UNCLASSIFIED

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Rock Pt^s+rr DOCK L$"QH Jy ' - MONKEY PT

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' ORDN ANCE PT EAST CORREGIDOR ISLAND N JOSE HOOK SOUTH DCr&K PT

SAN JOSE BAY

Wheeler Pt A B A L L

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Geary PI

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CABALLO ISLAND NOTE

The information contained in Combat Notes is classified as Confidential, principally due to the inclusion of unit and place identifications therein* In general, ty omitting unit and place identifications, the classification of the article may be reduced to Restricted*

BoMrGBfib£ir£ir3' Yjii"';, •, . DECLASSIFIED ill TEH 12 YKiiSS.' BIS saoo.io OOKTENTS

Goxragidor Pag© 1

Combat Hints from Europe ; Page I9

The Trojan Borse page 26

Know Your Japanese page 31

Assault and Reduction of Cave Positions Page 52

Japanese Artillery in Defense of High-way $5 Pags 38

Artillery in Reduction of Intramuros pa«e 10 GiNSl&L?

In the early part of February I9h5» Sixth Arny units were pushing south from the Lingayen Gulf to effect the early capture of the Port of Manila# The XIV Corps was driving into the city frcm the north and east while the I Corps was securing the Army's northeast flank against''stubborn '*• enemy resistance,. South of Manila, the 11th Airborne Division* following its swift advance from Nagsugbu Bay and Tagaytag Ridge, was driving the Jajianese from strong positions in the Nichols Field Area. The XT Corps , which had landed north of Subie Bay, had pushed east and south, seized Olongapo, and was now driving east across the 2&g-Zag Pass to cv off the Bataan Peninsula.

In order to utilize the Port of Manila as soon as the city was liber­ ated it was imperative to secure promptly the entrance to Manila Bay. Seizure of Gorrsgidcr Island was a part of the operation assigned to 32 Corps for accomplishing this objective. The overall plan contemplated an overland attack south from Orani to clear the east coast of Bataan, an amphibious assault op Mariveles, aind a combined airborne-amphibious assault on Corregidor. (See sketch) The Marivelest or South Force* under the conmaM of Brigadier General *• C. Chase* Comnanding General, 38th Infantry Division, wets composed of the 151st Infantry RCT (reinforced). The Corregidcp force* known as the "Rock Farce"* was under the cowannd of Colonel G. M. Jones, Comnanding Officer, $OJi Parachute Infantry RCP, ami was com­ posed of the 5°3d HOT and the 3d Battalion, 34th Infantry (reinforced).

D-Day for the landing in MariTeles Bay was 15 February 1945 aQd for the Oorregidor landing, D/l or 16 February. Rear Admiral A. D. Struble* U. S. Navy, was in cocmand of both of the amphibious mores. Since the Corregidor attack was to be a combined operation iwrolring both a parachute drop and an amphibious landing* the 3d Bn, 34th Infan­ try* accompanied the Mariveles Force in order to be in a better posi­ tion for the amphibious movement on the following day. Naval units of the S err ©nth Fleet* under command of Rear Admiral Berkey* conducted mine sweeping and bombardment operations in the southern Bataan-Cor- regidor area to pare the way for the isater move to Corregidor. Air operations supporting this action will be discussed with the parachute phase of the assault, inasmuch as they were so closely tied in with the vertical landing.

This operation represents one of the most difficult ever, carried out by paratroops, but its complete and overwhelming success fully justified the risks incurred. The Japanese were cau^it off guard where they least expected the blow to fall.

THE ASSAULT OF CORREGIDOR t

Preparations for the assault on Corregidor had begun as early as 23 January when the Fifth Bomber Command commenced a daily pound­ ing of the Island. During this period prior to the landing, a total of 3,128 tons of bombs had been dropped on the island - an area less than one mile square. In addition to the naval gunfire preparation on 16 February, continuous air pounding was set up to precede and cover the parachute drop, scheduled for 0830. From 0745 to 0800, one group of heavy bombers dropped 260 lb fragmentation bombs, each plane carrying 40 bombs. This was immediately f oilowed by one group of A-20's which strafed and bombed both Corregidor and Caballo Islands with 250 lb para-demo bombs. After 0830, air support was confined to areas outside the parachute drop zones (see sketch) and from 0830 to 0930 two groups of A-20,s covered these unrestricted areas. By this time the first lift of paratroopers were to be on the ground, and air support was then limited to three squadrons of A-20«s on air alert; one prepared to fly smoke missions**! call, and the other tto to support the second air drop of 1

LUBAO

DINALUPIHAN

OLONGAPO HERMOSA

SffB/C BAY

BALANGA

BAGAC

f><1 RCT (•) The parachute phase of the Corregidor operation was accomplished by the 317th. Troop Carrier Group with two lifts of 51 planes each (G-h-7 type - 15 of which were equipped with artillery dropping para- racks). Each lift was capable of dropping approximately 1#000 troops plus necessary bundles containing supplies and equipment which could not be carried by the individual soldiers. The first lift carried a part of the Regimental Headquarters and Service Company; the 3d Bn, 503d Parachute Infantry Regiment; Battery A (75™1 Pack Howitzer) and one platoon of Battery D (.50 caliber M3-) * 462a Parachute Field. Artillery Battalion; and Company C, l6lst Airborne Engineer Battalion. The second lift was composed of the 2d Bn, 503d Parachute Infantry with Battesry B and one platoon of Battery D, 4^2d parachute PA Bn attached.

Two drop zones on the "Topside* of Corregidor were selected for the jump and designated A & B (see sketch). Although A was the old parade ground and B the golf course, neither area could be classi­ fied as an appropriate jumping field. Both were too small to pro­ vide adequate space for the landing and in addition were littered with wreckaget tree stumps and anti-parachute obstacles. It so happened that these two areas were the only possible drop zones that had any resemblance to open ground on the top of the Rock. The limited» rubble-heaped drop areas and steep cliffs (see photos) pre­ sented every conceivable hazard for the success of the jump.

Because of the size of the fields it was decided to fly the planes over in single file, spaced 600 yards apart. It was initial­ ly planned that each plane would make two passes, dropping half a stick each tine* However, an aerial reconnaissance of the selected drop zones made by the majority of the jumpmasters indicated that the areas were too small for this method, consequently it was decided to make 3 passes, dropping one third of a stick each time* A confer­ ence was held between the troop carrier and parachute staffs to se­ lect "go points" for each field. This necessitated decisions as to the jump elevation and direction of flight. Troops would jump only when given the "go" signal (green ligjit) by the pilot* In the event that the pi*™* was not lined up properly with the field or the pilot was not sure of the "go point", the sigial would not be given and an extra pass over the area would be made. It was evident by this tims that normal wind was 10 to 15 knots from the northeast and, as the direction of flight was from the southwest, it was decided that jumpmasters would count three seconds before jumping. This would further compensate for the drift and prevent the jumpers from going over the cliffs and into the sea*

At 08I I of troop carrier planes approached fed by Colonel John Lackey* \

UJ CD

\ W r, t« M rV '• : ' *. J Conuaflffiflg-Officer of the'317'th Troop Carrier Group, was the conmand ship and carried Colonel Jones and members of his staff* Preparations had been made that in the event the top of the island was obscured by smoke from the preliminary bombing* the command ship would flash an order back to the other planes to orbit south of Corregidor until the smoke had cleared. A reading on the wind determined it to be 18 knots from the northeast. Upon flying over the Rock the conmand ship found it clear for jumping, and the leading coltnns came over, starting the drop at 0833* The conmand ship, circling over the form­ ation during the drop, detected that some of the jumpmasters were jumping too soon, the strong wind carrying the chutes to the steep cliffs on the southwest side of the Rock. The jumping altitude had originally been set at 1150 feet above sea level, the jump field being 550 feet above sea level,and as soon as it appeared that the wind was carrying the chutes over the cliff, orders were issued to bring the planes down to 1050 feet, thus shortening the drop time* At the same time jumpmasters were instructed to count six seconds after passing the "go point* instead of the original three seconds. These adjustments, made ty the conmand ship circling the area, mater­ ially improved the jump pattern on the ground and increased the number of effective troops landing. There was occasional enemy anti­ aircraft fire during this drop, but the close support of the strafing A-20's on each flank effectively silenced most of this fire. At 0940, after all planes had finished their drop, the Rock Force Com­ mander jumped and assumed conmand of the elements on the ground.

At 1030 the amphibious landing was made cn San Jose beach, by the 3d Bn, 34th Infantry (reinforced). This assault was covered by close naval gunfire support directed against the unrestricted areas on the Rock (see sketch) and enemy gun positions cbvering the ap­ proaches to the beach were temporarily silenced. The chief resis­ tance encountered was from lard mines installed in the beach area. Personnel casualties and equipment damage from the concentration of mines on the beach were heavy. The amphibious force quickly se­ cured the top of Malinta Hill against surprisingly light enemy oppo­ sition. The southwest entrance to Malinta Tunnel was blocked by a landslide started by bombing and the west entrance covered by our •50 caliber machine guns and a disabled tank.

The second lift of parachutists started their drop at 1250. The wird had increased to 20 krots, and as this had been anticipated, instructions were issued before the take-off from Mindoro that the jumpmasters were to count 10 seconds past the "go point" before jumping. This, plus the experience gained during the morning drop by all pilots, increased the proportion of effectives landing in the drop zones. The executive'officer, Rock Force, was with Colonel Lackey in^the carmand ship»$i&1rae same system of control was employed r""":.1 \ i W «• oL •• IT LOOKED LIKE THIS IN PLANNING

f;1.

THE REAL THING as used in the first jump. The drop was completed at 1342. Because of the presence of our parachute and infantry troops on the ground, it was not practicable to give the second lift the close support at A-20*s on the flanks of the troop carrier columns during the drop* Consequently, this lift received continual eneny antiaircraft fire, which fortunately was not very accurate, ten transports being holed and one crew member wounded. A recapitulation of the jump on 16 February revealed that a total of 2,022 men jumped, 12 of whom were killed and 267 injured or wounded during the jump, of the 12 killed, one was due to a malfunction of the parachute, and the other 11 were mortally wounded in the air or on the ground before they could get out of harness.

The initial waves of parachutists that landed in the inmediate vicinity of the two drop zones met only ligit resistance. During the heavy aerial bombardment just prior to the jump, the Japanese followed their customary procedure of taking cover in the many tun­ nels and oaves that existed on the Rock. Caves and gun positions were so constructed in the rock cliffs that no amount of bombing could appreciably disturb them. From the interrogation of a PI who was captured later, confirmation was obtained that the parachute* assault on the island was definitely unexpected and achieved complete surprise. Although the enemy commander had been warned by higher headquarters to be on the alert against an airborne attack, he con­ cluded, after a careful study of the terrain, that such an attack would not be feasible. The corrmander's estimate was a logical one since the terrain definitely did not meet any of the normal requi­ sites of a drop zone. Therefore, except for normal antiaircraft opposition, he prepared no defenses on the "Topside" against a ver­ tical envelopment. On the other hand, the enemy's preparations against an amphibious landing at any point on the island were complete in every detail. The Conmanding General, Sixth Arny, realized that jumping en the Topside" of Corregidor would be one of the most difficult jump­ ing assignments ever given parachutists; but he was convinced that in spite of the large number of casualties to be expected, the total would still be much less than if the seizure of the island were attempted by amphibious assault alone. The decision proved sound and the parachutists held the comoanding terrain on Corregidor be­ fore the enemy time to react to this unexpected turn of events.

The initial advantage was ours and a perimeter was quickly established from which to start operations down the ravines and roads feeding from the Topside". By our occupation of this high ground it was almost impossible folk enemy to regroup and concentrate his forces into one force num^Mlally stronger than ours for subsequent offensive or defensive In addition, the enemy was denied of his of comminication making uniform control

CP! I m •y&n'tri bJ i '•% ' i Pi I of his farces difficult. Initially, at course, the perimeter on Top­ side* was very small and most of the early action consisted, by ne­ cessity, of clearing the buildings and positions in the immediate area* The amphibious assault, two hours later, split the enairy forces located on the east and west portions at the island. The early seizure of Malinta Hill ty the 3d Bn, 34th Infantry, made it difficult for the enemy farce on the east end of the island to launch a successful attack to the west*

When the second lift of parachutists landed, the perimater on •Popside* was expanded and neutralization of all eneny positions still capable of delivering automatic and small aims fire began. Prior to dark on 16 February, the perimeter was drawn in to make a stronger defense for the night. Harassing fire by mortars and artil­ lery was placed in the ravines and natural avenues of approach to the perimeter positions. Physical contact had been made during the first afternoon by patrols from the 3d Bn, 5°3d Prcht Inf and 3d Bn, 34-th Inft but the main road from San Jose beach to "Topside" was far from secured. By dusk it was very evident that the enemy strength on Corregidor was much higher than the pre-invasion estimate of 850. However, at I830 hours it was recognized that the paratroops could definitely hold the high ground on "Topside", and the value of the vertical assault had been realized. As a result of this initial suc­ cess, an urgent wire was sent to XI Corps Headquarters requesting that the third lift of parachutists (1st Bn 5Q3d with Btry C and 1 platoon B try D, 4&2d FA Bn attached) scheduled to jump at 0830 the next day, 17 February, drop only their equipment bundles over field A1 then proceed to and land on the San Marcelino airfield in the Subic Bay area} and from there be transported to Corregidor in amphib­ ious shipping. This would prevent risking so many casualties which would be impossible to avoid in a jump on such difficult terrain and would make an intact battalion (reinforced) available nearly as socn as previously planned. This request was concurred in ty the Corps Comnander.

At daybreak on 17 February a coordinated attack was launched against Morrison Hill by the 3d Bn, 503 Prcht Inf. Although this important terrain feature would have aided the enerry defense, they did not defend it in great strength and it was captured by our troops shortly before noon. In the meantime, the 2d Bn was-assaulting the Wheeler Battery area, a southern coastal gun, position converted by the Japanese into a small fortress. This turned out to be one of the toughest positions on the island and was typical of the type of defenses that were encountered throughout the fighting. Capture of the Wheeler Battery fort was not completed until late the next after­ noon. Another essential area to be neutralize^T^M the ravine on the east side of Morrison Hill just in Corregidor Bay. There, were located thg powef ?hifeafe jadl llfelpaant. both of which fss» f \ 1 DROP ZONES WERE SMALL AND ROUGH

^"1 were strongly fortified. Since it was impossible to use the road from the beach to "Topside" until this sector was cleared of the enemy, this task was started as soon as Morrison Hill was secured.

Troops of the 3d Bn, 34th Infantry, were instructed to improve their positions astride Malinta Hill and were assigned the mission of containing the enemy to the east and protecting the beachhead. This was to be their sole mission until such time as the western part of Corregidor had been sufficiently cleared to permit a concentration of troops for an attack to the east.

On the morning of 17 February, at 0830 hours, the transports, carrying the third and final lift of personnel and equipment, approach­ ed Corregidor. Since the Rock Force coranander1s earlier request had been approved, only the equipment bundles ware dropped} the planes proceeding on to the San Marcelino Airdrome. It is interesting to note that an this mission the planes encountered their heaviest and most accurate antiaircraft fire. Out of the 1)4 aircraft in this . s lift, 16 were holed and five crewmen were wounded. Again, in the l/l| afternoon, 33 C-47's made a resupply drop requiring a total of |191 1 passes over the drop zone. However, by this time, the most effective enemy AA positions had been neutralized by our ground farces and none of the planes were damaged. During the l6th and 17th a total of I90 plane loads of personnel and cargo were transported from Mindoro to Corregidor, requiring a total of 601 passes over the drop zones.

At I630 on 17 February the 1st Bn, 503d (reinforced) arrived in San Jose Bay from Subic Bay in APD's. They were sent ashore in LOW'S and as the second wave approached the beach, it came under heavy automatic fire from the caves in the cliffs southwest of South Dock. The entire beach area was under heavy fire until destroyers moved in and silenced the enemy guns. The battalion was moved to the hi^x ground just east of San Jose beach where they established a perimeter for the night. On the following morning the battalion was moved to "Topside* and readjustment of boundaries was made, giving each of the battalions a definite sector of responsibility far de­ fense at night and mop-up operations each day. The west end of the island was divided roughly into thirds and each battalion commander given the objective of clearing his sector. Air support, naval gun­ fire, artillery, flamethrower teams and demolition teams were all at their disposal, it was emphasized that all caves and tunnels would be sealed. '

..At...0600 on 19^Feb^^c^\\t^p enemy launched a strong and well organized counterattack from the west end ofTopside" which succeeded in penetrating the perimeter of the 2d Battalion at some points. II ,

This attack was repulsedsed' a/^eWt'/ioss of personnel and equipment for the Japanese, However,^lfell||f©reest fighting on that day occurred in the 3^ Battaltion assault of Breakwater Point. Navy destroyers, firing broadsides into: the cliffs, supported this action which ended successfully jyst before darkness. Through 19 February, 1583 eneujy dead had been counted and 3 POWs taken#

On 20 February 53 caves and tunnels were sealed in the Break­ water Point area alone. The next day 5 caves located along the coast­ line west of San Jose Beach were found to contain 19 Q-Boats (fast suicide crash boats). During both these days the intensity of the fighting on the western half of Corregidor continued to be very heavy. Rock and Wheeler Points were scenes of some of the bloodiest fighting. In both of these sectors close support was given by the Navy, but as usual the infantry had to go in and dig the Japanese out. The Japanese had infested the channel north of Corregidor with controlled mines which prevented our destroyers from giving close support from that side without accepting great risk® Consequently, close air support by fighter bcrabers was used continually in the action on the north part of "Topside*. On the 20th the eastern half of Corregidor began to receive its softening up process both frctn the Navy and Air in preparation for our eventual attack east frctn Malinta Hill. Typical of the excellent air support given daily by the Fifth Air Force was one strike of 31 P-47's in which 4,000 gal­ lons of Napalm, 38 - 5°0 %*>' "bomb® and 31»000 rounds of ,50 caliber ammunition were expended to assist a company in the successful assault of one strongpoint. Late in the afternoon heavy shelling from destroyers caused a landslide that sealed the main entrance to Malinta Tunnel frctn the east. On the 20th, 352 Japanese were killed bringing the total to 2,190 killed and still only 3 POTHs. As of the same date 132 caves and tunnels had been sealed.

Since the first day of the invasion of Corregidor there had been speculation in the minds of all officers and men as to what would happen if the fanatical enemy should blow up the enormous store of explosives believed to be in Malinta Tunnel. Earlier, on 19 Feb­ ruary, one of the tunnels just east of the Corregidor Lighthouse had been blown, inflicting casualties on our troops occupying the ground above the tunnel. Naturally, the men most vitally concerned were those troops of the 3^th Infantry who.held the defensive line across the top of Malinta Hill. Documents captured a few days after the invasion not only confirmed the belief that this tunnel held a large amount of explosives, but showed that it was far greater than the most conservative estimates. Prompted probably by the landslide at the eastern entrance that afternoon, during the night 21 - 22 Feb­ ruary the dreaded explosion occurred. Not only did Corregidor roll like a ship at sea but the Bataan Peninsula reverberated and trembled,

ft ft . i"''h iff R JUMPING ON TOPSIDE M

A ROUGH SPOT TO LAND so great was the explosion. Flames poured frcm all the tunnel en­ trances* There were landslides and casualties but the question that had been in the minds of all far days was answered, Malinta Hill survived.

By 23 February the western half of Corregidor was sufficiently cleaned up so that plans could be formulated and orders issued for the attack on the eastern half of the island. Troops were moved to assembly areas prior to launching the attack at 0730 hours on the 24th. During the day of the 23d the two battalion conmanders con­ cerned, and their reconnaissance parties, moved to Malinta Hill to observe the entire terrain where the forthcoming battle would take place*

During this first week, and prior to the drive east, 2,466 dead Japanese were counted and six BOW s taken. Many enemy casualties in the sealed oaves and tunnels would never be counted* From the inter­ rogation of the prisoners it was established that there were approx­ imately 6,000 enerry on Corregidor at the time our assault began, at least 500 of whom were in Malinta Tunnel,

On 24 February the attack went as planned, with elements of the 3^ Bn, 34th Infantry taking the high ground in the vicinity of Engineer Point, At that time the 1st Bn, 5Q3& Prcht Inf passed through the 34th and began the advance to seize all ground east of Malinta Hill* The strongest opposition was encountered between Engineer and Infantry Points where the enemy launched a strong counterattack, but it was repulsed by vigorous tank and infantry action. By nightfall, the 1st Bn, 503d Inf bad advanced to a north- south line just east of Infantry and Camp Points* The 3d Bn had followed olosely behind the 1st Bn and was chiefly engaged in clean­ ing out islands of enemy resistance bypassed in the rapid advance of the leading battalion.

The 3d Bn, 34th Infantry was relieved by the 21 Bn, 151st In­ fantry, which arrived the afternoon of the 24th, and moved to an assembly area in the vicinity of South Dock prior to evacuation to Subic Bay the next morning.

The 2d Bn, 503d Inf, now responsible for the western half of the island was still encountering heavy resistance in the Wheeletr Point area, in all sectors artillery, air, and navy supported our troops throughout the day. On the first day of this attack 704 enemy dead were counted. During the night 24 - 25 February, eneeoy counterattacks begpn at $130 and continued until 0400. All were re­ pulsed ty oar sa nor tar, navy and artillery fire, ffl IP(5r>n n being very effective. The next morning the attack was * ~ 1 p.y nH l-M- 1-reSumed_ and at the e: ij, Jar our front line extended, to a north- |^nt|^> Monkey Point, extremely heavy' re­ sistance having been encountered in the Monkey Point area. During the day's action 533 more Japanese were killed.

Concurrent with the approach of our troops to the eastern end of the island, quite a few of the enemy attempted to reach the Bataan Peninsula by rafts, logs, and swinming. Initially, attempts were made to pick them up in LCM*s and FT boats, but it was soon discovered that the Japanese generally were armed with a rifle, pistol, saber, • or grenade and refused to be taken prisoner. Consequently, to avoid losing lives in an attempt to pick them up, filter planes, LCM's, and FT boats were allowed to fire at all targets of opportunity in the water. Pilots in liaison planes joined the fight, using small arms and grenades on the hapless Japanese. It is believed that very few of the enemy reached the shares of Bataan alive.

The resumption of the drive east on 26 February was met by a serious suicidal action on the part of the enemy who exploded a huge underground arsenal in the vicinity of Monkey Point. Elements of the 1st Bn, 5Q3d Inf had just secured the high ground in that area. when the explosion occurred. We suffered over 100 casualties from the action. The blast was so great that a tank near the entrance of the tunnel was blown into the air arid landed upside down. At 1600 hours troops reached the eastern end of the Rock and controlled all the coramarding ground on the island. Naval gunfire was still being employed to clear up the caves along the coastline, but since our troops now stretched across the entire length, of the island, air sup- port was not used for the first time since the battle for Corregidor started. Over 500 dead Japanese were counted from the day*s.action and 2 POW's were taken. This made a total of 4,215 Japanese killed and 18 prisoners taken since the l6th of February.,

The final assault of the extreme eastern tip of the island 7,/as made on 27 February , as mopping up operations continued in the otljer •areas. 1st Bn, 503d Inf, was returned to an assembly area on "Top­ side" and the 3d Bn assumed responsibility for the eastern half of the island. By the end of the day all organised resistance on the Rock was broken and only the mopping up of small isolated pockets of Japanese remained.

C0I.15HP3:

A few interesting sidelights 011 this operations

1. Between l6 - 25 February, 30 close air support missions were flown by fighter-banbers and the following ammunition expended} 'Ijilions of Napalm, 286 - 500 lb demolition bombs, and 158,5® rounds .50 caliber ammunition.

2* Two officers from the 592d JASCO made their first jump on this operation in order to provide communications for naval gunfire support. SCR 284 and 694 radios were dropped by parachute, and at 0937 hours on 16 February were in operation in the gunfire conmand net — just one hour after the first plane load of troops had descended on Corregidor. Between 16-28 February, 64 separate fire missions were fired on the western half of Corregidor alone. During the close support missions a navy spotter accompanied the assault troops with an SCR 300 and relayed gunfire information to the SCR 694 operated by JASCO. The fire control data was then passed on to the destroyers furnishing the fire support. Adjustments were made in terms of five and ten yards.

3* In the assault of caves, tunnels, and other fortified positions, the 5°3d Demolition platoon during the period 16 February - 1 March, expended 11,500 lbs of explosives, 43 fillings of flamethrow­ ers, 280 rounds of rockets, M9A1, and 320 IP hand grenades. The platoon participated in 37 separate assault missions and sealed over 200 caves and tunnels* Company G, l6lst Airborne Engineer Bn, in the same period, expended 23*000 lbs of explosives and sealed over 200 caves and tunnels.

4* As of 1 March the Rock Force had suffered 1,022 casu­ alties of whom 197 were killed in action* In the same period 4*497 enemy dead were counted and 19 prisoners of war taken*

This strongly fortified, natural defensive area, defended to the point of annihilation by a well equipped, numerically superior* and fanatical enany, was reduced in a period of twelve days* Careful planning, employment of the element of surprise, and the determined attack by skilful troops, perfectly coordinated with air and naval support, agpin proved an unbeatable combination*

- 18 - GrMBRiLt With tli© war against Germany at an end, the full might of Allies will be unleashed upon a weakened but stubborn Japan# Those combat troops from Europe's battlefields who join our forces in the Pacific will have many lessons to learn from us; in turn, however, we should thorougxly examine the lessons •which they have to offer* principles of leadership, small unit tactics, and the individual solution of technical and tactical problems applied in combat against the Nazis will be valuable to us in defeating the Japanese* We have already learned much in our own war here in the pacific, but it is always well to profit by the experience of others* Con­ sequently* a few well chosen extracts from the combat notes of ETC are presented* This collection of experiences of individual soldiers and unit leaders, all veterans of the war against Germany, should be of con­ siderable value to us* The problems to be met in combat against the Japanese sere fundamentally the same problems already met and overcome ty our forces in Europe, Ho attempt has been made to present an article on tactical doctrine or historical events, but rather a compilation of "Combat Hints"* PATROLIING MP HBPQNHAISSANCSi

Of all the lessons learned by the combat troops in Europe none was better learned than the one that sense is the most ixn portanfc factor in planning and preparing patrols* A patrol leader proves this in saying, "Only one mission should be given to a patrol and it &ould be definitely and clearly stated* If you are given two or more missions such as, 'penetrate as deeply as you can and bring back a prisoner', one of the two missions is bound to suffer* The result is that you are not successful in either* 1 like to have the assistant patrol leader briefed at the same time I am* Two heads are better than one and the assistant assumes more respon­ sibility when he is briefed with me"* It is not only important that patrols be thorou|$i3y briefed bu.t also the combat troops in whose front the patrols are to operate* The S-2 of an infantry regiment speaks on this subjects •It ±sn*t enougft to warn men on the outpost line that friendly patrols are operating to their front* They should aU be told where they are operating and what time to expect them to return"* 111) Pr b !si m ' 'V' p jr • Corps Commander adds the following comments!

•It should be emphasized that ground once gained cheaply should be held*. Time after time a patrol is sent out to deter­ mine the enemy strength on some hill and finds that the hill is unoccupied* Almost invariably the entire patrol comes back to report* Then seme unit is ordered forward to ocoupy the hill* It moves forward and finds the hill alive with enemy who smother them with fire from machine pistols« light machine guns and mortars*

"The same thing holds true at bridges* Several times a patrol has found a bridge not blown and the entire patrol has come back to report. Before another unit can get up to seize the bridge, the enemy has blown it.*

One patrol leader had these points to offen

"We had some success in detecting booby traps by having one man precede us through a known minefield holding a small stick ligfrtly between his fingers at an angle of 45 degrees, with the exrl about two inches off the ground* He detected eight booby traps in one day by feeling the pressure of the trip wires on the stick. Some trip wires are neck high, others only six inches or less off the ground* If you find one booby trap there are generally more*

•Just because you find a group of foxholes empty one day, don't assume they will be empty the following day. Don't be tempted to leave an ambush patrol in empty fcocholes* If the enemy catches on, he has plenty of time to move in and he is an terrain with which he is familiar."

Another experienced patrol leader stated} "Mary patrols have successfully accomplished their missions only to lose personnel by a hasty, noisy withdrawal* Night patrols go out stealthily, taking all precautions, but forget all that in getting back to safety* Remember it is as easy to get hit in the back as in the belly*"

OFFENSIVE COMBAT i In 2P0, troop leaders have partially solved the problem of maintaining friendly fire support during the attack by employing marching fire* Some©? $]i«lr comments on this technique werej

"When oqplc^JlBmarching fire we provide a continuous and well distributed volume.of fire by having the odd and even numbered men advance alternately* Each group moves forward four or five yards and the; men atop, fire to the front, right, and left, group moves forward. The light machine guns are fired from the4£line on the march. The heavy machine guns deliver fire either overhead or through gaps in the line. We have found marching fire equally valuable in woods and villages and recently used it in capturing a town and over 400 prisoners.

"When en attack is to be made, reeonnoiter so that you know what you are up against.. Having made your plan, make everybody open fire when the attack starts. Keep shooting as you move and move fast. This applies in wooded and open country equally. The Boche is afraid of our firepower and we do not make sufficient use of it# When you close in rapidly it is difficult for him to adjust artillery and mortar fires on you, especially as you approach his infantry,

"Recently one of our companies neglected the reconnaissance phase and walked into an ambush. The company commander ordered and led a bayonet charge and the men moved forward rapidly with fixed bayonets, firing everything they had. The ambush resulted in casualties but they took the position and killed or captured more Boche than their own losses. Rapid movement and heavy fire saved them©

"Remember that a man in a foxhole cannot tell from the crack of a bullet whether it is two inches or twenty feet above his head. Use your firepower to keep the enemy's head down."

The officers and enlisted men of an infantry battalion have this to say regarding ammunition resupplyj "Two bandoliers should be issued to every rifleman before an attack t o cover needs during reorganization without depending on additional supply. Every effort must be made to ^ get ammunition forward as soon as the objective is taken. Riflemen often use larger amounts in an attack when employing marching fire and feel insecure if they have only a clip or two left".

Problems similar to those met in Europe in attacking fortifications are being met and will be met in this theater. An infantry battalion commander gives us the benefit of his experience with the night assault of pillboxes* "Successful night assaults on pillboxes were made using the following plan: Assault groups consisted of a demolition party of two or three men with three 12 pound satchel charges of composition "C", and six to ten men armed with rifles, submachine guns, antitank grenades, and automatic rifles; Assault group leaders studied the terrain and ' pillboxes in daylight, selected routes and recorded azimuths. Just before the assault, time fire was placed on a number of bunkers, includ­ ing the ones to be attacked. This drove the enemy inside without indicating exactly which bunkers were to be assaulted. The assault igc\&\x0 used agrenades and other fires to kill guards and button up the "bunkers. Men climbed on top of each pillbox, and with a cord, swung a satchel charge into the entrance. As soon as it exploded another charge was thrown into the entrance corridor. In. every case this brought the Jerries out"#

After assault and capture of the pillbox one infantry division believes? "Pillboxes should be demolished immediately after capture to prevent their being reoccupied. Blowing of the aperture and doors does not make the pillbox untenable. It has to be completely destroyed, right down to the ground. One wall left standing leaves a place to fight fran. Someone should follow close "behind the assault with the equipment to completely destroy the pillbox",

TAHK-IKFAKTIg OFSRig1 IQHB s

The increasing use of tanks and infantry in coordinated actions in this theater gives an opportunity to profit .f rem the lessons learned in European combat.

In Europe both infantry and tank personnel were enthusiastic about the results achieved when infantrymen rode tanks into combat. The commanding officer of an infantry regiment made the following comments regarding this type of actions

"The infantry are above enemy machine gun fire which is generally set at grazing level.

The infantry becomes a more fleeting target for enemy automatic weapons. It is difficult for the enemy to traverse and elevate a machine gun from a dug-in hedgerow position to bring accurate fire on a tank moving from eight to ten miles per hour,

"The tank turret also provides some protection against small arras fire.

"The infantrymen on tanks are in good position to toss grenades into foxholes,

"The infantrymen are able to provide excellent protection for the tanks from enemy bazooka and antitank grenade fire.

"The infantrymen help to provide observation for the tank crews. " •

•' ' \ • \ } ' i B This practice undermines the German tactical doctrine of

- 22 » II ! 1 :\V co:-:;> >d :a llrfILt/ >%?-j /;7 £/ f" shooting the the tanks, Wnen German doctrine is 'undermined, - the their operations is greatly reduced.

"When the advance is retarded by antitank guns, infantry can dismount, deploy, and bring automatic fire on enemy gun positions."

One corps found that common improper practices of tank-infantry operation detract greatly from the value of the tank. They observed the following instances of improper employment of tanks by infantry commanders»

"Specifying SOP assignments for supporting tanks which break down tank units to the extent that employment of tanks in mass and depth is not possible.

"Bnploying tanks under conditions where tank crews did not have visibility even as far as bazooka range.

"Using tanks to draw fire along routes which offered no place for maneuver and employment of weapons.

"Having tanks occupy exposed positions for long periods of time without infantry protection.

"Operating tank dozers with inadequately trained crews.

"Employing tanks as fixed pillboxes or machine gun posts for long periods of time, thus violating the principle of fire and movement, and drawing excessive fires upon nearly infantry,"

DEFENSIVE TACTICS;

A company commander had this to say about protective fires? "When organizing a defensive area for over 12 hours we plan mortar and artil­ lery fires to fall from 50 to 75 yards in front of our forward positions. While the area is being organized, the fires are planned to fall 200 yards or more to our front, but are moved closer when the work is completed. All men sire required to prepare deep foxholes with cover. The system has several advantages. Enemy patrols can be knocked out- very close to our position without using small arms fire which would give away our dispositions; Germans can be captured easily when they rush forward to get out of the fires and — very important -- it has sold the men on the effectiveness of mortar and artillery fire and made them mare eager to follow concentrations closely in the attack."

"Sometimes tracers help," reports the G-2 of an armor, "German .f I ^ „ mIf ifM krfig fii*§e a ip ret- , prisoners attribute the failure of their attack on Bastogne, 30 December, in large part to the lavish expenditure of tracer bulleta by our forces. All prisoners questioned stated that the illumination by the tracers made every soldier feel that he could not go further without being spotted and the morale was lowered considerably because every tracer bullet 'looked as if it were coming rigjit at you'. Even enemy personnel that already had seen five years of warfare, including the Stalingrad battle, commented that the display was more frightening than anything they had experienced previously.* wymbi*

It is interesting to note that the following comments of a German artillery general are similar to those of a Japanese artillery commander on Luzon* "It seems to be an established principle of allied artillery not to fire in rainy or foggy weather, at lunch cr dinner time, or at night» When shelling took place at these times I concluded that special orders had been issued by higher headquarters and I immediately warned my unit commanders to be prepared for an attack".

To show the importance attached by ETO commanders to continuous artillery support, the following guides of one corps are notedj

"Unit commanders must be kept informed of the status of their artillery communication channels as a failure of these conmunications involves the grave risk of advancing or holding without adequate artillery support. Artillery observers, liaison officers, and artillery commanders are charged with the responsibility of notifying the canmanders of supported units when artillery conmunications are not working.

"Three forward observers should be kept with each infantry battalion at all times to insure that observers will be available far reserve companies that are hurriedly committed* Forward observers should remain forward during the night* Recently a strong attack at night on one of our units was repelled largely by an alert observer who brought in the fire of 15 artillery battalions."

CLOSE AIR SUPPORT OF GBOPUD TROOPS t Ground troops should remember that ,the quality of close air support rendered them by the air force depends largely on the amount of assistance from the ground. A field artillery battalion is convinced that* "Targets for bombing should be marked with two rounds of white phosphorus so that plants can distinguish the marking frcm other single rounds of whitebeing fired in the area". One air support party increased aij&a^yMrt by the following practice! "After marking /1 i-L / • H k ? the target with smoke for fighter-bdmbers, and about one minute before the bombers make their run, we fire one or two volleys of time fire over the target area. This practice has been effective in silencing enemy antiaircraft and the pilots have been very appreciative"# An infantry division believes that when using panels: "Be careful that only the front lines display panels# Once our own planes started strafing our command posts and everybody started putting out panels. The air never did know where the front lines were. If you have to use smoke, red smoke is best".

ENGINEER NOTESi

Combat engineers in ETO have found that the practices stated below have helped them greatly when committed as combat troops. One battalion commander maintains: "Train as many men as possible with bazookas and machine guns and continue to give short refresher periods of instruction. All personnel should be familiar with these weapons. Train a large number of men to lay and repair field wire. When woods made our radios ineffective we had to depend on wire for conmunication. Each company and platoon should carry at least one-half mile of combat wire and one field phone. Mount litter racks on at least one £-ton per company".

An engineer battalion experienced in Italy believes: "Bulldozer operators must be trained to construct bypasses at night. The operator must be able to feel the working of the blade without seeing it".

COMMENTS i

Success in combat has always depended on the application of sound principles and basic tactics. In this war, as in all others, unit leaders are "discovering" new methods and new tactics in combat — only to find that they are applying proven fundamentals. Learn these principles before going into combat, review the Field Manuals on the basic responsibilities of your job, ana you will be better prepared to cope vrith the situations that will arise in the continuation of this war against the Japanese.

$ h ^ S] , v • , r-3 J1 It h n t Lb\ \.s w n,.-, fa ft fci'i ^ics!• 1# M Si ^

GENERAL? The story of "The Trojan Horse" is well worth telling. It demonstrates again the individual ingenuity and practical initiative for which American troops everywhere have gained an enviable reputation# This simple, yet effective, solution to a seemingly difficult problem probably never occurred to the Japanese defenders of Port Drum, on El Fraile Island as they watched a small naval craft circling their impreg­ nable position.

Secure in- their belief that this concrete bastion, fashioned in the shape of a ship by its American designers and situated in Manila Harbor, could only be taken at a high ratio of loss of American lives, these eramy defenders settled back and waited —• waited for us to try. Later, as the last Japanese on Fort Drum died, he probably wondered at Yankee ingenuity when he realized th&t his entire defending force had been exterminated without the taking of one single American life.

The success of this creditable action was due to the careful combined planning for the deduction of Fort Drum by representatives from the 38th Infantry Division and the Navy.

NARRATIVE!

Fort Drum, built on a reef, El Fraile, in -the entrance to Manila Bay was constructed between 1912 and I922 to provide a permanent defense position in the harbor channel entrance. It mounted two turrets with two lif." guns each and double 6" guns in casemates on each side. Although the Fort itself was intact, the weapons had been rendered inoperative prior to the Japanese occupation in 1942. Concrete walls rising 2|.0 feet above the water line were 18 to 30 feet thick, and the deck covering 15 to 18 feet thiek. The only entrance to the Fort was through a sally-port which extended from side to side on the stetfh end (see photo) and connected with a galley that opened into the three decks inside.

Enemy strength defending Fort Drum was not known, but their occupancy had been revealed by ineffective small arms fire directed against light craft operating ±* harbor.. Ihile this garrison was completely cut <^£f withput ty of escape, and though they ilt necessary to eliminate them immiadia to their nuisance action. This task

- 26 - (

•v

FORT DRUM PRIOR TO ASSAULT

ASSAULT OPERATION (NOTE EFFECT OF NAVAL GUNFIRE)

•0t mmmrnmm f p. y611 to the 38th Infantry Division*

Plans of the Fort were studied and every available source of information canvassed to learn the arrangement of the rooms, powder magazines, doors, stairways and ventilators* It was this latter feature* the ventilating system with air ducts to every room, which provided the solution and prompted the final decision to pump oil and gasoline into the Fort and set it off with demolitions* An LCM previously had been converted to an oil pumping barge, popularly called the "Rube Goldberg", and had been employed successfully in the Caballo Island operation* It was ideally suited for this task for it contained storage druns, pumping apparatus and was fitted with a 300-foot discharge line* The plan of attack was to land an assault party to secure the top of the Fort, while Engineers sandbagged the oil discharge line from the LCM to the ventilator system and placed delayed fuse demolitions* This plan posed the question of how to reach the deck, forty feet above the water line*

This wall was vertical except for the last five feet which sloped inward at a 60 degree angle, making the use of scaling ladders almost impossible* Tests conducted with ladders demonstrated that the men would be too far away from the top due to the inward slope of the wall, erven thought ladders of sufficient length could be made available* Landing plans were considered and it was finally decided to construct a drawbridge on the top of an LSM, which could be lowered onto the deck of the Fort enabling the assault crew to land*

The 113th Engineer Battalion, assigned the task of constructing this device* promptly named it the "Trojan Horse" (See sketch)* This contraption was completed and moved to Corregidor, arriving the morning of 12 April where a rehearsal was held that same afternoon* The assault team was composed of the 1st Platoon, Company F, 151st Infantry and a platoon of Company A, 113th Engineer Battalion* During this same day, while rehearsals were being held, Fort Drum was shelled by a cruiser in an attempt to breach the wall or gun turrets. Although the casemates on each side were punctured and the sally-port was partially blocked, it proved impossible to breach the wall itself*

On the morning of 13 April, the two naval craft, the "Trojan Horse" and the "Rube Goldberg" LCM, moved alongside the Fort* ineffective small arms fire was received frcm the casemates, but prompt covering fire enabled the crew to lower the drawbridge of the "Trojan Horse" onto the Fort, allowing the assault team to land and secure the top deck* The demolition group moved aboard and placed thirty 20-pound satchel charges of tetrytol in the hatchway on the starboard side of the Fort, covering the entire fStled sandbags. Two of the satchel charges were primed* it toiiis&p^laiid 30 minute fuse lines were run* The_oMai ^"Rube Goldberg" oil barge,

- 28 -

Tine aboard and sandbagged it to the port hatchway. Ignition charges consisting of four WP grenades wrapped in primacard were connected to the oil line and attached to the demolition fuse line so that the oil would be ignited when the tetrytol charges were set off. After the assault groups had withdrawn to the LSK, the engineer officer signalled for the punps to be started and lighted the delay fuse*

About 400 gallons of oil had been pumped into the Fort when the oil line burst* This necessitated returning to the Port, cutting the fuse, and replacing the defective section of hose* Since it was noted that oil was running out of the 6" turret, the oil line was moved to a ventilator opening on the part side* Ignition fuses were again lighted and pumping resumed* The oil barge emptied its tanks after pimping approximately 2200 gallons of oil and gasoline into the Fart, and the hose lines were disconnected*

About 25 minutes after pumping had ceased and the barges had pulled out to a safe distance, the tetrytol charge went off, throwing pieces of concrete and steel high into the air* There appeared to be three additional minor explosions about 15 minutes apart approximately half an hour after the first explosion* For four days the interior was too hot to permit entrance below the first deck* Later reconnaissance disclosed 60 dead Japanese within the Fort* Three of these appeared to have coBxnitted HariH£ari and the rest appeared to have been killed either by concussion or by the burning oil*

COMflfflffi

This highly successful operation was executed with only minor injuries and at a minimum of effort* Careful and detailed planning, close coordination with support naval forces, and the effective use of single and practical equipment again demonstrated their importance as factors of success* The Japanese hare usually marked I * their mine fields and danger areas freely, on the theory that the average American cannot read them* There have been casualties in the past because of this fact* familiarity with these typieal examples may be of great value in the future where we can expect great coneentrat ions of mined areas. mm \mu TAKE CARE ft DANGER

r J1V

$

jm miwv DOKP TOUCH LAND MINKS DANGEROUS GENERAL*

The ij.Oth Infantry Division in its drive down the Luzon Plain toward Manila met an elaborate system of defenses in the foothills of the Zambales Mountains to the west of Fart Stotsenburg. These foothills were found to be honey-combed with an elaborate defensive system con­ sisting of caves, tunnels, automatic weapons positions, and fire trenches. Both caves and tunnels probably were prepared for storage and troop bivouacsj but the eneny became expert in using them as firing positions for the troops defending the terrain features on which they had been constructed* Consequently, they proved to be formidable obstacles to the advancing infantry, requiring painstaking effort and much ingenuity before they were neutralized and destroyed®

Methods employed by the lj.Oth Division to reduce these defensive ^ positions in the Port Stotsenburg area are explained in the ensuing paragraphs.

NARRATIVE!

Cave Construction

In designing the defensive positions in the foothills of the Zambales Mountains the enemy displayed exceptional tactical ingenuity. Dominant terrain features were organized so that each praninent hill mass constituted a self-sustaining fortress, provided with def ensesjjx depth and mutually supporting fires. Both forward and-rovwoe -at6pes were utilized, and cave positions on the same level were connected by inner communication tunnels. Work was conducted on positions dug into the sheer, steep cliffs from cat-walks which were constructed along the face of the cliff. These cat-walks extended down the face of the cliff and connected with other cat-walks on lower levels, thereby providing a means of movement from one level of caves to another.

Cave positions were dug straight into the hill, often as deep as 70 feet* The conmunicationa tunnels which extended laterally, connecting caves of th instances were so small that a man had I to! actically all of the caves were provided

li* $1 m ^ - 32 - wilii ,'i.i

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CHANGE FOR 0LOW 11\!<5- CATWALK approach.

SECTION TV4RU CAVE SECTION thru cave

HOLE IN «,OOf= WITH CHARCrE. DYNAMITE OLAC^O ON FLOOR OUGr in on DLTONATING SLOPE A50VE, W\RE

PCjOP TO SUPPORT CHACG-E JAP Z5Q KG- 5QNA5 \

ALL AT 45° AN&LE the advance to a position frcm which it could attack the enemy cave. When the assault group was in range, IP grenades were thrown inside. Covered by this smoke and the fire of the close support team, the flamethrower team advanced to the entrance of the cave and expended the entire load into the cave entrance. Simultaneously, the demolition team approached the position from above. Here, a trench was dug approx­ imately 18 inches deep to allow the insertion of a crater charge as near the center of the position as possible. After the charge was securely tamped and packed, W-110 wire was strung back to a covered position preparatory to detonating the charge. On a prearranged signal all members of the team withdrew to a covered position and the charge was detonated by the use of a Battery BA-38. In approximately 9Q£ of the cases, the explosion successfully neutralized the position. Each adjacent cave position was approached in turn and neutralized in the same manner. In the few instances where the location of the cave precluded demolition from above, charges were placed in the entrance and along the cat-walk approaches. This usually destroyed the cave entrance approaches to the position and prevented re-entry by the Japanese.

WP grenades and shells were continually employed to cover the advance of assault teams and materially assisted in driving the enemy from defensive positions so that covering riflemen could dispose of them. In addition, the smoke penetrated through the communication tunnels, disclosing other cave entrances previously undetected.

Direct fire weapons (M-7s, 90®® AA guns, 155mm. howitzers, 3" TD guns) were frequently used to support assault teams when the enemy cave was at a range too great for small arms. In such cases the direct fire weapons took the main eneny position under fire until our covering groups could get within effective range. At that time, the direct fire weapons would shift their fire to flanking caves which were capable of interfering with the assault team.

In seme instances the rugged terrain made it necessary for the enemy caves to be neutralized by the use of direct fire weapons only. It must be stated, however, that such a method was only a partial answer to the problem because these weapons could rarely destroy the position completely. By firing a smoke round into the caves and observing the extent of the inter-canmunication within, the power of several direct fire weapons could be brought to bear on all caves so connected. This denied the enemy the use of any one cave for counter- fire, While the method provided sufficient neutralization for the assault groups to work forward to the position and carry out demolitions, it still was necessary to keep other entrances under fire.

In the early stages, th,e Japanese would infiltrate through our lines and reoccupy ofcve^fcesffcions by digging out the entrances and |£&aw|^ei&t this*. demolition teams were employed to .destroy'' ion, blowing all tunnels and entrances. • ' When connecting cave positions were accessible to heavy equipment, holes were drilled with compressors, and dynamite was employed to blast the tunnels and close them completely# Aerial bombs proved exceptionally useful as a demolition device when buried over caves or in the entrance tunnels# Inmost cases# hand carried demolitions were the only solution for the slow tedious destruction of caves and tunnels which had to be carried out to prevent reoccupation by the Japanese,

COMMSHTSi Though the methods and equipment used in the assault of enemy positions in the Fort Stbtsenburg area were not novel or new, it is well to review them in detail to remind ourselves that future fighting against the Japanese will be met with this same type of defense# As in the case of city fighting, small unitActions, undetr trained and aggressive leadership will balance and tip the scale of final victory. GENERAL*

The Japanese defense along Highway #5. in the Balete Pass - Santa Fe area* presents an excellent illustration of eosmy en^loyment of artillery in mountainous terrain* Although our forces had superiority in numbers, firepower, and air power, the enemy greatly retarded our advance over a long period of time by putting forth an extremely effective and stubborn defense. While it is true that the mountainous terrain itself was a great deterrent to attacking troops and an advan­ tage to the defenders, enemy artillery played an important part in the later stages of this tenacious defense* Captured document a have since revealed a great deal about the eneoy pi Ana fox* employment of artillery and, ft*cm an artillery viewpoint, a study of this particular phase of the Luzon operation is enligitening.

NARRJff IVEi

Highway #5i along the Digdig River Valley as far north as Balete Pass, was the main avenue of retreat for the Japanese forces withdrawing north from the Central plains into the Cagayan Valley* partially wooded narxow-togped hills on either side of the highway rise sharply 2000 to 3000 feet above the valley floor and small streams draining into the Digdig River form occasional lateral canyon-like approaches into the hills from the valley*

During our northward advance from San Jose, the enemy fought a planned delaying action to cover his withdrawal to previously prepared positions in the Balete pass-Santa Fe area* That a small amount of artillery supported this action is evidenced by the destruction of three 10512m howitzers at Puncan, two Tffcan guns at the "S" turn 1500. yards north of Lumboy, and one 105mm howitzer 1000 yards north of the "S" turn* By the middle of March, the 25th Infantry Division had reached the Putlan area on Highway #5* while on the Villa Verde Trail to the west the 32d Infantry Division had reached Salacsac and had turned east on the trail toward Santa Fe* Here the main Japanese defenses were encountered*

.t Battle This TO BAYOM80NG t 1jL|IOFA

v , (< HOSHI

SALACSAC WA& x- ^ / A;3'[tli/ SANTA FE ASSIGNED TO - - "T" IMUGAN /s[t]4 75 MM , El 12 /tlE,-i lc|2 r^4 ~ IKOS Uf 150 HJ0 ASSIGNED SAN NICOLAS / ^ / #AME

ASSIGNED TO: WASHI >7 "* r* f'*~|4(2BTRY) 150 HOW El hato^m//^BALETE PASS T0KA.>{A/(ni]4) /

r^l2(2BTRY) +-WA 7 5 OR 155 M M ? WA 7 MED E*]4(2BTRY) A 150 MM' MORTAR 150 HOW FUNA J/ ASSIGNED TO S 1^2(2 BTRY) 75 OR 150 MM f~*~|4(2BTR Y) ,-uu, ^ASSIGNED TO: 150 ,HOW N 150 MM CZl4(2BTRY) j' 04 75 OR 105 MM 75 OR 105 MM [ji]5(IBTRY) f ASSIGNED TO. > KAPINTALAN BRIDGE11! ASSIGNED TO: REGT'L CONCENTRATION r^.SABUSA.. AREA ">'"KIEU [•> (2MED BTRY)| -9- ASSIGNED TO: [~**~l4(2BTRY ([V]4(l BTRY) - TARGET AREA 75 0R105 MM , ^ J T50H0W f1*~l2(2BTRY) BRIDGE*2 \ [32(IBTRY) 75 OR 105 M M 75 OR 105 MM — UNIT LOCATIONS ASSIGNED TO: SKETCH OVERLAY TO ACCOMPANY 10™ F. A. REGT'L FIRING PLAN

ASSIGNED TO: f*l2(2BTRY) El TO SAN JOSE y r> inization for combat of the 10th Japanese Field regiment; including a map showing the positions of subordinate units and their assigned target areas (see sketch), as well as a tabula­ tion of the allocation of ammunition, A study of the document and information fraa other sources indicated that the following elements of the 10th Field Artillery Regiment and the attached 7th Medium Mortar Battalion were charged with supporting the defense of the Villa Verde Trail and Higmay #5» Regimental Head quart ers, 10th Field Artillery Regiment* 2d Battalion: 4th Battery ------4/75mm guns. 5th Battery ------i|/lo5nm howitzers* 4th Battalion* 11th Battery ------4/l5Qnm howitzers* 12th Battery ------i|/l5Ctom howitzers* 3d Battery (atchd) ------lj/75nm guns. ?th Medium Mortar Battalion! 2 batteries ------llA5Ctom mortars each* The remaining elements of the 10th Field Artillery Regiment had been encountered, during previous engagements in our approach up the valley* Identifications of the artillery pieces arid personnel destroyed near puncan and Lumboy accounted for the 1st Platoon of the 1st Battery and the entire 2d Battery of the 10th Field Artillery Regiment* FW reports indicated that the 2d Platoon of the 1st Battery may hare been employed on the Villa Verde Trail but this has not been verified* The 6th Battery was reported destroyed at Zig-Zag Pass on Bataan and the entire 3d Battalion was destroyed on Saipan* Although only two batteries of the 7th Medium Mortar Battalion were indicated as being in the area, the organization of this battalion was believed to include an additional battecry itoose location is unknown* The dispositions of regimental and battalion guns were not included in the captured documents* x The plan directed that the main force of the artillery would occupy positions in the vicinity of Balete Pass and "with a part of a powerful force will occupy positions in the vicinity of the valley on the west flank of Santa Fe"* Depending upon the direction of attack, plans were made far artillery units to cooperate with the infantry force fighting in the sector under attack* The plan also stated that "though it (the artillery) will be expected to take the initiative in firing on its own accord, generally it will not carry out counter- battery on its own responsiblity". Fire was usually to be by single piece, but volley fire was to be used at opportune times* Survey was directed* Concealment of the air was stressed* In the « mm

fc-s

i

event of an attack from the south a platoon of the 2d Battalion was to occupy a position 4 Kin to the south of Kapintalan to disrupt the enany advance as far away as possible and to support the withdrawal* The number of rounds to be fired in various areas was to be determined by the direction and impetus of our attack* Amounts to be fired after the start of the attack usually were frcm 3 to 4 times as much as that to be fired during our preparation for the attack* The regimental concentration just south of Kapintalan, for example, called for 210 rounds "while enemy is preparing far attack" and 600 rounds "after start of eneny attack".

The advance of both our attacking division toward Balete pass and Santa Fe after 15 March was slowed considerably and, by 18 April, our front lines were only a few thousand yards farther north* The enemy had had sufficient time to construct prepared defenses, and was greatly aided by extremely rough terrain well suited for a defensive action* As can be seen frcm the captured map and from positions actually located, the enemy echeloned his artillery in depth* Ligjit artillery positions were usually 3000 to 4000 yards in rear of the £3LR, and medium artillery 6000 to 7000 yards to the rear of the MP* With few exceptions all artillery was emplaced in caves or tunnels* Although most positions were defiladed, some were in caves on the forward slopes of hills not defiladed frcm the front* Artillery so emplaced, had been able to withstand all fires except direct hits frcm our artillery and aerial bombing* Instances have been reported of the enemy withdrawing artillery into caves during our shelling; and, inmediately upon the cessation of fire, even in spite of direct hits on the cave openings, he commenced firing again* In one case an enemy artillery weapon continued firing throughout a period during which 9Ctam guns, l$5nm guns and iQ5nm howitzers were bracketing the position* One emplacement HE of Balete Pass remained active after 50 rounds of I55mm 25 rounds of 8" howitzer, and 4 rounds of 240mm howitzer ammunition had been placed on the position* Some emplacements were operational within a few hours after having been closed by our artillery fire* The attached close-up oblique photograph indicates the type of cave positions encoun­ tered* Hatural camouflage was employed to a great extent and concealment was usually good* Fifty percent of the camouflage nets seen were used to cover spoil from diggings rather than to conceal the cave openings* Several cave positions had thatched and log panel covers which were removed prior to firing* Artillery emplaced in these caves usually had a very limited field of fire and could seldom be employed in close support* On the other hand, regimental and battalion gunsA welt ffk camouflaged, and sited for direct laying on omLadvancing^ro0pg.,''weff

C.

JAPANESE 75MM SP GUN POSITION I

for this type of fire* Direct fire weapons, erven of the larger calibers* often held their fire until our troops were within a few hundred yards of the position* While mortars were employed chiefly in support of ground troops, they often were used to thicken artillery concentrations*

Througiout the operation, the Japanese artillery fire closely followed the 10th Field Artillery Regimental Flan* Fire was habitually placed on the indicated concentration areas by the unit indicated in the plan and a definite lack of flexibility was apparent in that devia­ tions were never made* Vhen Japanese artillery fire was received by our troops in one of these assigned areas, counter battery was quickly and successfully executed on the eneoy artillery battery responsible for the concentration* Eneny artillery invariably fired on assigned target areas with such regularity that their fire could be predicted with reasonable accuracy*

Enemy survey in the area was excellent* This was proven from the accuracy of fire delivered as well as the survey directions given in the plan and indicated from other captured documents* A captured overlay showed the concentrations, OPs, and gun positions surveyed in along the highway, and included diagrams which indicated that both traverse and triangulation were used* Survey information, mimeographed for distribution to artillery units, and an overlay showing the trian­ gulation survey of the Carranglan, Digdig, Santa Fe area, indicated that probably two or three months were spent in preparing the defensive position* For the Balete Pass area survey the notes showed that a bridge at Santa Fe was taken as the point of origin and was given arbitrary coordinates* Vertical control established by the enemy was excellent and afforded our artillery units useful data on points south of Balete Pass* Reports from civilians indicated that the Japanese registered in sane of the known concentrations prior to the withdrawal of his troops* The enemy seemed content to deliver 15 to 20 rounds of fire in an area over a period of two or three minutes, usually employing one gun* In general the fire migrt be classed as light, sporadic, and harassing* Ihile the regimental plan indicated the existence of artillery 0P»s and the necessary communications to carry an observed fires, there was little apparent effort made to attack targets of opportunity! and there was no evidence that artillery forward observers were employed* prior to 18 April, fire was not very effective, one division commander remarking that the slow progress of our troops was due to the well fortified infantry positions and not due to artillery fire* Massing the fires of over one or two batteries was apparently not considered by the enemy* In an effort to avoid detection by our liaison aircraft, most firing was done in the early morning, late evening, and during the nigit*

v M•* •.

JAPANESE SP GUN POSITIONS

§ The folldwi|ig indicate the eneny expenditure of amrranition on the front ofc 'ilfchldT divisions* The figures cover a period of 33 days duringthe mSrifns of March and April and are based on S-2 reports from I Corps Artillery:

Number of rounds received in 25th Infantry Division Area - - — ------4391

Number of rounds received in 32d Infantry Division Area ------3488

Total in entire area1 7879 Average number of rounds per day received in 25th Infantry Division Area ----- 133*1

Average number of rounds per day received in 324 Infantry Division Area ------105.7

Average per day in entire area: 238*8

Largest number of rounds received in one day:

25th Infantry Division Area ----- 278 32d Infantry Division Area ------ij.00

Based on an estimated 2k active enemy artillery weapons of all types in the Balete Pass area, the above figures indicate an average expenditure of 9*5 rounds per weapon per day*

After 18 April there was a noticeable increase in the effectiveness of enemy artillery fire* Counterbattery fire in the 25th Infantry Division area caused two of our artillery battalions to be moved in spite of their being emplaced in positions well defiladed from the front* In one of these instances 68 out of 70 rounds of Japanese artillery fire that fell in a short period were within the battalion area* Forty-eight of the rounds were direct fire and came from an artillery weapon emplaced en a hill to the rigit flank ifcile 22 rounds came from the front* It was evident that the fire was observed and adjusted* It is believed that adjustments were sometimes made either by radio equipped infiltrators or by fire direction personnel using sketches prepared by patrols*

COMMENTS: From a study of th4 employment of artillery in defense of Highway #5* it might'at fix«t||» concluded that his artillery technique

- 46 - y ,«v:' t;J i r< 'i

The enemy's only advantage was that of slightly- commanding terrain. He was opposed by 126 artillery weapons consisting of 84 light, 2k medium, and 18 heavy artillery pieces as against his own 36 artillery weapons of all types* Our artillery fired from well defiladed positions, some beyond the range of his artillery. American forces had adequate transport and aranamition for supply as against the enemy's negligible amount of both# We had tactical air support to augment the power of our artillery while he had none. During daylight our liaison airplanes kept his positions under constant surveillance while his observation was limited to terrestrial OPs# Wire communications were constantly being cut by our shilling and, although he prepared alternate positions, he was rarely able to move to them#

Under such conditions it is little wonder that the enemy artillery went underground in order to minimize the effect of our shelling# In selecting such positions he necessarily had to accept the disadvantage of limited fields of fire# Air observation indicated that he worked hard and diligently in repairing his battered positions, keeping them operational in spite of our accurate fire# The Japanese artillery plan, when considered .in conjunction with the task, was reasonably sound j and, considering the resources said the superior force opposing him* the execution of that plan was noteworthy# In future operations where opposing forces sire more nearly balanced, we may expect a correspond­ ingly more effective employment of Japanese artillery# The Okinawa Operation* where the enemy employed a mass of artillery, foreshadows the type of artillery opposition that may be expected in subsequent operations in enengr territory# During thelbattlebattle for Manila/Manila/which irhich was highlighted by the assault on Intranuros, manor unique artillery problems were encountered and solred by the 3JVti Division Artillery. This narrative on the role played by artillery in the reduction of the Vailed City follows the account of "Manila Victory" in the May issue of "Combat Notes", and is designed to present a more detailed report of the part artillery played in Hi is operation, particularly during the f inal assault phase* NARRATIVE.

The approaches to the Vailed City were swept by eneoy automatic weapons up to in caliber, emplaced in excellent positions and covering the streets with interlocking bands of fire* These positions were effectively supported by mortars, machine guns, and rifles. Such buildings as the Paco Railroad Station, the Manila ELectric plant on Provisos* Island, buildings of the University of the Philippines, as well as many other reinforced concrete buildings, were heavily fortified * and stubbornly defended. Their reduction was accomplished only by the use of maximum fire power*

As the attack progressed, the eneny steadily withdrew to reinforce the already heavily manned fortress of the Intramuros, The walls, forty feet thick at the base, provided excellent positions for field pieces emplaced on their tops and excellent fields of fire for dual purpose weapons sited to fire through ports in the walls* On the north was the pasig River; on the south Buraham Park* The eastern side was bounded ty a wide area of open ground while a similar area between the west wall and the port area was well covered by a system of trenches and pillboxes*

A3 the enemy fell back to his inner defenses, office buildings on the north bank of the Pasig, particularly the Ayala Building and the Great Eastern Hotel, were occupied by our forces and used as artillery observation posts* From vantage points in the upper floors, enemy activity wa^ under constant obse rvation. on the other hand, enemy observation posts in the Manila Hotel, the Maraman Building and the Customs House Tower, were destroyed by our artillery fire thus seriously "i

•i n dicapping the defenc

In order to reach positions for the assault on Intramuros, occupation of the heavily defended Water District Building and Ice House was necessary. From these points the infantry was able to move to the Post Office and Metropolitan Theater, the closest positions offering cover and concealment while assembling for the final assault* The 77ater District Building was taken under fire by tanks at less than 100 yards range with excellent results. The 135th Field Artillery Battalion (105mm Howitzer) and a battery of the 136th Field Artillery Battalion (155mm Ibwitzer), emplaced in direct fire positions on the north bank of the Pasig River, fired on the strongly constructed Ice House,

Difficult to demolish, the Ice House was finally abandoned by the enemy when the constant pounding of the artillery set it afire* Hundreds of rounds of artillery ammunition, with concrete piercing fuze, were fired into the Metropolitan Theater, finally rendering it untenable far the enemy. With this building secured, the Botanical Garden to the south became available for direct fire positions for the li).0th Field Artillery Battalion (105mm Howitzer), to be used in the final assault. Reconnais­ sance for routes and positions visis made during the three days prior to the attack. Positions were secured and cleared, despite the threat of attack from by-passed pockets in the Legislative, Finance, and Agricul­ tural Buildings, as well as snipers in the Walled City,

During the same period, the CG, 37th Division Artillery, ordered the 6th Field Artillery Battalion (105mm Howitzer) to level the stone embankment on the south bank of the river, and requested corps heavy artillery to breach the north wall of the city. Both missions were accomplished, thus providing the infantry with a suitable landing shore and an entrance way into the city itself.

The plan of the Division Artillery Commander for artillery support of the attack entailed the assignment of specific missions to artillery emplaced for both direct and indirect fire. Because of the size of the objective, in addition to the organic division artillery and the attached 82d Field Artillery Battalion (105mm Howitzer) of the 1st Cavalry Division, the Division Artillery Commander requested and received additional artillery from Corps: the 756th and 757th Field Artillery Battalions (155mm Howitzer), one battery of the 465th Field Artillery Battalion (8 inch howitzer), and the 544th Field Artillery Battalion (22).0mm Howitzer), Also available were the 637th Tank Destroyer Battalion and the 754th Tank Battalion. The Division Artillery Executive laid out and assigned zones of fire for ea< ^ ;he Intramuros and 155 mm HOWITZERS DID THIS

ARMOR ENTERING THE WALLED CITY THE ENEMY WAS WELL DUG !N

MACHINE CANNON FIRED FROM PORTS LIKE THIS i!'!& !'r' ' ' Port Area for this PWp&qkfi' /Transfers of •tise^^fS practicable because of previous adjustments made' on the ohj&otjLiBe [p$ tyjfe battalions in indirect fire positions. Thirty-six of the avarSiTOre artillery weapons were emplaced for direct fire, utilizing buildings as well as open positions# Those positions on the north bank were protected by machine guns sited to fire through, windows of buildings. Observation posts in buildings covered the entire zone of action.

Corps heavy artillery was assigned the mission of attacking old Fort Santiago at the northwest corner of Xntramuros. The mission of the direct fire weapons was the neutralization of the walls and openings, with particular attention to the Letran Building and the Philippine .Mint along the north boundary'. Li^it battalions were to neutralize the interior. Bnployment of specific artillery units is indicated on the accompanying sketch map.

H-hour was designated as 0830, 23 February 1945* At H-60 a one hour preparation for the infantry attack was opened by the combined fires of all artillery battalions, landing TOT in their assigned target areas. Observers reported that the artillery appeared to have rehearsed the mission, so well was it executed. A total of 7*896 rounds, I85 tons, of artillery ammunition were expended in the preparation.

Promptly at 0830, a round of red smoke marked the lifting of artillery fires. The infantry moved out of their assembly area in the post Office Building and along Taft Ave., embarked in assault boats, crossed the river, and entered the city without a casualty. During the advance heavy neutralization concentrations were placed on areas L, M, and N. Area R was smoked. (See sketch) Despite determined resistance in St. Augustine Church, the entire city was under complete control within 24 hours.

Subsequently, the three by-passed strong points in- the Legislative, Finance and Agriculture buildings were reduced, using direct fire artillery firing ammunition with concrete piercing fuzes, and unfuzed 155nm shell. Not until the firing ports were blocked by rubble pilled up by artillery fire, were our troops able to get into the first* floors of the buildings, and there, with demolitions and flamethrowers, finally overcame the fanatical enany resistance.

C0MLiaI?r3t

For the artilleryman this battle of Manila clearly demonstrates a principle enunciated in our Field Service Regulations, BK 100-5, Par 858, which read as follows:

B'.Vhen the enemy has organized the town into a strongly fortified position which cannot be avoided or outflanked, the *?g

advance may have to be . ^ artillery and other suppo: rng^ireapona", anci aided* by combat aviation*" That this principle was correctly applied, insofar as the use of artillery and other supporting weapons is concerned, is attested by the fact that all the available supporting fires including that of corps artillery, tanks, and tank destroyers were utilized in this assault* In fact, to increase the effectiveness of the supporting fires, many of these weapons were used for direct fire.

COMBINED ARMS RESEARCH LIBRARY FORT LEAVENWORTH, KS

* 3 1695 00300 3803

Itffi IBM mm * 1983

MAR 1 71983

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JAN 1 9 1988

REPRODUCED BY 69th ENGR TOPO. JULY, 1945