintained radio communication to numerous other islands in the atoll. intelligence work, nothing could be learned about the activities of the group. This included communication with radar stations, lookout stations, battery positions, z etc. (see Figure 41). Practically all of these minor stations were equipped with RADIO DIRECTION FINDING. Type TM mobile equipment. It appeared that very little, if any, light portable equipment was employed by the Navy. A rather extensive Radio Direction Finding system had been installed on ULALU, but had been almost completely destroyed in the bombing attacks on 30 April and 1 Radio Antennae: In general, the Japanese antenna construction was poor. No May, 1944. The only Installation left, was one short-wave D/F building containing coaxial cable was employed for transmission lines. Transmitting antennae entered a Type 93, Modification 1, short-wave battery operated direction finder. The Jap z dugouts by means of rubber insulated wire passing through pipes, or bare wire passing anese stated that the original installation consisted of twc medium frequency D/Fs through silts in the ground. The construction of receiving antennae was also poor. and three HF D/F equipments had been sent to Saipan, and little could be learned CO Virtually all of them consisted of a straight length of wire extended to some conven of the activities carried out by them. The Navy Signal officer stated definitely a ient length. In many cases a number of receivers operated off the same antenna. that the three HF D/F stations were operated simultaneously and an average taken z of the bearings obtained. Communication with ULALU was maintained by telephone RADIO COUNTERMEASURES. and radio. CO There was no evidence of any definite countermeasures plans. No special equip- WIRE. LU ment intended for Jamming radio circuits was found. Z Telephone: An extensive telephone system connected all of the major install - I RADIO ations on the atoll (see Figure 4l). Both common-battery and local battery systems were employed. Submarine, subterranean and aerial cable were employed, as well as o According to the Japanese, when the radio intelligence group at KWAJALEIN was single conductor (ground return) lines for locals. The system appeared to be annihilated in January, 1944 a specially formed group, attached to the fleet, oper fairly adequate to meet the defensive requirements of the atoll, but was in poor ated at TRUK from February, 1944 until April, 1944. They supposedly moved to condition generally at the time of the inspection. This poor state was due in part SAIPAN about the middle of April and were annihilated when SAIPAN was captured. to damage from bombardment, and in part to neglect after the surrender. The Jap At this time transportation of personnel to and from JAPAN was virtually Impossible, anese expected almost complete failure of the wire system in case of attack, and o so no replacement personnel and equipment could be sent to TRUK, and radio intelli provisions for communication by radio or other means to important installations gence activity ceased. Since none oX the original personnel were available for had been made. Z o to z LU Ul Z Picture No. 246 (PM 541) DIRECTION FINDER BUILDING. Picture No. 247 (PM 53*) TYPE 93 SHORT WAVE DIRECTION Picture No. 248 (PM 539) TYPE 93. SHORT WAVE DIRECTION ULALU. FINDER INSTALLATION: ULALU. FINDER: Modif. i, ULALU, showing raised platform. 92 19 Pr ISLAND en z LEQEND Submarine Cable Bvrle* Coble Aerial Coble OQ Seole i:It5t OOO FIGURE 41 o a. COMMUNICATIONS CABLE. INSTALLATIONS Z TRUK ATOLL z To Maen Is. CO a To Param I*. z Navat O Navy Air Torptdo Bomber Unit Z o CO Ul CO CO Ul z th Naval Constru&ion & Repair Unit O LEGEND Cable - , Rubber Covered Wire, Underwater Cable, To Eton Is Switchboard Termol tQ To Uman Is To Fefon Is FIGURE NO. 42 NAVY TELEPHONE SYSTEM DUBLON ISLAND 93 SIGNAL COMMUNICATIONS o I RADAR. The third type of ground-installed air search radar employed was the "Temp orarily designated Type 3, Mark 1, Radar, Model 3". Four installations of this Ground Radar Installations; In all, nine air search radar installations were type were made. The transmitter, receiver, indicator, and power supplies were employed on TRUK Atoll. These installations were divided among three of the main placed in caves or dug-in concrete structures. Leading from the transmitter chassis islands, MOEN, UMAN, and POLLE as indicated by Figure 43. The radars were of three were two-wire transmission lines to the antenna post which was mounted so that all types. The largest and most successful of these equipments was the Type 2, Mark 1, or at least half extended above the ground surface. (See picture No. 263). The Model 1, Modification 2, Search Radar, of which type there were four installations. antenna consisted of a lattice-work mast, triangular in cross section and 10" on a Z This radar Is apparently a modification of the Attu type radar (Mark 1, Model 1, side, made of wood members. This vertical ma6t was placed on a rotable mount thrust Modification 1, Electric wave detector). The receiver and indicator are apparently bearing at the base and held vertical by a guyed bearing ring about half way up the of identical design to the Attu type, while the transmitter case configuration mast. Above the bearing ring were four wooden cross bars, one above the other, on differs somewhat in design. A two-tube tuned-line oscillator acts as the RF source. which were mounted an array of four horizontally polarized dipoles, each with a Z> Peak power output is 30kw. Transmitter and antenna are mounted in a wooden shack dipole parasitic reflector. Thus the entire array was rotatable, its position being ax on a turntable, the antenna being mounted on one face of the transmitter shack. determined by a pulley at the bottom of the pole, over which passed a cable leading The turntable is continuously rotated by an electric motor drive, or may be manually to a drum at the operator's position in the cave. This drum had a few turns of positioned by the operator. The antenna consisted of a four dipole array, vertically cable passed over it and had a four-spoke handwheel for turning it, in addition to o arrayed with horizontal dipoles for transmitting, and essentially a twelve-dipole a bearing circle and wand. Parallel wire transmission line led from the transmitter a. array, four vertical sets of three dipoles each, horizontally polarized for receiving. to the guyed antenna support ring. From there a large unsupported fold of the par (See picture No. 252). The entire array was backed by a mattress reflector measuring allel wire transmission line led to insulators on the antenna pole and thence to z approximately 30' X 18'. No duplexer was used. The antenna was fed by parallel wire the array. Thus 360° continuous rotation was impossible. Also attached to the transmission lines. The frequency was given by the Japanese as 100M.C. 0;5M.C. Insulators on the guyed support ring was 2', unsupported, shorted, stub tuner with From the close resemblance of this radar to the Attu type It is likely that its a twisted wire shorting bar. other electrical characteristics are similar. These equipments had a remote bearing transmitter Installed in conjunction with the bearing control wheel. This was to The transmitter employed a 150 Me tuned line oscillator with two T-310 tubes. transmit bearing Information by electrical means to a remote bearing repeater. The The peak power was rated at lOkw. The pulse length according to the Japanese was remote repeaters had never been received. 10 micro-seconds and the pulse repetition rate was 500 pulses per second. A duplexer CO was used for the protection of the receiver. This consisted of a gas discharge tube Q The equipment was of good construction, being solidly built and of clean appear in which were placed two spark gap electrodes. The tube was simply mounted on a Z ance, without excessive exterior cabling. Attention had been given to operator com board and connected to the transmitter by means of a short length of transmission fort, the shack being roomy and well ventilated. The receiver and indicator equip line. To the same connections on the duplexer mounting board, the receiver Input ment was convlently placed on a desk at which the operator sat. No attempt at cable was attached. This cable was not coaxial but a parallel wire pair covered with CO water-proofing or fungus protection was observed. All four radars were in operating rubber and a metallic mesh shield. The receiver and indicator appeared to be of condition when the Japanese surrendered on TRUK, but have not been operated since. highly conventional type. The duplexer was considered a new development, although The performance of these radars has been reported to be good by all Japanese question it had been developed as early as February 1943, according to one Japanese technician. ed. The best range the Japanese had observed was 175 miles on a large plane. Little o loss of service from trouble was experienced. The construction of the entire radar was poor, particularly the antenna instal lations. The bearing errors were very large both due to the vertical character of a: The second type of these equipments was the Type 2, Mark 1, Model 2, Search the antenna array and to the crude antenna rotation mechanism. It was also a con Radar. Only one installation of this equipment was made. This radar was very siderable handicap not to be able to rotate the antenna through 360°. The perfor similar in many respects to the type 2, Mark 1, Model 1, Modification 2. The chief mance of equipment was poor and below the expectations of the Japanese. They had differences lay in the frequency of the transmitter, the antenna configuration, and been told that the equipment would have a range of 186 miles, but got about 62 miles O the fact that it is a mobile unit. The appearance of the two types of radar is as their best range. The performance became much poorer in deimp weather. Moisture very similar, the antenna being mounted on the operators shack. This shack, however-, proofing or fungus protection was lacking. These radars were allegedly designed to 5c forms the body of the trailer and is rotary mounted on the eight-tired chassis. The be transported by plane if necessary.# Thus the elimination of many desirable features rotation control, the interior plan of the shack, and the receiver and indicator In the interest of light weight, might be explained. There is also the supposition units of the Installation are all identical to the fixed Type 2, Mark 1, Model 1, that the inefficient antenna design was dictated by the desire to mount these radars Modification 2, radar, except for the slight change in the receiver due to the change in caves for protection, realizing that it would be impossible to adequately shelter Z in frequency. The transmitter is smaller with a peak power-output of 5kw. The the larger types. All four of these equipments were considered to be in operating o transmitter frequency range is 187M.C. to 212M.C. The transmitter employed a line- condition although they had not been used since the surrender. CO tuned oscillator using two T-310 tubes. The antenna consists of two identical mod Ul ified Sterba arrays mounted one above the other, the upper for transmitting and the CO lower for receiving. No duplexer is used. This equipment is also well constructed Z and gave good service. No fungus protection or moisture protection was observed. Other Radars: In addition to the land based air search radars, four additional The equipment was considered operative although It had not been in actual use for radars were found in a store room at the DUBLON seaplane base. These radars were some xime. The performance of this radar was not up to Japanese expectations, and Type 3, Aircraft, Mark 6, Model 4, and allegedly had been Installed in three-place Ul they attributed the short range to antenna trouble which they had not been able Zero float planes. No other radars aside from those previously mentioned were used CO to locate. Actual observed range on a large plane was 37 miles, but they had ex on TRUK. No fire control radars of any kind were found to have been used and no UJ pected performance more like the Type 2, Mark 1, Model 1, Modification 2, Radar. countermeasures equipment was found. Z 94 SIGNAL COMMUNICATIONS MOEN Island Installations: MOEN was the site of three radar installations, all extra pieces of equipment in the photographs. Power for this installation was fur in the same locality. Radar No. 1, a Type 2, Mark 1, Model 1, Modification 2, was nished entirely from a 6 KVA gasoline-driven generator located in a small cave Just the first radar installed on this island. It was placed on the crest of Mt. TAKEUN over the side of the saddleback. The performance of this radar was considered fair at an elevation of 8891• See maps in PART TWO, The coverage from this location was and free from breakdown. Coverage was from 309° to 175°. Maximum range, however, good from 314° to 175°. (See figure No. 43). Japanese radar siting practice places was only 37 miles. The radar was Installed during February and March of 1944, but all search radars on the highest peaks available, in order to afford nearly 360° was left in reserve after Radar No. 3 was installed in September 1944. I coverage for each radar. The summit of Mt. TEROKEN, however, was Inaccessible due to the nearly vertical slopes, while the crest of Mt. TAKEUN could be reached by a The last radar to be installed on MOEN (Sept. 1944) is designated as Radar No. KJ long saddle back from the eastern tip of MOEN. Power for this installation was gen 3. It was a Type 3, Mark 1, Model 3, radar and was located about 100 yards south erally supplied from the main generating plant for the MOEN Naval radio station, but east of Radar No. 1, over the edge of the saddleback, as shown by Picture No. 249. < In a shed 401 west of the radar was a 6 KVA gasoline engine driven generator used The transmitter, receiver, Indicator, and associated equipment were located in a 2 as a stand by. Power was fed to the radar from both power sources by armored cable cave. Due to the location of this radar, the coverage was from 084° to 175° only. laid on top of the ground. The performance of this radar was considered good; an Power to this installation came from the main MOEN Naval radio power station, but extreme range of 175 miles was claimed. in case of failure could be supplied by the 1 KVA mobile gasoline generator stored in the same cave. Extreme range on this installation was alleged to be 62 miles. The next radar to be installed on MOEN is designated as Radar No. 2. This is Radar No. 1, (the first to be installed), was operated three hours on, and the Type 2, Mark 1, Model 2, Trailer-mounted Radar. (See picture No. 251). This three hours off until Radar No. 2 was installed. After the installation of No. 2, Installation was located about 400 yards from the crest of Mt. TAKEUN in a northeast a full 24-hour coverage was maintained by watches of three hours each by Radars erly direction (See maps in PART TWO) on a small promontory of the saddleback. The No. 1 and No. 2. At the time Radar No. 3 was installed, Radar No. 2 was not used 8-wheeled chassis was well emplaced in a drained, low-walled, earthen emplacement. further, but left as a stand-by, while the 24-hour coverage was maintained between Spare parts for this equipment had been placed in the trailer, accounting for the Radar8 No. 1 and No. 3, o o. KJ z Z CO Z -J CO UJ Z - i o Picture No. 249 (PM 172) SITES OF RADAR MO. 1 & RADAR Picture Mo. 250 (PM 179) RADAR MO. 1: MOEM, Type 2, Picture Mo. 251 (PM 181) RADAR MO. 2; MOEM, SJtoving HO. 3: MOEN, as seen from Radar Mo. 2. Mark 1, Model 1, Mod if icat ion 1. site from Radar Mo. 1. z o CO LU CO Z Z < Picture Mo. 252 (PM 166) AMTEMMA & TRAILER OF RADAR MO. Picture Mo. 253 (PM 170) RIGHT HAMD INTERIOR OF RADAR Picture Mo. 254 (PM 168) INTERI.OR OF TRAILER OF RADAR 2: Type 2. Mark 1, Model 2, MOEM. MO. 2: MOEM. MO. 2: Type 2, Mark 1. Model 2, MOEM. Showing bear ing dial and bearing repeater dial. i 95 SIGNAL COMMUNICATIONS o o I 2 in ca O z u Z 0 Picture tfo. 255 (PM 171) TRANSMITTER OF RADAR NO. 2 : Picture No. 256 (PM 169) LOWER RIGHT INTERIOR OF Picture No. 257 (PM 167) INTERIOR OF TRAILER OF RADAR Type 2, Mark 1, Model 2, MOEN. Q TRAILER OF RADAR NO. 2: Type 2, Mark 1, Model 2, NO. 2: Type 2, Mark 1, Model 2, MOEN. MOEN. Showing spare units. Z — zUJ o_ i o z o CO ui CO z UI z a. < Picture No. 258 (PM 173) VIEW FROM REAR\K UtOF VAVHCAVE, RADAR Picture No. 259 fP# 175; TRANSMITTER OF RADAR NO 3 Picture No. 260 (PM 177) CAVE ENTRANCE, RADAR NO. 3: NO. 3: MOEN, showing bearing control whee I ,^ec,_w:e 96 SIGNAL COMMUNICATIONS UMAH IBland Installations; UMAN had four radar Installations, all located on The Installation designated as Radar No. 4 was also a Type 3, Mark 1, Model 3, the broaa crest of Mt. URORAS, at an elevation of 9581 • The radars designated as and located Just over the east brow of Mt. URORAS. See map for exact location, Radars No* 1 and No. 2 were located on slight promontories at opposite ends of this This radar was housed in a concrete dug-out, the entrance to which is shown in mountain top; Radar No. 1 being on the west end and Radar No. 2 on the east end. Picture No. 265. The concrete shelter entrance was well protected and the shelter (See pictures Nos. 861 & 262). Both radars were Type 2, Mark 1, Model 1, Modifica- was made very solidly The antenna protruded through the shelter roof, up a shaft, tion 2. The performance of these radars compared very well with that of the same and above the ground surface. The coverage was from 000° to 225°. Power for this type on MOEN. Coverage was good for high flying planes for 360° for both radars, installation was also furnished by the main UMAN Naval radio station. and good for all planes In the sectors from OCX)0 to 275° and from 280° to 319°. Power was furnished to these Installations from the UMAN Naval radio station gener 2 ators at 3300 volts AC* This was transmitted by an armored cable laid along the ground. An 8 KVA gasoline generator and a 6 KVA gasoline generator were used as standbye. The Installation designated as Radar No. 3 was a Type 3, Mark 1, Model 3, and located In the center of the crest. The transmitter was housed In a concrete dug-out shelter, the entrance of which had been blocked by debris during an ex ceptionally heavy rain and so was not available to Inspection. The antenna protruded from the ground surface through the dug-out roof. (See picture No. 263). Power was furnished to this Installation from the main UMAN Naval Radio station power plant, although three 1 KVA generators were available as emergency power. z z to O z -I to ui Z Picture Mo. 263 (PM 301) ANTENNA OF RADAR NO. 3- Type 3 - i Mark 1, Model 3, UMAN. o at Picture No. 261 (PM 298) RADAR NO. 1: UMAN, Type 2, Mark O 1, Model 1, Modification 2. z O CO LU CO Z Picture No. 262 (PM 297) RADAR NO. 2: UMAN, Type 2, Mark 1, Model 1, Modificat ion 2. CO Picture No. 264 (PM 299) ANTENNA OF RADAR NO. 4: Type 3 Picture No. 265 (PM 300) CONCRETE SHELTER ENTRANCE Mark 1, Model 3, showing dugout entrance to right. RADAR NO. 4 UMAN. OMAN. 97 SIGNAL COMMUNICATIONS There were two radar installations on POLLE, both fair but alleged to be very poor during wet weather. Coverage was from 134° to located on the western end of the main island ridge* The installation designated as 003°, The cave had communications with a signal hut further up the ridge by voice Radar No. 1 was a Type 2, Mark 1, Model 1, Modification 2* It was looated on the tube and telephone. The equipment was installed during November 1944 to February ridge at an elevation of 295*• For exact locations see map* It was discovered upon 1945. Power for this Installation also came from the two 15 KVA diesel AC gener visiting the site that the map contours were slightly inaccurate* In locating the ators. Two 1 KVA mobile gasoline generators were available for standby. o radars on the map, the relation to contours shown has been considered of first impor tance. This will make slight errors in the location of the radars with respect to I the island coordinates* Radar No* 1 was mounted on a truncated earthern pyramid lo1 SUMMARY. a: in height and had a coverage of from 116° to 006°* Neither POLLE radar installation was made on the highest point on the island which rises to 679'. Apparently the sum The intention of the Japanese in siting the TRUK Atoll radars was to cover by mit of Mt. TUMUITOL on TOL, which rises to 1,422', was considered completely inaccess sectors all aircraft approaches. In order to best accomplish this, the Type 2, Mark ible* For that reason the POLLE radars both had coverage In a very limited sector. 1, Model 1, Modification 2 radars were originally installed. See radar coverage map The installation was well made and performed comparably to other installations of the for coverage of these radars. In addition it was also considered desirab\« to site same type. The radar was Installed June to November of 1943 and was hit by strafing this type of radar so as to give as near 360° coverage as possible on high flying in April 1944* The damage was not great, however, and the equipment was soon placed planes if other radars went out of action. However, the sites were also chosen for in operative condition. Power to the installation was furnished from two 15 KVA reasons of accessability, and this led to poor coverage from POLLE.. As can be seen diesel generators, and a 6 KVA gasoline generator vra6 held as a standby. from the radar coverage map, the atoll is left without adequate coverage in the z sector northwest from the center of the group. The MOEN and POLLE coverage limit The radar designated as Radar No, 2 was a Type 3, Mark 1, Model 3. This eventually intersect at a distance from MOEN of 40,000 yards but at this distance LU installation was located farther up the same ridge at an elevation of 3441. The only high-flying planes would be picked up due to the elevation of the major lobe. transmitter was installed in a concrete lined cave approached by a 301 slit trench. A low-flying plane would remain undetected. (See Picture No. 268). The antenna projected through the roof of the cave, up a shaft, and above the ground surface. The performance of this radar was considered o uCL z v Z CO Q Z CO UJ Z O Picture No. 266 (PM 533) RADAR NO. POLLE Picture No. 267 (PM 534) INTERIOR OF RADAR NO. 2: Picture No. 268 (PM 535) RADAR NO. 2: POLLE. Shouting POLLE. Showing transmitter, indicator, and bearing entrance to concrete equipment shelter. indicator. Z o CO UJ CO Z CO Ui z Picture kw HIGH FREQUENCY TRANS- Picture No. 270 (PM 30s) ARMY MOBILE RADIO: Type 94 Picture No. 271 (PM 545) ARMY 50-LINE SVITCMBOARD Type HITTER: DUBLON. Mark 3A - UMAN Army Headquarters. 99. DUBLON. 98 Mt. Takeun 889* o I a: 2 Mt. Teroken 1,214' CO Z i— LU =5 OQ o a. z CO Mt.Tumuitol O 1,483' Z —I CO UJ Z o Radar No. 4 Radars No. 1,2,3 Mt. Uroras 958' O Z o CO UJ CO Z \ \ CO UJ \ Z LEGEND COVERAGE LIMIT LINES \ \ Type 2,Mark I, Model 2, Coverage Limit. FIGURE NO. 4 3 Type 2?Markl9 Model 2 Coverage Limit. RADAR COVERAGE DIAGRAM ON TRUK ATOLL Type 35 Mark i, Model 3, Coverage Limit. SIGNAL COMMUNICATIONS When the danger of attack became great, it is assumed that another type of radar 3 to 6 months. Several relatively sample substitutions codes or ciphers of local was thought desirable due to the difficulty of adequately concealing and sheltering composition were available, but were only Intended for use in actual combat. These the large type radar. It is thought that the Type 3, Mark 1, Model 3 radars were were Intended to change daily. Since direct contact with Japan virtually ceased supplied for this reason. This is Indicated in part by the fact that these equip after February, 1944 it was impossible to obtain replacement strategic and tactical ments were always last to be installed on each island. All radars were under the code books after that time. Evidently few if any, "Reserve on board" codes were O control of the Navy and word of the approach of aircraft was communicated to Fleet Headquarters, DUBLON. This communication was accomplished by telephone generally, held. I but radio communication was available in case of telephone failure. According to AIR GROUND COMMUNICATIONS. Japanese information the individual island radars operated in watches, but at all times until July 1945 there were three radars in operation. After July 1945 only Since all airfields and seaplane bases had been bombed almost out of existence, one radar was in operation at a time. most of the installations had been completely destroyed. Such installations as were found have been discussed under "Radio". The Japanese had planned the Installation POWER EQUIPMENT. of an aircraft beacon station on the eastern tip of MOEN, but one part of the equip ment failed to arrive and it could not be installed. Presumably the equipment that Most of the power equipment on the atoll consisted of dlesel-driven AC and DC did arrive was later destroyed in a bombing attack. No other type of aircraft generators of good design and in good condition. Power for all the communication beacons or homing equipment was on the island according to the Japanese. installations appeared to be quite adequate, and at every major installation, auxil METEORLOGICAL STATIONS. z liary equipment was provided. In almost every case, the installations were well protected and concealed. As long as fuel for the diesel and auxllliary gasoline- The main Navy Weather Center was located on DUBLON. According to the Japanese UJ driven equipments was available, It is not considered likely that any power shortage _ i it was completely destroyed by bombing. This weather central handled or controlled _ i would occur. all weather activities for the entire South PACIFIC. An air force weather unit known z> as "Eastern CAROLINES Air Group Weather Unit" was located on MOEN and was solely VISUAL. concerned with aircraft weather reports. The following chart shows the organization and general duties of these two meteorlogical activities. o Eleven Navy Visual and Lookout Stations were located on TRUK. All served the dual functions of a visual signalling agency, plus the function of air and surface 4TH WEATHER UNIT. V lookout stations. In addition, those located near radar groups, served in an ad Z ditional capacity as Radar Warning Stations. Supposedly, these stations received SECTION PERSONNEL ATTACHED RESPONSIBILITY DETAILED DUTIES AVIATION WEATHER reports from the various radars in the immediate vicinity, evaluated the individual reports and forwarded the information direct to Naval HQ on DUBLON. Telephone was Clerical P.O. 1 Preparation of Monthly weather Aerial weather normally used for these reports, but radio was available in case of failure of the group Junior Tech- weather infor reports. maps of Inner wire lines. The following is a list of these stations: nician 1 mation. Yearly weather S. Seas, Outer 1 Gunzoku (Civi reports. S. Seas and Far No. 1 - MOEN Radar Warning Station. 886 elev. lian employee) 1 Far East wea- East. No. 2 - MOEN No. 1 Lookout Station. 1,200' elev. 1 ther chart. CO No. 5 - DUBLON No. 2 Lookout Station. 770 elev. S. Pacific Q No. 4 - DUBLON No. 3 Lookout Station. 1,200* elev. weather chart. Z No. 5 - DUBLON No. 1 Lookout Station. 511* elev. No. 6 - UMAN Radar Warning Station. 950• elev. Weather Officers 1 Sending and Transmitting Transmitting No. 7 - FEFAN Lookout Station. 900• elev. CO forecast P.O. 3 receiving wea scheduled wea stratosphere No. 8 - FALEU Lookout Station. 35* elev. section Junior Tech ther reports. ther reports weather report No. 9 - TOL Lookout Station. 1,530' elev nician 1 for Inner S. to Inner S.Seas No.10 - POLLE Radar Warning Station 656f elev. 1 Gunzoku (Civi- Seas area 6 twice daily. No.11 - PARAM Lookout Station. 180 elev. lian employee) 10 times daily. Transmitting O Weather warn- aircraft wea £2 The equipment of these stations was very nearly the same for all stations and ing reports tra- ther report consisted essentially of the following: nsmitted to for S. Seas Inner S. Seas 6 10 times dally. Binoculars, 12cm times dally. Binoculars, 8cm Receiving wea Binoculars, 7 Power ther reports Signal light, 30cm for Central and Signal light, Type A Outer S.Seas 3 Very Pistol times dally. Very Pistol Shells z Signal Flags Hydrogen P.O. 1 Making Hydro- Semaphore Flags generator Enlisted men gen for wea o Horn (Or Siren) 1 CO section Gunzoku (Civi- ther balloons. UJ lian employee) 3 CO PIGEONS. Z EASTERN CAROLINES AIR GROUP WEATHER UNIT. UJ The naval forces had a relatively small number of pigeons (49) based in a loft u. at the headquarters of the 41st Naval Guard Force. These were Intended for use in emergency communications, but according to the Japanese were never used except for SECTION PERSONNEL ATTACHED RESPONSIBILITY DETAILED DUTIES AVIATION WEATHER Ul occasional homing practice. Q MOEN P.O. 3 Receiving aer- Receiving sche- UJ Receiving aer- CO CODES AND CIPHERS. Island Enlisted men 2 ial navigation duled weather ial weather re- base. weather reports. reports for ports Inner S. All Naval Codes and Ciphers had been destroyed. Most of them were destroyed Seaplane P.O. 3 Inner S. Seas SeaB 10 times in June, 1945 when an English Naval Task Force bombarded the atoll. The remainder base. Enlisted men 1 6 times dally. daily. were destroyed when the surrender was announced. According to a coding officer they Receiving wea- Receiving upper employed a strategic code consisting of numerical groups, with additive tables for ther reports layer weather additional'security. This code was supposedly changed once or twice a year. A for central report twice tactical code (for the use of ships) employing four Kana character groups was used, area 3 times daily. and changed every 3 to 6 months. Another tactical code (for use with planes) em dally. Flight observa ploying two or three Kana character groups was uaed, and this code also changed every tions once per day. 100 SIGNAL COMMUNICATIONS Army Radio Equipment - DUBLON. No replenishment supplies of any kind had been received at TRUK since August, 1944 according to the Japanese,, As a result there existed a general shortage of 51st virtually all expendable supplies. The most serious shortages as far ac Navel UNIT1 3IG, INF TRANSP INDPT 111th TOTAL Communications was concerned, was on radio tubes, dry batteries and battery acid. UNIT REC- These shortages had not seriously handicapped communications up to the date of sur 1-KW SW Transmitter I render but were becoming more and more severe. TRUK acted as a Central Fleet 500K'.J Sw Transmitter 1 < Supply source for the entire South PACIFIC, all supplies coming direct from JAPAN TM SW Mobile Wireless Set 1 and being redistributed from TRUKC Fleet repairs were also made., and it appeared Truck Mounted Wireless 3et \3) 3 that the base was well prepared to do all types of repair work. No doubt che pre Truck Mounted Wire 3ss Bet (0) 3 sence of skilled repairmen and replacement materials accounted for the fact that Smallcraft Wirelesb I TRUK radars and other com.T.unication installations gave better performance than -was Land Mk 4 Wireless 2 apparent in other locations. Type 91 Special Mk 4 Wireless Set 2. Type 94 Mk3-A Wireless Set 12 3 15 Type 94 Mk3-c Wireless 2 1 3 ARMY COMMUNICATIONS. Type 94 2% 5 Wireless 3 15 11 33 hti Type 94 Mk 6 Wireless 10 12 20 52 General: The Army communication system on TRUK was almost entirely subordinate Division Cornm Units Secondary 12 12 to the Navy, and consists principally of tactical installations. While not directly Receiver under Navy control, they were obliged to depend on the Navy for much of their as supplies. A lack of cooperation between the two was apparent, and with the Navy MOEN dominating the overall picture, it followed that the Army played a very subordinate o role. The Army headquarters was located on DUBLON and most of their communications UNIT 150th INF.REG. 51st 1MB COMM UNIT TOTAL a. Installations were in the vicinity of the headquarters. The communication systems Type 94 Mk 3-A Wireless 2 1 3 Z on the other islands of the atoll were of a purely tactical nature intended to serve Type 94 Mk 3-c Wireless 1 1 the units defending each island. Type 95 Mk 5 Wireless 12 1 13 \J Type 94 Mk 6 Wireless 8 8 Organization: The Army Signal Organization on TRUK is shown in the following a. tables: FEFAN Z 31st Army Communication Unit. UNIT 51st 1MB 11th IMh COMM UNIT TOTAL Type 94 Mk 3-A Wireless 1 1 1 First Lieutenant Type 94 Mk 5 Wireless 3 1 4 2 NCO's Type 94 Mk 6 Wireless 6 6 a 8 Privates 10 Gunzoku (Civilian employees) UMAN z CO UNIT 69th INF.REG. COMM UNIT TOTAL 52nd Division Communication Unit. Type 94 Mk 3-A Wireless 1 1 UNIT HQ TELEPHONE TELEPHONE RADIO RADIO SUPPLY & TOTAL S. TOL RANK 1st Plat. 2nd Plat. lstPlat 2ndPlat REPAIR o UNIT 51st 1MB COMM UNIT TOTAL Major 1 1 Type 94 Mk 3-A 4 2 6 < Captain 1 1 2 Type 94 Mk 5 Wireless 16 1 17 1st Lt 1 1 1 3 Type 94 Mk 6 Wireless 10 10 2nd Lt Div Comm Unit use Sunday Receivers 1 1 wo 1 1 MTSgt 4 4 N. TOL Sgt(Cpl) 3 5 5 9 2 1 25 Pvtc 16 29 30 74 24 22 195 UNIT 51st 1MB 58th ANCHORAGE UNIT TOTAL Att. Civilians 3 3 Type 94 Mk 5 Wireless 2 2 cc TOTAL 26 35 36 84 30 23 234 Type 94 Mk 6 Wireless 4 4 I— Z RADIO. UDOT o General: The Army depended primarily on the Navy for the handling of most of UNIT 51st 1MB TOTAL CO LU their radio traffic outside the atoll. They were included In an Army radio net which Type 94 Mk 6 Wireless 3 3 CO covered a large area of the Pacific, (shown in Figures Nos. 40 & 44) but apparently Z most of their traffic to and from Army Headquarters, Tokyo was passed by the Navy. POLLE ai In the main Army radio station on DUBLON they had one lkw high frequency transmitter and one 500 watt high frequency transmitter. According to the Army signal officer UNIT 51st 1MB TOTAL these transmitters were not military equipment, but were civilian equipment that had Type 94 Mk 6 Wireless 3 3 CO been turned over to the Navy and in turn given to the Array. Inspection of these UI transmitters indicated that they were of rather conventional design and construction. PARAM The following tables show the types of radios installed on the various islands and z the general characteristics of each equipment. Due to an acute shortage of dry UNIT 51st 1MB TOTAL Qu batteries for the portable equipment, lt is not believed that the Army tactical radio Type 94 Mk 5 Wireless 1 1 system could have operated efficiently for very long. Type 94 Mk 6 Wireless 4 4 r ji ~ 1 ; 101 SIGNAL COMMUNICATIONS CHARACTERISTICS OF ARMY RADIO EQUIPMENT o o RECEIVER I TRANSMITTER a: FREQUENCY SOURCE FREQUENCY SOURCE MANUFAC TYPE RANGE OUTPUT RANGE METHOD TUBES USED OF POWER MANUFACTURER RANGE TYPE TUBES USED OF POWER TURER 5 1-UF109A Dry Bat Japan in Type 94 80 KM 10W 400 KC Oscillating 1-UY510B Manually Japan Signal 350 Kc Superhetro MK 3-A 5700 KC Radiation operated Co. 6000 Kc dyne 2-UF134 teries Signal Co. Wireless generator 1-UZ133D 500 - 7 V 1-UZ135 Type 94 Telegraph 10W 400 Kc Oscillating Manually Japan Signal 350 Kc Superhetro 1-UFlllA Dry Bat Japan • MK 3-C 60 Km 5700 Kc Radiation 2-UX202A operated Co. 6000 Kc dyne 1-UF109A teries Signal Co. Wireless Telephone 2-UY47B generator 2-UF134 40 Km 400 - 6 V 1-UY133A 1-UZ135 Type 94 Telegraph 3W 900 Kc Oscillating 1-UZ12C Manually Oki-Electric 800 Kc Autodyne 1-UF109A Dry Bat Okl-Elec =3 5700 Kc 1-UF134 OQ MK 5 40 Km 5700 Kc Radiation operated Co. teries tric Co. Wireless Telephone generator 1-UZ133D 20 Km 150 - 6 V o Type 94 Telegraph 0.5W 13 Me Oscillation 1-UZ30MC Manually Anritsu 13 Me Superhetro 1-UZ30MC Dry Bat Anritsu Q. MK 6 4 Km 35 Me operated 35 Me dyne teries Wireless Telephone generator 2 Km 135 - 3 V Vehicle Telegraph 20W 3500 Kc Oscillating 3-UY807A Storage Oki-Electric 3500 Kc Superhetro 9-UT6F7 Storage Oki-Elec Mounted 60 Km 5500 Kc Radiation Battery Co. 5500 Kc dyne Battery trlc Co. < Wireless Telephone 12 - 2 V B 40 Km Vehicle Telegraph 20W 20 Me Oscillating 2-UT6F7 Storage Oki-Electric 20 Me 'Superhetro 3-UT6F7 Storage Oki-Elec Mounted 20 Km 30 Me Radiation 2-UY807A Battery Co. 30 Me dyne Battery tric Co. Wireless Telephone 12 - 2 V CO C 10 Km Q Land MK 1500 Km 60W 4 Me Oscillating 4-UY807A Motor Futi Signal 4 Me Superhetro 9-UZ606 Motor Futl Sig Z 4 20 Me Radiation Generator Co. 20 Me dyne Generator nal Co. < Wireless 400 - 6 V CO 1 KW SW 4000 Km 1 Kw 4 Me Oscillating 2-UY47 220 V Japan Wire Ul Radio 20 Me Radiation 3-UX860 3 Phase Radio Co. Z crystal con 1-UV812 trolled type 2-UV861 8-XV972 o 2-UV221A < 1-KX80 ARMY RADIO EQUIPMENT RECEIVER TRANSMITTER FREQUENCY SOURCE FREQUENCY SOURCE MANUFAC Z TYPE RANGE OUTPUT RANGE METHOD TUBES USED OF POWER MANUFACTURER RANGE TYPE TUBES USED OF POWER TURER 500 W Oscillating 1-UY47 220 V Tokyo Elec o SW Radio 3000 Km 500W 4 Me Radiation 1-UV814 3 Phase tric CO 15 Me crystal con 1-UX860 IXl CO trolled type 1-UV861 Z 6-HV972 2-HX966 TM SW 1000 Km 250W 3500 Kc Oscillating 1-UX202A 220 V Tokyo Radio 3500 Kc Autodyne 2-UZ77 150 - 6V Tokyo Mobile 12000 Kc Radiation 1-UV814 single Co. 20000 Kc 2-UY37 DC Radio Co. vacuum tube 2-UV812 Phase CO Radio 1-UZ41 LU controlled 4-HX966 Z troe Type 91 3000 Km 1 Kw 100 Kc Self 1-SN205C 220 V Tokyo Radio 100 Kc Autodyne 500 V Tokyo Special 15000 Kc Oscillation 3 Phase Co. 15000 Kc 6 V DC Radio Co. MK 4 Wireless Wireless 200 Km 50 W 500 Kc Self 3-UY807A 2- 12 V Tokyo Radio 500 Kc Superhetro- 6-UT6F7 2- 12 V Tokyo A for 5700 Kc Oscillation 1-UT6F7 Storage Co. 15000 Kc dyne Storage Radio Co. small Battery Battery craft 102 SIGNAL COMMUNICATIONS RADIO COUNTERMEASURES. Type 92 Insulated Wire (sm) 40 8 48 Type 1 10 Circuit S\7itchboard 2 2 The Army Signal Officer maintained that they had no special equipment or any 25 Circuit Switchboard 1 1 plans for radio countermeasures. N. TOL RADIO INTELLIGENCE. UNIT 51st 1MB 58th ANCHORAGE TOTAL o The Army allegedly had no radio intelligence activities of any kind on TRUK. Type 92 Telephone 10 4 14 Type 92 Insulated Wire (sm) 38 5 43 I RADIO DIRECTION FINDERS. UDOT The Army had no radio direction finding equipment. UNIT 51st 1MB TOTAL WIRE: TELEPHONE. Type 92 Telephone 4 4 Type 92 Insulated Wire (sm) 2 2 All Army telephone equipment was local-battery equipment. Some of the switch boards were capable of operating into a common battery or automatic system. Part of the Army system on DUBLON employed underground lead-covered cable, but much of POLLE the system consisted of field wire overhead lines. On all Islands other than DUBLON, z the entire system consisted of field wire lines run overhead or laid on the ground. UNIT Rainstorms, plus the bombardment of the atoll had caused considerable damage to the Type 92 Telephone 5 5 LU lines, but supposedly they were able to repair them without undue delay. In case Type 92 Telephone Insulated Wire 2 2 of an actual landing on TRUK, with the pre-invasion shelling and bombing, the Army expected their telephone system to fail. Telephone communications between islands PARAM 00 was by means of pairs in the Navy cables that had been assigned for Army use. UNIT 51st 1MB O Type 92 Telephone 4 4 The Type 99, 50-line, cordless switchboard installed at Army Headquarters, 2 Q. DUBLON was of Interesting construction (See Picture No. 271). Fifty local-battery Type 92 Insulated Wire (sm) 2 line drops (in units of ten drops) were at the top of the board. Underneath these were 600 small plug-type switches (twelve rows of 50 each) that were operated by RADAR. being pulled out. One switch in each horizontal row was associated with each line, and by pulling out two or more switches in any row, the parties associated with the The Army had no radar equipment. z switches were connected. The board was limited to twelve simultaneous two-party calls, but the entire board could be set up as a conference call. Twelve super POWER EQUIPMENT. visory drops were located to the left of the board (one for each horizontal row of switches). In addition to the fifty local battery drops, six drops were located The Army had only one power plant that was employed primarily for cominunlcations, on the right side of the board for common-battery or automatic trunks. 72 switches and it was located in a cave near the main transmitting station on DUBLON. This was were associated with these drops in the same manner described above. While some a dlesel-driven, 220V, AC, 25 kw generator. Normally the Army radio station operated z on power from the Navy power plant (3300V AC) run in by underground cable to a trans what clumsy, the construction of this board was apparently fairly good. The board CO was entirely operative at the time of the survey and was being used. former vault near the station. The diesel generator was for emergency power primarily, Q but was used periodically to keep it operative. Most of the smaller Army equipment ZCO The following list of telephone equipment indicates the distribution to various operated from hand generators or dry batteries. islands. The diagram of DUBLON is shown as being typical of the installations on LU the other main islands. VISUAL. Z _» Army Telephone Equipment - DUBLON. The Army maintained visual stations on DUBLON, MOEN, UMAN, S. TOL and FEFAN. These stations were equipped with signal flags and blinker. Good communication was o maintained with all islands except S. TOL, which was too far away for good communi < DIV 69th SEA 9th 3rdBN 51st cation during the day. UNIT SIG. INF TRANSP INDPT 111th 1MB TOTAL UNIT REG UNIT ENGRS IMR PIGEONS. Type 92 Telephone 96 31 8 4 8 7 154 Type 92 Insulated Wire (sm) 250 60 16 18 12 20 376 The Army depended more on emergency communication by pigeon than the Navy. Type 93 12 Circuit Switchboard 1 2 Arrangements for this type of communication had been made from the Headquarters on Type 1 20 Circuit Switchboard 1 1 1 DUBLON to FEFAN, UMAN, MOEN, S. TOL and UDOT as well as to subordinate Army units Type 99 50 Circuit Switchboard 1 1 on DUBLON. Most of the pigeons were allegedly trained for round trip flights. cc MOEN CODES AND CIPHERS. Z UNIT 150th INF.REG. 51st 1MB COMM UNIT Most of the Army codes and ciphers were destroyed at the same time as those of o CO Type 92 Telephones 36 2 the Navy. However, one copy of Army Code No. 4 was retained on orders from Tokyo, LU Type 92 Insulated wires (sm) 16 20 15 and was being employed to decode messages received from Tokyo. According to the C/l Type 1 20 Circuits Switchboard 1 Army Signal Officer, no messages were sent from TRUK in code, and the only reason Z th2 code was being used was for reasons of brevity in transmitting long messages. LU FEFAN AIR-GROUND COMMUNICATIONS. LU CO UNIT 51st 1MB 11th IMR COMM UNIT LU Type 92 Telephono 12 4 8 The Army supposedly had no air-ground communications on TRUK. Type 92 Insulated wire (sm) 35 6 z Type 93, 12 Circuit Switchboard 1 METEORLOGICAL STATIONS. Q. UMAN The Army depended entirely on the Navy for meteorlogical information. UNIT 69th INF.REG. COMM UNIT SUPPLY AND REPAIR. Type 92 Telephone 5 1 Type 92 Insulated Wire (sm) 6 8 The Army supply situation was somewhat critical due in part to the isolation of TRUK and in part to the fact that they had to depend largely on the Navy for S. TOL supplies. Cooperation on the part of the Navy wa6 not apparent.in this respect, and as a result the Army had many critical shortages. Perhaps the most critical UNIT 51st 1MB COMM UNIT TOTAL shortages were, on the radio tubes and dry batteries. The Army depended on the Navy Type 92 Telephone 22 4 26 for major repairs to communication equipment. 103 SIGNAL COMMUNICATIONS Panape X oc 2 m Rabaul Z STATION FREQUENCIES CALLS SCHEDULES POWER oo TOKYO 14175 KCB. KE FU MU 0300 1 lew. o Mortlock 7077.5 KI U RE 0700 a. 0900 V 1100 Z 1300 1500 1700 Tokyo 1900 2100 2300 Z PAGAN 6053 KCB, MA SHI TO 0200 1 kw. 2000 CO Q 2400 Pagan Z ENJEBI 5203 KCB. MI KAU 0730 1200 CO 1500 Enjebi PALAU 12656 KCB. MA RA KI Standby MORTLOCK 5248 Kcs. MA KO E 0500 o 1000 2100 RABAUL 6400 KCB. WA KE E 0800 500 watts. 1400 O 2000 PONAPE 6018 KCB. SHI NI YU 0530 250 watts. 0700 1730 1900 z o CO LU CO Palau Z LU a LU CO LU z FIGURE NO. 4 4 PACIFIC AREA RADIO SYSTEM (ARMY) 104 r« fa •"*. & • * o o TO TOL ISLAND I Construction Battalion en z TO MOEN ISLAND RtgUatntol Supply ', O Anii-Aircraft CQ /•' ''^ P ' ^ ? Division Commond Undtr O ' ' ^ " " \ ReceivinrStation xConst Hrodquartcrs a. Z Trarisportatlon^.-*^\* *~ Undtr Construction a. */G«ntrol Z Eosttrn Branch \j Office CO Independent^ x yauarters Q Construction *^ Z CO LU Z Hospital^' _ l o esc < z o CO TO FEFAN LU ISLANO CO 4th / Rtfueling Z Construction / Pi«r LEGEND and'iRepair / Ordnonct Duty Unit Coble CO Seaplans s Rubber Covered Wire LU Base f Underwater Cable Switchboard Terminal Telephone TO UMAN ISLAND FIGURE 45 ARMY TELEPHONE SYSTEM DWBLON ISLAND r ^ 10 5 o JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1946 No 2 LOOKOUT /\J KJT. No I LOOKOUT No 2 LOOKOUT No 2 GUN BATTERY ARMY 4TH FLEET DUBLON I. ARMY UNITS DEFENSE HQ HQ FORCE HQ No I GUN BATTERY 85TH SUB BASE MESAGON I. GUN POSITION EAST CAROLINES DUBLON SEAPLANE 4IST GUARD BASE UNIT IMS 4TH COMMUNICATIONS JiiS UNIT NAVAL LANDING LEGEND FORCE UNITS TELEPHONE COMMUNICATION MESSENGERS 4TH ANCHORAGE VISUAL COMMUNICATION UNIT CARRIER PIGEON RADIO COMMUNICATION TRUK TRANSPORTATION UNIT 4TH SUPPLY UNIT NOTE: THE DEFENSIVE COMMUNICATIONS SYSTEM OF THIS ISLAND MAY BE 4TH CONSTRUCTION CONSIDERED AS REPRESENTATIVE UNIT OF THAT ON THE OTHER ISLANDS OF THE ATOLL 4TH ENGINEERS I04TH AIR ARSENAL 4TH NAVAL HOSPITAL 4TH NAVAL METEOROLOGICAL UNIT FIGURE 46 DUBLON ISLAND NAVY DEFENSIVE COMMUNICATION SYSTEM NAVAL ACTIVITIES GENERAL. boilers used to drive two water pumps and a 6KV D.C. generator. Time required to drain the drydock completely is 2^ hours. TRUK was primarily a naval base at the beginning of the war. The excellent har bor could provide anchorage for the entire Japanese fleet If necessary. It was the No dredging equipment was looated at TRUK. headquarters for the 4th Fleet until the units were sunk or were forced to retire to areas nearer JAPAN, Floating Cranei On December 15, 1945, a floating crane of 30 metric tons capa city was tied alongside of pier #1 at MOEN. This crane was operative and was being In early January, 1944, the army moved defense garrisons to the atoll and the used by the American occupation forces for unloading supplies. tactical purpose of the base changed from the offensive to the defensive. Construc tion was started on defensive positions and the naval units were assigned defense The main power plant consists of a 250 HP 6 cylinder dlesel engine driving missions. a 135 KW generator. The naval shore establishments were never extensive, with little repair facili Two 75 HP electric motors provide power for propulsion, and a 15 HP elec ties for large ships. The larger ships were fueled by tankers lying In the harbor or tric motor operates the anchor windlass. by oil barges from one oil pier on DUBLON. Two 30 HP and one 50 HP electric motors provide power for the cable drums After the fleet left TRUK and It was virtually out off from JAPAN the defense of the lifting unit. IU forces began Improvising defensive weapons. The one-man controlled torpedo and the torpedo-carrying landing craft were the main evidences of this activity. Mine fields The only other floating orane was a 20-metrio ton steel crane. This crane In the passes and Inside the atoll as well as small model beach defense mines were has no means of propulsion. considered the main defense weapon against Invasion. All passes were heavily mined except NORTH and SOUTH Passes, which were used by the Japanese. Controlled mines were located In NORTH Pass. O a. Naval Installations; See engineering report for location and description of naval construction, shore facilities, and naval barracks, Drydooks & Marine Bflijivflyflt The only marine railway at TRUK Is the MATSUSHIMA u Branch of the 4th Repair Depot located on the south side of DUBLON. The railway can handle ships up to 100 tons with winch equipment and cradle still usable. Several other slipways for smaller ships are located alongside the marine railway. They are Piers 8t Jetties; Fuel oil pier - One pier was found at TRUK. It Is located on Z of concrete with steel channel Irons laid down to slide the vessel out of water. A the south side of DUBLON. The pier Is 1,120* long X 10* wide rock Jetty with a 601 power winch Is Installed for the smaller ships. The oapaolty of each slip Is shown wide concrete end section. Two 10* oil lines ran to the head of the pier from oil on Figure No. 47, Page dl7. tanks located Just off the base of the pier. A 3" fresh water line also ran to the head of the pier, A destroyer could dock at the face of the pier, and according to z A marine railway was under construction on the west side of DUBLON, The Japanese information, ships as large as a cruiser could take oil from a floating oil concrete slab was laid but construction was then stopped. This marine railway was line off the end of this pier where there is deep water with no obstructions. The designed to handle ships up to 300 tons, position is shown on the map of DUBLON, (See PART TWO), A floating dry dock, 115 meters long X 14.7 meters wide which can be sunk The table following gives details on the more Important piers. They are 4.8 meters beyond Its normal displacement, Is located off the west side of DUBLON. numbered on the table with corresponding numbers appearing on the general maps of Tbie drydoek, the only one at TRUK, can accomodate a destroyer. It has two coal each island. o cc o Z o CO LU CO Z CO LU z Picture No. 272 I PH 9) DUBLON: Marine railway at MAT- itcture No. 273 (PH 193) FLOATING CRANE (30-TON) Picture No. 274 (PM 195) POVER PLANT FOR 30-TON FLOATING SUSHIMA repair depot. CRANE. 107 m to z < ' OF F OF PIER PIER AT MORE AT MORE AT END AT END OF AND OF •(' AND OF OF OR OR 1 1 1946. (FATHOMS) DEPTH ACCESSORIES CAPABLE TRAFFIC LENGTH 3 OUTER END APPROACH REMARKS WHEELED WITH DEPTH DIMENSIONS CONSTRUC BEARING TION (FATHOMS) REMARKS TYPE NAME NUMBER DEPTH APPROACH 3 ACCESSORIES C TRAFFI LENGTH H WITH DEPT END E CAPABL OUTER G BEARIN D WHEELE S DIMENSION TYPE CONSTRUC TION NAME NUMBER a CD O CD 3 H P o to X Ol o o o H 250 £ O O O 1 CD MARCH < CD H D 3 O ct ct 4 3 O 3 CD 3 C ^ CD CD COO H O P • CD CO CD cr Oi X 3 Ol o t-j CD ct o CO CD ,_, CO O CD ct 1^ CO H »-J o H £ H 15 O ctO 3 O O • d CO 3 CD »^ CD o 3 a CD Ol p< o CO o o o O O CD •-* p • • =»»* a H 5 o § p ct g ct Ol CD CD O 3 P» ct § 3 O O o d to 1 O •• to 1 - CD HJ CD Ol CO X Ol 3 CD H CO 3 HJ o K H a o o to oi ct 3 Pi O H to o 3 0 CD ct CD O 1—J o >• MQ H HJ •o et H- 3 i o OO t, Pi o o CD o Pi to CD »d H 3 CD CD a CD 3 Xo o CD K CO O OlO o OiH O 3 P {3^* ct CO o p> H pr p d o o ? o »d 3 CD O < 3 CO 3* 3* Pi o P P *1 O H h* CO Ol • ctO B Ol * O 1 3 CO HO I CO CO CO P Ol Ol 3 » ft° s; co ^^ o 00 o 50 p? o CO o P H- CD <* CD 3 oi CD 1 mm CD a Ol 3 CD CO O4 H $r o o a Ol a o O CD ct O ct ct ct CO CD O p H CD a CD ct *^ »-J ct P* to p Ol CD P o P H* a P o I-* • • •d d CD top ct CO CD to 5' p ' O •• mm CD Pi CD aCD a CD D C Ol CO 3 «: o Ol o o HH o CD o o o o o o o g"^ C *1 *d •d *< <• to CD >t mm CD ct CD CD CD O ct 3 CD l.fT » ^ ct 3* o 7 o _ co P«P a *• CO O C t c P.O CO •1 o CD t t c ct Ol ct ct OO O 100 P p CO 1 < £ P H* *«3 (^ t^. 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CINCPAC-CINCPOA BULLETIN 3-46, TRUK ATOLL, CAROLINE ISLANDS Ol fci O> et ct to o to o o H CO C P Mi J O CO O H p 0 5 O * B H> D I ct H" 3 ag 3 H- ct ct O O ct CO O O O O ct C p O O *1 3 C H CD CO CO c+ B P» H CO 01 Ol O O o P P to Ol CD a 3 o < o 3 3 •* O +i Mi a ON CD CD a CD Oi o» 3 H O O Ol P o 3 3 i P CO TO ^ S 3*H et o tr 3*P o 3 * CO CD o 4 CD o >•* CD p H_C .O^OO^CQOJD t-'fc O „ a CD to 8 to o Ol Oi • — ^rH CD - CD ct P PiO CO 3 i^ ri CD CD CD K CD o> j-, CO o X O O P CO P H- CD o o H O O a H CD O o H CD Pi • CD Hfc 3^ 3 O ._„ O Oi CD CD O oi ct 3* B 3 1 3 C 3H 3H 3Hpi tor 2! -P« A. .^-_ -O CD P* Ol CD ct CD *XJ » »•* CD O o o J-J Ol to CD H CD * CDCDErCDCDLrCDCDCD£rHCDP'HCD CDctPCDctpCDCDctPHCDOHCO CD OitO CD 1^ 3 CD CD cp ^ a ^ • CO CD Pi O O a p| a3 ft" ^ H CD HP H*O * Its J3fl CD P oq H> H ct P O P a Ol * 3 CO O> O O o o t, a JAPANESE DEFENSES . O CD 1-* *J ft» Oi to CO ct CD CD o oo P o o I-J a a Sfc a Ol o o o CD to OO a CD H 3 3 CD et o • p to ct CO »•* P ct O*H CO O* H* CO B P o Hco f» (D *< CD CO O ••$ CO 3 O et CO ct CO »1 CD fj 3 P O O X CO O H to CO o> o o o CD O 3CD 3 3 3 to * H o a CD Ol O 3 o Ol tt) T < • O Ol < OO P< CD t t c P CD 3 o> o> ^ P5 O H o S3* 3 *i H et \0 CD p- O 3 CO a 3 CD OO 3 § o O *CJ pi — — H WH X X -o H < piO CD P-H toto toto co Ol ct p ct «_» *i CD o H> O o o 3 •* CD 1 O o mm,'\i CO "TJ * O 3* Ol fcoo CO o ^ ^ o ct o OlOi o K ct CO Ol op CO CO a H o l-te cr CD O OlOl aaCD a HO O tOH ft. \V 3 OCO « < . CD I 3 *! O O o 3* P ft H - • 1 _ 3* ct -P« O) CD p> CD O i- 4 3" 3* 3* co co HO ct c o oo M OZA N cUH O le r i UKAS C »x) rd z BIZ U M ETO N atte i MAXE AND CD ^ 1• i ct r:UKBER S 3* t i O CD «o a *«5 ^ »tl <6 Ol l-» E CD c •• a <» ^B t-» tr1 tr1 r • o o o o o o o o o 0 --- o o o o o o o o o 0 p- CO CD CD K co P*K co CO TYPE OF ° CD CD CD • CD CD CD CD BB WM 3 ft" CONSTRUC 10 *i o O OO O CD O O O TION O O 3 O O K Pi KP3 tV 3 R» »1 R» 1 CD CD CD CD ct CD 10 g. ?5 .*8 ct ct 3" 3* 3* Co Ol o> CO Ol ro oi OJ 50 o> "O •D* Ol o o» § o •X I 8 ^0 "O 8 X DIMENSIONS 1 X g U |J^ ^j ^J^ •.» rj PIER o CO to ^0 Cl> O9 ^li ** ^^ 1 Ili^H -CD -CD o m Is> CAPABLE OF c a a K *n h<^ ^ a BEARING M its DM^DM^DSI CD IS CD O CD CD O 0 > o o CD CD CD CD CD WHEELED ID |a CD CO TRAFFIC 5 O* H H CD CD LENGTH AT OUTER END O H o O CD Ol 01 to o* < H WITH DEPTH O OIOI Ol 1 8 8 3 piO - - 8 3 OR MORE *s" CD H Hct H HO> « H DEPTH AT *** END OF PIER • (FATHOMS) o a a a a a aa a c o o o s 0 00 0 O ACCESSORIES w 3CD 3CD 3CD CD 3CD CD C33D C3D 3CD ^. •dio a»* et O itfo a QB o*S O OO O*d CD »i 0 a o CD »d *d wt* 3 APPROACH * CD CD CD CD ^1 09 T © *1 PlCt CD CD CD CD CD P» CD P H tj Hjj HO 3 •1 HP 3 H< 3 •1 CD3*H 33 3*1 to • CO * • C 3 O CD C 3 CD CD 3 O CD CO • O 3 O ro CD 10 r C3 Co n t- H H 5 H H O> O>*>O> to H NAME AND NUMBER 1 IE S PIER ^\ Oft O CJ o ? •-• »J O o O OOO OO O o O CD 4 O O (K) O O O O p 3 ct{B CD CD CD CD CO P>C0 TYPE OF i. H • CD H H CD CD CD CD CD CD ? % ft> 3 CONSTRUC O o HO CD O O O O CD O TION O ct o ct S. 2. £. P. 8* o «< CD a» ft* ft* <• A i « ct ct O CD CD O CD CD O 0} to QQ 3 3 1 1 ct ct 3* 3* CD OJH lOOI HH rf> to Ko ss POM Ol 0(0 CO 01 OD OJ -Ol o - o O -O OlO Ol Ol 0 *: x t, X XXX DIMENSIONS t «*- H OJ H CO HH DEPTH AT 0^ J END OF PIER f > (FATHOMS) 1 t r a a 2! a a a O 0a 00aa0a 0 0 2; *> o o o ACCESSORIES l . CD C3D CD CD 3CD C3D C3D C3D CD C3D Ii-. ^ o a o a O oo a o a OO OOOO O o 1 3 3 tro> vJ 3 O A3 ^J t^ APPROACH sf 85 §*? CD *"S CD CD CD CD 3 *1 3 "* H « o CD JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1946 ^^^^^^NWR* JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1946. JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. ClNCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1946 JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1946., to •O o I o JO o o I OO O O CO o CJ >3 .t ?9 • I Picture No. 305 (PM 468) TOL PIER No. 10 Picture No. 306 (PM 467) TOL PIER No. 11. Picture No. 307 (PM 475) UDOT PIER So. 1 o Q- z z CO Q Z o cc Picture No. 308 (PM 474> UDOT PIER No. 2 Picture No . 309 (PM 473) UDOT PIER No . 3 Picture No . 310 (PM 479) EOT PIER No . 4 o Z o (/> UJ CO Z CO UJ Z Picture tfo. 311 (PM 478) UDOT - PIER A'o. 5 Picture .Vo 77 J 00071 - P/£/? tfo. "6. Picture A'o. --J23 rP^/ 551) PIER OX TOSELlk. 113 NAVAL ACTIVITIES Improvised Torpedo Attack Units: "Daihatsu1a", standard Japanese 501 landing One-Man Controlled Torpedo Bases:' The controlled torpedoes were based on sev bargee, were modified to carry two torpedoes which they were able to launch. The eral islands within TRUK Atoll. They were housed in caves cut in the rocky side of o boats were kept in covered revetments built of rock usually among the mangroves on the hills. Tracks were laid leading into the water, and in many cases extended over the edge of the larger islands. The boats were kept in these hideouts and were ready the shoal fringing reefs to deep water. A typical layout of a torpedo base at FANEU o for an invasion. The following table shows the number of boats on each island and is shown on Figure No. 50. Many of the bases were not completed. Construction on caves was stopped mainly due to lack of explosives. A list of the bases follows. X the torpedoes and men attached to the units. The General Maps show the locations of the bases and Figure 48 shows a boat in its revetment. The locations of the bases are shown on the general maps of the islands. TYPE CONTROLLED TORPEDO RAIDING FORCE ISLAND TORPEDO NO. DAIHATSU MEN POSITION REMARKS MOEN 96 4 2 16 South Completed ISLAND TORPEDOES NUMBER PERSONNEL POSITION REMARKS UMAN (1) 91 4 2 16 West Incomplete STRENGTH (2) 91 4 2 16 West Incomplete (3) 91 4 2 16 East Completed FALAS Type 90 2 5 South Completed en UDOT 91 8 4 32 South Incomplete BERA Type 90 2 5 South Completed TOL 96 4 BUET Type 90 2 5 Southeast Completed z TOL 91 2 3 24 West Completed SALAT Type 90 2 4 North Completed t— MOR Type 90 2 4 North Completed UJ Capability of the torpedoes: FANEU Type 90 2 4 Southwe st Incomplete Type 96, 45 knots; 8,000 meters. UMAN Type 96 2 4 Northeast Completed Type 91, 30 knots; 3,000 meters. UDOT Type 96 2 4 Incomplete EOT Type 96 2 4 South Incomplete Mine Attack Units: TOL Type 90 1 4 Southwe st Completed o Type 96 1 4 Southwe st Completed EOT - Two "Daihatsu1s" were kept at the southwest end of EOT for use in POLLE Type 90 2 4 West Completed planting mines across channels used by an invasion force. They had eight aerial type FALO Type 90 2 4 Southwe st Completed moored mines. Nets & Booms: No nets or booms used at harbor entrance. Individual ships used anti-torpedo nets. According to the Japanese, large combatant ships lying in the z anchorage were protected against torpedos by encircling nets as shown in Figure No. 49. to O z co UJ Z _ i FIGURE N0.47 FIGURE NO.48 o MATSUSHIMA BRANCH IMPROVISED TORPEDO BOAT < (4th REPAIR DEPARTMENT) (SECTION VIEW) DUBLON ISLAND =3 I MARINE RAILWAY oc h- 2 SHIMOMURA DOCK Z (CAPACITY) o A 25 TON D 20 TON CO LU B 30 TON E 13 TON ZCO C 30 TON LU u. LU Q LU CO LU Z I NOTE: DAIHATSU CREW - 8 MEN CAPACITY- 2 TYPE91,45 cm TORPEDOS -40% COMPLETE IN CONSTRUCTION WORK. 1 14 NAVAL ACTIVITIES v - one-Man Controlled Torpedoes: According to Japanese accounts there were two handle. The cockpit was out of water and the "operator could see his target. He types of torpedoes converted for use as one-man controlled torpedoes. These were the was forced to rely on stealth because he surely didn't have the necessary speed. Type 90 k Type 96 which had been altered to hold the operator who was to guide the This was not considered a suicide weapon by the Japanese as the operator was supposed torpedo towards its target. A streamlined cockpit was built on the top side of the to leave the torpedo when assured that it would hit its target. The Type 90 torpedo after half of the air flask section. The operator sat in this cockpit and controlled as redesigned had a speed of 3 to 4 knots at 8,000 meters range and 5 to 6 knots at the torpedo. The housing on both type torpedoes was the same. (See Figure No. 51). 1,000 meters. The redesigned Type 96 had a speed of 3 to 4 knots at 2,500 meters o An additional rudder and horizontal elevator had been built onto the housing so range and 5 to 6 knots at 500 meters. The figures were furnished by the Japanese. probably the gyro was not connected for this run. These adjustments were designed Type 92 electric torpedoes were also believed to be used but were not reported by o and made at TRUK. The range and speed had to be sacrificed by giving the torpedo the Japanese. The number of one-man torpedoes at the various bases is shown in table I a cold run in order that the torpedo would not be too difficult for the operator to form under Torpedo Raiding Force. u CC WORK BEGAN DEC. 1944 90 % COMPLETE STORAGE CAPACITY 2 TORPEDOES O a. CUT THROUGH / REEF WAS PLANNED Z BUT NOT POD CARRIED OUT PLAN DIAMETER OF i z ANTI TORPEDO NET LENGTH 12 M.APPROX. STEEL FRAME BEDROCK B WIDTH 12 M.APPROX. STEEL FRAME CO z O FIGURE N0.49 CO ANTI TORPEDO NET FOR BATTLESHIPS FIGURE NO.50 o ONE MAN TORPEDO ATTACK BASE FANEU ISLAND O FIGURE NO. 51 ONE MAN TORPEDO- SIDE VIEW Z o COCKPIT FOR TYPE 90 TORPEDO CO LU 3 TO 4 KNOTS 8000 M. CO Z 5 TO 6 KNOTS 1000 M. LU U LU o LU CO LU Z 00 b 4.1 M. t 9.IM. Picture No. 314 (PM 472) UDOT: Torpedo caves south- Picture No. 315 (PM 65) ONE-HAN CONTROLLED TORPEDO AT east corner of island. SUB BASE ON DUBLON. 115 NAVAL ACTIVITIES Experimental Recording Torpedo Heads; In the Navy arsenal building on FEFAN Table 1 shows type of mine, number of mines, length of lines, Interval ^- there were two 24" experimental recording torpedo heads for use with the Type 93, between mines, depth of mines, number of mines swept and the number of mines un o Model 1, Modifications 1 and 2, torpedoes. The heads were complete and operational accounted for in each of the various mine rows of Figure 52, and the path recorder had the following limits: I Mines Laid: In the defense of TRUK the Japanese employed the following mlneB ac Depth: 40 meters. Port & Starboard List: 120°. (excluding beach mines): Speed: 55 knots. Endurance: 55 minutes, 2 Mark 5 Modification 1; a moored, contact, chemical horn mine, made of steel. in The Type 92 gyro shown In Picture No, 318 was used with these torpedoes when used The case containing the charge of 182 pounds is 32.7" in diameter and there are four for recording data. No shore launching installations were available and the Japanese horns equally spaced around the upper hemisphere. said the torpedoes were launched from ship. A light and a smoke pot were mounted on the head for location purposes in night and day, Type 93 Model 1; a moored, contact, chemical horn mine, made of steel. The case is circular having a 34" diameter carries a 220 pound charge and has four horns MINE WARFARE. 90 degrees apart alternately 16.2" and 11.6" from the top center of the case. From Japanese sources it was stated *hat the aircraft mines mentioned in Table 1 are an General: The Japanese were quick to recognize the suitability of TRUK for mine adaptation of the Type 93 mine rigged with parachute. Type 93 Model 2 mines were warfare as all the mines and mine laying equipment necessary for the mining of the also used the only diffet»ence being a fifth horn on the top of the mine. No distinc atoll were on hand prior to the isolation of TRUK, tion is made between the two in Table 1, m The waters Inside the atoll were ideal for mining activities and a relative Mark 6 Model 2; a moored, contact, chemical horn mine carrying a charge of ly high number of mines were planted, Including 1,792 moored contact mines, 12 con 440 pounds and 41,3" in diameter. The case is steel and there are four horns equally trolled moored mines, 4 acoustic mines, 3 magnetic mines and 5,784 beach mines (Small spaced around the upper hemisphere. Model Mine, Model 1), Each group of mines is considered seperately. Figure 52 shows z the location of all mines, except the beach mines on the large islands. None of the Type 92 Model 1; a moored, magnetically or acoustically monitored, controll passes were guarded with submarine nets because of excessive tidal currents. ed mine, the case of which is 41,5" in diameter and 5.5" long carrying a charge of 1,100 pounds of Temp. Type 1 Explosive. These are discussed in detail at conclusion Moored Mines: All of the passes were mined to some extent but two of the most of this section. navigable passes, the NORTH Pass and the SOUTH Pass, were weakly defended by mines, while the other prominent passes were very heavily mined, as in the NORTHEAST Pass Acoustic and magnetic mines were seven in number and were made in Germany. z and the WEST Pass. The NORTH Pass and SOUTH Pass are considered in detail below. The two mines used were the TMC and TMB (German Designations) and no information was Rows of mines were placed well within the atoll also, but the moored mines were obtainable on the type of firing units. The mines were ground mines and are marked Intended primarily for the defense of the various entrances to the central islands by their large charges, TMC having 2,060 pounds of explosives and TMB having 1,220 CO inside the atoll. pounds. Q Z CO UJ Z o ac V -I -J O < t— z O CO UJ to Z CO UJ Z Picture No. 316 (PM 53°) PATH RECORDING INSTRUMENT FOR Picture No. 317 (PM 529) MODEL u EXPERIMENTAL RECORD- Picture No. 318 (PM 532} TYPE'92 GYRO FOR USE WITH THE MODEL n RECORDING TORPEDO HEAD VHICH RECORDS DEPTH. ING TORPEDO HEAD FOR USE WITH 24", TYPE 93. MODEL 1, TYPE 93 MODEL 1. MODIFICATIONS 1 AND •*. TORPEDOE IN RE SPEED, AND LIST FOR THE RUN OF THE TORPEDO. MODIFICATIONS 1 AND 2 TORPEDOES. CORDING SHOTS. 116 NORTH PASS 1 £$ SMALL MODEL MINES */TYPE 92 T-4 MINES T. 3 N-l . N4 , N2 /• A m TO 6\ .TO 6(ft) Z BUOY OBSTACLES 7(2) SUNKEN SHIPS S 28 NEW SUNKEN SHIPS (PORTION OF HULL *, FALAS IS. OR SUPERSTRUCTURE ABOVE LOW WATER 8(2) HI 5 / o SMALL MODEL ^ a. MINES TORPEDO BASE « TO 27(2). /^LSMALL MODEL MINES \ HI 4 TO 25^_V^iN«ACOUSTIC MINES Z ^1 Z -fit \J to Z /HI-I SMALMALL MODEL MINEMINES ULALU IS. o MAGNETIC UDOT IS MINE(B) PARAM IS. FALA BEGUETS TARIK IS., PIAANU PASS FEFAN IS. z MAGNETIC | 2 1° o MINE(C)-J>" CO UJ to z \H1 10 to LU Z S2(A) S 3 S 2 TO 24 NEW /^d^TO 24 T9 SALAT PASS NEW SMALL S4(A) S4 MODEL MINES^^ . MAGNETIC MINE (A) r 'SMALL MODEL MINES SMALL MODEL T20 MINES HI 9 FIGURE NO. 52 FAN AN IS. MINEFIELDS, SUNKEN SHIPS a SMALL MODEL MINES BUOY OBSTACLES SMALL MODEL MINES MESEGONIS. 117 NAVAL ACTIVITIES "US i • ^ •**• •"• f -- .' kirn I Sweeping; With the end of the wa*J the Japanese began sweeping operations inside and where two rows were used tne distance between rows was usually 6 meters. (See the atoll and were later checked by operations of U.S. forces. Of the 1,792 moored Figure 53). No instances were found which Indicated that any were booby trapped o mine8 planted, 999 were disposed of, leaving an unaccounted balance of 793 mines. nor was any attempt made to increase the effective overall radius of the mines by I This is a high percentage of unaccounted mines and it may be attributed to the time use of bprbed-wire entanglements connected to the horns. None were to be used on u in the water (planting: began in 1941) and the excessive currents experienced in the land although a few were held as replacements on some of the islands and could have passes. The mines in the WEST Pass were planted in the summer of 1944 thus explain been used as land mines. ing why most of them could be swept. 2 The mines were all removed and disposed of by the Japanese forces, and The special mines were also disposed of by the Japanese and checked by Table 3 gives the mines unaccounted for which had been under Army Jurisdiction. No U.S. forces. The Type 92 mines were disposed of from their control post on TONELIK. figures were given on the Navy mines accounted for but it may be assumed the propor tion would be the same. Reports froff the Japanese indicated that many of the small Acoording to the Japanese no actual explosions were .loted in the sweeping model mines had been in the water so long as to be non-functioning and attempts to of their own magnetic and acoustic mines but after many sweeps of the areas in which fire most of the mines resulted in either no explosion, a low-order detonation or Z they were laid the areas were declared safe. Sweeping was also done for U.S. In a very weak high order detonation. fluence Mines laid in the various passes and the areas declared safe again. No mines were swept. DEFENSE OF THE NORTH AND SOUTH PASSES. 13 Beach Mines; The only type of beach mine used in the TRUK Atoll was the two Due to the arrival of Japanese ships and submarines at TRUK at various times CO horn hemispherical ground mine 20.5" in diameter having a charg of 44 pounds of the enemy felt it necessary to keep the NORTH and SOUTH Passes open to their vessels Type 88 explosive. The Japanese designation is "Small Model Mine, Moael ln. The and yet have some underwater defense or underwater detection. In both passes the beach mines were planted on some of the islands of the reef and on most of the lar Japanese had magnetic underwater detector coils completely covering the passes and o ger islands within the atoll. These mines were laid both by the Army and Navy these were used to detect the presence of all vessels entering TRUK Atoll. The a. forces, the numbers controlled by each being given in Tables 2 ft 3. The mines lines other passes were sufficiently mined to be disregarded; at least this was the Jap are plotted for all of the large islands, (See Maps in PART TWO). The reef islands anese belief. In the NORTH Pass the water was mined with Type 92 controlled mines mined are indicated in Figure 52 and designated in Tables 2 & 3. which were to be fired by the defending forces only, thus safeguarding their own z shipping. The SOUTH Pass was heavily mined about 3,000 meters inside the pass but v this did allow ships to enter the atoll if they knew the clear channel. In the Most of the beach mines were planted in the water along the shore and NORTH Pass there were no moored contact mines planted. u along the reefs surrounding the islands. Mines were planted at 6 meter intervals Z CO Q Z o TYPE I HYDROPLANE MARK I ELECTRIC . LARGE MODEL MAGNETIC CABLE "• o DETECTOR - LOOP SIZE 750 X 150 METERS 3 eg 2 MONITOR MARK I z ELECTRIC CABLE o CO Ul CO Z UJ LL. UJ 4/ Ul SOUTH PASS A 4 METRIC MAGNETIC CO UJ A DETECTOR LOOPS (4) Z MINES LAID AT 6 METER INTERVAL FIGURE NO. 53 FIGURE NO. 54 TYPICAL SMALL MODEL MINE LOCATIONS TYPE 2 UNDERWATER MAGNETIC DETECTOR (TONELIK ISLAND) ( SOUTH PASS) 1 ' ' tf •• ft 118 .s/ i^jatt jfcr NAVAL ACTIVITIES South Pass: Type 2 Magnetic Underwater Detector - The Japanese had magnetic is 1,700 meters from the north end of FALEU. Loop "c" bears 095° and Is 1,800 meters underwater detector coils in both the NORTH Pass and the SOUTH Pass. These coils from the north end of FALEU. Loop "f" bears 097° and Is 1,895 meters from the north were used to detect the presence of any shipping in the passes by recording magnetic end of FALEU. The length of cable used in the large detector loop was 8,400 meters variation when a ship passed over the coll6. Both units were identical and those and for the 4.5m. loops it was 3,350, 3,600, 3,500, and 4,000 meters for Loops "c", in the NORTH Pass were used in conjunction with the Type 92 controlled mine fields H d H , H e", and H f N respectively. Between FALEU and UMAN two lengths of 15,000 meters there. were used. The Type 2 Magnetic Underwater Detector was fully completed and opera tional until the surrender of TRUK. General Description - The Type 2 Magnetic Underwater Detector in the SOUTH Pass consisted of 4 - 4^ meter loops and 1 - 750X150 meter loop located as shown in Installation of a Type 92 Mine Acoustic Monitoring Device was planned Figure 54. Each of these loops was connected to a cable which le" to FALEU in the but not carried out. SOUTH Pass where they entered a relay post and a terminal box and were then connected to a single conduit which led to the control station on UMAN. Pictures 321 and 323 Operation-Type 2 Underwater Magnetic Detector - The Type 2 Underwater Mag show the relay post and terminal box. Apparently two cables were laid to UMAN since netic Detector consists essentially of four portions, the underwater magnetic detect one broke and rather than repair the broken conduit a new one was laid and the other ion loops, the sensitive galvanometer and photo cell amplifier, the light and audi left in place. Figure 56 shows the approximate location of the operating room on tory alarm panel, and the paper tape recording device. The loops are connected UMAN for the Type 2 Underwater Detector and Figure 55 shows the details of the oper through a balancing network to the galvanometer. The amplifier unit has a lamp in Z ations room. It and the beam of light from it is returned to a photo cell by the galvanometer mirror. The amount of light to the photocell Is proportional to the galvanometer deflection. (See Picture No. 319). The amplified current is transmitted to the Characteristics of the Station in the SOUTH Pass - The Japanese employed tape recording device shown in Picture No. 322, and deflections are recorded in ink two means of communication with the shore station: By means of TM Radio with the on the paper strip. When the deflection of No. 1 recorder reaches three units, Guard Force Headquarters and by means of ordinary Exchange Telephone with 4th Fleet indicating an approach of a ship to within 150 meters of a loop the alarm sounds from Headquarters and Guard Force Headquarters. The Command Post was on UMAN in the the alarm No. 1 panel and light No. 1 goes on. If two ships approach lights No. 1 O same tunnel as the Guard Defense Station. The large Magnetic Detector Loop (750 X & No. 2 go on. When a ship approaches the loop associated with No. 2 recorder, its 150 meters) was marked by two buoys on either side. From the North end of FALEU alarm panel Is actuated, and similarly for the rest. (See Picture No. 322 for alarm Z one buoy bears 060° and is 1,575 meters away. The other bears 090° and Is 2,755 panel). Three complete units were Installed on UMAN and 5 units at NORTH Pass. The meters away. The four - 4.5m. Detector loops are located to the south of the large equipment was Installed in April of 1943. The equipment was considered satisfactory I loop and are designated as "c", Hd", "eM , and *t* in Figure 54. Loop "c" bears by the Japanese and was alledged to be of sufficient sensitivity to detect vessels 091.5° and is 1,575 metere from the north end of FALEU. Loop "dH bears 093.5° and containing even a small amount of iron. z CO Q Z CO UJ Z BATTERY ROOM o < WATCH PORT CHARGER SWITCH- MONITOR BOARD RESISTER USED FOR z CHARGING SUSPENDED TYPE o CO TYPE I \ HYDROPHONE UJ HYDROPHON CO Z MARK ICABL LU FIGURE N0.56 U. UJ SUSPENDED TYPE Q UJ CO MODEL I HYDROPHONE UJ FIGURE N0.55 UMAN ISLAND z WATCH STANDERS DIAGRAM OF INTERIOR OF DAYROOM GUARD STATION UMAN ISLAND L19 NAVAL ACTIVITIES o I cc in z o Ptctur.e JVo. 320 317J TTfS 2 MAGNETIC DETECTOR ALARM u CL PANEL; UMAN. Z Picture No. 319 (PM 315) TYPE 2 MAGNETIC DETECTOR SENSI Picture No. 321 (PM 492) RELAY POST FOR TYPE 2 MAGNETIC z TIVE GALVANOMETER AND PHOTO CELL AMPLIFIER. UNDERWATER DETECTOR ON FALEU, SOUTH PASS. CO z O -1 CO o cc O Z o to UJ GO z Picture No. 322 (PM 553) 'CONTINUOUS PAPER TAPE RECORDER Pictur.e No. 323 (PM 488) TERMINAL BOX FOR THE FIVE DE- Picture No. 324 (PM 561) GENERATOR ROOM, FUEL TANK ON FOR TYPE 2 MAGNETIC UNDERWATER DETECTOR COILS. TECTORS LAID IN SOUTH PASS. LEFT AND FIVE FRESH WATER TANKS; TONELIK ISLAND, NORTH PASS. North Pass; Controlled Mine Field In NORTH Pass - The NORTH Pass was guarded Between the two fields \:as located tne Type 2 Underwater Detector Coils CO by two rows of Type 92 controlled mines, six mines In each row. These were laid which could be used as the monitoring mechanism for both mine fields. The arrange ui In February, 1942. The outer row was In an east-west direction and the Inner row ment was the same here as in the SOUTH Pass with the control going directly to Z In a northeast-southwest direction across the pass, the rows being about 1,200 meters TONELIK. Here each of the colls was operated seperately there being an automatic apart. The mines In each row were planted In the center of the channel at a depth and visual recorder for each of the detector coils. The control station here was of 15 to 20 meters below the surface, 160 meters apart and covered about 3/4 of entirely above ground and in excellent condition in spite of 4 or 5 strafings. It the channel, the remainder being negligible because of the proximity to the reefs. is shown in Figures 54, 56, & 57. The Inner row of mines were acoustically monitored For the Type 92 mine the control cable Is built-up to act as the mooring line from from the mine case; the listening station was on TONELIK. the anchor, and each of the six control cables lead to a central conduit which Is planted along with the mines. This In turn leads the six circuits to the control The control station on TONELIK was entirely above ground In a frame shelter station via a single conduit. This Is shown In Figure 57. The control station for with a coral wall about 41 high on its seaward side. The generator room was located the NORTH Pass was on TONELIK. the eastern guardian of the pass. nearby but had no protective walls around It. The power was furnished by a 25KW 120 NAVAL ACTIVITIES die eel generator with a 6KW and a 3KW generator acting as the standby. The generator water detector colls. The mines were never fired throughout the war and with the shack and the fuel and water tanks are shown in Picture No. 324. The 25KW generator surrender the Japanese destroyed the field, all mines detonating indicating that is shown in Picture No. 328. the mines maintained their usefulness In adverse tidal currents for a period of three years and seven months. •o The Type 92 mines with acoustic mechanisms were monitored from a switch o board a8 shown in Pictures Nos. 326 & 331. A selector switch made it possible to Acoustic Underwater Detector UMAN Island - This detector had nothing tc. listen to all six of the mines collectively or individually. The arrangement of do with the defense of the passes in the TRUK Atoll but is being considered here the mines allowed for the acoustic listening devices to be tested periodically and since it pertains to underwater detection. it was also possible to test the firing circuit when desired. The panel could be used to monitor a field of 72 mines. Picture No. 325 shows the mine detonating con In addition to the underwater listening devices Installed in the control trol panel. The mine field at TONELIK was controlled from the central selector mines, only one installation of underwater listening devices was made in TRUK Atoll. 2 switch of the control panel since there were only 12 mines. This installation was made on UMAN. See Figure 56 for location. The equipment was a "Temporarily named Suspended Type Model 1 Acoustic Detector" and was housed in the Due to the limitations of the control panel the minimum number of mines 6ame cave as the magnetic loop detector gear. A cable led from thi3 cave to the which could be detonated at one time was two. The mines were connected so that the suspended type hydrophones, a distance of 350 meters off shore. Eleven hydrophones two central mines of each row fired together and each of the two wing groups fired were used arranged in a circle a few meter in diameter. The amplifier and bearing individually. All 12 mines could be fired as a unit and both fields were controlled Indicator were housed in two units. The entire device was battery operated. The z from the same panel. device was useful in determining bearing only. It was set up in July of 1944 but soon removed as its performance was unsatisfactory. All hydrophones were left in Telephone and radio communications were maintained with MOEN and it is their original positions off shore, "or a picture of the two remaining portions of belelved that permission had to be obtained from MOEN In order to fire the mines. the Installations see Picture No. 329. Explosion of the mine field would have no effect on the usefullness of the under- o Q- z z CO Q Z in o Picture No. 325 (PM 573) TYPE 92 CONTROLLED MINE DETON Picture No. 326 (PM 574) TYPE 92 CONTROLLED MINE LISTEN- o ATING PANEL: Capacity, 72 mines. ING PANEL: Capacity, 72 mmrs . To right is battery t— charger. Z o CO LU CO z CO LU Z Picture No. 327 (PM 557) SWITCH BOARD PANEL FOR TYPE 2 Pictur e No. 32 8 (PM 55^ ) 25 KW GENERATOR ON TONELIK, Picture No. 329 (PM S 1 ^ ) SUSPENDED TYPE MODEL 1 USUER MAGNETIC UNDERWATER DETECTOR IN NORTH PASS . NORTH PASS : Thi s ^e ne rat o r supplie d th e Powe r fo r tn e WATER SOUND DETECTOR, LOCATED OS UMAN ISLAND, SHOVING type 9 2 controlle d mine s and i,ype 2 magneti c underwate r BEARING INDICATOR AND AM?UFIER. detector. 121 DEFENSE STATION AT KO SHIMA DIAGRAM OF CONNECTIONS BETWEEN -o TYPE 92 MINE AND DEFENSE STATION o I 2 in TYPE 92 MINES (I LINE) O O Z JUNCTION BOX SOUND ROOM a. VNELIK ISLAND Picture No. 33 0 (PM 556) VISUAL PANEL FOR TYPE 2 MAG CO NETIC UNDERWATER DETECTOR. O JUNCTION BOXx Z MAIN CABLE to TYPE 92 MINES O (2 LINE) cc o ACOUSTIC MONITOR; => cc 1 1 JUNCTION CDETONATOR CONTROL) ! BOX z BATTERY ROOM o t_ _ _ j CO LU CO DETONATING z RESISTOR-^^ SOUND ROOM CO Picture No. 331 (PM 555) TYPE 92 CONTROLLED MINE LIST ENING PANEL INSTALLED ON TONELIK ISLAND, NORTH PASS: With switchboari tn background. FIGURE NO.57 J •: OIAGRAM OF CONTROLLED TYPE 92 MINES IN NORTH PASS JRUK ATOLL 122 H H3 i3 *a H 3 3 H 3 3 3333 3 3333 ^ t-3 3 3 OOOOO D O O O OOOOOO OOO3 O o o o o o o oo oooo OOOOO Designation of ro to rororo ro HH MH H 00 00 • oicoco^i t r OJ OJO to tO O»rfk05 OO I I I I Mine Line to to o o to ro to ; 525 a to 53 5 3 ro ro CD CD ss to CD CD 25 ; CD CD 3 CO 3 3 3 3 d 3 3 3 3 33333 3 S S S S s a a s Ol 3 Mine Employed o Pi o Hto ro rf^-OJ H OJ N)H O1CJ1CJ1 HH»^5H hHH to HO I cno Ol -vlOlHH o o oo oi OO CftCO 01 OJ O ->i 0000 OJ O O l O l OI-NIOOOI O i Number o f Mines H»-3 tttd t xj• M HH tO to ton tore H ro ro to HH^I^5H to o Length of Row MM OlOi Ol OJ p too ro 01to OJ -otf*oi-a GJ to to to- Interval Between H hiHh H H OJHH HHH H O Mines (Meters) Ol Ol Ol CJ oi en o i O) o i0)0)000 O Ol Ol Ol O OiOcnOO OOOOO OOOOO ooooo ooooo O O O l O OOOOO ooooo ooooo OOOO O oooo o ooo o o o o o o oo o ooOOOOO OOOOO Depth ofMin e H H H H (Meters) to to toco to ro to to to OJ oi Oi O) OJ OJ OJ OJ OJ OJ OJ OJ OJ OJ OJ O l OJ O O1O» O OlOlO 01 OOl O OlO OlOJ O l Ol O l Ol Hto to OJ OlHfOW t * O l OD O Ol OJ ^ HWO1O1 tf^oio^oioioioo 5 Mines Unaccounted to - > > > •-3SS C H £j tB W W W 2M 33 MM E; co oi oa 0303 3 3 3 3 3 »-3 ^3 »-3 »-3 »-3 »-3 i-3 1-3 H 3 CO H- D H* O H- H -J. p. H- 1 o < H Ol Oirf*. Ol tO- 1 ^rf^ i ro H Oi ^ OJ ro Designation f TO 3 O h* P" H- - " o o O CD CD CD O CD 3 CD 3 CD 3 CD C HtO wro H o to o •<«OirfK- J tO H Mine Line CD CD CD m O CO ^J Ol Ol tl^ CO ""^ c* *-* c t tO O H> t d H o o O > o i-3 -»• CD CO 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 Mine Employed t 3 ^ CD CD CD H "CD CD CO to O o to to OJ i£ rf tO il^ rf^ •^ ton to to O Number of Mines 01 Ol H H OJ J 01 Ol OlOIOI o o too oOCD^O O o o ooo O tOH O tO5*88 0 (Meters ro ro ro ro to toro ro tOH H roHroH w to to to to to ro .14 5 H ,40 0 ,68 0 ,34 0 ,80 0 H Length of Row 78 0 Oi I I I tOOO . 00 00 00 00 0000o H H OJ -OH H H 01O1H tO oi ) I 1 I OOO ooooo o o O o : rf^ 03 Otf*Ol o I I I OOO o oo o oo o oiOl Ol O« Ol O\ Ol Ol Oi Ol Ol Ol Ol Ol Ol OiO O O O o Interval Between I OJ Mines (Meters) J o o o OOOOO oo o oi Ol Oi O l O) Ol Ol Oi Ol Ol Ol Ol Ol Ol Oi Ol Ol Ol Ol Ol Ol O l O l O l C o I o o o OOOOO oo O Oi Ol Ol Oi Ol O l Ol Ol Ol Oi Ol Oi Ol Ol Ol Ol OlO O O O ooooo Depth of Mine Ol § (Meters) I 3 01 Ol OJ 0 1 O l OJ OJ OJ Ol 01 Ol Ol W Ol O l O loiroro oi oiOl Ol OJ Ol Ol oi toro to to to rororo re to to P o Pi * P« O Ol Ol tO O l OJ OJ H OJ tOrf^ to to oi OJJt o y-'H HOlHOl K 01 Ol H H too o oo o oi ro • H H Mines Unaccounted o O O O OHO H G1GJOJO! ro to it* oi o oitf*to oioi o TV» ro HO £»• #» O l H to toro oito O-vIOlH * to CO JAPANESE DEFENSES ON IRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1946.* NAVAL ACTIVITIES TABLE NO. 2 TABLE NO. 5 NAVY SMALL MODEL MINES ARMY SMALL MODEL MINES o ISLAND TOTAL MINES WHERE LAID REMARKS ISLAND TOTAL NUMBER LAID DISPOSED OF UNACCOUNTED I MOEN 150 Shore near 1st airstrip Laid in 2 rows, 6-10 MOEN 1,689 1,649 40 \J NW part of island. meters interval, inside DUBLON 577 568 9 shoals giving complete < FEFAN 715 712 3 coverage of airstrip. UMAN 425 425 0 FEFAN 150 Northside of island between Laid 2 rows, staggered, ME SAGO N 110 100 10 322 & 352 line8, taken from 50 meters off-shore. 6 UIJEC 60 55 5 Mt. SANRAI. meters Interval between FAN AN 80 72 8 rows & mines. TSIS 92 92 0 FALEU 15 West side of island near pier. 135 mines blown up in NORTH TOL 79 78 1 CO bombing raid before be NORTHWEST TOL 50 50 0 Z ing Installed. SOUTHWEST TOL 327 308 19 NORTHEAST Surrounding island. On north side in two rows UJ the rest in one row. 6 _i meters interval 30 meter from shore. TOTALS 4,204 4,109 95 CO TONELIK 200 Surrounding island. Two rows, 6 meters inter val, between mines. OBSTACLES. First row 50 meter,s trom shore. Distance between Anchored Buoy Obstacles: Moorlne buoys with smaller buoys between were rows 20 meters. together with steel cables and anchored "o^f several of the islands as obstructions DUBLON 300 West part of DUBLON Proposed field 6 meters to landing craft. These obstacles are located on Figure No. 52. Figuro No. 58 interval. shows the detailed construction of a moored obstacle. OTTA 145 Surrounding island. 40-60 meters from shore. 6 meters interval be Underwater Beach Obstacles: Underwater obstacles were placed along the reefs tween mines. fringing most of the larger islands. These were built of coconut logs or steel "IH SALAT 120 In 3 fields at North, South, 20 meters from shore; 6 beams. The obstacles were driven into the coral with their tops at approximate CINCPAC & Western sides of island. meters interval between level of low water. Figure No. 59 shows the typical construction. The obstacles mines, are located on maps contained in PART TWO. co ELIKANIBU 150 Eastern shore. Cover beach at gun em placement. 50 meters off Z shore in one line. < MOR 150 Surrounding island. 50 meters offshore in two rows. 6 meters between rows and mines. o O COCONUT LOG UNDERWATER OBSTACLE z PORT USE INSTRUMENT LIST o NAME SIZE QUAN. NAME SIZE QUAN. CO BUOY 4 TON 6 ANCHOR CHAIN DIA 45 MM I6LINKS Ul LENGTH 25* n .. 5lA 40MM CO SPECIAL STYLE BUOY 9 5 LENGTH 25K II LINKS II DIA 36MM Z ANCHOR 4 TON 1 1 FNGTHPKN 4 LINKS II .1 DIA 40MM 2 TON 3 LENGTH !>3* 2 LINKS 1 TON 2 CABLE 32MM0IA I250M " 0 5 TON 2 24MMDIA 1250 M. SINK ANCHOR 2 TON 4 UJ CO UJ SUPPLY OIL PIER Z FIGURE NO 58 \\ TRUK ATOLL w BUOYS USED TO OBSTRUCT SMALL CRAFT DUBLON ISLAND STEEL RAIL UNDERWATER OBSTACLE FIGURE N0.59 3-3 i TYPICAL UNDERWATER OBSTACLES ]24 NAVAL ACTIVITIES VESSELS. Engine Horsepower 380 HP o Heavy Oil Capacity 6.8 metric tons The following is a list submitted "by the Japanese forces of ships and small Fresh Water Capacity 6.0 metric tons I boats located at TRUK Atoll at the end of hostilities: Crew Officers - 2 W.O. - 2 SHIP SPECIFICATIONS (TUGBOATS) P.O. -31 Non-rated-12 OWNERSHIP SHIP HORSE- PRESENT Seaworthiness Fit for ocean travel OF VESSEL NAME OF SHIP TONNAGE POWER CREW CONDITION Special Minelayer No. 5: SHUNKAI MARU 9.4 45 5 Serviceable KODAMA MARU 6.5 25 4 Serviceable Di splacement 296 tons en YOSHII MARU 6.0 25 4 Serviceable Maximum Speed 9.5 knots Z IKEDA MARU 8.0 30 4 Serviceable Cruising Range 2,420 nautical miles Government No. 1 SHIMASGU MARU 15.0 50 5 Serviceable Overall length 35.70 meters UJ Owned Mk-1 INOUE MARU 6.0 25 4 Serviceable Maximum Beam 6.5 meters 4th NAMPO MARU 8.5 45 5 Serviceable Mean Draft 2.35 meters Fleet UME MARU 8.2 45 5 Serviceable Engine Type Single action, 4 cycle, solid CO YAKITSU MARU 15.0 60 5 Being repaired injection, Diesel engine < Mk-1 DAIMEN MARU 15.0 50 5 Being repaired (one) OMURA MARU 6.0 30 4 Being repaired Engine Horsepower 400 HP o MK HO TSUCHIYA MARU 8.5 45 6 Being repaired Heavy Oil Capacity 13.1 metric tons Fresh Water Capacity 11.5 metric tons Crew Officers - 3 No. 6 SAKURA MARU 15.0 75 5 Serviceable W.O. - 1 No. 4 SAKURA MARU 13.2 65 4 Serviceable P.O. - 41 a South Seas KAMONE MARU 11.0 35 4 Serviceable Non-rated - 10 Development Co. MAI MARU 20.0 40 4 Serviceable Seaworthiness Fit for ocean travel (Civilian) TAKA MARU 21.7 40 4 Serviceable TSUBAME MARU 10.8 35 4 Being repaired co FUTAGAMI (combined salvage vessel and tug) a SHIP SPECIFICATIONS (SMALL BOATS) z Displacement 625 tons OWNERSHIP FREIGHT? NUMBER Maximum Speed 14 knots OF VESSEL TONNAGE) OF BOATS PRESENT CONDITION Cruising Range 800 nautical miles UJ CAPACITY Overall Length 48 meters Z Maximum Beam 9 meters _i Government 5.0 1 Serviceable Mean Draft 3.6 meters Owned 3.0 12 Serviceable Engine Type Reciprocating engine; Fuel: o 4th Fleet 3.0 7 Needs repairs coal and heavy oil. Engine HP 2,200 HP < Fuel Capacity Heavy oil: 28 metric tons 8.0 2 Serviceable Coal: 82 metric tons 5.0 6 Serviceable Present Amounts Heavy Oil: 25 metric tons 3.0 2 Serviceable Coal: 60 metric tons Crew South Seas 9.0 4 Needs repairs Officers - 2 Development Co. 5.0 14 Needs repairs P.O. - 39 (Civilian) 4.5 3 Needs repairs Non-rated - 17 4.0 2 Needs repairs Seaworthiness Fairly well suited for 6.0 1 Needs repairs ocean travel z 3.0 8 Needs repairs o 300-Ton Tug (Official Designation: 761): CO UJ CO NAVY SHIPS AND BOATS. Di splacement 300 tons Z Maximum Speed 8 knots Special Minesweeper No. 5:• Overall Length 36 meters UJ Maximum Beam 7 meters Q Displacement 222.15 tons Mean Draft 3.2 meters UJ Maximum Speed 10 knots Engine Type Reciprocating Engine CO Cruising Range 1,754 miles Fuel: coal UJ Overall Length 32.6 meters Engine HP 1,200 HP Z Maximum Beam 5.93 meters Fuel Capacity Coal - 35 metric tons Mean Draft 2.3 ineter s Present Amount Coal - 25 metric tons Engine Type Single action, 4 cycle, solid Crew P.O.- - - 1 injection, Diesel engine. Civilian employees 6 (Fuel: Heavy oil). Seaworthiness Fit for ocean travel 125 NAVAL ACTIVITIES OXhers: SMALL BARGES ^>.MK H 1946. 4 Shipborne Motor Torpedo Boat 1 "Cw Army 2 3 No 5 Heavy 90 Same as above in Motor Boats: Type r Steel oil 18 meter Motor Boat 1 Construction. 15 meter Motor Boat 2 12 meter Motor Boat 3 LIGHTERS 9 meter Motor Boat 1 "7 7 meter Motor Boat 1 1 15 No - - Same as above Am Launch 1 H— Ul SUNKEN SHIPS Special Cargo Barges (TN: carried aboard (TRUK) submarines): Located on Figure No. 6 14 meters 34 13 meters 2 DUBLON AREA o Water tankers NO. NAME OF SHIP GROSS TONS REMARKS KJ 150 metric ton capacity 1 (APPROX) loo metric ton capacity 1 z Not self-propelled, 1 SHINKOKU MARU 10,000 Mast exposed. 100 metric ton capacity 1 2 YAMAGIRI MARU 10,000 Approximate position. 3 DAI SAN TONAN MARU 10,000 Bottom exposed. Lighters: 13 4 HEIAN MARU 10,000 Buoyed. 5 KANSHO MARU 5,000 Buoyed. z Cargo Barges: 3 6 KIYOZUMI MARU 10,000 Buoyed. 7 HOYO MARU 10,000 Buoyed. Tugs: 8 (all froni 6-15 metric 8 SAPPORO MARU 1,000 Buoyed. CO tons) 8a Submarine 2-169 Approximate position. Q Power Boat (270 metric tons) 1 9 FUJISAN MARU 10,000 Buoyed. Z 10 NIPPO MARU 5,000 Approximate position. Civilian-owned craft used for military purposes: 11 MOMOKAWA MARU 5,000 Approximate position. CO 12 AIKOKU MARU 10,000 Approximate position. Large fishing vessels 5 Ul 13 SEIKO MARU 5,000 Approximate position. Small fishing vessels 25 Approximate position. Z Small tugs 14 HOKUYO MARU 5,000 5,000 Approximate position. Small lighters 1 15 NAGANO MARU o 111 D^n i* f* !* fl 16 SAN FURANSHISUKO MARU 5,000 Approximate position. oc 9 c 17 REIYO MARU 5,000 Approximate position. SHOTAN MARU 5,000 Approximate position. All these are In bad condition and can barely navigate inside the 18 reefs. 19 KIKUKAWA MARU 5,000 Buoyed. 20 HOKI MARU REPORT ON SMALL CRAFT (ARMY) ON 28 AUGUST 5,000 Approximate position. 21 FUJIKAWA MAHJ 10,000 Mast exposed. o LARGE LANDING BARGES PTTTTT. 22 DAI ROKU KAIUN MARU 5,000 Approximate position. TONNAGE SEAWOR- AMOUNT 23 GOSEI MARU 5,000 Approximate position. 24 RIO DE JANEIRO MARU 10,000 Approximate position. TYPE NO. (Loaded) THINESS CREW TYPE (Liters) REMARKS TAIHO MARU 5.000 Approximate position. OC "KA» Extra 1 15 No 7 Heavy 26 YUBAE MARU 5,000 Buoyed. H- 400 Hull corroded. 27 DAI NI HINO MARU 1,000 Buoyed. Large Navy oil Z Mod Steel 28 SANKISAN MARU 5,000 Bow exposed. o 29 AMAKINSAN MARU 1,000 Approximate position. CO "KA" Navy 7 8 No 7 Kerosene 200 Hull corroded; 30 Unknown 1,000 Approximate position. y11j 1 CO Mod. Steel 1 under repair. Z Construction, TOL AREA "DB Army EF E 3 10 No 7 Heavy 180 Hull corroded; 31 HANAKAWA MARU 5,000 Mast exposed. Q Type; Steel oil 1 unusable. Ul Construction. FALEU "TO" Army 1 8 No 7 Gasoline 180 Hull in poor 32 Fishing craft Engine exposed 100 yards offshore. Type; Wood condition. Construction. JAPANE ! 126 NAVAL ACTIVITIES NAVAL COMMUNICATIONS. ping, the 4th Construction Department, the Floating- Drydock, and the MOEN Transmitting Station. No particular damage wa6 inflicted. Covered In the communications report. From 0830 to 2130 on the 15th there were raids all through the day by several o HYDROGRAPHIC INFORMATION. planes at a time, but the bombing and strafing was not intense, and they were mainly carrying out spotting during the periods when bombardment was being carried out by I The entire atoll of TRUK 1B well surveyed and provides excellent anchorages for the ship1s guns. cc a large number of ships. The U. S. Hydrographic Office charts #6046 to #6051 were copied from the best Japanese charts available and may be referred to for information Four cruisers and two destroyers opened bombardment from the east at about 0900 on anchorages and passage through the reef. Many sunken ships provide a hazard to and continued till about 1030. The targets of the cruiser's fire were: eastern part navigation especially in the area of the former Japanese anchorages near DUBLON. of MOEN, DUBLON, and ETEN. The destroyer fired at HITSUJI. in Tides & Currents: The tides inside the atoll are Irregular and vary in range * Firing range's: Cruisers - About 15,000 - 20,000 meters. from I1 to 21 . Currents in the passes through the atoll are often strong, reaching Destroyers - About 10,000 meters. 5 knots. The currents inside the lagoon are weak, generally not greater than 0.5 knots. No particular damage worthy of mention was inflicted. MISCELLANEOUS. Our batteries maintained silence throughout, in order to keep their position secret; except for fire against enemy planes. Moreover, that night a sea plane was Interrogation of Japanese Naval Authorities (4th Fleet) regarding the operational launched from a secret base to carry out an attack on the enemy carriers. However, loss of the Japanese Submarine 1-169. the plane was lost and the attack failed. < CONDITIONS OF THE SINKING OF SUBMARINE 1-169. Materials delivered by Japanese Supply submarines to TRUK o The management of the submarine before and after the sinking was a matter in 1-362 (Entered harbor 21 Sept., !44) a. charge of the 6th Fleet. The exact details are not known to the 4th Fleet but are somewhat as follows: z Time: 2 April, 1944, about 1100 the submarine submerged to lie on the bottom Rations, vitamin foods, etc ------i#5 metric ton because of an air raid. It did not come up again. Aircraft parts & repair materials 30 metric cubic meters. Telephone & wireless telephone materials ------Z Estimated Cause; From the investigations of a diver after the sinking, it wa6 Construction materials, dynamite, fuses, etc ----- l metric ton determined that the upper valve of the storm ventilation tube in the after part of Medical supplies slight amount the bridge was opened about 80 mm. It is believed that they either forgot to close Mail ------— - - slight amount CO the valve when submerging, or that they opened the valve by mistake (assuming the Q valve was closed when the ship began to rise), and water flooded the ship. It is 1-363 (Entered 21 Oct., »44). Z believed that even though the watertight compartment doors within the ship were < closed, the ship could not surface because the control room was flooded or "blow" Rations, polished rice, vitamin foods, etc - - - - 16 metric tons. -j air was exhausted. Aircraft parts & repair materials CO Sulfuric acid, carbide, tools Measures taken after the sinking: Since the submarine did not surface after the Seeds for self sustenance air alert was over, a diver was sent down to investigate, and there were responses Medical supplies 1 metric ton. to hi8 hammer signals from four out of the five hatches—all except the conning tower, Mall ------____ ------slight amount. o thus indicating that the amount of water that had entered was very slight. Work was begun to hoist the bow of the boat (torpedo tube room) with a 30 ton crane, but about 1-365 (Entered 15 Nov., «44). oc 1530 on the 3rd, the cable broke while the boat was being hoisted, and we knew that the amount of water that had entered the boat was greater than we had estimated. Wa6 bound for MEREYON; we received only mall and some medical supplies. Even though holes for air supply were opened and air pumped In to blow the ballast tanks, at that time there were answers from only one of the compartments - the after 1-371 (Entered 18 Jan.,f 45). torpedo tube compartment, and we could not make the signal understood that those still alive inside should open the air valves to the ballast tanks. At 2330 on the third, Army signal equipment all answers from within ceased, and the attempt to rescue the crew ended in failure. Construction materials and tools. 3 The unceasing air raids during this time stopping the work, and the lack of sufficient Aircraft parts and repair materials. DC life saving apparatus made the task extremely difficult. \— Mail - ----__--__-_-- --_ slight amount Z The work was afterward continued by divers in order to determine the cause of Medical supplies about 1 metric ton the sinking, and to recover the bodies inside the ship. About 1& months were spent o CO and 32 bodies were brought up. 1-366 (Entered 13 Feb., »45). UJ CO After it was determined that raising the boat was impossible, the hull was de Rations, vitamin foods Z stroyed by means of depth charges, but not completely blown up. This demolition was in charge of the 6th fleet. (6th Fleet not present at TRUK at time of interrogation), Medical supplies „__--_--_------ 1.2 metric ton Signal equipment, spare parts, repairs. uu MTflflET.T.ANETHia. Clothing slight amount CO Aircraft parts. UJ Answer to questions submitted to Japanese Naval Authorities regarding the bom Some mail Z bardment of TRUK by a British Unit. 1-367 (Entered 4 May, »45). Army signal equipment. THE ATTACK ON TRUK BY THE BRITISH TASK FORCE, (By: Narrative By Japanese 4th Fleet Construction materials. Headquarters). Seeds for self-sustenance. Navy signal equipment, spare parts & repair materials. The attack began with a raid by four planes at about 0530 on 14 June, 1945, and Weapon repair materials & tools. until about 2230 that evening there were eight waves of about 15 planes each (SPIT Aircraft parts. FIRES). The main points of attack were all air bases, the 41st Guard Division, Ship Medical supplies ___-_-__---__--_ 3 metric tons. ~ 127 25' 30' 35' 50' NORTH PASS TRUK ATOLL LAMOIL I. NORTHEAST I. •FANUET I. FALAS I.V QUOI I. FANAMAR I. MOR I YAW ATA SHIM A NORTHEAST PASS 3 Of BEACH NO. 9 BEACH NO. 10 BEACH NO. 13 SMALL BEACH NO. 7 BEACH NO. 14 ELI KANIBU I. )M REEF 25' BEACH NO/ll ULALU I. BEACH NO. I BEAC^ H IW" BEACH NO. f EOT I. OUBLON l> TOL I. Q BEACH N0.3 Z EIOL I.® • FANAMU I. PA RAM TEN I. ONAMUEK* BEACH. NO. 5 20 1 . FALA PIAANU PASS * ONNA f BEGUETS CBEACH ALANELIMO I TORRES I 12 BEACH NO. 6 o FANURMOT I. TSIS a: • TONUAMU I. UMAN I. EDAT I. FANANAN I BEACH N0.4 ^ 0 O ^FANEU I. t— 5' •OZEN I. 15' :*: FALEU I. «& SALAT PASS •EO I. jfSALAT I. cc t— UPUT I«H\IOTTU I. Z o . NEURUI PASS to UJ ^FALEASIOZ REEF <^FANAN I. to & ULIGAR PASS Z 10' I04 OTTA PASS £• I M !^^UIJECDKN '' to MESEGON I. UJ FIGURE NO.60-LOCATION OF LANDING BEACHES z GIVRY I. 5' KUOP ISLANDS FOR MORE COMPLETE AND ACCURATE DATA SEE PART H , ENCLOSURES A -H 7°0' LAUVERGNE I. NAUTICAL MILES O 5 10 SOUTH I. 20' 25' 30' 35' 40' 45' 50' 55' I52°O' 5' 10' 128 BEACHES GENERAL. Dimensions; 3001 long. TRUK IF characterized by the paucity of landing sites for landing ships. TRUK Composition: Low earth fill with a rock sea wall along the face with top at o lagoon is about 30 miles in diameter, and is enclosed by a barrier reef. All of approximate high water line. o the large islands; DUBLON, TOL, MOEN, FEFAN, UDOT and UKAN lie within the lagoon. The large islands are fringed by wide reefs and mangrove swamps with steeply rising Suitability; May be used by all type of landing craft. I hills and mountains Just beyond the mangroves. Sand beaches are rare on the large cc islands and where found are usually Inaccessible to landing ships because of the Landmarks: An earth fill projecting into the bay with several houses built reefs, The terrain behind the beaches is swampy, usually hilly and wooded. Dis along the seaward edge* 2 persal areas are restricted and movement for vehicular traffic is rather difficult. Approach and Hazards: Clear deep water approach through a wide channel into The small islands are also surrounded by fringing reefs, and occasional man the bay. No obstructions in the channel, coral reefs on both sides. grove growth, but in general they have scndy beaches and a low sandy interior cov ered with trees. Surf; No surf, well protected. An effort was made to approach possible landing sites over the reef. A Jap Contiguous Terrain: The flat low landing area has a strip of low ground be z anese "DAIHATSU" (large landing craft) was used for this purpose. Its forward draft hind this area. was about 1' and about 2.5' aft. During most of the survey there were good boat ing conditions because of the light winds and consequent fairly smooth water, Nor Exits and Dispersal: A 50' wide causeway with a rock road leads to the flat mally the "DAIHATSU" grounded when an attempt was made to pass over the reefs. The dispersal area along beach. Roads run along shore line and connect with the main 13 average depth of the v/ater over the reefs was about 2.5' road system. During the survey of northern TOL a northeast wind arose which attained a vel o ocity exceeding 18 knots. The waves broke over the fringing reef and it was dan Q. gerous to approach the reef in the "DAIHATSU". z Obstacles, small model mines and stone walls were employed to hinder landings on the islands. Details are shown herein on charts of the islands on which the installations existed. Gunfire defenses are covered in ARTILLERY AMD ORDNANCE section DUBLON ISLAND of this report. SEAWALL MEAN SEA LEVEL Z 1 Very little surf was observed during the 10 day stay at TRUK. The barrier reef -o \J m M M •— Ml • •"•• — has a great influence in keeping the waters within the lagoon in a relatively calm • S *m •m. " 1 B • M a. •m to B -• . m state. In fresh winds light swells were observed. m «l " • K •» •• H n Q >. H> Z • > "1 Elevations are from mean sea level. - m- m DUBLON. •= -20 0' 50' 100' 150' BEACH NO. 1. FIGURE N0.6I - PROFILE OF BEACH NO Location: On the northwest side of the island between two piers. o Dimensions: 3001 long. Composition: A loose rock sea wall, I 1 elevation, flat ground behind level with top of the sea wall. Small boat ramp 40* wide at north end. o Suitability; May be used by all types of landing craft. Large craft may not be able to reach the shoreline. Landmarks: The two piers with sea wall between. Approach and Hazards: Approach is clear of shoals until within 601 of the sea Z wall where a coral reef with 2 1 of water over It lies near the center of the beach. o Landings may be mada on either side of this reef or over It at high water. to UJ Surf: No surf in ordinary weather. in Z Contiguous Terrain: Flat area behind the beach with steep hills rising behind this area. Exit8 and Dispersal: The flat area behind the beach is a good dispersal area with roads leading along the eeacoast in both directions. Connects to island's UJ main road system. z Profile: Taken near center of beach. Q. Improvements: Sea wall must be breached for tanks, or ramps built. BEACH NO. 2. Location: On the south side of the large cove on the ea6t side of DUBLON. AIR PHOTO SO. l, BEACH NO. i Picture No. 9^2 (PM 1) DUBLON: Looking southwest Beach faces north. DUBLON, SCALE i .'5 , ooo. at beach No. 1 and Pier No* 2 . 129 BEACHES Profile: Taken near east and west sides of the beach. Exit8 and Dispersal: The area behind the beach is flat with approximately I1 elevation; the flat area can be used for dispersal. A road leads Inland from this Improvement at A ramp should be built connecting the fill to the old shore area and Joins the main road system. line all along the beach. At present only a 50* wide ramp exists. BEACH NO. 3. o Location: On the south side of the Island off DUBLON Town area. I ! 1 DUBLON ISLAND 400 long. SEAWALL MEAN SEA LEVEL Composition: Concrete and stone sea wall with a 95' wide boat ramp leading -o1 into the water. Two piers located on the landing area. * r in s, • E y ffl i mm - X Suitability; All types of landing craft can use this landing area. • < -1 t F • Landmarks: A marine railway is on the east side of the landing area* Two J m wooden derricks and several sheds are in this area. s = t4- -20' Z Approach and Hazards: Clear, deep water approach to the sea wall or piers. * B Surf: No surf. 0' 20' 40' 60' 80' 100' Contiguous Terrain; Flat area behind beach with a hill rising steeply behind FIGURE NO.62 PROFILE OF BEACH N0.2 this flat area. Area on either side of beach is flat. o a. Z DUBLON ISLAND -, SEAWALL MEAN SEA LEVEL z -0 CO Q Z -20' to o 0' 20' 40' 601 80* 4 0 FIGURE N0.63-PR0FILE OF BEACH N0.3 O AIR PHOTO NO. *. BEACH NO. 2, AIR PHOTO NO. 9. BEACH NO DUBLON, SCALE 1:5,000. DUBLON, SCALE 1 ."5. 000. z o CO UJ to Z UJ to Ul z Ptcturg JVO. 999 (PM e, ) DUBLON BEACH -SO. 2 :» 'Li* ohn? Picture No. 3CJ4 (PM 4) DUBLON, Remains of small boat Pictur e No. 99 5 (PM 11 ) DUBLON: From seaward, lookin g nort hue st from hi\L I : be hind hideou t near beach No . ^. north a t beach No. 9. ^M±J i .. 130 BEACHES a Profile: Taken off sea wall near center of beach. Contiguous Terrain: The area behind the beach is the flat sea olane narking area with hills rising in the background. Improvements: None necessary. Exits and Dispersal: The se* plane area provides good dispersal and roads lead o Defense: A stone wall 51 high and 31 thick runs along the beach about 50* back from the area In an east and vest direction along the seacoast. of beach. o Profile: Taken near east end of beach. I BEACH NO. 4. Improvements: Necessary to flatten the sea wall. It is constructed of loose Location: On the south side of the Island off the seaplane base. rock and this would be easy, A low spot near the center of the beach area should be filled. Dimensions: 1200' long with two 100' wide sea plane ramps. Defenses: Concrete obstacles were placed at the heads of the sea plane ramps. Composition: A rock sea wall, 51 elev., with ground behind, 21 elev. Two They were loose blocks of concrete laid on the rarap. Two rock and earth pillboxes concrete seaplane ramps, one on each side of a concrete pier. were located 50* west of the western sea plane ramp, m Suitability: May be U6ed by all types of landing craft. ETEN. Z Landmarks: A concrete pier with crane mounted on its outboard end marks the BEACH NO. 5. east end of the beach. The concrete ramps and concrete pier lie on the western end. Location: On the northwest side of the island near the center of the airstrip. Approaches and Hazards: The approach to the beach are I a channel CQ between ETEN and DUBLON. Close to the beach there are a few coral heads. They Dimensions: 4001 long. cr.n be avoided. The approach to the sea plane ramps is clear. o Surf: Very little surf. a. Z KJ DUBLON ISLAND z SEAWALL MEAN SEA LEVEL 1 CO -o Q Z -J CO LU -20' 0' 40' 80' 120' 160' Z FIGURE NO. 64-PROFILE OF BEACH N0.4 O AIR PHOTO NO. 4. BEACH SO. 4 AIR PHOTO NO. 5. SHOVING BEACHES NOS. 5 O DUBLON, SCALE 1 : 5 ,000. ETEN, SC4LE 1:10,000. z o CO LU LO z ux Q LU CO LU Z Picture No. 396 (PM 17) DUBLON: From sea plane ramp Picture No. 997 (PM 20) DUBLON: From seauari at sea Picture No. v?8 (PM 158 ) ETES: From, ie award I looking east at beach .V o . 4 ani Pier No. 7 . plane ramp on west side of beach No. 4. southeast at beach No. 1. 131 S JAPANESE DEFENSE SON TRU KATOLL, CAROLINE ISLANDS. CINCPAC-CII MCPOA BULLETI N3-46, 15 MARCH 1946.\ CONFIDENTIAL to break Intheseaw end ofarea.All load ovexthesea near thesouthwest lees arampwabu clay) levelwitht parts oftheislan BEACH NO.6. concrete pier. Ing areawithdeep then straightI on theothersid loading. the hillsonDUBLO 300' airfield. for landings. inland, levelwltt coralreefst Landmarks: Suitability: Profile: Composition: Exits andDie Approach and Improvements: Contiguous Te Location: On Defenses: Surf: Dimensions: Composition: Nosur Tak Co we st Pict T - persal: \ L Hazards: all. wall. he topof d. types oflandingcraftmayusethibeach.Larg< of theisland. rrain: f. vered frompositionsinthehillbehinairt N. lit ortheywererestricteda30'vidrampnow oward thesea lie smallramofthsouthwestendbeachcanb en nearcenteofbeach. arts 100 1,000* alongthenorthwestfacand50 thetopofsea ure A smallboatramp30'widewith15$slopliesne? A rocksea water between. end ofthebeacharea. the northwestsidofETENa]ongsouthwess A rockseawall5 corner Breaching theseawallandbuildinrampswoul. No.q?g(PM Thenortheastsidofthbeachis500'sout Smalloraftwouldberestricteolanding Areasurroundingthelandinisflatexcep' ofthe Theairfieldprovidesgoodispersalan< ApproachthrougTAKESHIMAChanneliscl< 1 wall. northeastofthenorthwescornerandis wall, wall. islandlooking northeast. i57J 4 1 1 Coralreefexistsoneachsid< elevation,withaflateart wall. elevation,vlthflatareabehl ETEN: Fromseawar d off north x ir thesouthwest sxits toall rip andfrom nd gravelarea ction ofthe Lnd (gravelanS\ ;raft canun Dersonnel un t forthehill 3ar ofreefs west froma facilitate un- 3 oftheland- southwest face, - in existence seen asa not suitable J>! hindtl alrplai E: L* BEACHES wall, vithoui loading AT Ii C< D sjidmarks: tits andDispersal:Therunwaymakeagooexitdispersalarea. jntiguous Terrain:Largeflatareaofthrunwaybehindlandingarea, sfenses: Dprovements: irf: Dproach: Deepwatertoseawallwithtwcorashoals1.000 ; improvements. iltabillty: Largecraftcanlandvehicles. le sea ie revetmentwaslocatednearthnortheassidoflandingareaJusbe OH They arelocatedonthH.0chart. Nosurf, FIGURE wall. AreacoveredfromhillonETENanthehillssoutherDUBLON. *" "•" Thecornerofthseawallwithwoodenone-storyhouse.Aearth ft 0' s Breachingtheseawallandbuildinrampswoulfacilitatun 100'200' NO. E (- SCALE AIR PHOTONO. 6,BEACHESVOS.7 &8. 65— 1:5,000. L L •> E PROFILE 1 E 's J 1 C L S ./ s A OF \ Smallcraft,personneonly C ) k BEACH MOEN, A s E /: U NC c ;E s :A 1 offthesea ). -40' -0' LEVEL 5S6 2O on 1 BEACHES MOEN. Exits & Dispersal: The airfield with surfaced runways and parking area mokes a good dispersal area with roads leading in both directions along the coast. BEACH NO. 7. Profile: Taken near north and south side of beach. Location: On the southwest corner of the island facing west off the end of o airfield Nc. 2. Improvements: Ramps built out to deeper water and the removal of several small coral heads would be desirable. Dimensions: 500' of sand beach 10' wide with a 75' wide seaplane ramp Just south of the sand beach. Defenses: A pillbox is located at the head of the Jetty. The north side of the seaplane ramp has coconut log piling driven along the water edge, Composition: Fine sand vith lc$ slope. BEACH NO. 6. Suitability: Good landing beach for small craft. Large landing craft will ground short of the beach, and earthen or floating ramp would be necessary. Location: On the southwest corner of the island facing south. 1 Landmarks: A small coral jetty marks the north side of the beach. The sea Dimensions & Composition: 650 total length. From west to east is a 350' CO plane ramp marks the south side. rock seawall with its top at high water level, a 140* concrete seaplane ramp, and z a 1601 rock seawall at high water level. The area behind the seawall is earth and Approach: Clear approach to within 500' of the beach where small coral heads gravel fill sloping from the top of the seawall inland with a b% gradient. with 1 fathom or more over them will be sncountered. Within 1501 of the beach there are two small heads with •£ fathom. Suitability: May be used by all types of landing craft. CQ Surf: No surf with prevailing winds. Landmarks: Flat area behind the beach with the air strip behind. The concrete ramp marks the beach. o Contiguous Terrain: Area behind beach is the flat low airfield with hills rising behind. Approach & Hazards: Approach is clear of reefs straight in to the beach, A a. shoal coral reef on the west flank extends well offshore. Z QL. Z — NO. SIDE MOEN ISLAND — SO. SIDE MEAN SEA LEVEL EASTPS,DE ISLAND — 0' i—i - WEST SIDE MEAN SEA LEVEL z -. m •asa - -a •• •to. aa -» — mm • * •a •V ! a > aa -0' la. •K M • a ai •aa •• • •a a,, a. > « t to a "a. aa k a an • *> •a. a • a . Ba ka. aa - i •a. a) aa a. •a •aaa ai a ««, aa -a •a s •• -. -20' ]' a. te I . .11 20 o *t 0' 20' 40' 60' 80' iod ' 0' 200' 400' 600' FIGURE NO. 66-PROFILE OF BEACH NO. 7 FIGURE NO. 67-PROFILE OF BE£ o CO LU CO Z LU z Picture Ho. mo (PM IQ8) HUES Looking north f r u Picture So. -j .j l \ P^ 204) .V 0 E S : From s e au J r 1 looking Picture No . j 4 •<> (PM jo^J MOES: Fro m seawar d lookin g s out n en1 of beach So. 1 . at soutnwest half u f be2cn So. at northeas t hal f o f beach So . 2• 133 BEACHES Surf: The prevailing winds cause a light surf on this beach. Approach & Hazards: Clear approach straight In to the beach with no reefs. A coral reef extends offshore northwest of the landing area. The southwest half of Contiguous terrain: Flat area behind the beach with the hills rising abruptly the beach is shoal with a few rocks for the last 150'. behind and to the east. Surf: No surf. This beach is protected from the prevailing wind6, and there o Exits & Dispersal: The air field provides good dispersal and exit to the roads is no surf. which lead along the seacoapt in both directions. I Contiguous terrain: Flat airfield area behind the beach. This is very low Profile: Taken at east and west side of beach and off the seaplane ramp. ground approximating I1 elevation. Behind the field to the east a hill rises abruptly. Improvements: No improvement necessary. Exits & Dispersal: The runway and parking area makes a good dispersal area Defense: An earth revetment lies near the center of the beach Just behind the with roads leading south and east. water line. It is 301 long and 51 high, Profile: Taken near north and south ends of beach. BEACH NO. 9. Improvementa: Extension of the filled area for approximately 1501 on the south Location: On the northwest side of the island along the southwest end of air west half of the beach, field No. 1, facing northwest. BEACH NO. 10. Dimensions: 600' long. Location: The southwest end of airfield No. 1, facing southwest. Composition: Rock and earth fill for the airfield. < Dimensions: 5001 long. Suitability: The northeast half if filled out 150* farther than the other half o and is suitable for all types of landing craft. The southwest half can be used by Composition: Irregular gravel beach. CL small craft now or large landing craft after Improvement, Suitability: Can be used by all types of landing craft. Landmarks: Near the southeastern corner of the airfield. Z CO MOEN ISLAND MOEN ISLAND MEAN SEA LEVEL MEAN SEA LEVEL Z r > •fc, . ft 1 s Si y >s *• H: F -o >s s. y s s fca, s s k s * -20' •a —« Ma -20' 0' 100' 200' 300' 400' 500' 0' 100" 200' FIGURE N0.68-PR0FILE OF BEACH NO.9 FIGURE NO. 69-PROFILE OF BEACH NO. 10 t— Z to Z. z Picture No. ?4? (PM 211) MOEN: From seaurl Looking Picture No . ^44 { PM 2 ICJ ) MOEN: h rom se awarl Looking AIR PHOTO NO. 7 BEACH NOS. q b 10. MOEN northeast at beach So. 9 . northeast at b e a c n No. 4. SCALE 1:5, 000. 134 BEACHES 1 Landmarke: The south end of the surfaced air rield. Very low, I elevation. Except ior strong east to south winds, there appears'to be very little surf which would hinder landing ships. + Approach: Clear deep water approach with no shoals. o The beach defenses are covered in other sections of this report. Surf: Well protected from prevailing winds, no surf. o X Contiguous terrain: Very low flat airfield with a steep hill rising behind and to the east of the beach. Exits & Dispersal: Airfield makes a good dispersal area with exits along coast line in both directions. Profile: Taken near northwest and southeast side of beach. Improvements: No improvement necessary. TOL. Because of the presence of many reefs, coral heads and mangrove swamps together with the hilly terrain, TOL offers very little in the way of landing sites for land ing ships. All the piers except those specifically described are primarily for small craft. The best, and perhaps, the only feasible beach exists on the southwest tip of o POLLE Peninsula situated on southwestern TOL. The harbor is known as ILLICK Harbor, As can be seen from H. 0, Chart No, 6049, the entrance to the harbor is re stricted by the reef which encloses the harbor except for two narrow passages. The southeast passage is approximately 350 yards wide while the narrower passage to the southwest of the wider passage is approximately 150 yards wide. There are numerous small coral shoals lying to the southeast of the wider passage. Consequently the approach into the harbor 16 hazardous for landing ships. There is deep water to z the pier. The beach is approximately 1,800' long and averages about 251 in width. <^> The best water lies to the westward of the pier which is near the right flank. The best landing areas for an LST are to the right of the pier, and the area extending CO 200' to the left of the pier. Farther around to the left or westward, the beach Q becomes less desirable because of coral reefs close to the beach. Z A road parallels the beach in the vicinity of the oier. The terrain behind to the beach is level with open type vegetation (over-hanging coconut trees) and is suitable for vehicles. Dispersal areas are available behind the beach. AIR PHOTO NO. 8, BEACH ON SOUTHWEST TIP OF POLLE PENISSULA o ON TOL, SCALE 2:5,000. o o LLJ z z Picture No. ^4^(PM 457 ) TOL: Looking east alon f landing Picture No. ? 4 6 (PM 459J TOL: From seaward looking Picture No. 347 (PM 458) TOL: Looking west along landing beach on s out hwe st side POLLE. north at Landing b e .. beach on s out hwe s t side of POLLE 135 BEACHES z o UMAN. PARAM General: Entire island surrounded by shoal coral reefs making landings dif Like the rest of the islands of TRUK, it is surrounded bv fringing reefe flcult. southeast coast bordering the airstrip is not suitable for landing ships because of the reef and coral heads. There are mangroves and a retaining wall of stone along BEACH NO. 11. the seaward side of the airfield. There are numerous reefs and coral heads in the approach from the southeast which also present a hazard to landing sni^?. Location: On the north end of the island along its western face. The northeast coast is not suitable for landing ships because of the wide shal Dimensions: 1,000* long by 201 wide. low reef. Composition: Firm sand. The most probable landing site is on the western side of the island Just to the north of the road which crosses to the airstrip. The beach is 2801 long and Suitability: Small craft can get close to the beach at high tide; care must about 81 to 10* in width. Coconut trees are at the water's edge at high water. z be used due to many shoal coral heads. A dirt road parallels the beach, A road Intersecting the beach road near Landmarks: Flat area surrounding beach with a snail wooden pier near the south the right flank of the beach runs across to the air strip. Also a road runs from end of beach. the center of the beach inland and is suitable for dispersal in the area behind the beach. Approach and Hazards: Clear approach to vrithin 2001 of the landing beach, then the coral reefs are numerous and shoal into the beach. Probably landings would have Approach to the beach is from the southwest. There is deep water up to the a. to be made by troops wading ashore or by amtracks. reef which extends .abo r 60 yards off the beach. However, it is not suitable for landing ships becr-v.r° ^ the reef. It could be used by amphibious vehicles. Z Surf: Light surf with westerly wind. UDOT AND EOT. Contiguous Terrain: Flat area behind beach with steeply rising hills zo the south. A survey of UDCT and EOT Islands reveals that they are not suitable for land ing ships because of the reef which surrounds both islands, and the many coral heads A road leads from the area in a southerly direction. and mangrove swamps. The piers are essentially for foot traffic and for unloading z small craft, FALA-BEGUETS. to FEFAN is in general mountainous, rising steeply *_om the coastline. The beaches Q which could be used are meager and movement inland would be difficult. The entire BEACH NO. 12. Z coast except for small areas is mangrove lined and the fringing reef which surrounds the island makes it unsuitable for landing ships. All the piers on the island ex- Location: On the north side of the island near western end. CO cept pier "M" are for small boats and foot traffic only. Pier "M" could be used to unload landing ships bow to end of pier with ramp on pier end. Dimensions: From west end of beach area 300* of landing area, 200' of shoal Z mangrove flat, 3001 of landing area. Sand area is 101 wide. The most suitable landing site is in the vicinity of pier "M", There are num erous coral reefs to the eastward and northeast of this pier which would be haz Composition: Sand beach with 10# slope. o ardous for landing ships, but small boats could land at 'ligh tide if care were taken to avoid coral heads. Suitability: Small landing craft. O a: »— O z ui z Picture No. 148 (PM 9 g 0 )*>, F Of A tf:. Looking north at Picture No. 34 q (PM 476) UDOT: Loo km? north from Picture .V 0 . j 5 0 ( PM 4 7 H ) UDOT : From se i L 0 0 n shoreline north of p i e r» j pier No. 1. southeast in vicinity of pier Mo. 5 . 136 BEACHES /£S V... tt. 1 fc.' «i Landmarks: A small corrugated iron house stands near the center of the west Contiguous Terrain: Flat low sand spit with flat low wooded area to the north half of the beach. east. o Approach: Several narrow channels through the outlying reef into a shoal Exits and Dispersal: Good dispersal area northeast of beach with trails lead fms average depth) lagoon. The best channel is to the west of the beach area ap ing north and east along the coast line. proaching on a southeasterly course. Few shoal coral heads inside the lagoon. Profile: Taken near center of beach. I Surf: None# Improvements: None necessary. Contiguous Terrain: Flat low grassy area behind the beach with hills rising 2 TARIK. Just east of the landing area. Flat area probably swampy after rains. in o Exits and dispersal: The flat area behind the beach can be used for dispersal, TARIK offers no suitable landing beaches for landing craft. A coral reef en A road runs east along the beach and one rune south along the foot of the hill. circles the island and would prohibit boats drawing over 21 from crossing the reef. At spring high tides small landing craft could probably cross the reef. The piers Profile: Taken near center of beach. are poor and could not be used except for very small scale operations. UJ Improvements: None necessary. TSIS. ULALU. The entire island is surrounded by a shoal coral reef awash at low tide with 00 a deeper lagoon inside the reef. The fringing ree* rises abruptly from deep water. < BEACH NO. 13. Possible for small landing craft to cross the reef at spring high water. The north ern half of the Island has sand beaches. o Location: On the northwest side of the island. a. TONELIK. Description: A firm sand beach 300' long by 15' wide with a 10$ slope. May z be used by small landing craft for unloading personnel. Approach through a break The only approach through the coral reef surrounding TONELIK is on the south v in the fringing reef but many coral heads exist in approach area. Approximately side through a channel 60' wide with 3 to 5 fathoms up to the pier. This approach 60• off shore is a ragged coral reef with less than 31 of water covering it. Per leads to a cement pier to which had been built a coconut extension at an angle of sonnel oould wade ashore from this point. Area behind beach is flat and heavily 40°. This pier leads to the only path on the island and the beach on both sides is u wooded. marked by upended coconut logs and massive piles of coral to prevent any landings. Z The beach itself was of small pieces of coral extending completely around the is land. BEACH NO. 14. CO Location: On the southwest corner of the island facing north west. The approach was not mined and neither was the area within the pier. The is a land was so small that the guns on the island could be moved to cover any of the z Dimensions: 250' long with a b% slope. beaches. CO Composition: Firm sand. Landing is on a sand point 40' wide at southern end PIS. of beach and 200' wide at inshore end. The approach to PIS Island is through a channel 80' wide. The pier is of Suitability: All types of landing craft can use this beach. coral rock with 500' beaches on both sides suitable for landing operations. No defenses were located on PIS Island. o Landmarks: At the end of the wooded area on the southwestern point of the < island. FALEU. Approach: Clear approach through a channel the width of the beach. Sand There is a small beach approximately 150' long on the southern tip of the bottom all the way to the beach with no coral heads. Shoal reefs on each side of island. It is suitable for amphibious operations. It has a sand and rock bot the approach channel. tom. The west end of the beach is bordered by the only pier on the island. The rest of the beach surrounding the island is shallow and a reef exists 50 to 100 Surf: No surf with prevailing winds. yds from shore. There were no obstacles on FALEU. Z o CO UJ CO Z FALA-BEGUETSISLAND ULALU ISLAND UJ VIEAN SEA [-EVEL Q UJ MEAN SEA LEVEL CO ! J _ -0' -0' UJ m m a n >1 It, Z •N •• * m • ••a • HI a a •• as •i •at a • • OB >• Bi Bi •a •B aa 91 m mm •• •i IB -- • •ai •• m • Bi »•» ai m m m wm ae •a >c •T8™ *•• Bl BR *»s -20 -20' 0' 100' 200" 300' 400' 0' 100' 200 "i ; 300' i, FIGURE N0.70-PR0FILE OF BEACH N0.I2 FIGURE N0.7I-PR0FILE OF BEACH NO. 13 137 AVIATION GENERAL. PERIOD UNIT COMPLEMENT AIRCRAFT I At one time TRUK had powerful air defenses and, in addition, was i^aed as the ? u major staging point for aircraft to RABAUL, the SOLOMONS, the MARSHALL'S and the 3-44 to 5-44 202 Carrier Group Zero Fighters 20 GILBERT Islands. However, Japanese air power would have played a very small part 7-44 to VJ Day East Caroline Air Group 950 Zero Fighters 7 in the final defense of the islands, as American aircraft had almost completely de SAIYUN 4 stroyed all air facilities and aircraft. MOEN, Airfield No. 2. CONSTRUCTION OF AIR FACILITIES. 2-44 to 4-44 902 Air Group ? Type 0, 6 The Japanese furnished no date on the construction of ETEN Airfield, which was Recon. Seaplane their only Class A field. It may be presumed that this was completed before the Type 0, z outbreak of hostilities- Ob se rv.Seaplane 2 UJ 5-44 to 6-44 253 Air Group ? Zero fighters 8 5-44 to 6-44 151 Air Group ? Type 2, Carrier 8 Construction was started on MOEN Airfield No. 1 in November, 1941, and complet Recon. ed in December, 1942. The MOEN Seaplane Base was started in November, 1941, and z> 7-44 to 8-45 East Caroline Air Unit 00 completed in April, 1943. MOEN Airfield No. 2 was started in February, 1944, and was rapidly completed by May, 1944. PARAM. o The PARAM Airfield was started in June, 1943, and was completed by January, a. 2-44 to ? 562 Air Group 1944. 40 Type 97, Carrier 5 u Bomber z The DUBLON Seaplane Base was started in March, 1942, and was completed in 2-44 to ? 251 Air Group 150 GEKKO 10 August, 1942. In March, 1944, an attempt was made to convert the parking area (night fighter- into an air strip but this effort was abandoned because of shortages of material no radar). in June, 1944. 2-44 to 7-44 551 Air Group 600 TENZAN 27 z Type 97, Carrier 13 An air strip was also planned on MESAGON and work was started in January, 1944. Bomber 3-44 to 5-44 503 Air Group 450 SUISEI 45 This work was soon stopped due to shortages. Type 2, Carrier CO Recon 3 a In general, construction work was very difficult due to lack of materials and 6-44 to 7-44 301 Air Group construction equipment. For the same reasons, repair of runways was difficult. 200 No planes. z The Japanese were never able to maintain a repair-rate equal to the destruction- 7-44 to VJ Day East Caroline Group 460 No planes. rate after sustained air operations against TRUK were started. CO ETEN Airfield. DISPOSITION OF AIRCRAFT. 6-43 to 3-44 101 Base Force 260 No planes. i'he table below showing the disposition of aircraft at the various fields is 2-44 to 3-44 204 Air Group 200 Zero fighter. 80 2-44 to 7-44 253 Air Group probably not too accurate but will give some idea of the effort made by the Jap 600 Zero fighter. 20 o 3-44 to 7-44 251 Air Group 250 GEKKO 10 OS anese to maintain control of the air in the vicinity of TRUK. It is difficult to 2-44 to VJ Day East Caroline Group believe, for example, that no fighters were stationed at ETEN Airfield until Feb 250 No planes. ruary, 1944. DUBLON Seaplane base. O Disposition (Distribution) of Aircraft; i— MOEN. Airfield No. 1. 12-41 to 4-42 17 Air Group 300 ? ? 4-42 to 7-42 4 Base Force 120 Type 94, Recon 4 PERIOD UNIT COMPLEMENT AIRCRAFT Seaplane. 7-42 to 11-42 21 Air Group 500 Zero Type Recon 16 8-43 to 11-43 1st Air Squadron ? TENZAN 12 Seaplane. Z 12-43 to 2-44 2nd Air Squadron ? SUISEI 12 Type 97, 5 1-43 to 2-44 11th Carrier Force ? Type Zero Transport 9 Flying Boat. o (Twin Engine) CO 11-42 to 8-44 902 Air Group 800 Zero Recon. 20 UJ 1-44 to 3-44 582 Air Group ? TENZAN Type 97, 10 Zero Observ. 16 CO Carrier Bomber 6 Type 97, Flying 9 Z 2-44 to 3-44 753 Air Group ? Type l,Land Bomber ? Boat. ? ? 705 Air Group ? Type l,Land Bomber 40 8-44 to 11-44 4th Fleet Air Group 300 Zero Recon. 5 2-42 to 11-44 22 Squadron ? Type 96,Land Bomber ? 4 engine transports 2 UJ Type 0, Transport ? 11-44 to VJ Day East Caroline Group 370 Zero seaplane 6 CO 3-44 to 7-44 755 Air Group ? Type l,Land Bomber 6-8 4 engine transports 2 UJ 4-44 to 4-44 151 Air Group ? Type 2,Carrier 3-4 Z Recon as z""5 > 138 AVIATION DESTRUCTION OF JAPANESE AIR POWER AT TRUK. Damage Ships: I During the GILBERTS and MARSHALLS campaigns planes were staged forward from SHIPS DESTROYED BADLY DAMAGED SLIGHTLY DAMAGED TRUK but no active part was played in the campaign by the forces stationed at TRUK. 500 to 1,000 tons 1 In February, 1944, TRUK had strong defensive air forces and, in addition, had Smaller 28 11 5 many planes waiting to be staged to RABAUL. When a reconnaissance plane appeared over TRUK in early February, all forces were fully alerted for several days. The Airplanes on Land. VF VB Heavy VB Reconnai ssance alert was finally ended and the carrier planes struck the next day, achieving al most complete surprise* The devastating effect of this raid can best be seen from Burned 12 13 3 10 o the table below giving Japanese figures of their losses. Badly Damaged 5 Z Damage - February Carrier Raid: Aircraft in Air: VF VB Heavy VB Destroyed 27 ISLAND BLDGS. PERSONNEL VEHICLES CLOTHING FUEL MATERIAL FOOD oa Dest.-Damaged Dead-Wounded Dest.-Damaged Dest. Dest. Dest. Dest. At the time of the MARIANAS campaign the air strength at TRUK had been built < up to a total of about sixty planes, half of which were fighters. Also about five DUBLON 21 3 28 19 of an original ten night-fighters were left* These however were not equipped with o MOEN 5 3 1 12 radar and were very ineffectual. All of the planes, with the exception of the night ETEN 12 1 17 fignters, were used in the MARIANAS campaign and most of tnem were lost. a. PARAM 1 6 1 TOTALS 40 7 52 32 13 10 88 tons 30 tonfe - 240 tons- 57 to After the MARIANAS campaign the remnants of five air groups were combined and z reformed as the East Carolines Air Group. Total planes available were eight fight Damage - February Carrier Raid (Ships): ers, three night-fighters, and six reconnaissance seaplanes. Z SHIPS SUNK OR BURNEDi BADLY DAMAGED As the land-based multi-engine planes began regular attacks against TRUK, the u Japanese were powerless to defend themselves. Fighters were ordered to attack only 10,000 tons, plus 8 single plane8 and no attacks were made on large formations, as they systematically CO 1,000 - 10,000 tons 18 wiped out all installations above ground. The Japanese found themselves hard pres Q 500 - 1,000 tons 2 sed to maintain even a landing runway for their carefully hoarded handfull of planes. Less than 500 tons 6 5 Z However, TRUK did serve as a reconnaissance base. When the B-29s started at Damage - (Planes): tacking JAPAN, five "SAIYUNS" were sent to TRUK from JAPAN. The Japanese claim that four trips were made to the MARIANAS and ULITHI and that all the bombing of the UJ Planes on Ground.. VP^ VB Hvy Bombers Re connals san c e VP MARIANAS was done from information secured by these planes. Z Land Sea Land Sea -j Burned 90 5 43 1 5 60 0 In February, 1945, four more "SAIYUNS" were sent down to do reconnaissance work. Badly damaged 16 0 6 4 0 4 2 They made ten trips to ULITHI and two to ENIWETOK. They also made pictures before o and after the suicide attacks at ULITHI. Planes in Air: VF (sea) VF & VB land < In July, 194o, pianes were getting old, so replacements were sent via MARCUS. 6 to 8 15 to 18 However, these planes were either attacked or caught in a MARCUS raid, as only one arrived. They next decided to send planes by submarine. The F-14 arrived with two, o After the February Carrier-raid the Japanese managed to repair fields and stage but VJ day arrived while they-were being assembled. in more aircraft, although attacks on a small scale had begun by multi-engine, land- based planes. The carriers returned in April after the HOLLANDIA operation and » A full-scale attack from TRUK on the carriers at ULITHI was being planned. struck again with such force that the Japanese never recovered. Results of this Twenty-four "GINGA" were to make a "Kamikaze" attack. Efforts had been made to raid are tabulated below. lengthen the runway at PARAM to 1800 meters in preparation for receiving these planes but work was abandoned in May, 1945. Z Damage - April raid: o TRUK was almost completely cut off from JAPAN after the PHILIPPINES campaign CO ISLAND BLDGS. PERSONNEL VEHICLES started. However they did succeed in getting one flying boat through each month] UJ CLOTHING FUEL MATERIAL FOOD CO Deet •-Damaged Dead-Wounded Dest.-Damaged Dest. Dest. Dest. Dest. flying during the period of the full moon. Z Ul DUBLON 110 31 42 132 After VJ day., total air strength remaining in TRUK was as follows: u. MOEN 48 21 49 58 Ul FEFAN 13 4 "SAIYUN" (Myrtle). 4 (two serviceable)• a 1 Ul UMAN 3 0 Zero Fighter. 3 CO ETEN 29 1 3 2 Type 97 Carrier Attack. 1 UJ PARAM 23 4 25 36 Zero Reconnaissance Seaplane* 3 PATA 1 0 1 z ULALU 7 5 A complete description of airfields and air facilities will be found in the TOTALS 234 62 - 123 230 - 4 15 - 182 tons - 10 tons - 665 tons-285 to Engineer's Section. J 139 AVIATION O a. Z z 1 Q Z 47/? PZ/OfO A^O. 9. PARAN AIRFIELD. o a: o I— z o LU CO Z LU z AIR PHOTO NO. io. ETEN AIRFIELD VITH DUBLOS SEAPLANE BASE IS BACKGROUND. 140 JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1946.! to JAPANESE DEFENSES ON TRUK ATOLL, CAROLINE ISLANDS. CINCPAC-CINCPOA BULLETIN 3-46, 15 MARCH 1946. TJA r *-t ; c > > o MEDICAL AND SANITARY CONDITIONS INTRODUCTION. The main hospital on DUBLON consisted of several large wooden structures, well o ventilated but with no screening. There were five wards: a contagious ward; sur Many of the hospital facilities for both Army and Navy were not functioning gical building; administrative building; warehouse; bacteriological laboratory; and I in their original capacity; buildings had been destroyed or torn down or activities several barracks with galleys. Other buildings were destroyed or in the process had been abandoned and removed to the central hospitals. Information extracted of being torn down to provide building material on other islands. Of from documents and translations received in reply to a series of inquiries were for the most part verified by personal investigation and interviews with both Army and The wards were large single-storied buildings with wide verandas encircling 2 Navy medical officers, Japanese medical officials and their assistants were co the central ward space which were utilized for bed space. By using all available in operative In facilitating this investigation. In many cases questions were antic floor space 60 to 70 steel cots could be Installed in each ward. A small isolated ipated and data was collected before the interview. As a whole the sources of infor building was employed for the tubercular and open paratyphoid patients where rigid mation were reliable. Surgeon Captain TANEDA, Surgeon Cmdr. Takeo OKAMUHA, and mask and gown technique was employed. Pharmacist Cmdr. MURAKAMI gave much assistance in completing this investigation The main wards were about evenly divided length-wise into surgical and medical z GENERAL. cases. All buildings were on raised platforms and seemed reasonably clean. The medical facilities seemed adequate; In general the military patients were Two large well-lighted rooms with concrete floors were used as operating rooms; receiving satisfactory medical treatment according to their standards. But it was each held two tables and were in a separate building with a scrub room, sterile difficult to supply proper food to malnutrition cases because of the -scarcity of goods supply room and officers1 dining room. The nearest surgical ward was 50* to CO provisions. 60' away. < The supplies of medicine and equipment were ample even though the last large Surgical and medical supplies were adequate. Large unit kits containing special o shipment was received in October, 1943. After the SAIPAN campdgn shipping was cut surgical instruments, dressings, drugs, and plasma were plentiful. One portable yj to a minimum. X-ray machine was in use; two larger ones were not functioning because spare parts Z and X-ray film were not available. Sterilization was accomplished by boiling or u The Army and Navy functioned as Independent units with little cooperation in by a large single jacket autoclave suspended over an open fire. dispersal of trained personnel and supplies. With the exception of a few special items (drugs, dleuretics, X-ray film, and traction splints) ther;> was a year's sup The branch hospital at MOEN in contrast to the main hospital was dirty and ply of medical stores. The Army had limited quantities of sulfaguanadlne and car disorganized. The unit was in the process of being destroyed but some buildings Z basone supplemented occasionally from naval sources; occupation forces madt these were still standing. All patients had been evacuated to DUBLON, The buildings drug8 available. were scattered throughout a large area on a hillside in close proximity to open latrines and drainage ditches. The structures were for the most part corrugated to The general public and natives had no medical facilities; the civilian hos metal over wooden frames; three large 30 to 45 bed wards were still standing and Q pital on DUBLON was annexed to the main Army hospital in the same area. Natives seemed rather clean. A complete analysis of conditions on MOEN could not be ob- Z received medical attention at neighboring military sick bays and dispensaries. tained. There were no civilian doctors or nurses; several natives were employed doing odd Jobs in the hospitals. Army: Medical facilities under the Army consisted of a main field hospital on DUBLON and several branch hospitals on the larger islands. These were aug The diseases widely spreading among military personnel were malnutrition, mented by small medical dispensaries on the smaller Islands and units attached to z battle dropsy, beri-berl, amoebic dysentery, paratyphoid A, tuberculosis, leg ulcer, each Army group or organization. The total bed capacity was about 950 to 1000. _l scabies, and Well's disease. The latter was common in those who worked in swampy All seriously ill patients were transferred to larger branch hospitals or to the o areas. There was a considerable number of cases of yaws among the natives. main field hospital on DUBLON. Supplies for the most part were adequate although cc there was a shortage of X-ray equipment, carbasone and sulfaguanadlne. MEDICAL. Each branch hospital was staffed well with medical officers and trained hos Nav.v: The Navy medical facilities consisted of a main hospital base on DUB pital corpsmen. Most units had facilities for examination and treatment while LON Island and four branch hospitals on TOL, MOEN, FEFAN, and UMAN. There were no operating rooms were available only in the larger establishments. The hospital O other dispensaries but small sick bays each accommodating 5 to 10 patients were areas are described as follows: scattered throughout the Islands and at the reef barrier; each was adjacent to military activities. The total bed capacity was about 1,200; all seriously 111 patients were evacuated to the base hospital at DUBLON. DUBLON UMAN FEFAN UDOT MOEN TOL Of all the hospitals on TRUK only the base hospital on DUBLON and the branch Z on TOL were in use at the time of this investigation. UMAN, FEFAN, and MOEN unite Unit were being dismantled; small sick bays furnished medical care to these islands and o to military groups throughout TRUK. • CO • •p r . p LU to a H C ^H H 143 MEDICAL AND SANITARY CONDITIONS y. The main Army hospital on DUBLCTPitortsi-sfeed of-severalfcafcfl^wooden buildings Refuse pits and commissary suppjv areas were noted as rat breeding centers each holding 10 to 20 patients and the former civilian stone hospital. Originally but no action was taken against them, Murine typhus and plague were unknown in there were 8 to 10 underground rooms near the main building each capable of hold TRUK; rat bite fever was not recognized. I ing 10 or 12 patients but the bombing attacks destroyed part of the underground system and It was later aDandoned, Control of Insect Borne Disease: There were no mosquitoes belonging to the Anopheles group found; Aedes aegypti and Aedes albopictus were very numerous. The wards consisted of platforms in adjacent rooms; separate beds or cots were not employed. The quarters were usually crowded but fairly clean. Patients with Malaria was non-existent but a few cases of dengue fever were present on the amoebic dysentery and paratyphoid were put in separate rooms or In a small building islands. In March, Aoril, and May, 1944, there was a great epidemic of dengue with that constituted the contagious ward. low mortality but; great morbidity. There may be some immunity among the natives and military personnel who have lived here for several years but sporadic cases of The operating room was Inadequate - the room was small, dirty and poorly light dengue are the usual thing. ed. The instruments were those borrowed from the Navy. No X-ray was available, the treatment rooms were dirty and poorly ventilated. Frequently latrines and refuse There was no active policy for control of mosquitoes. In some areas near pits were adjacent to water supplies. In general, conditions were not so favor the quarters a day was set aside each week to drain ditches and shell craters. able as tnose at the Naval hospital, Frequently covers were put on water containers and the growth of larvae prevented by mixing in seawater. z> SANITARY CONDITIONS. Control of Lice. Bedbugs. Roaches, and Files: Lice, bedbugs, and roaches CO Control of Intestinal Diseases: Amoebic dysentery and paratyphoid A were en- were not present In any amount but the number of files was remarkable. demic in the Japanese forces at TRUK, In one branch hospital there were 150 deaths o in a 3-month period due to these diseases. Amoebic abscesses of the liver were Flies were present everywhere - In living quarters, galleys, refuse pits, a. frequent and required surgical Intervention. latrines, and hospital buildings. Medical personnel noticed them but took very little action in destroying them or preventing their increase. Fly spray was used z Because of lack of unified control over housing and absence of adequate sew- in very limited amounts; phenol solutions were used to a limited extent. age, drainage dysentery spread rapidly. In hospital and barrack areas lime was used in latrines and water was boiled or chlorinated but this policy was not universal. Q- Prophylactic injections against paratyphoid were given once a year and anti- amoebic drugs were given by mouth routinely every three months to military per sonnel on a compulsory basis. o In hospitals these patients were isolated and special attention given to ex creta. Medical officers U6ed special technique in handling infected patients: z aqueous phenol solution was sprayed frequently throughout the ward and on the shoes of all those entering or leaving the contagion buildings. Sewage Treatment. Kitchen Wastes: There was no sewage system at Housing of Troops: A few one or two-story buildings were employed for bar- all except to a limited extent In z racks. Conditions were crowded, often a 20' x 30* floor space for 25 to 30 men. hospital and barrack areas. Re- Most of the buildings were destroyed by bombing. Buildings had no adequate sew- fuse piles, open latrines, and o age systems; washing was all done at a central pump, (See Engineer's Report). shallow ditches were the usual sight, Water Purification: (See Engineer's Report). Both Army and Navy had spec ialized personnel In Water Purification Unit's whose only function was to main A few latrines were treated tain an adequate pure-water supply. Many reservoirs and dams were constructed with chloride of lime, but for throughout the islands. the most part half-barrels and o holes were used until filled and Purification was accomplished by chlorination, filtration, settling tanks and then abandoned. Sanitation was boiling. From central reservoirs water was pumped to military areas. Men, how better In controlled areas. ever, had access to contaminated water and Its use was wide spread. Conditions in native villages Food Control and Mess Sanitation: Most of the food was cookea in central gal were notoriously bad where gar z leys although the Army in small units frequently cooked their own food over or?en bage and human waste were piled O fires. high within throwing distance CO from their straw huts. UJ The main food was sweet potatoes mixed with some rice with occasional side CO dishes of vegetables and fish. Every available area was planted in potatoes; the There was no live stock on the Z diet was sometimes supplemented with breadfruit, bananas or coconuts. Both mil islands and the use of night soil itary personnel and natives had a diet deficient in fat, protein and vitamins. No was unusual. fresh meat was available; fish were decreasing In number within the atoll after large supplies were caught by using explosives. Malnutrition and avitamlnosls were very common; death from these causes at z one time reached several hundred a month. Picture No. 95j (PM 241) BRASCH HOSPITAL < Rat Control;!* Rats, we re common everywhere on the island; it is most remark (\'AVY), HOES: Rear view of former Surgery able that very little was done to destroy them. Occasionally arsenical poisons s/iowmf sterilizer , center, an 1 elaborate and traps were employed. Captured rats were often eaten by soldiers. rain u.ater collector, left center. 144 APPENDIX 5 Q BIBLIOGRAPHY OF PERTINENT DOCUMENTS FORWARDED TO THE WASHINGTON DOCUMENT CENTEK BY ClNCPAC-CINCPOA CONFIDENTIAL LETTER, SERIAL ADM-150800, DTD 15 MARCH 1946. ft o o I This bibliography lists all questionnaires prepared by the Study Group for pre 21. Diagram of DP gun revetments on PATA. 1:1,000; Undated. OS sentation to the Japanese at 'TRUK, and all documents, inventories and maps submitted 22. Diagram of a 12cm gun position, OP, ammunition room, ration dump, wtc. on by the Japanese in reply. The documents received from the Japanese have, with few FEFAN 1:200; Undated. exceptions, been listed by the original titles, translated if in Japanese, and if in 23. Diagram of a 12cm gun cave emplacement on NW DUBLON. 1:200, 1:5; Undated. in English, retaining the original spelling and phraseology. A few documents pertaining 2 PP. to the defenses of TRUK received from other sources have been Included. Unless othfer 24. Diagram of a 12cm gun position on MOEN. 1:100; Undated. wlse stated, all documents listed were prepared by the Japanese at TRUK. 25. Diagram of a 15cm gun position on UMAN including details of ammunition dump and fire control center. No scale given. Undated. z Document 26. Diagram of a 14cm gun emplacement on S. UMAN. No scale given. Undated. Number TITLE AND DESCRIPTION. 27. Diagram of a 15cm gun revetment on TOL. 1:400; Undated. 28. Diagram of a command post. 1:50; Undated. UJ Questionnaires. 29. Diagram of a gun chamber. 1:50; Undated. 30. Diagram showing views and measurements of a gun chamber, connecting passages, 1. "Required Intelligence Data." 8 December 1945, 20 pp. and generator chamber. 1:50; Undated. CQ 2. "Questionnaire for Historical Analysis." 2 pp. 31. Diagram of a 12cm twin mount AAA emplacement on ETEN. 1:200; Undated. 3. "Questionnaire for Strategical and Tactical Information.11 2 pp, 32. Diagram of 12cm AAA positions on x^FAN. 1:500; Undated. o 4. "Questionnaire for Order of Battle Information.11 1 p. 33. Diagram of 75mm AAA positions on PARAM. 1:500; Undated. 34. Diagram of a 7cm AAA emplacement. 1:100; Undated. z REPLIES. 35. Diagram of an 8cm AAA position on FEFAN. 1:500; Undated. 36. Diagram outlining the functions of a 110cm and 150cm searchlights. 1:1,000; 5. Historical Analysis, prepared by Japanese 4th Fleet Hq. Undated. 11 pp, Undated. SE 6. Order of Battle Information, prepared by the Japanese 4th Fleet Hq. Undated. 37. Diagram of a 150cm searchlight on PARAM. 1:100; Undated. 3 pp. 38. Diagram of a 150cm searchlight and mount on DUBLON, 1:100; Undated, 7. Reply concerning the Navy, prepared by the Japanese 4th Fleet Hq. Includes 39. Diagram of searchlight attached to 20cm gun on MOEN. 1:100; Undated. list of all construction personnel, inventories of construction equipment 40. Chart of underwater minefields along shore of FALEU. 15:55,000 (1:3,667); Undated. CO and tool8. Undated. 84 pp. a 8. Reply concerning the history of Submarine 1-169, including Japanese Fleet 41. Chart of underwater minefields along shore of NORTHEAST Island. 20:55,000 z anchorages at TRUK, and hydrographic charts of the TRUK Islands. Prepared (1:2,750); Undated. by the Japanese 4th Fleet Hq. Undated. 73 pp. 42. Chart of underwater minefields along shore of W. DUBLON. 5:55,000 (1:11,000); 9. Historical Analysis, prepared by the Japanese 31st Army Hq. Undated. 22 pp. Undated. CO 43. Chart of underwater minefields along shore of OTTA. 15:55,000 (1:3,667); 10. Order of Battle Information, prepared by the Japanese 31st Army Hq. Undated. UJ 1 P. Undated. Z 44. Chart of underwater minefields along shore of SALAT. 15:55,000 (l:3,667); 11. Reply concerning the Army, prepared by the Japanese 31st Army Hq. Includes _i inventories of ammunition, chemical warfare and signal equipment. Undated. Undated. 76 pp. 45. Chart of underwater minefields along shores of ELIKANIBU. 40:55,000 (1:1,375); o 12. Document pertaining to the South Seas Civil Government on TRUK. Includes Undated. detailed plans of buildings constructed, inventory of civilian crafts 46. Chart of underwater minefields along shore of MOR. 30:55,000 (1:1,833)* < (available and destroyed) and water facilities. Undated. 34 pp. Undated. KJ 47. Diagram of Airfield No. 2 and Seaplane Base on MOEN. 1:10,000; Undated, MISCELLANEOUS. 48. Diagram of Airfield No. 1 on MOEN. 1:10,000; Undated. 49. Map of TRUK and location of airfields on MOEN. 1:250,000; Undated, 13. Explanatory data on location and size of magnetic detector loops ax TRUK. 50. Diagram of installations on 104th Air Force Base. No scale given. Undated. 51. Diagram of facilities of the 4th Repair Department. No scale given. Undated. Undated. 6 pp. 52. Chart of Generator data of the 41st Naval Guard Force. Undated. 2 pp. 53. Diagram of generator and compressor installed in cave. No scale given. t— MAPS. CHARTS. AND DIAGRAMS. Undated. 54. Data chart on refrigerators. No scale given. Undated. Z 14. Map indicating the location and appurtenances of 20cm guns on MOEN. No 55. Diagram of Charlie Pier. 1:500; Undated. o 56. scale given. Undated. Diagram of an air conditioned cave on DUBLON. No scale given. Undated, CO 57. UJ 15. Detailed diagrams of 20cm gun fire control centers and alternate control Diagram of power generator positions and power distribution system on MOEN. 1:20,000; Undated. to centers. 1:100; Undated. 58. Z 16. Map of 15cm gun positions on DUBLON. 1:100; Undated. 2 pp. Diagram of power generators and power distribution system on DUBLON. 17. Diagram indicating outline of 15cm gun revetments on S. TOL. 1:100; Undated. 1:10,000; Undated. 18. Diagram of a 15cm gun revetment on S. TOL. 1:100, 1:50; Undated. 2 pp. 59. Diagram of the UNYU (transportation) Pier. 2 views, top 1:50, cross 1:50; Undated. UJ 19. Diagram of a 15cm gun emplacement on FEFAN including data on gun character CO istics. 1:200; Undated. 3 pp. 60. Diagram of the Air Force Depot pier and crane. No scale given. Undated. 20. Diagram of 14cm gun battery on MOEN and details of emplacement plans. 61. Diagram of the MOEN Airfield No. 2 depot storage caves. No scale given. 1:200: Undated. 2 pp. Undated. JICPOA 60322 1 thru 159 145 APPENDIX I (CONT) Document Document .Number TITLE AND DESCRIPTION*! fl Number TITLE AND DESCRIPTION, o o 62. Diagram and construction plan of the 4th Fleet Hq. 3 views,'top 1:200, front 112. T8ble of Organization of the 69th Inf Regt. Undated. 1:200, cross 1:50; Undated. . .) 113. Map of heavy artillery -positions on MOEN. 1:10,000; Undated. I 63. Diagram of location of 4th Fleet Hq and adjacent buildings. lY5,000; Undated. 114. Map of heavy artillery positions on DUBLON. Includes specifications for the construction of cave emplacements for mountain artillery, naval guns, AAA, on 64. Diagram of Naval Hospital Buildings. 1:5,000; Undated. 65. Diagram of the 4th Naval Hospital and facilities. No scale given. Undated, and pill boxes for mountain artillery. No scale given. Undated. 2 pp. 66. Diagrams of hospital, rooms, and wards. 3 views, top 1:200, front 1:200, 115. Map of heavy artillery positions on ETEN. No scale given. Undated. 2 cross 1:50; Undated. 116. Map of heavy artillery positions on FEFAN. 1:10,000; Undated. in 67. Diagram of pill "boxes, MG emplacements, OPs and mortar positions. No seal© 117. Map of heavy artillery positions on UMAN. 1:2,000; Undated. given. Undated. 118. Map of heavy artillery positions on PARAM. 1:10,000; Undated. 68. Electric circuit diagram of a type 2, underwater magnetic detector. No scale 119. Map of heavy artillery positions on UDOT. 1:10,000; Undated. given. Undated. 120. Map of heavy artillery positions on S. TOL. 1:10,000; Undated. en 69. Diagram of the various underwater mines. No scale given. Undated, 121. Map of heavy artillery positions on N. TOL. 1:25,000; Undated, Z 70. Detailed chart of mine fields,. number of mines, length of fields, depths, etc. 122. Map of heavy artillery positions on W. TOL. 1:10,000; Undated, No scale given. Undated. 4 pp. 123. Diagram of an automatic gun emplacement. No scale given. Undated, 71. Diagram of the crude oil fuelling pier on DUBLON. No scale given. Undated. 124. Map of defense positions of the 5th Company's left flank. 1:2,000; Undated. 72. Diagram of fuel oil tank farm and supply system on DUBLON. No scale given. 125. Map of CD guns and mountain artillery positions, including fields of fire, Undated, range, OPs, and details of gun emplacements on MOEN. 1:10,000; Undated. 2pp. 00 73. Diagram of the water distribution system on MOEN. 1:1,000; Undated, 126. Map of CD guns and mountain artillery positions, Including fields of fire, < 74. Diagram of the water distribution system on DUBLON. No scale given. Undated, ranpe, OPs, and details of gun emplacements on DUBLON. 1:100; Undated. 4 pp. O 75. Diagram of water mains and storage facilities on DUBLON, 1:5,000; Undated. 127. Map of CD guns and mountain artillery positions, including fields of fire, 76. Diagram of MOEN water storage facilities and their construction details. No range, and OPs on FEFAN. 1:10,000; Undated. z scale given. Undated. 2 pp, 128. Map of CD guns and mountain artillery positions, including fields of fire, 77. Chart of small craft harbors, base, and facilities. No scale given. Undated. range, and OPs on UMAN. 1:5,000; Undated, 78. Chart of torpedo boat units. Undated. 4 pp. 129. Map of CD guns and mountain artillery positions, including fields of fire, 79. Diagrams of small craft and tank obstacles on DUBLON. 1:500; Undated, 3 pp. range, and OPs on PARAM. 1:10,000; Undated. 80. Diagram of military installations on FEFAN. No scale given. Undated. 130. Map of CD guns and mountain artillery positions, including fields of fire, 81. Map of defense positions of the 43rd Naval Guard Force on TOL and UDOT. range, OPs and details of gun emplacements on UDOT. 1:10,000; Undated. 6 pp. 1:20,000, 1:10,000; Undated. 131. Map of CD guns and mountain artillery positions, Including fields of fire, z 82. Map of TRUK with naval troop dispositions, suicide torpedo sites, and mine range, and OPs on S. TOL. 1:10,000; Undated. fields at the various passes. 1:26,300; Undated. 132. Map of CD guns and mountain artillery positions, including fields of fire, CO 83. Map of troop disposition and defense installations on DUBLON. 1:5,000; Undated. ran^e, and OPs on N. TOL. 1:25,000; Undated. Q 84. Map of troop disposition and defense installation on MOEN and FALEU. 133. Map of CD guns and mountain artillery positions, including fields of fire, Z 1:10,000; Undated. range, OPs, and details of gun emplacements on POLLE. 1:10,000; Undated. 2pp. 85. Map of troop disposition and defense installation on UMAN. 1:5,500; Undated. 134. Map of Ground Organization on MOEN (including FALEU). 1:10,000; Undated. 86. Map of troop disposition and defense installations on FEFAN and TSIS. 135. Map of Ground Organization on DUBLON. 1:5,000; Undated. 5 pp. 1:10,000; Undated. 136. Map of Ground Organization on ETEN. No scale given. Undated. 87. Map of troop disposition and defense installation on PARAM. 1:4,000; Undated. 137. Map of Ground Organization on FEFAN. 1:10,000; Undated. 88. Map of troop disposition and defense installations on ULALU, UDOT, and FALA 138,. Map of Ground Organization on UMAN. 1:5,000; Undated. BEGUETS. 1:10,000. TONELIK and FALEU. 1:2,000; Undated. 139. Map of Ground Organization on PARAM (including TARIK and EIOL). 1:10,000; o 89. Map of troop disposition and defense Installations on S. TOL and POLLE. Undated. 1:10,000; Undated. 140. Map of Ground Organization on UDOT. Includes diagrams of artillery and auto < 90. Map of troop dispositions and defense Installations on N, TOL and PATA. matic weapons emplacements. 1:10,000, 1:5,000, 1:2,500; Undated. 3 pp. KJ 1:10,000; Undated. 141. Map of Ground Organization on S. TOL. 1:10,000; Undated. 2 pp, 91. Map of PARAM airfield. 1:4,000; Undated. 142. Map of Ground Organization on N. TOL (including NW TOL). 1:10,000, 1:2,500; 92. Map of seaplane base and facilities on DUBLON. 1:1,200; Undated, Undated. 2 pp. 93. Diagram of MOEN Naval Branch Hospital. No scale given. Undated. 143. Map of Ground Organization on W. TOL. 1:10,000, 1:2,500; Undated. 3 pp, 94. Diagram of the 4th Naval Hospital on DUBLON. No scale given. Undated, 144. Map of Artillery fields of fire at TRUK. No scale given. Undated. 95. Map of 41st Garrison Sub Base. 1:3,000; Undated. 145. Map of mine fields and shore obstacles, tank traps on MOEN. 1:10,000; Undated. 96. Map of the 4th Repair Department on DUBLON. 1:1,000; Undated. 2 pp. OS t— 97. Map of installations and facilities of the 4th Munitions Dept. in the Charlie 146. Map of mine fields and shore obstacles, tank traps on DUBLON. 1:5,000; Undated. Area. 1:600; 30 June 1943, 147. Map of shore obstacles on ETEN. No scale given. Undated. z 98. Diagram of installations of the Munitions Dept. including those in the vicinity 148. Map of mine fields and shore obstacles, tank traps on FEFAN. 1:10,000; Undated. o of the Hq on DUBLON. No scale given. Undated. t/> UJ 99. Map of UMAN Radio Area. No scale given. Undated. CO 100. Map of installations in 4th Communication Unit Area. No scale given. 149. Map of mine fields and shore obstacles, tank traps on UMAN. 1:5,000; Undated. Z Undated. 2 pp, 2 pp. LU 101. Map of traffic facilities on MOEN; roads and trails. 1:10,000; Undated. 150. Map of underwater mine fields and shore obstacles on PONES, FANAN, UDIDAN, 102. Map of traffic facilities on FEFAN; roads and trails. 1:10,000; Undated. UIJEC, MESAGON, and OTTA. No scale given. Undated. 103. Map of traffic facilities on POLLE; roads and trails. 1:10,000; Undated. 151. Map of mine fields and shore obstacles, tank traps on PARAM, EIOL, and TARIK. 104. Map of traffic facilities on N. TOL; roads and trails. 1:25,000; Undated. 1*10,000; Undated. CO Ul 105. Map of traffic facilities on S. TOL; roads and trails. 1:10,000; Undated. 152. Map of mine fields and shore obstacles, tank traps on UDOT, 1:10,000; Undated. Z 106. Map of traffic facilities on UDOT and EOT; roads and trails. 1:10,000; Undated. 2 pp. 107. Map of traffic facilities on PARAM, EIOL, and TARIK; roads and trails. 153. Map of mine fields and shore obstacles, tank traps on S. TOL, 1:10,000; Undated. 1:10,000; Undated. ' "1% 154. Map of mine fields and shore obstacles, tank traps on N. TOL4 1: 25,000; Undated. 108. Maprof -traffic facilities on fMAN; roads and trails. 1:5,000; Undated. 155. Map of mine fields and shore obstacles, tank traps on POLLE. l: 10,000; Undated. 109. Map of defense disposition oniDUBLON. Shows defense sectors, units, and gun 156. Diagrams of various tank traps. No scale given." Undated. 3 pp. positions. 1:12,500; 31 March 1945. 157. Map of conimunication network on MOEN. 1:25,000; Undated. 110. Map of. strong points and layout of defense positions on N. DUBLON. 1:1,000; 158. Map of communication network on DUBLON, 1:12,500; Undated. Undated. 159. Map of communication network on FEFAN. 1:25,000; Undated. 111. Map of landing obstacles on DUBLON. Including mine fields and tank obstacles. 160. Map of communication network on UMAN. 1:25,000; Undated. 1:5,000; Undated. 161. Map of communication network on PARAM (including EIOL and TARIK). 1:10,000; Undated. 146 APPENDIX I (CON'T) •o Document I Number TITLE AND DESCRIPTION, 3. All extra copies of the reproduced translations, including 162. Map of communication network on UDOT. 1:10,000; Undated. mimeographed material, ozalid sketches, photographs, etc., are being delivered separ 163. Map of communication network on S. TOL, N. TOL, and POLLE. 1:25,000; Undated. ately to Prospective Commander, TRUK and CENTRAL CAROLINES OCCUPATION FORCE. Address 164. Road and communication (wire and pigeon) network map of DUBLON. 1:5,000; all request for additional copies of the translations to that command. In addition, Undated. Commander TRUK Occupation Force is being furnished all original manuscripts, original 165. Map indicating the Japanese Army, TRUK Garrison Force, Disposition on the translations, stencils used in reproducing translations, and overlays and photograph various islands of the atoll. 1:50,000; Undated. ic negatives used in reproducing charts, maps, and sketches. This material affords 166. Diagrams of machine gun emplacements and pill boxes. 1:200; Undated. 4 pp. the means of easily reproducing further copies of the translations if such are 167. Diagram of suicide torpedo and base on FANEU. 1:1,500; Undated. 2 pp. required. By copy of this memorandum, Commander TRUK Occupation Force is requested z 168. Diagram of a Model 1, Hydrophone installation on UMAN. No scale given. to make appropriate disposition of this material when it has served its purpose. t— Undated. LU 169. Diagram of various offshore and shore obstacles. 1:100; Undated, _J 4. To facilitate use of the translations, the system of classifi- _J 170. Diagram showing the layout of the type 2 underwater magnetic detector. cation or grouping used in their preparation is herewith explained: OQ 1:15,000; Undated. 171. Diagram of mine control station on TONELIK. No scale given. Undated. (a) For convenience in reference, the documents have been classified into 172. Diagram of an Acoustic Room. No scale given. Undated. the following basic groups with a key letter for each group as Indi o 173. Map of underwater mine along shore of Airfield No. 1. MOEN. No scale given. cated: Q_ Undated. z BASIC GROUP KEY LETTER (S) Troop Strength, Tactical Dispositions and Ordnance T The following is the list of documents received from the G-2 Section, Head Hydrography and Shipping H quarters, Island Command, Guam with the covering memorandum: Military Government MG z Medical M Supply S CO G-2 SECTION Engineering and Construction E Q HEADQUARTERS ISLAND COMMAND, GUAM Documents have been assigned to one of these groups on the basis of Z the primary Importance of their contents; many documents, however, 1 November 1945, contain material of secondary importance relating to different subjects, co Memorandum For: Distribution List. and all documents should be examined regardless of the specialized nature of the information sought at a particular time or by particular Subject: Documents furnished by Japanese at TRUK, translations of. staff officers. For example, documents in the H series (Hydrography and Shipping) may contain information of significance to those con- O Reference: (a) G-2, Island Command Memorandum, dated 15 September 1945, cerned with operations ashore, such as location of beach mines, or to same subject. those interested in supply matters, such as amount of various fuels on hand. Enclosure: (A) Index to subject Translations. (B) Chart of Distribution of subject Translations. (b) Within each basic group documents have further been assigned numbers, solely on the basis of time of completion. There is no other signifi 1. In response to our demands for information on a variety of cance to the numbers. Documents essentially related in subject matter military subjects, the Japanese forces at TRUK furnished a mass of written materials, and which probably should be consulted in connection with each other, overlays, sketches, marked maps, etc. The translation and reproduction of this for example "strength and Disposition of Army Forces11 and "Strength material, which has been an extensive process, is now complete. Durirg the course and Capacity of Gun Position (Army)", though both appearing in the z> of this work, translations have been furnished to addressees concerned, as soon as T-series, will bear such widely separated numbers as T-3 and T-15, completed, as announced in reference (a). It'is therefore considered unnecessary merely because one was translated earlier than the other. Addressees z to make further automatic distribution at this time. Instead, addressees are here will please bear this in mind in studying the documents. o with furnished an index to the entire series, Enclosure (A); examination of the Index co will indicate which, if any, translations have not been furnished and which may be (c) Attention is invited to the fact that some documents only to TRUK ATOLL, LU desired by particular addressees. Extra copies are available to satisfy such needs but others contain information relating also to areas as far west as CO upon request. Enclosure B, a distribution chart shows the distribution which has the PALAUS and as far east as the MARSHALLS-GILBERTS area. already been made, z 2, Because of the bulk of the complete series It Is impracticable to assemble and distribute complete sets. In lieu of this, the index is furnished CO and with its aid addressees can assemble the translations in a manner best suited to /S/ H.N. STENT LU their individual needs. Included in the Index are notes which specify the number of Col., USMC mimeographed pages, sketches, photographs, etc. which are comprised by each trans ACofS, G-2. z lation; comparison of translations on hand with these notes will Indicate whether or not translations on hand are complete. Incomplete translations can be made complete by appropriate request for missing items desired. 147 APPENDIX I (CON'T) o X KJ oc ENCLOSURE (A) Index to TRUK Translations Engineer. Construction, and Signal (Parenthetical notes indicate number of pages of mimeographed material, ozalid E-l Signal Equipment, Material, *.nd Location of Signal Stations, (pp. 1-2 and sketches, photographs, etc., comprised by each translation.) one photographic annex). E-2 Aircraft, Air Facilities, Maintenance, (pp. 1-6 and five sketches, annexes A-E). E-3 Particulars on Explosives Storage (Navy), (pp. 1-2 and two sketches, Accompanying Note annexes A and B). E-4 Water, Food, Barracks and Medical Installations In TRUK Islands (Navy). Japanese - English Place - name Equivalents, TRUK Atoll. (pp. 1-5 and two sketches, annexes A and B). E-5 Water Supply, Food Supply, Barracks and Medical Facilities (Array;, (p. l). 03 Medical E-6 Reports on communications Liason (Navy), (pp. 1-10, including mimeographed annex 13; and 14 sketches:- annexes 1, 1.1, 1.2, 2, 3, 4 (mimeographed), 5, M-l Medical Department Personnel Register, Navy, TRUK. (pp 1-13). 6, 7, 8, 9, 10, 11, and 12). o M-2 An Inquiry* of Medical Conditions on TRUK (NavyMpp 1-3). E-7 Principal Construction (installations)- TRUK (Navy), (p. 1-25 and 13 sketches, a. M-3 Quantity of Present Medicinal Supplies (NavyMpp 1-21). annexes A-M). Z M-4 Location and Number of Personnel of Medical Units, TRUK (Navy). (pp 1-7; two sketches, Parts 1 and 2). Military Government KJ M-5 Medical Facilities, TRUK (Navy)(p. 1 and Annex A (sketch). M-6 Diagram of Army Hygiene Facilities and Medical Personnel in the TRUK MG-1 Matters concerning civilians, (pp. 1-2). Islands, (pp 1-2 (legend) and Map.). MG--2 Civilian Doctors vone chart). Z M-7 List of Army Medical Supplies, (pp. 1-16). MG-3 Concerning the Resident Population (Army), (pp. 1-2). u Troop Strengthr Tactical Dispositions,, and Ordnance Hydrography and Shipping CO T-l Sketches of Gun Dispositions (including mine laying sketches) (Army). H-l Plans for Sweeping Mines off Beaches and Dismantling of Beach Obstacles a (p. 1; Sketches 1-11; and Legend). (pp. 1-5). T-2 Maps of Location of Powder, Bomb, Ordnance and Ammunition Dumps (Navy). H-2 Unloading Facilities (Piers, Cranes, Tugs, Boats), (pp 1-5 and chart, annex A). z (p. 1 (index); and 33 sketches: annexes A-J, K (l) - K(9), L-Y). H-3 Key to Mines Laid in TRUK Area (Except small model, i.e. water1s edge, mines). - I T-3 Strength and Disposition of Army Forces, (pp. 1-37). (pp. 1-7). CO T-4 Table of Strength under Command of Cominch, 4th Fleet, (p. l). H-4 Further Navigational Data. (p. l). T-5 List of Forces under Command of, and attached to, the 31st Army, (one sheet, F-5 Condition of Ships and Boats and Repair Facilities, (pp. 1-7). reproduced by ozalid process). H-6 Repair on Small Craft (Army) (p. l). O T-6 Disposition of Army Forces on all Islands, (one sheet, reproduced by H-7 Tide and Current Data. (pp. 1-4 and 4 photographs). ozalid process). See also overprinted Hydrographlc Charts (H.O. 6046-6050) furnished separately. < T-7 Position of Army Forces, TRUK, (one sheet, reproduced by ozalid process). T-8 List of Army Commanders (on all islands), (pp. 1-6). Supply T-9 Army - Plan for Dismantling and Location of Existing Obstacles, (two photos), T-10 Army - Plan for Placing Weapons and Ammunition (TRUK). (pp. 1-3 and one S-l Military Equipment, Navy. (pp. 1-58; and 9 sketches, Annexes A-H, J). sketch Annex). S-2 Rations (Navy), (pp. 1-2). T-ll Army - Diagram of Defense Districts and Location of Headquarters of Battalion S-3 Clothing (Navy), (pp. 1-2). and Larger Units, (two photographs). S-4 Record of the Ordinary Articles of the 4th Naval Hospital (pp. 1-4). ZD T-12 Army - Chemical Equipment, Offensive and Defensive, (pp 1-2). S-5 List of Army Clothing, Rations, and Goods, (pp. 1-5). oc T-13 Diagram of Areas Suitable for Occupation and Native Concentration, (one S-6 List of Ordnance. Ammunition (including Signal Shells), and Vehicle Fuel photograph). Army. (pp. 1-11). Z T-14 Explanation of Army Barracks and Housing (p. 1 and 9 sketches, annexes 1-9). S-7 Ordnance (Navy), (pp. 1-130). T-15 Strength and Capacity of Gun Positions (Army), (pp 1-2; and 11 sketches, S-8 Ammunition Storage (Navy), (pp. 1-28; and 5 sketches, Annexes A-E). o No's 1-11). CO UJ T-16 Strength of Naval Defense Units, (pp. 1-21). Note: Enclosure (B), Distribution Chart, mentioned in paragraph one of the CO T-17 Plans for Disarmament of Garrison, TRUK (Navy), (p. 1). Memorandum is not attached. Z T-18 Answers to Questions concerning Troop Strengths and Dispositions (Navy) Ui (pp. 1-8; and 8 sketches, annexes 1-8). T-19 Concerning the Security Force, (p. l). T-20 Army Plans for Mine Disposal and Ordnance collection, (pp. 1-2). CO T-21 List of Army Chemical Warfare Equipment, (pp. 1-2). LU Z Enclosure (A) Cont'd. r, /**• *'\ 148 APPENDIX II BIBLIOGRAPHY OF GENERAL REFERENCE WORKS USED IN PREPARATION OF THE REPORT o •r- I cc 5 in z Document Document t— Number TITLE AND DESCRIPTION Number TITLE AND DESCRIPTION LU WEAPONS 14. "Order of Battle of the Japanese Armed Forces". Confidential. Military CO 1. "Japanese Infantry Weapons." Restricted. CINCPAC-CINCPOA Bulletin No .55-45. Intelligence Division, War Department, 1 March, 1945, with changes. 15 March, 1945. 15. "Handbook on Japanese Military Forces". TM-E 30-480. Restricted. War Depart- o 2. "Japanese Infantry Weapons." Restricted. Military Intelligence Division, ment, 15 September, 1944, with changes. Ou War Department, Special Series No. 19. 31 December, 1943. 16. "Japanese Tanks and Tank Tactics". Restricted. Military Intelligence Service, Z 3. "Japanese Weapons." Restricted. Prepared by AC of S, G-2, Ordnance War Department, Special Series No. 26, 15 November, 1944. Intelligence Unit, Headquarters, USAFISPA, December, 1943. 17. "Japanese Tank and Antitank Warfare". Restricted. Military Intelligence Divi 4. "Japanese Artillery Weapons." Restricted. CINCPAC-CINCPOA Bulletin No. 26-45. sion, War Department, Special Series No. 34. 1 August, 1945. KJ 20 February, 1945. 18. "Supplemental Sailing Directions, CAROLINE Islands". O.N.I. 31. Restricted. a. 5. "Japanese Artillery Weapons." Restricted. CINCPAC-CINCPOA Bulletin No. 152-45. CNO Navy Department, 25 March, 1942. 1 July, 1945. Z AERIAL PHOTOGRAPHS 6. "Japanese Field Artillery." Restricted. Military Intelligence Division, War Department, Special Series #25, November 1944. 7. "Japanese Mortars and Grenade Dischargers." Restricted. Military Intelligence VD-1 - Fleet Air Photographic Squadron One - Date Flown 9 September, 1945. CO Division, War Department, Special Series No. 30. 15 March, 1945, with Verticals. Focal length 12". Altitude 10,000 feet. Q subsequent publisned changes. Z SIGNAL EQUIPMENT CO MAPS AND CHARTS 8. "Japanese Radio Communication Equipment." Restricted. War Department Technical Manual, TME 11-227A. Signal Communication Equipment Directory. December, 1944. TRUK Islands, CAROLINE Group, 10 Sheets, 1:20,000. Compiled by the Intelligence 9. "Japanese Hand Generators." Restricted. Technical Intelligence Bulletin No. Section, Fleet Marine Force Staff, Mar-June, 1935. 19. Army Services Forces, Signal Section. AC of S, G-2, USAFMP, 12 July, o 1945. Defense and Terrain Maps, 1:25,000. Confidential; MOEN, DUBLON, TOL, FEFAN, 10. "Technical Data on Japanese Radio and Radar Equipment." Confidential. Radio PARAM, TARIK, FALA-BEGUETS, ULALU, UDOT, UMAN. Prepared by Fleet Air Photo Division, Naval Research Laboratory. January, 1945. graphic Interpretation Squadron Two - Interpron Two-261. GENERAL H.O. Chart #6046 TRUK Islands. 1:126,350 H.O. Chart #6047 TRUK Islands, Northern Part. : 55,600 O 11. "Mine Disposal Handbook". Confidential. Navy Ordnance Pamphlet No. 1330, 1 H.O. Chart #6048 TRUK Islands, Southeast Part. ; 55,600 ^ November, 1944. H.O. Chart #6049 TRUK Islands, Western Part. : 55,180 12. "General Survey-TRUK". Confidential. JICPOA Bulletin No. 41-44, 1 April, 1944; H.O. Chart #6050 ETEN Anchorage 12,000 see also No. 47-44, 10 April, 1944; and No. 51-44, 15 April, 1944. H.O. Chart #6051 Plans in the TRUK Islands 1:15,000 13. "Joint Army-Navy Intelligence Study of CAROLINE Islands". Confidential. SOUTH Pass; NORTHEAST Pass. Volume No. 1 of 2. Joint Intelligence Study Publishing Board, April, 1944. Z o CO UJ CO Z UJ CO UJ Z 149 L50 5* a. z CO LU LU w Q Lu Z CO LU LU LU o o < >•• -i" 1 1 •J •J CO z Z -r u a to _J UJ a. o CQ _J X LU Z o <* • i i 5 MAR PM NO. 22 25 24 44 44 43 34 30 29 26 23 20 12 41 41 28 10 47 47 46 42 40 33 32 27 21 19 17 15 14 13 38 8 n 49 48 45 39 37 36 35 31 16 11 65^ 18 56 54 4 6 61, 60 55 50 59 57 63 62 58 51 53 52 8 4 3 9 7 6 5 1 2 *m j153.8 - \ •156.3 - 157.8 - 154.0 - 157.0 - 157.0 - 157,2 - 154.1 - 154.0 - 153,8 - 157.8 - 154.1 - 156,3 - 153.8 - 158.4 - 156.0 - 155.9 - 156.7 - 157.3 - CAMERA 157,1 - 153.8 - 155.9 - 154.6 - 154.4 - 155.9 - 153.9 - 157.0 - 156.2 - 156.0 - ~ \" n it n N N it tl n II n II It II II II it t it tt ft It r II i H n it It tt ti II II it i t t STATION 548.2 n 547.5 548.0 548.5 n 548.1 547,1 548.7 549.8 548.5 547.4 547,5 547.4 549.4 550.3 547.9 547.8 548.4 n 549.3 547.7 550.0 550.3 554.0 549.3 547.6 547.7 549.0 549,5 547.8 549.0 h a n n it it i II it it it it tt tt n n i it i n ti n ti rt II H II it i it it i it it tt it n t t t t t N& N ?J* 15Dec45 ",MangroveSwaum. 16Dec45 15Dec45 17Dec45 14Dec45 '?. DATE f « " FNAVALINTELLIGENCE O tt t ti tt tt rt II ti II it ti II it n II it II it GRAPH, NUMBERS LISTED HEREINREFER LOCATION GRAPHS it n n n ti it it u II it ti it II II " i II II N tt II WERE ft n II it i THE THE it ti it II it it II II II n II it i t t *». -Submarine Base,DUBLON PHOTOGRAPHS HAVEBEENDIVI FOLLOWING Large Cran&Pier. Marine RailwayPierNo.1 Beach No.1&Pier Pier No. Oil Line&GatValves. Planer, Boring Machine,Horizontal Lathe, Quay &Pier,DUBLON. Quay LinedwithOilDrums Vertical Shaper. DUBLON, BeachNo. DUBLON, BeachNo. Underground MachineShop. Marine Railway,DUBLON. Winch andMotor. Remains DUBLON, BeachNo. Turret Lathe,22"x72". Generator,65kva(AC)-65kw(DC). Lathe, Punch &Shear. Lathe, Bomb &TorpedoTruck. Lathe, Radial Drill,48"x48". Drill Presr,FloorType. 74kw Generator. l,000kw Transmitter Installations Hammer, Shaper Seaolane Base,DUBLON. 4th NavalComm.Recv.Station . " Air RaidShelter,DUBLON . DUBLON,Trans.Station #2. Shear, Cupula 1-man Torped o Submarine. Seaplane BasArmory. Shaper, 1 INTENDED IT tt OF it II it it II it ti it It n B 11 11 " ,PierNo. II " , H II n " ,BeltDriven. it n II II it ti OF II ,PierNo. n ,PierNo. ,PierNo12. H II II SPECIFICSUBJECTS DOES " ,l00kva(AC). W SUBJECT n n n HeavyDuty. (ANSANO-JUYKO), PrecisionTyoe. (Furnace). HeavyDuty. AirforceArsenal. Gate. EACHPHOTOGRAP II H of SmallBoatLair.",BeachNo it Generator. BeltDriven. IndividualMtr. 20"stroke. it Barriers. AT ti n A Ib TO T 1. 1. NOT II t n n ti II BE B it II COMPLETE APPEAR II n II II MADEINTO Q BY t 9. 8. 8. 5. 5. #3 i it 3. 3. 2, 2, 4. 4. II ti ti n II C1NCPAC-C1NCPOACONFIDENTIALLETTER, IN * IS IS LI TO TO Wl Wl i 2. 2. , THISREPORT. PANORAMIC-PHOTOGRAPHIC STR DED 1NTOTWCATAGOR1ES: ST TH LITTLERECORDEDGROUN . Looking300°fromsea, . TheFairbanksCompany . DUBLON,Trmtg.Station PRESENTED THE PAG ALLPHOTOGRAPHSTAKEN OF MATSUSHIMA RepairDpt. Mid-Section KABOCHO, TOKYO Petrlck &HarveyCo. From SeaplaneRamp. Looking Nfromsea. View fromEntrance. Oil Tanks(background) Japanese Mfg, Looking North fromsea. From SeaplaneRarap. Looking Nfromocean. J. Blacksmith's Shop. DUBLON. MINOURA &Co.,Ltd. Looking 20°fromsea. NE fromsea. East fromsea. General View. 90 Rahn LarmoCo.Cincnti. Oil Tanks(background) 1,700 Interior View, Old MachineWorks. 41st Gar.MachineShop Old MachineWorks. In RepairShipyard. 150 " YANOJAWA PressMfg.Co. General Interior View. North (Main)Entrance . Transmitters. Generator Installation- NW Entrance. East Entrance. Interior View. Seaplane Base. Interior Overall View . North Pier . North Entrance . Interior View. 19 n II F. HP DieselEngine. ti n n 0 n ti ii REMARKS PAGE HP DieselEngine. " 320°fromsea. n 11 N it M H II II It II II 320 NW fromsea. If HP DieselEng. 1H Mfg.,OSAKA, K. THISREPORT OF THEMAPENT ON NW from 1 THE s Quarters. of Tunnel . it o II of Pier. II n It II II ORIGINAL II ft Hill. ff 2. 2. it GENERAL #2 WH1 ON 1 110 110 109 109 130 109 129 110 130 110 130 131 131 107 CONTROL DATATHEREOF NEGAT 115 TLED .88 .88 "GENERAL PHOTOGRAPHS IPS ( BY BY 35 35 39 37 35 35 35 35 37 41 37 35 37 35 37 37 35 39 39 37 39 88 39 37 88 37 88 87 87 87 87 89 87 64 51 51 51 NO APPENDIX III CH SAIDPHOTOGRAPHAPPEARS; SEE PAGES12-21)WITHCONSIDERABLRECORDEDGROUNCONTROLDATA. THE STUDYGROUP "LOCATION IVES SER PHOTOGRAPHS AL A[U'-15080] THEPHOTOGRAPHSLISTED OF i ! 70 72 72 PM NO. GROUND OF 103 101 108 109 125 102 100 106 105 124 127 128 126 110 107 104 130 132 156 161 160 133 129 158 131 157 159 89 87 87 98 94 94 85 79 80 80 86 88 81 81 90 90 91 91 82 82 83 83 99 96 78 95 76 71 71 69 84 75 68 93 93 74 73 77 67 92 92 97 66 to tc 154.0 154.1 154.8 158.3 157,6 - 155.4 158.7 154.2 153.9 153.9 156.9 156.5 155.8 - 154.0 158.7 CAMERA STATION 158.8 157.3 153.9 157.9 154.0 153.6 - 158.6 155.2 156.9 156.2 9 - 156.9 156.0 " AND AND TTRUK A 123 155 tt it II II II ti it H it ft n tt it i n it n II II II ti n it n II H it it it n it II t DTD PHOTOGRAPHS", ENCLOSURE(\) inclusive, THE LATTER inclusive, ------"PANORAiVil AND MARCH1946 15 547. 548. 549. 549, 548. 549. 548. 549. 547. 548. 549. 548. 548. 550. 548. 547. 547. 549. 548. 549. 547. 548. 549. 547. 564. 546. 547. ti n tt it n it i n n n ti it II « n it II II i tt ti n II n II it it it it II n n t t IF 9 5 8 5 6 6 1 0 8 8 8 3 2 6 0 0 4 4 4 2 0 0 0 8 4 IS IS 7 2 14Dec45 16Dec45 15Dec45 14Dec45 C PHOTOGRAPHS" 15Dec45 15Dec45 DATE See "PanoramicPhotographs". HERE PACE NO BEING PHOTOGRAPHS See "PanoramicPhotographs" PRESENTED HEREIN n tt tl il H n a n ti n ti ti it n it N R n II II it II II it ti it ti it ti II II H II II H i II i II a it II II it n II ii it it it II n it t t 1 N Marine Railway,DUBLON. Marine Railway,DUBLON. Rock CrushingPlant. Pillbox,37mm Gun. AT Barrier,OilDrum&Earth Machine Shop,DUBLON. Locomotive,50 Pier No. 4th FleetTrans.Station Barge, Interior Torpedo LoadingPier. Fire-fighting Equipment. 47mm Floating Drydock. Torpedo LoadingPier. Naval Hospital,WaterTank. HAVE BEENFORWARDED Generator. Hand-operated winches. Beach No. Sub TorpedoGauge. NANKO Pier,DUBLON. 8era Ice StoragPlant,DUBLON. 127mm Twin CHARE Dock,DUBLON. Command PostCave. 10,000-ton OilTank&Dyke Seaplane Base,DUBLON. Carryall, Seawall &SmalBoat Dock. Seaplane Base , ETEN. NUMBER it ii It n " ,DentalRoom " ,Pharmacy. " ,Ward. II 11 ti " ,Surgery. " ,)UrayRoom. II tt ti ti ff n H it " ,37mmGun. II w it II « " , n ti ti II CD Gun. II tt ti ti II II II n n n GunEmplacement. AT n B " ,75kva. ti THE it H 100-ton. SUBJECT it n L IS , of OxygenCave. 1, ETEN. HeavyMachineGun FOR ti 6-ydcapacity. "PAWT OF 1, ETEN. " II OF ti II DP , ti it it n U II ti Gun. AT it M FORV.ERBEING ISTE HP GasEng. Guns. TERRAIN REFERENCEPURPOSES. n II SupplyBldg D AFTER T'AO". TOTHE T AND A PHOTO- Vv'H PHOTO THE PAGE . Closeup . InteriorView. . ExteriorView . EastBeach . OverallView, OFFICE View View View fromRoad. Pier &Crane.(10-ton) ICH Motorcycle, View Exterior View. Exterior View, Ramp No. Interior View, Along Beach. Antenna Tower . Fighter Plan e Radio. Bow Battery Locker . Interior,Mt.FUOUKANAN Overall View. Ricochet Embrasure. NE fromSea. General View. Closeup, Interior View. Exterior View, Overall Overall fromSea. Interior View. Gauge (meters)• Interior Interior Interior View. Overall View. 260° fromSeawall. Overall View. Overall View. Entrance Narrow GaugeRailway. Closeup. Sub Base,DUBLON. 130° fromSea. Closeup l,000kva. Control Tower. THE it n n II tt it it tt II II II it to Stern. REMARKS II it it n n tl it II II II of Entrance, of Entrance, of Entrance. H it tt n n of Bow. of Bow. of Building. of Building. of Roof. 2. 2. tt II (Pump). ii PAG2 NO. . 77 131 132 110 47 47 47 47 71 71 85 29 71 71 71 69 63 57 64 57 64 69 71 69 69 69 71 63 64 69 71 71 63 69 63 64 64 69 APPENDIX 1II (CON'T) "GENERAL PHOTOGRAPHS PM NO. CAMERA STATION DATE SUBJECT REMARKS PAGE NO. PM NC/. CAMERA STATION DATE SUBJECT REMARKS PAGE NO. o 162 152.7 554.2 17Dec45 Seaplane Base,Rec.Stat.MOEN. East Entrance 90 234 151.5 556.0 16Dec45 Rock Crusher, MOEN. Overall View. 63 I 163 II II II ii it II n it ODerating Positions. 90 235 II it it II n II Diesel Power Plant. 63 164 fl R II it ti II ti n R R 236 n n n n II n Crushing Machine, 63 165 ii n H R II II It II West Entrance. 90 237 n it H ii n it Overall View. 63 166 155.3 - 557.5 fl Radar No. 2, MOEN. Antenna & Trailer. 95 238 n it R II R It Men Crushing Dynamite. 63 16? II n II tt H It II Interior of Trailer. 96 239 153.1 554.4 n Seaplane Hangar Cave, Camouflaged Car. 58 168 fl H n R II fl H n ti ti 95 240 ii R H R fl R Overall of Entrance. 78 169 fl II n It R tl R II n II 96 241 n n it ii n ii Interior View. 77 170 fl n N ti n ii II fl II it 95 242 153.2 554.5 N Aviation Supply Cave. Interior, Spare Parts. 78 171 H n H R II n it Transmitter, Type 2. 96 243 it II II II it it Exterior View. 78 172 154.9 - 557.1 n n it lf n Sites,Radar Nos. 1 & 3 . 95 244 153.3 554,5 17Dec45 Oxygen Plant, MOEN. Interior View. 78 z it tt " 3 " it II ii it n It H 173 155.0 - 557.1 View from Rear of Cave . 96 245 n 78 I— H II R II it n ' n 174 General View. 246 ti ti H n ti n H 11 78 UJ 175 II R II R M R II Transmitter, Type 3. 96 247 152.8 555.0 II Naval Hospital, MOEN. Water Sterilizer. 144 II R H tt ft tl H it II H H ft U 176 Power Supply,lkva GasEng. 248 Exterior of Ward. 77 Z> 177 R H II fl it ii n Entrance. 96 249 II n II II II It Interior of Ward. 77 OQ 178 II tl II II It II H Antenna. 250 158.2 558.0 It Lighthouse, MOEN. Panorama at 132 • 179 155.3 557.5 It n " i '< Overall View. 95 251 N it II n n H n 235°. 180 fl R fl Radio Station, MOEN. View from Radar No. 1. 252 II n II n it " " 280°. o 181 H R n Radar No. 3, MOEN, n it II II n 95 253 II ti n H II B " 020°. Q. 182 157.0 557.8 II MOEN XMTA Station, Type 98, Mk 2, Model 2 > 254 II H H n II " " 085°. 183 fl H n n II II Rectifier. 255 158.5 558.0 ii Searchlight, MOEN. Overall View, 57 z 184 fl R II " " , Room No. 1. Left Side View. 256 it n R n n Interior Shelter. 57 185 n II II R R H tl 11 Right Side View. 257 it II It OP near Lighthouse. Overall View. 50 186 R tt n II II H II o Overall View. 258 158.6 557.7 tl 8" CD Gun. Top View. 50 187 II it H II II II R fl Right Side View. 259 II II II II II II Front View. 50 188 11 H II It 11 II H tl View of Aft End. 260 II II II II R II Powder Storage, 50 fl M II H H tl 189 MOEN Transmitting Station. NW Wingv 89 261 12cm CD Gun, Exterior View, 49 190 H n H R H R H H II it n R Closeup. 262 Rear Entrajice, 49 CO R II II II 11 H It 191 Transmitters, Type 97. 89 263 152.8 559.9 MOEN Airfield,Rock Crusher, Overall View, 77 Q 192 H H fl fl R II Front View. 89 264 R II n n II II H Showing Quarry, 77 193 151.5 - 557,5 16Dec45 Floating Crane, 30-ton. West from Beach. 107 265 151.7 557.7 ti 11 " .Pillbox. Improvised Light MG. 51 Z 194 it II H Pier No. 1, MOEN. 240° from Beach. 195 266 n it it It II H Heavy Machine Gun. 47 195 H II II Floating Crane, 30-ton. Power Plant. 107 W% 196 tl It n II R II R Motor (50 HP). 26? to 281 inclusive , See "Panoramic Photographs". 197 151.0 556.7 II Pier No. 2, MOEN. East from Sea. 111 198 151.8 553.7 II Beach No. 1, MOEN. North from South End. 133 282 154.0 556.3 17Dec45 Reservoi~. Settling Tanks. 199 R II N H fl R II SW end of Airstrip. 283 H it n II It fl 200 151.7 553.9 17Dec45 R H It fl 150° from North End. o 201 151.8 553.9 H ii ti n ti Log Pier. 284 to 293 inclusive , See "Panoramic Photographs", 202 151.2 553.8 II It tt II H 60° from Sea. 203 152.4 553.3 II H " 2 " NE Section from Sea. 133 294 155.1 541.1 15Dec45 Pier No. 2, UMAN. East from Sea. 110 204 it it fl It II It R SW Section from Sea. 133 295 157.2 539.2 R R " 4 " 320° from Sea. 110 II w 205 155.0 - 557.7 Pier No. 4, MOEN. Concrete, from Sea. 111 296 157.4 540.2 fl ,. 5 ; « 270 " 110 206 154.7 556.1 H R tt It It From End of Pier. 111 297 156.2 540.2 II Naval Radar No. 2, UMAN. Type 2, Mk l,Model 1^ 97 n ti K R H ti II It II H II II R 207 158.7 - 557.4 n D NW from Sea. 111 298 Radar No. 1, UMAN. 97 it « »fi " 208 157.6 - 558.5 R South from Sea. 111 299 II H II R it 4 n Antenna. 9? 209 154.3 559.5 II it n c fl 195° from Sea. 111 300 It fl n n II it ti Concrete Shelter Entr. 97 z> II fl .. lQf n II 11 H H N g tl 210 151.6 - 559.6 130° from Sea. 111 301 Antenna. 97 I— 211 151.0 - 559.0 II Beach No. 3, MOEN. 45° from Sea. 134 302 n R II Army Mobile Radio, UMAN Army Headquarters . 98 n Z 212 151.1 558.8 it II " 4 20° from Sea. 303 155.6 541.0 II UMAN Transmitting Station. Rectifiers. 90 213 H tt n n it II II 65° from Sea. 134 304 n II 11 II II ' II XMTA Relays, o II it II ti ii it 214 154.4 - 558.3 18Dec45 75mm Mtn. Gun. Field of Fire. 305 Interior View, 90 CO 215 n II n II II R View of Emplacement. 27 n R 11 ti II ti Type 99, Keying Unit. 90 UJ 306 CO 216 158.5 - 558.0 N 20cm, 40 cal. Gun, Left Side. 25 30? II II It II B H Generator, Diesel. 217 R H II II H II II Right Side. 25 it R II II II R Z 308 View of Entrance, 92 UJ 218 II II It II II II R Breech View. 25 309 n n R II It H Antenna Vents. 92 219 H II II II It II II Outside View. 25 310 tt it II H H II Antenna Installations. 92 a 220 H R fl II II It 11 Broadside View. UJ 311 155.9 539.3 22Dec45 Underwater Sound Detector. Rear of Cave. CO 221 n II H II II II It Command Post. 25 312 n n II n II II Indicator & Amplifier. 121 UJ 222 158.2 558.0 II II II II H Field of Fire, OP. 313 n n II n it H Warning Panel, Z it it it it ti II 223 R 11 II tl 11 32 314 II tt n n n II a n 224 158.5 - 558.0 n Searchlight in Cave. 20cm Battery. 25 315 II ft n II it n Type 2, Magnetic. 120 225 H n n II II it Operating Platform. 25 316 n n II tt H fl Left Cave, (Housing). 226 157.9 - 557.6 n 12cm Gun Emplacement. Interior View. 25 317 II II it it n II Alarm Panel, Type 2. 120 22? ft N ti ti n it Exterior View. 25 318 tt n ti it II ti Listening Gear. 228 157.2 557.6 n 8cm CD Gun. 13 yr.Type. 27 319 155.9 539.2 18Dec45 Mountain Gun Emplacement. Type 94. 229 tt R H it R II Exterior View. 27 320 it it it 14cm Naval Gun. Left Side. 31 230 155,0 557.5 It 15cm, 45. cal. Naval Gun. Front View, 27 321 II II II II it ti Head View. 31 231 H II II fl II II n H Right Side View. 27 322 156.0 539.3 19Dec45 155mm, 60 cal. CD Gun, General View. 232 R H R n u n it II Left Side View. 27 323 n it ti 11 II R II II Right Side View. 33 233 II II II n it tt n n Breech View. 324 n II n ii n ti ii ti Left Side View. 33 151 APPENDIX III (CON'T) ^iinrS GENERAL PHOTOGRAPHS PM NO . CAMERA STATION DATE SUBJECT REMARKS PAGE NO. PM NO. DATE REMARKS PAGE NO. ?4tA CAMERA STATION SUBJECT I 325 156.0 - 539.3 19Dec45 155mm, 60 cal. CD Gun. Breech View. 422 151.2 - 547.4 19Dec45 Range Finder, Waterproof. Mount 8. 326 n II II Range Finder, 3.5 meters. General View. 33 423 n it H Machine Pistol, 7.7mm. BERGMANN, Type. 327 tt it n ti n ti n Track to Cave. 33 424 H a ft II II n rt , Magazine. 41 328 it n r. ti I I ti it Housing Caves. 33 425 H tt n ti ti n Held by Jap Sailor. 329 n n n B C s Binoculars. 12cm x 20 power. 33 426 146.0 - 547.7 n Gun Sights,Local Mfg. 12cm DP Gun,10th yr.tp. 33 in 330 155.9 - 540.0 18Dec45 14cm Gun, YUKOKA. Exterior View. 47 427 n it H 12cm DP Gun,10th yr. Type. In AA Position. 33 331 N n it n II II Interior View. 428 144.8 - 547.1 20Dec45 Lathe,18H Swing,36" Gap Bed .Auto Repair Shop, PARAM .39 332 n n it Type 93 Range Finder & OP. Exterior View. 49 429 it n « Drill Press, 20" Swing. it n II n 39 it II n II it • 333 14cm Gun, OP. Interior View. 49 430 n Diesel Engine, 1 cylinder. YANMAR Engine Wks.,Lmtd. 39 en 334 H n D tt II n Exterior View. 58 431 n it n Auto Maintenance Shor>,PARAM.Belt Pulley Drive. 335 n II II " " , Ammo Storage. Interior View. 49 432 n n n n it it II Exterior View. 39 H-z 336 it n II " " , No. 2. Incomplete Form Work 49 LU 337 n it II ti n it n Exterior View. 433 to 442 inclusive , See "Panoramic Photographs". _ J II 1 338 156.2 - 540.0 Latrine• Interior View. 60 339 n ti II it Overall View. 60 443 145.9 - 547.5 19Dec45 12cra AA Gun in Cave,PARAM. Bent Rail Reinforcement .47 CO 340 II II II II Interior View. 60 444 it n II " B n .. Tunnel. Log & Rail Support. 49 341 II n II Naval Barracks,Tele.S/Board. Overall View. 445 145.8 - 547.5 20Dec45 150cm Searchlight, PARAM. Log & Net Support. 57 342 n it ft " " , Latrine. EM, Interior View. 60 446 119.3 - 544.4 ti #2,6" ARMSTRONG Gun,POLLEC. Interior of Ammo Mag. 49 a.o 343 M n tl " " , Quarters. II it n 61 447 II tt ti it it n it n Interior of Air Shaft. 49 u 344 156.1 - 539.8 II 15.5cm Gun in Open Pit. Shoreline Background 50 448 II II it II ft It H ft MG Pillbox Defending. Z 345 n H II 11 " , Ammo Storage. View of Entrance. 50 449 123.5 - 549.8 21Dec45 Searchlight,NORTH TOL. Exterior View. 57 346 n N tt n n ti n Interior View. 50 450 tt II H it it it Gen.& Instrument Panel. 61 347 n It II n n Breech View. 33 451 II n n II rt ft Gen.& Water Tanks. 61 348 n II II " B , Camouflaged. General View. 57 452 123.8 - 550.0 N Barracks on NORTH TOL. Exterior View. 61 a. 349 it tl II Searchlight. Entrance. 61 453 126.9 - 546.4 19Dec45 Pier No. 7, TOL. 210° from Sea. 112 350 ti N II 15.5cm Gun, OP. Interior View. 50 454 126.5 - 545.0 II Grave of American Aviator. Wooden Grave Marker. z 351 tt It II Range Finder & OP Entrance. Exterior View. 50 455 125.8 - 542.6 ti Pier No. 6, TOL. North from Sea. 352 155.4 - 540.8 II 37mm Anti-Tank Gun. Interior,Double Embr . 47 456 117.9 - 543.9 if n ti it II 330° from Sea. 112 II it n it it II CO 353 n Exterior View. 58 457 117.8 - 544.0 n Sandy Beach, SW POLLE. East Along Beach. 135 a 354 155.3 - 540.4 II Pillbox, HMG, Shore of UMAN.Interior View. 458 118.0 - 544.0 II n II it n West Along Beach. 135 355 n a II n ti tt II II View of Entrance. 52 459 117.8 - 543.3 n n it n n 10° from Sea. 135 z 356 ti ti n it ti it II it Embrasure. 460 120.4 - 545.6 n Pier No. 5, TOL, Stone. 140° from Sea. 112 < 357 tt II it Anti-Tank Rock Wall. Overall View. 52 461 121.5 - 550.1 II tt II A tt II SW from Sea. 112 CO 358 156.2 - 538.6 n Pillbox, Light MG. Covering South Point 462 121.8 - 550.6 H " " 3, " , Concrete. North from Sea. LU 359 a ii it n if II Log Embrasure, 463 121.6 - 550.5 II II n II n ti NE from Sea. 112 Z 464 121.3 - 550.8 n Beach on NORTH TOL. 70° from Sea. _i 360 to 387 inclusive, See "Panoramic Photographs". 465 123.9 - 550.5 n Pier No. 2,N TOL, Rock. West from Sea. 112 466 124.5 - 549.7 II " " 1 / " , Stone. SE from Sea. 112 o 388 153.1 - 546.8 16Dec45 Pier No. 4, FEFAN. West from Sea. 467 127.4 - 547.5 20Dec45 " " 11,N TOL, Coral. West from Sea. 113 389 152.9 - 546.8 II II n n n East from Shore. 111 468 127.3 - 546.6 n " " 10," " , Rock. W from Sea. 113 390 n it it Shoreline N of Pier No. 4. North from Shore,. 136 469 126.3 - 546.0 n « " 8,N TOL, Wood. tt II it 112 391 153.4 - 541.9 tt Pier No. 3, FEFAN. NW from sea. 111 470 125.6 - 546.3 it " " 9, Wood & Stone. n it N 392 152.8 - 542.0 n n it tt rt SE from Shore. 471 125.5 - 546.7 II " H ", NORTH TOL. South from Sea. 112 O 393 153.0 - 542.0 n Shoreline NE of Pier No. 3. North from Shore. 472 139.0 - 548.4 18Dec45 Torpedo Boat Caves, UDOT. 20° from Sea. 115 394 151.4 - 546.5 18Dec45 AA Gun, OP, FEFAN. Mt.NISHIKI,Exterior. 61 473 136.2 - 549.0 tt Pier No. 3, UDOT, Stone. 350° from Sea. 113 395 II it II II II it II " " ,Interior. 474 135.5 - 549.0 n n n p II II 20° from Sea. 113 15 396 ti ti it Air Raid Shelter. ti ti n 52 475 135.0 - 549.5 n II it n ' M n NE from Sea, 113 OS 397 151.6 - 546.4 n Searchlight, 75cm. " " \Overall. 57 476 135.3 - 549.6 it rseach North of Pier No. 1. North From Pier. 136 398 n II n " , Generator. » " ,FEFAN. 60 477 137.6 - 549.7 II Pier No. 6, UDOT, Stone. 160° from end of Pier. 113 z 399 151.3 - 546.4 ti Water Storage Tanks. Overall View. 61 478 138.9 - 549.5 n tl II c II H 210° from Sea. 113&136 400 151.6 - 546.0 n Gun Director. 12cm AA Battery. 479 139.2 - 549.7 n " " 4, EOT, Log. NE from Sea. 113 COo 401 i t N H 6-gun,12cm AA Battery. Overall View. 51 For Searchlight. 51 • •I 480 139.3 - 550.3 20Dec45 Type 2 Director, EOT. UJ II II II n II CO 402 12cm AA Gun Emplacement. Closeup. 29&51 481 n 12cm AA Gun & Fuse Cutter. Overall View. 51 Z 403 tt It II Communications Center. Interior View. 60 482 II ti II 40kva Generator. For Searchlight. 60 LU 404 ti II n Observation Shelter. Exterior View. 51 483 138.0 - 549.3 it 12cm in Cave, UDOT. Wall Embrasure. U. 405 151.9 - it 12cm Gun, Mt.NISHIKI,FEFAN. Overall View. 47 it n n LU 546.0 484 Shelter for 12cm Gun Crew. Interior View, 61 406 it tt it Water Collection in Tunnel. Interior View. 60 485 138.2 - 549.4 n 20 HP Diesel & Saw-Mill. UDOT, Overall View. 69 a it LU 407 151.9 - 545.1 13mm MG, Mt.UFUNO, FEFAN. Exterior View. 61 486 20Dec45 14cm Gun Emplacement,MINAMI .Abandoned. 23 CO 408 151.2 - 545.9 19Dec45 75mm Gun Emplacement, FEFAN,Field of Fire. 29 487 ti Generator Building, MINAMI. Partially Destroyed. LU 409 151.1 - 545.4 n 12cm Gun, 3rd yr Type. Exterior View. 29 488 ti 31ockhouse, MINAMI. Interior View. 120 Mm"T 410 151.7 - 545.7 n " " , Type 10. AA and Fuse Cutter. 31 489 II MINAMI. General View. 411 151.7 - 545.4 ti 12cm, Tyoe 10, DP Gun. Fuse Cutter. 31 490 n Observation Tower, MINAMI. II II 412 n n n it it n it it In AA Position. 31 491 it Water Tanks & Latrine. MINAMI,Exterior View. 413 II it tt ^Dwer Supnly & Tele.Circuit.Battery CP. 492 it Underwater Detector, MINAMI .Control Box & Cables. 120 ti it ^nkii It n it n II 414 \ *?""''' i Telephone. 493 Pier on MINAMI. General View. 415 II - Bl II V • a n ' Director, Type 2. General View. 31 494 156.9 - 546.7 18Dec45 Radio Station, ETEN. View of Rear. 79 416 151.2 - 546.4 X « 24Jtw Generator. For Searchlight. 31 i 495 II M n n ti II Damaged Roof(Inside). 79 r K 417' % .161.5 - 546.5 8cm Anti-Aircraft Gun. General View. 29 496 It H II Air Raid Shelter, ETEN. Overall View. 418 3i 150.2 - 547.6 II 15cm CD Gun, ARMSTRONG. Spanish, Left Side. 31 497 II II n n it II II Baffle Wall & Door. 79 It n it II it 11 419 II , Right Side. 31 : 498 tl ft tt it it II II Direct Bomb Hit. 79 420 II H II II II it it " , Front View. 499 It II II Radio Station, ETEN. Control Building. 79 421 151.2 - 547.4 H Range Finder, 1^ meter. Waterproof. 41 500 ft tt n H n it Interior Damage. 152 APPENDIX III (CON'T) GENERAL PHOTOGRAPHS PM NO. CAMERA STATION DATE SUBJECT REMARKS PAGE NO PM NO. CAMERA STATION DATE SUBJE.T REMARKS PAGE NO 501 157.0 546,7 18Dec45 Caves on ETEN. S End of Airfield. 79 538 119.3 544.5 20Dec45 Short Wave D/P, ULALU. Installation,Type 93, 92 n tt n n II n n » it it II II 502 Iron Supports, 539 H Type 93-,Modification 1. 92 I 503 it II it it Overall of Entrance. 540 n n Switchboard. 504 156.9 546,7 n Radio Station Power Plant Inside Damage by Dud. 79 541 it it Exterior of Building. 92 OH it tt ti n 505 H n " " " Bomb, 79 542 157.0 549.4 18Dec45 Naval Receiving Station. DUBLON,Antenna Towers. 87 506 it it " " " Dud. 79 543 II it if n n 507 157.0 549.3 15cm Gun, 40 cal., DUBLON. Breech View, 544 n II tt n Console Panel. n it ti II 508 II ti ti General View. 27 545 154.8 548.0 Army 50 Line Switchboard. Type 99, DUBLON. 98 509 158.6 549.3 Director, Type 95f DUBLON. 12.7cm AA Battery. 29 546 ti n Transmitter, lkw. High Frequency,DUBLON. 98 it II n it 510 H 12.7 cm AA Gun CP, DUBLON. General View. 29 547 n II it 29 511 II " Range FinderJ3tereoscopic, 4.5meter. 548 155.9 548.0 Transmitting Station, DUBLON Seaplane Base. 89 CO it 11 u n 29 II n II 512 tt " , Type 89. Battery oh DUBLON. 549 Interior View. 89 z 513 158.6 - 549.6. 8cm Gun, ARMSTRONG Type. Position on DUBLON. 27 550 it it Naval Seaplane Base. 88 514 Short Mortar, DUBLON. Type 89,General View. 551 Pier on TONELIK. From Sea, 113 UJ 515 it II II it n ti it 552 25kw Generator on TONELIK. Power for Type 92 mine .121 n n 516 13ram Antl-Tank Gun,DUBLON 97 ^ 553 Recorder for U/W Detector. Paper Tape. 120 it II ID 517 554 Underwater Detector. Closeup of Panel. OQ 518 Telescooe Sight,Type l,ModH47mm AT Gun, Type 1 555 Mine Listening Panel. TONELIK, NORTH PASS. 12? 519 II n 556 U/W Detector, Tyoe 2. Visual Panel. 122 520 154.8 550.5 8cm Short AA Gun,5th yr Tp. From Mine Sweeper, 557 II II n " it Switchboard Panel. 121 o n a 521 41 558 90cm Searchlight. TONELIK,NORTH PASS. 57 Q. 522 it n 60 KG Rocket Launcher. Local Manufacture. 27 559 25mm Gun Position. II * II n z 523 ti it It It It N Rear View. 41 560 Undergrowth. 524 II it Flame Thrower. Large Type. 41 561 5, 5-ton Trucks(Fresh Water) 120 525 H n 2,000 KG Capacity, 41 562 Armored Tractor Crane, Pier, Beach & Pillbox. < H n n II n II " II 526 II 563 Aboard Ship. 13Dec45 UDOT. 002° 30' from Sea, a. 527 II II Tractor w/Alr Compressor. Type 97. 41 564 n it II FEFAN & OLLAN. 042° 30' ti it u 528 II n Service Truck. Left Rear View. 565 n it it UMAN. 056° 00' Z 529 151.2 547.4 20Dec45 Torpedo Head, FEFAN. Practice. 116 566 tt II it TSIS & FEFAN. 031° 30' 530 it n Path Recorder. For Torpedoes. 116 567 II II II Reef, TOL in background. 312° 00' 531 II n Very Pistol, Triple-Barrel, General View. 568 n II II CO UMAN, (Entering SOUTH PASS). 045° 00' Q 532 ti n Gyro for Torpedoe. 116 569 n ti it it 047° 00' 533 119.3 544.5 Radar Antenna, ULALU. 98 570 it it it UDOT! 326° 00' Z 534 it n Transmitter. 98 571 II it it UMAN. 005° 30 • 20 535 M it Radar Shack, ULALU. View of Entrance 98 572 n n it DUBLON. 353° 00' 20 CO 536 II n Radios on ULALU. Overall View. 573 Type 92 Mine Detonator. Closeup. 121 537 II n Radio Antenna. ULALU. 574 Listening; Panel. 121 575 15Dec45 Machine Shop Truck. Type 97, Gap Fed. 41 o PANORAMIC PHOTOGRAPHS PM CAMERA DIRECTION VERTICAL LOCAL PAGE PM CAMERA DIRECTION VERTICAL LOCAL PAGE NUMBER STATION OF LENS ANGLE OF TILT TIME DATE SUBJECT NO. NUMBER STATION OF LENS ANGLE OF TILT TIME DATE SUBJECT NO. STATION "D» (MT. FUOUKANAII, DUBLON) (Continued) 1 to 109 inclusive, See "General Photographs". 140 155 .0-550.0 153° Mag, Minus 11° 1113 15Dec45 Mt.TOLOMAN, DUBLON. 14 STATION "E" (MT. URIMOGURU, DUBLON) 141 II n 200° it it II 1113 tt FEFAN. 14 110 158.2-549.: 255° Mag. Minus 06° 1354 14Dec45 Mt.TOLOMAN, DUBLON 17 142 II it 245° ti it n 1114 H H 14&15 Ill 287° " 1355 Mt.FUOUKANAN, DUBLON. 17 143 ti II 183° it II it 1115 It FEFAN & DUBLON Channel 14&15 Z 112 315° 1358 MOEN. 17 STATION "F" (MT. TOLOMAN, DUBLON) 113 342° 1400 n 17 144 154.9-548.7 343° Kag. Minus 12° 1445 15Dec4!5 MOEN. 17 o II it it II II CO 114 008° 1405 West Tip of KOEN. 17 145 n 020° n 1446 17 U l 115 027° 14Q8 Sea View. 16&17 146 it II 052° II it it 1447 tt NE Part of DUBLON. 17 CO 116 052° 1410 Searchlight. 1G 147 II tt 088° II II n 1448 ti SE Part of DUBLON. 17 Z 117 052° 1410 ft 16 148 n it 160° II 11 II 1448 UMAN. 16 118 081° 1412 Summit of Mt.URIMOGURU. 16 149 II II 190° it n n 1449 it it 16 119 115° 1413 it II II H « " tt Terrain. 16 150 166° 1452 16 LU 120 149° 1414 Terrain & Sea. 16 151 ti tt 205° II It II 1453 it Southern FEFAN. 16 CO 121 185° 1415 UMAN. 16 152 it H 235° II ft it 1454 tt Mt. NISHIKI, FEFAN. 16 122 209° 1416 ETEN. 16&17 153 it H 280° II H II 1456 it UDOT & EOT. 16 123 246° 1417 DUBLON Town. 17 154 it II 330° it tt II 1458 n MOEN. 17 155 n II 315° n It II 1459 n Anti-Tank Barriers,DUBLON . 17 124 to 132 inclusive, See "General Photographs". STATION "DB (MT, FUOUKANAN, DUBLON) 156 to 266 inclusive, See "General Photographs' i 133 155.0-550.0 253° Mag. Minus 1105 15Dec45 Northern FEFAN. 15 STATION »C" (HILL 754, MOEN) B 134 " " 288° 1106 Small Boat Pier. 15 267 152.6-559.2 125° Mag,, Minus 19° 1145 17Dec45 Hill 800, MOEN. 14 135 " " 315° 1107 MCEN. 15 n tt n n it ti N.C.B. Canro, MOEN. n 268 160° 1146 14 136 it n 355° 1110 15 269 it it 193° it n it 1147 II FEFAN. 14 II n 137 056° 1111 Outer Reef. 14 270 it II 221° it it it 1148 ti Floating Crane, FEFAN. 14 138 090° 1112 NE Point of DUBLON. 14 271 II it 252° it n II 1149 ti USN Anchorage. 15 139 120° 1112 DUBLON Town. 14 272 II it 287° II " " 1150 II LST Landings. 15 153 APPENDIX III (CON'T) PANORAMIC PHOTOGRAPHS o o PM CAMERA DIRECTION VERTICAL LOCAL PAGE *~ NUMBER STATION OF LENS ANGLE OF TILT TIME DATE SUBJECT NO. I STATION "C" (HILL 754, MOEN) (Continued) m t •*' '* -• * • • ^ /-*^ *"\ 273 152.6-559.2 319° Mag » Minus 19° 1151 17Dec45 Sea View. 15 II H n II H N m& % t" V IP /' '' •* * ^^ J* fen 274 350° 1152 Terrain. 15 fl H II N H •w ti %gffJL ' ..' * ^ % L f\ • '} f%' 27 5 350° " n 1225 15 276 ft H 350° w R 11 1225 II n 15 i n 277 fl R 020° " n ft 1226 It FALO. 15 „ - ** 278 II ft 052° n n N 1227 It Headquarters, IsCom. 14 279 H H 080° " R tt 1228 H Causeway, MOEN. 14 • 280 H H B H fl 1229 H Hil l 800, MOEN. 14 ft ft 110° n z 281 150° " n n 1230 It 1200, MOEN. 14 282 and 283, See "General Photographs1 LU STATION "B* 1 _ J (450 *RIDGE, MOEN) _ J 284 154.4-558.5 213° Mag , Minus 10° 1555 20Dec45 Terrain , Mt.TER0KEN,M0EN 13 H ^ 285 it n 235° R n 1556 n USN Anchorage. 13 CD 286 it n 265° " fl tt 1557 n Hill 754, MOEN. 13 287 II II 298° M ft tt 1558 R 21st Mar.Camp Area,MOEN. 13 288 n H 320° " H it 1559 R Causeway, MOEN. 13 oOu STATION "A" (4501 RIDGE, MOEN) Z 289 154.5-558.4 200° Mag Minus 10° 1606 20Dec45 S Ridge of Mt.TER0KEN,M0EN. 13 B H u 290 « n 167° H 1607 ti Hil l 889, MOEN. 13 291 n fl 127° " H It 1608 n Terrain , MOEN. 13 292 n R 078° " fl n 1609 N Lighthouse,Hil l 351,MOEN 13 fl n It II H Q - 293 033° " 1610 FALO. 13 Z 294 to 359 Inclusive, See "General Photographs". STATIONUG" (MT, URORAS,UMAN) 360 156.1^540.2 320° Mag, Minus 15° 1100 18Dec45 FEFAN. 18 CO 361 R R 346° " n n 1101 n DUBLON. 18 362 R N 015° " II n 1102 n ETEN & DUBLON. 18 36 3 R It 042° " n H 1103 ft Outer Reef. 18 364 fl It 085° « n n 1105 it R It 18&19 CO 365 II II 110° " R n 1106 n Terrain & Sea. 19 366 fl n 135° n fl N 1107 n FANEU. 19 367 n tt 160° " fl II 1108 n Outer Reef Islands. 19 z R R R II H 1 368 212° " 1109 Summit of Mt.URORAS. 19 • J STATION "I" (MT. NISHIKI, FEFAN) 369 151.5-546.5 294° Mag. Minus 28° 1003 19Dec45 Mt.SANREI, FEFAN. 21 370 H H 329° " M n 1004 " Terrain, FEFAN. 21 u 371 It fl 350° n n n 1005 n MOEN. 21 372 H R 025° " H H 1006 n II 21 373 II H 052° " ft tt 1007 n DUBLON. 21 374 ft H 080° " H it 1008 n ETEN. 21 o 375 N H 115° " n n 1009 it Outer Reef Islands. 20 376 ft ft 135° " tt n 1010 n UMAN. 20 377 ft R 166° " fi n 1011 R EBUN. 20 3 378 R R 188° " it II 1012 n TSIS. 20 M R R ti 1— 379 215° " 1013 n Outer Reef Islands. 20 z 380 R N 250° " H it 1014 n TARIK. 20 381 tt H 285° " H B 1015 II PARAM. 20&21 o% • w CO STATION "J (MT. NISHIKI, FEFAN) LU 382 151.6-546.4 195° Mag. Minus 21° 1030 19Dec45 TSIS. 2 1 CO 383 H n 170° " n H 1031 it Mt.ARASHI, FEFAN. 2 1 H n H tt LU 384 144° • 1032 n UMAN. 21 M U . 385 it R 110° II 1033 H Outer Reef Islands. 2 1 LU 386 R fl 079° " N ti 1033 it ETEN. 21 387 n II 046° w It w 1034 n DUBLON. 2 1 LU CO L U 388 to 432 inclusive, See "General Photographei" . STATION "H" (HILL 236, PARAM) z 43 3 145.7-547.5 065° Mag. Minus 09° 1432 19Dec45 DUBLON & FEFAN. 18 < 434 n it 105° " H n 1433 n FEFAN. 18 435 H fl 147° • H ti 1434 u TSIS. 18 436 fl N 180° " H ti 1435 n Terrain & Sea. 18 ft II II II H v W :,_ 437 215° " 1436 TARIK. 19 43 8 fl It 240 o « H n 1437 n PARAM Airfield . 19 439 II N 255° H ft it 1438 H TOL & EIOL. 19 440 rt R 284° " H II 1439 n Terrain , PARAM & UDOT. 19 \ •' 441 fl It II tt 1440 n Terrain on PARAM. 19 314° n" 44 2 H n 343° H ti 1441 n n tt it 19 3MBINED A RMS RESEARCH I IBRARY fl || FORT -EAVENWORTH, K 44 3 to 575 inclusive, See "General Photographe 1 1 3 169 5 00539 721 1 154