Attention!
You are viewing a news item in the old website format. There may be display issues in some browser versions.

Close

The Chieftain's Hatch: Amtanks

I am most pleased to introduce Mr Harry Yeide to The Hatch. He is the author of a number of books on the US Army in WWII, to include "The Tank Killers" and "Steel Victory." His first contribution to The Hatch is an overview of one of the greatly overlooked parts of the US Army and Marine Corps machine of WWII. Please make him welcome.

Forgotten Battalions: Amphibian Tanks in the Pacific War

The U.S. Army’s Armored Command starting in October 1943 reorganized nine tank battalions as amphibian tank (amtank) or amphibian tractor (amtrac) battalions and raised more from other sources. Nearly all served in the Pacific Theater. The Marines also organized three amtank and eleven amtrac battalions. The army’s amphibian tank battalion had a headquarters and headquarters/service company (four amtracs) and four seventeen-tank companies organized into three five-tank platoons and a two-tank headquarters section. In January 1944, the number of amtanks per company rose to eighteen, and companies received two amtracs each; the headquarters company received three amtanks. The amphibian tractor battalion consisted of a headquarters and a service company, plus two line companies with fifty-one amtracs apiece. The battalions by 1945 were reorganized into three line companies, each with sixteen amtracs. Each company had two maintenance LVTs and its own mechanics, electricians, and radio repairmen.[i]

 Army amphibian units appear to have adopted wholesale the doctrine being worked out by the U.S. Marine Corps—which pioneered the use of tracked amphibians—through often-bloody trial and error in the Pacific. When Col. William Triplet arrived at Fort Ord, California, in 1943 to organize the 18th Armored Group (Amphibious) to train amtank and amtrac battalions, he asked what manuals were available. “There are no manuals of any type,” he was told. “The Marines are starting to train five battalions at Camp Pendleton, but all they have is the Navy stuff on boat landings. Training manuals will probably be written after a study of your experience.”[ii] Army manuals on amphibious operations did not even mention Landing Vehicles, Tracked (LVTs), Navy terminology for both amtanks and amtracs. An Army history of amphibian battalion training in the Pacific wryly termed the instruction available to the first outfits to go into combat “improvised.”[iii]

 

The Amtanks as Hardware

 Amphibian tanks were built on the LVT(2) amtrac chassis and were designed to provide the assault wave with tank gun support on the beach. They had the same drive train as the LVT(2) and reached similar top speeds on both land and water but were more stable at sea because of their greater weight and could likewise bull through up to 8 feet of surf.[iv] With armor ranging from 1/4 inch on the flanks to 1/2 inch to the front, they were suitable for general use only in the Pacific Theater, where the threat from Japanese tanks and antitank guns was relatively low.

The 16-ton LVT(A)(1) was basically a covered amtrac with an M5 light tank turret mounted on top. As on the M5, the amtank had a 37mm main gun and a .30-caliber coaxial machine gun, and the roomy vehicle carried a hundred four shells for the cannon and six thousand machine-gun rounds. The turret had both hydraulic and manual traverse systems, and twin hatches were provided. The commander had two periscopes and the gunner one that incorporated his sight. Twin hatches on the rear deck had scarf mounts for .30-caliber machine guns. The six-man crew included commander, driver, assistant driver/radio operator, 37mm gunner, and two scarf machine gunners. The vehicle had a radio and intercom system.

 

The LVT(A)(1).

 Crews found the 37mm gun powerful enough for coconut tree log bunkers and simple concrete pillboxes encountered early on but inadequate for many prepared positions as the enemy dug ever deeper into the islands. The gun could handle Japanese tanks, but such encounters were rare. The scarf guns turned out to be the most important weapons on the tank. After landing, gunners fired into trees to eliminate snipers, and many times they saved their vehicles during close Japanese infantry assaults. On the other hand, scarf gunners suffered the highest casualty rate because they had little protection.

The LVT(A)(4) was similar in design to the LVT(A)(1) but carried the turret from the M8 Howitzer Motor Carriage assault gun mounted further toward the stern for proper trim (which eliminated the scarf gun positions) and weighed nearly 17 tons. The open-topped turret had a short-barreled 75mm howitzer and a .50-caliber machine gun mounted to the rear, and the vehicle carried a hundred rounds for the main gun and four hundred for the machine gun. The vehicle had a crew of six men, including commander, driver, assistant driver-radio operator, gunner, assistant gunner, and ammunition handler. The vehicle had a radio and intercom system.

 

The LVT(A)(4).

 Crews liked the new gun but found the amtank vulnerable to Japanese infantry attacks as the commander had to fully expose himself to fire the .50-caliber machine gun at a ground target. LVT(A)(4) and LVT(A)(1) amtanks were intermingled in platoons so that the latter could provide close-in covering fire, and a .30-caliber hull machine gun fired by the assistant driver was added to late-production LVT(A)(4)s. Some units mounted extra .30-caliber machine guns into the two side hatches. Another field modification was add-on armor plate to better protect the engine and pontoons.

LVT(A)(4)s began reaching units in May 1944 and first served with the 708th Amphibian Tank Battalion during the invasion of Saipan on 15 June. With the addition of the 75mm howitzer, one experienced commander assessed that an amtank battalion could give a good account of itself against even one or two Japanese destroyers should it be intercepted during a water march close to shore.

In light of the vulnerability of amtanks as compared with land tanks, Central Pacific Base Command and Tenth Army subsequently established a guide for the use of LVT(A)(4)s as artillery after initial landings. Artillery missions became an important secondary function of the howitzer-armed amtanks; amtanks nonetheless again provided close support to infantry advancing inland during subsequent landings in the Philippine and Ryukyu islands, including Okinawa.[v]

 

Amtanks in Combat

 Specialized battalions played a substantially larger role in the Pacific than they did in North Africa or Europe, particularly amphibian units. U.S. Army amtanks and amtracs first entered battle during landings on Kwajalein beginning 31 January 1944, when the 708th Provisional Amphibian Tractor Battalion (the temporarily reorganized 708th Amphibian Tank Battalion less Company D plus three infantry antitank companies converted to LVTs) landed with the 7th Infantry Division. Company A of the 708th went into battle in LVT(A)(1) amtanks, while other elements used LVT(A)(2) or LVT(2) amtracs.

 

During amphibious landings, the usual approach was to use a lead wave of amtanks followed by waves of amtracs at one-to-three minute intervals, although some units instead put amtanks on the flanks and interspersed a few among the amtracs, which is what the provisional battalion did for the main assault on Kwajalein. In either case, only the first wave came in firing.

The ocean blue amtanks and LVTs hit the beach at Kwajalein at 0930 hours, and the scarf gunners concentrated their fire in the treetops to kill any snipers who might be hidden there. Gunners quickly learned that their 37mm cannon was able to knock out coconut palm field works, but one had to blast a hole into a concrete bunker with AP and then follow up with high explosives.

On Beach Yellow 2, Lt. Frank Tallman commanded a platoon of LVT(A)(1)s supporting the 184th Infantry; the after-action report recorded: ”They received considerable small-arms fire while in the water and also after reaching the shore at the western tip of the 1200-yard long island. Lieutenant Tallman’s tank and two others crossed to the lagoon side of the island, leaving the two remaining tanks of the platoon to move down the seaward side. . . . Tallman took his three tanks to the reef and escorted the infantry as far as a pier about halfway down the island. They received bursts of small-arms fire at intervals during their slow progress, and on one occasion Lieutenant Tallman was wounded slightly when, after raising his head from the turret to talk to an infantryman who had asked for assistance, he was cut on the cheek by a ricocheting bullet.”

 Water-proofed standard tanks from the 767th Tank Battalion (called “land tanks” by amphibian units) with wading gear followed the assault wave ashore from landing craft, and the standard tank battalions with their heavier guns and armor took over most of the tank work. Amtanks and amtracs nonetheless continued to work with the land tanks and the infantry against enemy positions inland.[vi]

 

Saipan: Amtanks Fight as Land Tanks

 Saipan was the next major operation for the amtanks, and more Armored Command personnel (including the army amtrac crews) participated there than in D-Day at Normandy. The 708th Amphibian Tank Battalion provided the armored fist for the 4th Marine Division’s landing on 15 June 1944. By the time of Operation Forager, the 708th Amphibian Tank Battalion was organized into four companies, each consisting of four LVT(A)(4)s and thirteen LVT(A)(1)s.

The battalion, less Companies C and D, were attached to the 23d Marines, and the other two companies were attached to the 25th Marines. The battalion was to form the first wave for the entire 4th Marine Division front, each company leading an LVT-mounted assault battalion. The amtanks were to help the Marines seize and secure a phase line designated O-1 and then assist the infantry as ordered.

 

The Navy provided a massive bombardment, and the assault waves followed rocket- and gun-firing LCI(G)s toward shore. When the amtanks reached a line about 600 yards from shore, heavy artillery and mortar fire crashed around the vehicles. Marines crouched in the amtracs not far behind the amtanks, hoping and praying that none of the shells would find them. A moment later, the amtanks opened fire in return, although the gunners could see nothing through the cloud of dirt and debris raised by the naval bombardment. Indeed, fire from 5-inch naval guns continued until the assault wave was 300 yards from the beach.[vii]

“Observation was limited to about fifteen yards,” recalled Lieutenant Semmes, who was with Company A’s amtanks, “and it is a frightening thing to go into something you cannot see, so the tanks stopped momentarily. The beach, however, was receiving a lot of shellfire, and it was urgent that the tanks move inland. The platoon started ahead ten yards at a time, halted, fired a few rounds, and then moved another ten yards.”[viii]

The amtanks accompanied the Marines to their objectives in most places and stayed with them fighting as land tanks. D-day losses in the 708th Amphibian Tank Battalion amounted to eight amtanks destroyed and six damaged by enemy fire, plus seven put out of action for other reasons. Twelve men were killed and eighty-three men wounded, and five men were listed as missing. Over the next eleven days, losses of men and equipment would nearly double.[ix]

 

LVT(A)(1) (left) and LVT(A)(4) amtanks belonging to Company D, 708th Amphibian Tank Battalion, line up to attack with the Marines on Saipan in June 1944.

 The 708th Amphibian Tank Battalion judged that the use of its amtanks beyond the beachhead had been a mistake because they lacked sufficient armor and mechanical stamina. The battalion therefore proposed that its 75mm howitzers be put to use as artillery once a beach had been secured. Central Pacific Base Command and Tenth Army endorsed the idea. The battalion also urged that the amtanks be camouflaged for land instead of painted light blue, as the dust raised by bombardment obscured the enemy’s view of the vehicles when in the water.

 

 The 776th Amphibian Tank Battalion first saw action when its Company D assaulted Angaur on 17 September beside elements of the 81st Infantry Division. The company, like the rest of the battalion, which was headed for Leyte in the Philippines, was equipped with a mix of 75mm-armed LVT(A)(4)s and 37mm-armed LVT(A)(1)s, eleven of the former and seven of the latter. The battalion also had two LVT-M4s, which were outfitted for maintenance crews. The tankers had trained thoroughly with the 81st Infantry Division back in Hawaii, including practice operating with the GIs off the beach as land tanks.

 

A 776th Amphibian Tank Battalion LVT(A)(4) supporting the 81st Infantry Division’s landings on 17 September 1944 at Angaur, Pelau Islands, fires its 75mm main gun at Japanese troops from the waterline. 


 

Amphibious Mechanized Cavalry

 Each infantry division in the U.S. Army had a mechanized cavalry reconnaissance troop organic to its organization, each designated by the division’s number. The 6th Cavalry Reconnaissance Troop appears to have been the first mechanized cavalry outfit in the Pacific to operate completely armored and tracked. Shortly after arriving in New Guinea in mid-June 1944, the troop was fully mounted in 13 LVT(A)(1) amphibian tanks (amtanks) and four LVT(A)(2) amphibian tractors (amtracs).

As of 23 June 1944, Japanese troops were strongly dug in on high ground dubbed Lone Tree Hill, where two battalions of the 20th Infantry Regiment were cut off and fighting for their lives. The 6th Infantry Division commanding general, Maj. Gen. Franklin Sibert, explained to Capt. Jean LaPlace that his troop, along with Company K, 1st Infantry, was to conduct an amphibious assault just west of the hill and clear out the resistance. At 0800 hours on 24 June, the troop’s amphibians with the infantry aboard moved out by road and entered Maffin Bay at the Snaky River. The outfit performed a column left and swam along the shore until it reached a point 1,000 yards off the landing point, where the vehicles performed a flank left and advanced toward shore in a line.

Japanese artillery opened up when the amphibians came within 500 yards of the beach, and the amtanks immediately replied with their 37mm guns. Tracks churning, the amphibians crawled up onto land and moved into hull defilade positions behind a six-foot embankment. The infantry dismounted from the amtracs but immediately went to earth in the face of vicious machine-gun and sniper fire. Privates Donald Thompson and Harland Worra were awarded the Silver Star for dismounting from their tank and recovering wounded GIs under fire, and several of the armored vehicles began to operate as ad hoc ambulances.

As one LVT(A)(2) headed out to sea loaded with wounded men, a 77mm shell sank it, leaving the desperate men struggling in the water under machine-gun fire. Sergeant Harold Leake immediately directed his LVT(A)(1) to the site and banged away at the Japanese while his crewmen pulled three survivors from the drink. A 77mm round struck a scarf gun and killed one man and wounded another, but the armor fended off further damage.

By 1230, the tanks and infantry had finally suppressed the Japanese fire, and Company I, infantry, landed aboard amtracs to help mop up. The troop’s first mission had been a great success.

*

The 31st Cavalry Reconnaissance Troop also was equipped with LVT(A)(1) amtanks to support the invasion of Morotai Island, Netherlands East Indies, by the 167th Infantry Regiment. The operation was a gamble, because a nearby garrison of 50,000 Japanese troops could conceivably counterattack and cause quite a ruckus. The cavalry troop’s 12 amtanks rolled off four LSTs at 0815 hours on 15 September 1944 on the heels of a naval bombardment, followed by LVTs and landing craft. The 31st Recon had experimented with a single amtank on Dutch New Guinea in July and evidently been pleased when the gunner had knocked out a Japanese machine-gun nest with six rounds of 37mm canister. The cavalrymen now were the first assault troops of Tradewinds Task Force to land, and the tanks rolled 200 yards through coconut groves and underbrush before they stopped to wait for the infantry. The landings, as it turned out, met no opposition, and PT boats interdicted piecemeal Japanese efforts to shift troops to Morotai.

A detachment of cavalry tankers saw a good deal more action when the troopers and two assault companies from the 2d Battalion, 167th Infantry, landed on Bras in the Mapia Islands, just northwest of New Guinea, on 16 November. (This action is incorrectly placed in September by the Army’s official battle chronology of the division and merits but a passing reference in the official history.) Three cavalry amtanks and infantry-bearing LVTs approached Bras from Pegun Island, which had been captured the preceding day without a fight. A company of fanatical Japanese from the 226th Regiment, 36th Division, defended the beach, and machine-gun and rifle fire killed 12 and wounded 10 of the debarking GIs. The reconnaissance troop’s after-action report is missing, but silver-star citations in the unit records provide snapshots of the assault.

“When the periscope was shot off the [amtank] which he was commanding as it approached the beach, Staff Sergeant [Clifford] Gonyea with complete disregard for his own safety opened the hatch and stood up in the turret exposing himself to heavy enemy fire in order to direct the movement and fire of his tank. Though hit by enemy fire, he held his position until the enemy position to his front had been knocked out.”

“When the machine gun for which he was an assistant gunner on an [amtank] became jammed during an especially heavy fight with the enemy beach positions, Technician Fifth Grade [James] Smith. . . climbed outside of the tank and gave covering fire with his submachine gun while the first gunner cleared the stoppage. When, as a subsequent wave of infantrymen hit the beach enemy machine guns opened fire, again he left the protecting armor of the tank, jumped down into the water, and under continuing enemy fire pulled a wounded soldier, who was still being fired on by the enemy, to a protected position. . . .”

“When an infantry rifle company was caught in a heavy crossfire from concealed enemy pillboxes, Sergeant [Clarence] Curb ordered the two [amtanks] of which he was in command to move in on the enemy from the flank. When it soon became apparent that, because of the heavy undergrowth and poor visibility, the tanks could not maneuver or fire effectively, he dismounted and under heavy enemy fire directed them to firing position. Having returned to his own tank, he directed the firing until the other tank became stalled and its radio inoperative. Once again he dismounted and under continuing heavy enemy machine-gun fire and rifle fire ran to the disabled tank and verbally directed its fire into the targets. Not only was he responsible for the annihilation of a superior enemy force as was evidenced by the approximately 100 enemy dead around his tanks but also prevented heavy casualties among our infantry.”

“When the driver of his [amtank] was seriously wounded in the chest by a sniper as he attempted to repair the immobilized tank, Technician Fifth Grade [Robert] Licsauer. . . left the armored protection of the tank, exposing himself to sniper fire to help move the man out of the line of fire. After having accomplished this, he returned and succeeded in getting the stalled tank to run, but only in reverse. By skillfully maneuvering, he ran the tank over the enemy pillbox that was firing on them, crushing its occupants [and] thereby clearing a path for our advancing infantrymen.”

The 31st Division’s history recorded, “By noon of the 17th, the enemy had been encircled and could not withdraw from his prepared positions. Progress was slow, as it was necessary to destroy the Japanese position by position. . . . By displaying exceptional courage and skillfully employing tank landing craft which they manned, [the 31st Cavalry Reconnaissance Troop] made it possible to eliminate the last of the resistance.” The total body count was 159. On 19 November, two other cavalry amtanks spearheaded landings in the nearby Asia Islands, which proved to be unoccupied.[xi]

 

Lieutenant General Krueger’s Sixth Army, which was to go ashore along Leyte’s east coast, consisted of X and XXIV Corps and had 174,000 troops available for the initial assault phase. The XXIV Corps landing force had been scheduled to take Yap as the second phase of the landings conducted on Angaur and Peleliu on 15 September. In light of the absence of effective Japanese air opposition, the High Command decided to abandon the Yap operation and divert the entire landing force, which included half of the available assault shipping in the Pacific Fleet, to the Leyte operation. Plans for Yap had evolved to deal with landing areas protected by a coral reef, so LVTs rather than landing craft were allocated to carry the troops to shore. Leyte offered long, smooth beaches suitable for even LSTs. It was too late to change plans, so XXIV Corps would conduct a Pacific Ocean Area-style assault, though following waves were to land by boat.[xii]

In terms of armor, there was a remarkable disparity between the corps of the two operating areas arising out of the different campaigns they had waged to date. XXIV Corps was to attack with two amphibian tank battalions, X Corps with none. The two XXIV Corps divisions had a complete land tank battalion each, whereas the X Corps divisions shared the equivalent of one battalion.

The first 767th Tank Battalion Shermans, from Company A, landed at 1015 in the second wave on Beach Violet 2, in the 32d Infantry’s zone, just behind the amphibian tanks in the first wave.

*

 

An amphibious tank exits an LST in deep water.

Beginning on 27 November 1944, the 776th Amphibian Tank Battalion in late November contributed its Company C (less all LVT[A][1]s) plus the LVT(A)(4)s of two Company B platoons participated in the first of a series of amphibious raids up the west coast of Leyte in the Philippines in cooperation with the 7th Infantry Division. The provisional battalion was loaded onto Landing Ships, Medium, on 27 November and transported to a spot off Santa Cruz near the southern tip of Leyte. There, the LVTs disembarked and traveled under their own power 100 miles to the 7th Infantry Division’s zone of action north of Baybay, the longest water march ever conducted to that point by LVTs under their own power.[xviii]

The AAR described the action at Balogo: “At 0635 the company, which was in column formation headed north, executed a movement by the right flank and advanced toward the shore in line formation firing howitzers and machine guns. About 200 yards from shore, on radio command of the battalion commander, the company executed a movement by the left flank and continued to move north in column. Turrets were swung to the right, and the shelling of Balogo and Tabgas continued. The company arrived at the mouth of the Tabgas River at 0700 and made an unsupported landing by maneuvering from column to line formation. . . . As the amtanks landed, Jap infantrymen were observed evacuating beach positions under the company’s machine-gun fire. Ravines, reverse slopes of hills 380 and 910, and other likely areas of enemy concentration were taken under howitzer fire with HE and smoke shells.”

 

Okinawa: The Last Battles

 

For more on the amtanks, see:

 Harry Yeide's Website

 Weapons of the Tankers

 The Infantry's Armor

 Steeds of Steel

 

Copyright for this article remains with Mr Harry Yeide.


[i] Staff Officers’ Field Manual for Amphibious Operations, Fleet Marine Force, Pacific, 10 September 1944. Pacific Warfare Board Report No. 70, 5 October 1945, NARA, RG 94, 4-7.70/45, box 24464.

[ii] William S. Triplet, A Colonel in the Armored Divisions (Columbia, Missouri: University of Missouri Press, 2001), 46.

[iii] “Army Amphibian Tank and Tractor Training in the Pacific,” 1st Information and Historical Service, records of the 708th Amphibian Tank Battalion, NARA. (Hereafter “Army Amphibian Tank and Tractor Training in the Pacific.”)

[iv] William S. Triplet, A Colonel in the Armored Divisions (Columbia, Missouri: University of Missouri Press, 2001), passim.

[v] AAR on the Leyte campaign, 776th Amphibian Tank Battalion. Memorandum, “Special Report of the Operation of the Provisional Armored group (Amphibious) with the 77th Infantry Division for the Period 26 March to 26 April 1945,” Headquarters, Provisional Armored Group, 26 April 1945.

[vi] Rogers, 30-31. Journal, 767th Tank Battalion. (Hereafter Kwajalein Atoll.)

[vii] Journal, 708th Amphibian Tank Battalion. History, 534th Amphibian Tractor Battalion. Hoffman, 48ff.

[viii] Semmes, 30.

[ix] Journal, 708th Amphibian Tank Battalion. Gugeler.

[x] AAR, Company D, 776th Amphibian Tank Battalion. AAR, 776th Amphibian Tank Battalion. History, 726th Amphibian Tractor Battalion. Capt. Jerry V. Keaveny, “Operations of Company A, 322d Infantry (81st Infantry Division) in the Cleanup Phase of the Capture of the Island of Angaur, 11-22 October 1944 (Western Pacific Campaign) (Personal Experience of a Company Commander),” submitted for the Advanced Infantry Officers Course, 1949-1950, the Infantry School, Fort Benning, Georgia.

[xi] AAR, 31st Cavalry Reconnaissance Troop. History of the 31st Infantry Division in Training and Combat: 1940-1945 (Baton Rouge, Louisiana: The 31st Infantry Division, 1946), 21-23, 97-98, 101. (Hereafter History of the 31st Infantry Division.) AAR and journal, 31st Infantry Division.

[xii] “Seizure of Leyte—Report of the Participation of Task Force Seventy-Nine,” memorandum FE25/A16-3(3) from Commander, Task Force 79, to Commander, Seventh Fleet, 18 November 1944.

[xiii] AAR, 776th Amphibian Tank Battalion.

[xiv] AAR, 776th Amphibian Tank Battalion. S-3 journal, 536th Amphibian Tractor Battalion. Maj. John Collier, “Amphibians in Leyte Operations: Amtanks,” The Cavalry Journal, May-June 1945, 38. (Hereafter Collier.) “The Flame Thrower in the Pacific: Marianas to Okinawa.” Cannon, 77.

[xv] Journal and AAR, 780th Amphibian Tank Battalion. AAR, 788th Amphibian Tractor Battalion.

[xvi] AAR, 763d Tank Battalion. AAR, 96th Infantry Division.

[xvii] Journal and AAR, 780th Amphibian Tank Battalion.

[xviii] AAR, 776th Amphibian Tank Battalion. Lt. Charles Shock, “Amphibians in Leyte Operations: Amtracs,” The Cavalry Journal, May-June 1945, 42.

[xix] AARs, Companies A-D, 708th Amphibian Tank Battalion.

[xx] Field Order 1, Operation Iceberg, files the 776th Amphibian Tank Battalion. AAR, 776th Amphibian Tank Battalion.

[xxi] History and AAR, 780th Amphibian Tank Battalion.

[xxii] History and AAR, 780th Amphibian Tank Battalion. AAR, 7828th Amphibian Tractor Battalion.

[xxiii] Appleman, et al, 149ff.

[xxiv] AAR, 708th Amphibian Tank Battalion.

[xxv] Ibid.

Close