I k0-41io ARMO'R ON OKINAWA A RESEARCH REPORT PREPARED BY COL2JIaTTEE 1., OFFICERS ADV~ANCED COURSE THE ARIJJDD SCHOOL 1948-1949 MAJOR J.1L. BALTHIS ML.AJOR P. Go. SHOMffONEK MAJOR R. B. CRAYTON4 M.,AJOR L. H. JOHNSO CAPTAIN T. Q. DONALDSON CAr~PT'l4 D. L. JOHNvSON CAPTAIN W. Jo HYDE 1st LIEUTENANTd.To. WOODSON, JR. FORT K§v"OX, KH&!TUCKY MA1Y 1949 e A t- L - A ARMOR OKNA WA "-4j ~i4L f -' lip .V1 (1', July 1886-i8 June 1)/45) bon3 ul 1I6 ie&P Iunf ordile Ky., son of the cel-ebrated Confederate general, Simon Bolivar Buckner. The onerBuckner ch,,ose a mii ta,,r career, as had his father. 1 fter attending the iirgnia ilitry Istiute, he entered th-e U-,nited States Ml itary AIcadem, from.r which. h-e graduated in 1903. He was instruc- w--r in -,ilit-ry tactics at WIest Point from 1919 to 1923, and- COM- 2andant of cadets from 193)'2 to 1936 . Dudring World .Jar I, h-e comn- -unaded aviat'1ion training brigades. -:ieral Buckner was given, comuand of th e 1 1as a r6efenie force in dyan 940plyeda pomientrole in t1,e recapture of the -euionsin 1942-43. He was awarded the D.S.M,. in Oct. '1943, ' 1 Promoted t te4te iplDorary rank- o.L eter Generl. 1-was - Ler sent to t-he Ccntral PacifcComn, hr ho gai-ned cormmand the, new,, U.S. TNT1H A2LY. T1his a ,under his cormmand, invaded JNL~kI, on 1 A'pril 11945,95in1 three days bef'ore the lose of the Okinawan camnaign, General Buckner was fatally wounded r by a piece of coral, ahrcwn by the expl1osion of an c-eyartill cry S'4 PREFACE The capture of OKINAWIA was essentially en infantry effort with the result tha-).t armor wtuas at all times in support of infantry units. Becauss.of the scattered nature of such armored activity, detailead reports on. the operations of tank battalions were not available. Where some armored unit after-action re-ports were found, the repetitious accounts of individual small-scale tank actions failed to haveo an orderly sequ(,nce which could be related to the over-all campaign. Only by piecing together many separate, brief reports of tanks supoorting small infantry units wa's a logical sequence attained. Of considerable assistance h,Jhru gaps existCd in after- action reports, wetire the interviews with officers who had particip- ated in the Battle of OKINAWA. Credit is given to Lt. Col. John Collier, 776th ~Aphibious Tank B-attal1ion; Capt. A.E. Furgeson, 7th Infantry Divis.ion; Capt. C. E. Haze,35_34th Amhibious Tractor Battalion; and Capt. Ai.A. Todd, 711th Tank Battalion, who were able to give authoriatiw observations and to augment ailable ocmets The subordinate role of armor in the batteb rpredtdo rm theanfr newr nwihtesal * * additional consic~ration given to fragmentary re_counts of other tank units when noteworthy performance warranted commr-ent . Ainalysis of the present armored doctrine, which emphasizes mobility, mass, great fire power, deep penetration arnd exploitation, is hardly applicable to the armored action on OKINWA'where most of the tank fighting was limited to tank-supported inffntry actions. Only for a-brie,: f period during the mopping-up phase, after organized Japanese resistance had been overcomec, iwere tanks massed in formations as large as a company. However, a study of this campaign reveals the many proble.ms of close tank-infantry coordination which would not be so apparent in a fast moving, predominantly armored, campaign. He.-1rein is the value of rncount- ing the many small tank-infantry battles which gave momentum to the steady infantry advance which shattered strong defenses and destroyed a determined enemy. Ac') TABLE OF C0NTE1TS FRONTISPIECE ***** ...................... ... i PREFACE *. 0.0.a.V*0*a*0*g* * * * * * * * * TABLE OFCONTE'TS .... MAPS .. * .0 *0 , * *9* *v*i PHOTOGRAPHS. 0 a.. .. ................................... viii CHAPTER PG I INTRODUCTION.,..0 ................. 0**a** 6 .10 General Organization.........................*0 Characteristics of the Area .0 . .** * 3 Amor's SupportingRole............... 4 Schedule ofCamnpaign . .. * 7 II TRAINING OF THEn ARIJRED AND AMPHIBIOUIS UN4ITS (Prior tol1Aprill945) -e- 0.. 0 9,0 0. 0 ...... 0 0 10 Preparations of 20th Armored Group..............0. 11 Rehearsals. .0.0.0.*.&.0 0.. .I. a 16.a. 18 Waterproofing,7 E quipmennt.......IV.. 0,e* 23 III EBARKATION AND i DVEMS4aT TO OKINAWJA (2 March 1 A4pril 45) 27 Loading Arrditse is....... 4 ,. 27 M1ovemnent to Attack.................. 33 IV AiQIHIBIOUS ASSAULT L4NDINqG (1 3 Atpril 45) . 0..0.6 .9. 36 Inva sion Bombardment. .. ..# a. .. .* .. .6.0. 36 Landing Organization. .* 0 ..... .... 37 Beachhead .9 * .. a e.,a.* o .. * .. .. .* .. 40 V OVL1RRUNN INTG THE OUT'PUT SYSTB2 (4- 19 April 45) ..... 46 711th Tank Battalion Aidvances South (4- 14 Apr 45) .. , 47 The Pinnacle.* ... ,...**.* 49 Triangulationil.l.....,,0 *,52 Technique of Operation, 711th Tank Battalion.s ... 56 v VII BFU44AKING TH.] 41CIIDhATO LINt (14- 24 April 45) .0 73 7th Division Attacks. *4* ..... ... 78 Skyline Ridge .r ..... ..... 79 Rocky Crags .8 0 96th Division A1ssa-ult .8 7 K akazu Ridge,~0.................8 ... ... 9 VIII 711th TANK''1,. BATTAiLION HITS T12I SHUR.I Lflh-- (25 April 9 IMay 19450 0 .. .... 95 Japanese Pos-itions. ......................... 95 Terrain 7th Division Zone......... .. 96 Operations 711th Tank, Battalion (25 April- 9 May 1945) 2 Jap Counterattack (4 -5M1ay1945). .... 9 24th Division Attacks (4 _1-.ay 1945). o9..... a 0 3 Op,.rations 711th Trnk Battalion (6 - 9 May 1945). .. .b . 105 IX 763rd TALIK BAT1TALION TIROUGH TI-L SHUN IMID."L (25 ri 31 LMay 1945) 0... 6 0 ... ... ... 1038 MAMD S±MA :,;T. ... .0.009..0 .. .. 103 96th Division Reente-Drs thu- Line ..... ill1 RoliJ-. of 7th Infantry Division (9 - 10 Miay 1945) .... 113 Capture of Conicel-Dicx, Hills (10-16 1May 1945)..... 115 Assault A1gainsc-t Sugar-Oboe Hills (16 - 29 Mla y 19 45)...12 Shun '.Defenses,qBroken (29 - 30 May 45).0.9. 0.0.a..0.0.122 X MiOP UPPHA%(2li y-3O June1945). ..... ... 126 "Final Kill" (15 Junel1945) 9 9 9 9 l 9 9.134 Death of' L r1Buckner. .6.0.i. .. .a.a*0.0.a.a*0*139 Contribution of' Alrmor *.0 *. 41.. 0.. .. 11 Tank Losses ....................... 142 Japsnts Doctrinea .......... 143 Conclusions *.*.* ..... ..... 10 144 Analysis of Aippliccetion of Pre-sent XAru.-ored Pnincipl a . 146 AP E(i:ND ICES . w . .*a 0 99e9 9 9 9 9 9 I 6 . 4 ERI C NOR011OFB1TTL:,.-.0"OF,..... i B JAPANSE ORD1XLOF1BA1T TLE... .. .. i C STA1TISTICS OF OK2IIAUA CA1~i,,IG .... ... V D iaMPHIBIOUS VW±1ICLES .,ND LANDING CR,.FT .. , ... .. ix vi ~1 1. Organization Ten thhA'rny.....,........ 1 2. Organization 20th Arm~red Group. ,..........2 3. OKIN4AWA SHIM/i. .. a 5 4. OKIN AA 6 5.v OKINAWA CALWAIli........... 8 6. Tenth Array' s Advance (1-3 A"pr il) .* 38 7. Through the Outposts (4 8 April) . * 48 8. Terrain Sketch Island of OKINAJA .a 68 9., Concentri"c Defense Plan for Main Battle Position ... 69 10. J0IV Corps A',ttack, I9 ApriI. .. .. 75 11. Enemy Operations (7 - 24 Aopril) .IV .... 86 12. Breaking T!AABA'RU-NESHADARU Defenses (17-23 ,April 19L6) 93 13.a The KOCHI-ON.,,G~ Sector . .1 ....... 98 14. Enemy Operations (4is"Aay- 21 Mvay).... .* 103 15. Actioni A'gainst hVth ESCARPb±N'T. 112 16. Relief of 7th Infantry Division (9 - 10 May) .... 114 17. Capture of CONICAL1-DICK HILL (10 . 16 may) ..... 118 18. Assault ,,gAinst SUGA,%R-OBOE HILLS (16-29 May) .... 123 19. SHURI Defenses Broken (29 - 30 i!&ay) ........ 125 20. Fall of SHURI (30 - 31 May). .* . .* .. .. *. 129 21. End of Organized Resistance (is - 21 June) . 0 .. 131 vii PHOTOGILPHS PAG 1. Assault Waves Landin,-P 1 April 1945 .... ... 39 2; Close-in Tank-Infantry Teamwork,, OKINAWA141 Campaign. 56 3.0 Flamnethrower Tank of the 713th Amored Flamethrower 4. Typical OKINA''7hi Terrain, 7th Infantry Division, Lookingesouth f romTCDREMHILL. *. .41, W.0.4 .a.a 71 5. Tanks and Infantry Ar'ttack the ROCKY CRAGS. 0.0.. 2 6.9 Flame Tank of the 713th Tank Battalion Supp-orts Infantrymen of the 96th Division.......... 31 7. Tanks of the 711th Tank Battalion lay down fires on a Jap Escarpment . ... .. .. ... .... # .. 1_35 8. American Tanks move in on the Enemy at LkED4,.22 June, 9. Tanks ,ttempting to Dodg e Jap 75 mm shells during attack on tMhMz, 22 June 1945...10. * .. 137 10. 713th Flame throwing Tank destroying escarpment on a coral outcropiw 17 Junel1945.9 . .. .. 13 CHAPTER I IIWTtODUCTIoN OKINA"IAt The last barnrier to the Japanese Mai'nland. American power was massed for invasion and readied for a deter- mined step toward final victory. The Joint Chiefs of Staff issued the directive for "OPERATION ICEBERG"', as the Okinawan campaign was to be known, to Gino POA (Commander in Chief,, Pacific Ocean Area) late in, September 1944 with a target date cf 2 L.-arch 1945 which was later changed to 1 April 1945. Lt. Gen45ra1 Simon B. Bucknr..rs TENTH ARMY composed of the United Statasz? XX.IAV Corps and the III Mfarine Amphibious Corps, was assigned the missioni of seizing OKINAWVA. (See Figure 1, and Appendix A). XXIV kf*T" CORPS fIII 1CARIIT AMP!!. CORPS 7th Inf ant-ry Division 1st Marine Division nr iiin2dMrnI9t ii o In 196th Infantry Division J6tn Marine Division Corps TroopsJ Corps Troops L2o0thArmo re dGrouj Figure 1 N Each infantry division had attached or assigned one standard tank battal-ion, two amnphibious tractor battalions and one amphibious tankr battalion from 20th Armored Group. (See Figure 2) Flame thrower tanks from the 713th Armored Flame Thrower Battalion were attached later on in the campaign on the basis of one company per army division, and within the Marine tank battalions there were twvelve flame -throwers tanks assigned, four per combat company.