603 Tank Company (attached to 41st Infantry Division): Tankmen's Gallantry on Biak

by Dr. Hargis Westerfield, Division Historian, with 603 Tank's 1st Lieutenant George Hallanan (and others)

The 12 tanks of 603 Tank Company on Biak were important to save many 41sters' lives and winning for us. Each General Sherman tank was actually an armored light 75 mm piece with machine gun, highly mobile for front-line action. To fully understand Biak Battle, we need the history of 603 Tank Company's two Platoons attached for Biak. (The other 603's Platoon fought for the 41st in the Wakde Operation.)

On 27 May 1944, eight tanks landed on Biak from LCTs (Landing Craft, Tanks). Damage to LCTs from coral reefs was expected, but these LCTs beached safely at Bosnek Jetty by 1000 hours. Six of the eight at once joined 162's 3rd Battalion pushing through Parai Defile to capture Mokmer Strip.

Bad terrain and an underground river from below Parai Cliffs retarded us, but C Company 116 Engineers' T/5 Winkler helped our crossing with his bulldozer. At 1400, our tanks fired on Japs at the cliff base, helped 3rd Battalion move on by 1430. At 1500, we shot pointblank into Jap pillboxes. By 1620, 3rd Battalion had dug in before Mokmer Village. Our 2nd Lieutenant Cruse was wounded in action, and 162 Infantry lost two killed, six wounded - with 15 dead Japs.

On our second Parai Defile day at 0645, Captain Thierolf with six tanks neutralized heavy mortar and machine gun fire and advanced with 3rd Battalion 162 again. Then by 1100, fire from the cliffs cut off 3rd Battalion and G Company. Jap Infantry attacks began. About 1400, we first sighted light Jap tanks and infantry at 1200 yards. We repelled the tanks and damaged one. We killed 2nd Lieutenant Murao and three Jap enlisted men.

Jap mortar fire increased. Hidden 70mm dual purpose anti-aircraft guns dropped shells that damaged three tanks. One Sherman took a dual purpose shell into its 75 mm cannon muzzle. The shell split the muzzle for several inches, but the gun could still fire. When our lead tank emptied shell cases from its "pistol port," a shell exploded nearby and blew in fragments. The tank flamed, wounded two of six crewmen in it.

Safe behind armor of the next tank, Peralta saw the inside of the damaged tank in flames. With a fire extinguisher, Peralta dared the Japs to run 25 yards to the flaming tank. He put out the fire. (Peralta would die in battle later.)

When a tank intercom failed, Captain Thierolf risked his life to stand outside his tank and guide other tanks by hand signals. Early on the third morning in Parai Defile, Jap tanks with infantry made a supreme effort to destroy 162's forward companies. Whether their light tanks and infantry could have won is of course uncertain. But 603 Company's tanks surely were more effective than unaided infantry in killing all seven of the tanks that fought us. Our thicker armored tanks were superior range and caliber of main armament.

Tanks like the Japs' light "Ko-Go" machines had been formidable against tankless armies in China and the Malayan jungle. With three-man crews, each mounted a 37 mm gun in the turret. A 7.7 mm machine gun was posted in the right rear of the turret, and another 7.7 machine gun in the hull. Armor plate was half-inch steel. Such tanks had fought well in Malaysia where Anglo-Indian troops lacked tanks of their own - and had no training to fight tanks.

Instead of little 37mm guns our Sherman’s mounted 75mm guns. Each tank had a 3.3 inch machine gun, and even a 2-inch smoke mortar in the turret top. Difficulty to replenish ammo in usually roadless New Guinea had caused us to often carry a 110 round overload. Core of these 110 was 75 high explosive shells with 20 rounds armor piercing. There were five rounds of white phosphorus for flaming caves. Each machine gun had 8-12,000 rounds. Our five-man crew sheltered behind armor as thick as 3.94 inches in turret front and sides and hull front. Other armor was .5 inches thick, like all Jap tanks' armor. Our tanks could outfight any Jap tank on Biak.

On 162 Infantry's third day on Biak (29 May 1944), 603 Tank Company fought the first tank battle in the Southwest Pacific against 36 Tank Company of the Japs 36 "Tiger" Division. At 0700, the Japs first marched a company-sized unit down the road at us. Before they could deploy, H Company's heavy machine guns with E Company shot them down. Then Jap motors began humming out of sight up a slope and around a jungle curve in the Parai road. Why those tanks did not charge our lines at once before our tanks arrived, we can never know. They might have panicked many men.

Happily, 162's men heard the rumble of our tanks behind them and past their lines. The two General Sherman’s came to a halt with those two beautiful.75 guns leveled already.

1st Lieutenant Iwasa's little tank tottered into view from the road curve and fired its .37 gun. Three more Jap tanks formed in a rearward slant on Iwasa' s left and opened rapid fire, Projectiles ricocheted off our tank turrets and bow curves. But those lighter shells only made grooves 1/4 inch deep in our 3.94- inch forward armor.

Our Sherman’s blasted. At 50-100 yards, just one round of .75 armor-piercing per tank halted all four tanks dead in their tracks. Tankmen saw one "AP" shell pierce the right flank of a Jap tank and go out through the rear wall. It left a hole a foot in diameter from the front through the rear.

But it was not enough to pierce half-inch steel and immobilize the tanks. Jap killers might still lurk inside. Our tanks changed to High Explosive (HE) shells. They rammed through front armor and exploded inside. All the Japs and all four tanks were dead.

About 30 minutes later, a second wave of three tanks charged down the road and deployed in the same backward slanting formation in the coconut grove. Instead of two of our tanks, they now fought three. One die-hard lap gunner put a shell through the shield protecting aperture where the .75 projected from one tank. The shell locked the .75 so that it could not move to adjust on target. Expertly, the driver dropped his tank into a shell-hole and brought the gun to bear to smash a Jap tank.

Thus had our three stronger tanks destroyed seven weaker Jap tanks. We lost just three wounded: Ulrich, Sergeant Gilliland, and 1st Lieutenant Breitag. As for the Japs, besides losing 2nd Lieutenant Murao and two men killed the previous day, they had 17 more dead soldiers: 14 men, plus 1st Lieutenant lwasa, 2nd Lieutenant Kambe, and Warrant Officer Tsubota. They still had left three more tanks which would die in combat against 186 and 162 Infantry before West Caves on 14-15 June.

After helping guard 162's retreat from Parai Defile, 603 Tank Company did not fight for two days. Then on 1 June, the Japs tried to kill 3rd Platoon and Headquarters tanks, in bivouac with 162 Infantry west of the water-point below Ibdi Pocket. From heavy mortar fire, the tanks moved west 1,000 yards. Here a probable mountain gun struck at them near dark fall. Japs had meanwhile captured the water-point and cut the Bosnek road. Captain TheroIf's tank ran through machine gun fire and escaped to Bosnek. A Jap 75 gun shelled the other tanks which were parked among abandoned Jap gas drums scattered throughout the area. As tanks turned to flee, Driver Zamora's hand was paralyzed by shell fragments. After turning his tank, Zamora gave the controls to the assistant driver.

The tank backed to escape - but hit a Jap gas drum that splashed the tank and fired its outsides. Zamora's wounded hand was burned. Despite orders to leave the tank, he took the driver's seat again and drove high speed while his assistant driver stood on a fender and guided him through the road-block. Roadside brush and dust put out the fire. (Three men and an officer were wounded, but only Zamora was named.)

When 162 Infantry tried to force Parai Defile again on 3 June, 3rd Platoon's tanks guarded the recon in force by L Company. An air-strike and field artillery fire helped us as far as the road-fork near Parai Jetty where we had fought the Jap tanks. But L Company lost three dead and was cut off west of the underground river. Two tanks forwarded to extricate L's Platoon.

Lack of infantry training to work with tanks was the cause of death and wounds in our first tank. Infantry withdrew behind our lead tank and blocked off fire from the second tank.

Shielded by our own infantry, a Jap in U.S. uniform topped the lead tank and dropped a live grenade down the driver's hatch. DiCesaris, T/5 Nolan, and T/4 Gallant were wounded. Driver Peralta would die.

Despite serious wounds, bow-gunner Gallant replaced dying driver Peralta and turned the tank to flee. But logs in the narrow road retarded the tank, Tank Commanding Officer Sergeant Earl leaped from the turret and in full view of the Japs guided the tank past the logs to safety up Parai Road.

Beginning 7 June, 603 Tank Company had to fight for 186 and 162 Infantry to secure Mokmer Strip. For 162 Infantry was still blocked in Parai Defile, and 186 Infantry had prematurely seized Mokmer Strip while Jap forces still held the heights above the Strip.

On 7 June, three tanks of 3rd Platoon landed under fire to help 186 Infantry against those heights. We first destroyed some beach-side Nippo pillboxes. Then we dueled and silenced a Jap 20 mm gun and a 75 mm gun that opposed our landing. Next day, our 3rd Platoon tanks took fire from a mountain gun and mortars. To draw fire, we had to expose our tanks. The guns blew off a track of one tank, but we silenced guns and two strong pillboxes.

On this same 7 June, 162's I and K Companies bypassed the Jap block east of Parai Jetty and landed on the jetty. Six of our tanks reinforced 162's Companies. Next day, three more tanks landed at the Jetty. With 162 Infantry, all nine tanks tried to push west to contact 186 Infantry near Mokmer Strip, but mine-fields of 6-inch Jap naval shells retarded us. East Caves plunging mortar and automatic fire drove our tanks into cover, halted 162 also.

On 9-13 June, our Parai Jetty tanks worked to help 162 Infantry move by land past East Caves to reinforce 186 Infantry and our three tanks already on Mokmer Strip. We also battled the Japs still holding Parai Defile east of us.

For example, on 9 June, three of the Parai tanks bypassed the Defile on LCTs and fired from the sea on East Caves and nearby ridges. We knocked two Jap observers out of trees and caused two landslides that seemed to block some cave mouths. The three tanks then moved by water east of the Jetty to fire for an hour against the Parai Defile Japs. (Not until 13 June, however, could a truck convoy run the coastal road for the first time without being shelled. Last Japs in Parai Defile were wiped out only the day before.

From 9 June on, 603 Tank's mobile armored forces bombarded to help our infantry win West Caves. We fought mountain guns and machine guns to clear the ridges for infantry assaults. (But on 12 June, a Jap air-raid on Mokmer Strip wounded six tankers, of whom three were evacuated. Reported names of these wounded were Barnett, Willingham, Dollyhigh, and Kline. One 17 June, 1st Platoon killed a mountain gun and two machine guns to help 162 storm Horseshoe Ridge which had guarded the right flank of West Caves.

On 20-22 June, our tanks battled the final strong resistance of Japs holding the West Caves area. When a K 186 Platoon attempted to capture Hill 320 northeast of West Caves, they were pinned down and needed help. A gun of unknown heavy caliber repelled five tanks of our 1st Platoon when it got out K Company. At 1300, two 1st Platoon tanks tried to help G 186 to advance. The heavy gun forced us back to call for field artillery help. Results were not known.

On that same 20 June, two tanks of 3rd Platoon fought for 162 Infantry against West Caves themselves. Beginning at 0830 against unceasing mortar, rifle, and machine gun fire, we dueled the West Caves Japs - claimed a kill of 30. After re-supplying and taking another tank with us, we fought 1530 to 1730. Once a Jap shell pierced a gun shield and locked a turret.

On 21 June, we fired into fighting West Caves Japs again. We faced the premature explosion of a mine attached to a Jap on the road before us. Another Jap flamed a tank side with a Molotov cocktail which went out harmlessly. We slew the Jap. We covered teams rolling flaming drums into the caves. Rifle fire wounded a tank commander, probably Sergeant Self.

That night, most surviving Japs charged into 186' s lines. Called at 0700 on 22 June to help 186 Infantry, we claimed a kill of 30 of the 119 Japs. Thus ended 603 Tank Company's main war on Biak, although 2nd Lieutenant Cross was wounded on 27 June. (Note: Jap's report was of an all-out naval, air, and tank attack on them - and killing 75 Yanks. I have never seen or heard of any evidence that this statement is true.)

On Biak, 603 Tank Company fought bravely and efficiently. We lost no tanks. We had two killed and 14 wounded-a high rate of 25 percent casualties in the 12 tanks. But in Parai Defile, on Mokmer Strip and before West Caves, we surely prevented more than 100 casualties for the 41st. Men like Rudolph Peralta, Alcide Gallant, Joseph Zamora, and others deserve high honor.


CREDITS: Basis of this great saga is 20 letter-size single-spaced pages of typescript (but not all full pages). Narrative is eight pages long, with 12 pages of often useful detail. Lieutenant Hallanan signed for all but 1.5 pages by Commanding Officer Captain Richard Thierolf. R. R. Smith's Approach to the Philippines was highly useful, and award stories of these seven tankmen: Rudolph Peralta, Alcide Gallant, Richard Thierolf, Wallace Earl, Joseph Zamora, and Raymond Nolan. I collated all of this where possible with journals and narratives of 186 Infantry and 162 Infantry on Biak. Jap report consisted of a legal-sized sketch and perhaps a page of single-spaced typescript of actual narrative, along with nearly two pages legal-sized typescript of technical details. This report was filed under the heading "Enemy Tactics, Materiel and Terrain.”