The Battle of Biak Island

By Lieutenant N.P. Kimler, 1st Glider Group

From information by Captain Sherry of the 41st Division Intelligence Corps


The Island of Biak is one of many coral formed islands dotting the South West Pacific and of doubtful history or geographic importance. It was only by virtue of its proximity to the Dutch New Guinea holdings that the island was claimed by any nation at all. Triangular in shape, it measures about 40 miles from north to south and but slightly more at its East to West base.

The Japanese, in their march Southward toward Australia, established an intermediary garrison with airstrips on the island. Here then, the island of Biak becomes a point of military value-one more rough and rugged stepping stone of the Yanks in their march from Moresby to Morotai, and on to Manila!

The staging for the landings on Biak, to be coordinated with a simultaneous operation against the Jap held island of Wakde, was conducted at Hollandia, and aerial strikes against the Jap positions were sufficient for any normal opposition. However, the experience on Biak proved a near catastrophe due to unprecedented opposition. Trouble, however cannot be laid to the air forces, nor to air reconnaissance. The Japs were found to be dug into a network of natural caves, which were improved to almost impenetrable fortresses of rock. Photo recon does not show this nor could bombardment soften it. There remained then nothing but the Bloody Battle of the Caves.

Last minute intelligence caused a slight change in plans and the operations against Wakde were started a few days ahead of schedule. But at 0700 hours of May 27th, 1944, the assault troops of the 162 and 186 regimental combat teams, 41st Division landed at Bosnek and Sariari jetties, Biak. Due to the coral shelf that extends far out into the water, the LSTs were not able to pull right up onto the beach as in typical landings. Instead, the flotilla laid off shore the necessary hundred or so yards and the big bow doors swung open to disgorge troop laden amphibious track vehicles, and thus began a man's size job for a bunch of boys.

Not that the 41st Division was made up of a bunch of raw recruits, but it soon developed to be an oversized assignment for 4,000 invading troops to tackle 10,000 well established defenders. Fortunately, the landing was made with little opposition. As it happened, the logical goal of the strike was the Mokmer airdrome and consequently, the Japanese had placed their main defenses around the drome. The attack plan then, was to make the landing at the jetties about eight miles east of the drome, group the attack forces on land, and proceed along the beach road to the drome defenses. This maneuver permitted our forces to land all the troops in combat condition and all the men were immediately committed to the attack. However, the Japanese were to some extent able to bring heavy fire to bear on the attackers with heavy naval guns they had imbedded in the cliffs overlooking the expected landing area. Enemy air action also took its toll and so developed an incident related to me by my brother, Lieutenant S.J. Kimler, Staff Communications Officer for the 7th Fleet. As the LSTs were regrouping after the landings, the signalman on the staff ship was interrupted in his work of painting a rising sun on the conning tower, to receive a message from a smoking escorting destroyer, 'Next time you escort us' .

In the plan of attack, the attacking forces were to proceed along the beach, overcoming any resistance in route, and achieve control of the drome for resupply planes to land on the 4th day. It developed that the first plane was able to land after the strip was secured - June 22, almost three weeks later!

So the eight mile trek was on, and it started off with little incident. Good progress was made and, despite the late start after landing operations were cleaned up, 2.5 miles were covered by evening and the perimeter was set up at the native village of Ibdi. So far only occasional sniper fire harassed the troops, which obviously was little impendence. However, the path to the objective, was presenting many apprehensions among the men as it led along the narrow beach beneath cliffs rising to sheer heights of a hundred or more feet. Surely their every step was being observed and innumerable defensive weapons were trained on them every minute. When would the defenders strike? That night, surely!

But no, the night passed without incident' and the march continued with the first light of day. Again, the march seemed to be allowed to continue with only irritating snipers contesting the progress. What gives? Is there a trap laid out for us ahead? Yes, about three miles along the second day's march the road hugged the rising cliffs and the white coral walls were pocked with shadows of cave entrances and at the point where an underground river breaks from the cliff, all hell broke loose. It wasn't a surprise, but the sharp realization of the trying hours of apprehension caused many a taught nerve to snap. But the fight was on and the 3rd Battalion of the leading 162nd Regiment was forced through. The remaining forces were forced to withdraw to the Ibdi perimeter of the night before.

Meanwhile, the 3rd Battalion fought on so that by the third day they had reached Mokmer village and set up a perimeter with patrols extending nearly to the strip. The Battalion's position was put to severe counter attacks on three separate charges in addition to a merciless barrage of automatic weapon and mortar fire. In the many months of planning the defenses, the Japs had grid charted every inch of the areas and, with the Battalion pinned down to the barren coral, the Japs could comb the area in a systematic slaughter, bringing their mortar fire to bear on any grid zone with but a few predetermined

clicks of the adjustment mechanism. There was no escape from this fire, the coral permitted no "digging in". There was nothing to do but lay there and take it. Casualties were higher than ever before, and as buddies went to comfort their stricken mates, another shell would plop, adding another to the mounting and frightful list.

Meanwhile, there was no retreat! Between them and the parent forces, was engaging the most ferocious of Jap Banzai counter attacks. The Japanese had formed a pocket of resistance and attack in the elevations just above the Ibdi perimeter. Thus engaged, there was no advancing to the relief of the cut off battalion now frantically radioing for assistance. But the only help to be offered was artillery and destroyer fire, so the only alternative was to give up the gain and evacuate the beleaguered men. Again the amphibious tracks, Alligators and Buffaloes, were called upon. Under what cover the heavy fire we had could give them, these vehicles made their way along the shoreline and put in at the beach where our troops lay, and during the remaining night, the evacuation was achieved ... with a final count of 137 of the original 650 men either dead or wounded. Witnesses give highest praise to the valor of the Negro drivers of the Amphibs and relation of the experience reveals untold heroisms, such as drivers, already beyond shelling range, turning back into the face of an almost solid rain of shell to assist or tow disabled vehicles.

Here then, with the 4th dawn on which the resupply planes were to have been able to land on Mokmer Drome, the assault was stymied at Ibdi, the mark of the first day. Expeditious thinking was called upon and a small force of troops and engineers made a new landing on a small neighboring island, Owi, and work began which in four days produced a tactical strip of 3,000 feet which was rapidly extended to 5,000 feet to accommodate all types of aircraft.

Meanwhile, the twin operation on the island of Wakde was successfully completed and the available troops were called upon to assist in the Biak battle. These men, of the 163rd, were called upon to be used as reserves, as they had just participated in more than a week of combat. But upon their arrival at Biak, the action was so intense that they were of necessity immediately committed to battle.

 The stalemate in Ibdi was being criticized by higher authority and decisively desperate plans were laid. The 162nd, again in Amphibs, took to the surf to circumvent the Jap defenses at the underground river defile and make a direct frontal attack from Parai in the face of enemy defenses set up in the east and Mokmer caves. The 186 went back to a point near Sariari to achieve an enveloping movement along the crest of the ridges. And the newly arrived 163rd, upon reorganization after landing, was to carry on with mopping up actions along the bypassed beach and cliff side pockets.

This type of fighting, digging out pillbox after pillbox is slow and expensive. A near reversal of the presidential casualty score of nine or ten Japs for one of our men attests to the odds the enemy enjoyed with their natural defenses. A manually constructed pillbox is vulnerable to bazooka and high explosive poundings, but the caves could only be attacked from the face and even though a direct hit were scored in the entrance, baffles constructed on the inside protected reserves who immediately replaced the dead. Probably the worst of all came in the night fighting where, due to our thinly spread troops many a pocket was passed up, or infiltration by the enemy made easy, so that many a Jap was soon behind our lines to harass the troops from the rear and cut off supplies. It might seem incredible that with supply lines never more than a few miles that forward troops went for days on chance hoarded candy bars or a can of processed cheese, and with clothing and shoes cut to ribbons by the sharp coral, they fought on without relief.

However, progress was being made, and the contested strip was appearing within possibilities, so the Japs risked much on another aggressive assault. This appeared as an all out drive, and led by eleven light tanks, the Japs came out in full battle dress. Slain officers were later found to have worn their best, even to silken underclothing. The site which the Japs chose to meet our men in open battle would in some cases gave them an advantage in that they were coming from higher ground. But the road hugged the cliffs in a horseshoe, the other end of which gave us cover to await the assault. So, as the Jap columns, spear headed by their tanks entered the horseshoe, our forces held their fire in cover until the last Jap tank had come into view. Then our four Sherman’s came into view and chose this last tank as the target! Next, the first tank! Blockaded this way, the remaining tanks found no escape forward nor to the rear, and the heavier Sherman’s had a field day in methodically erasing the Jap armored column. It should be noted that this was the first successful use of tanks in the SWPA. Heretofore, the bogs and close growth of the New Guinea theatre jungles made the tanks easy prey for anti-tank teams. The success on Biak, made additionally spectacular in its decisiveness, gave the singular engagement the name of the Battle of Tanks.

However, the tank war did not end the determined Jap assault. And they came on, and on, and on. As one leader fell another was ready with his sword to spark the charge. The fanatic impulse may best be illustrated by the action of the Jap officer who reached the line of tanks and wildly hacked away at the firing cannon barrel. His enthusiasm exceeded his immortality and the next blast of the cannon disintegrated him. Similarly, the rest of the Japs, as they came out into the open to fight, met a withering rebuff that evened the score and soon put our men ahead far enough so that they were able to push on to the strip.

Concurrently, the ten day battle along the ridges progressed to where the joint forces converged on the air strip area and the engineers were able to clean things up for supply planes to land. However, the battle was far from over. In fact, all work on the strip was accomplished only through shear daring as the strongest Jap defenses were centered in the West Caves, directly over- looking the strip below. To be assured of adequate drome facilities, the 34th Regiment of the 24th Division was assigned the achievement of secondary strips at Sorido and Borokoe. There was little opposition and the few casualties were as likely self-inflicted by unseasoned troops.

There remained then the problem of the Jap stronghold on the West caves. A word of description would- help in giving to understand the assault problem. The so called West Caves were formed by three large open pits, each around 80 feet in diameter and 30 to 50 feet deep. These three pits formed a triangle with connecting passages to a central cavern larger than any ballroom or auditorium in the States. Within this underground fortress the Japs were prepared to withstand any siege, what with quarters, kitchens, hospital, power plants, all air conditioned! Against this were poured all manner of weapon; automatic, mortar, bazooka, flame throwers, and even tank and artillery pieces pulled up to fire point blank into the entrances. And yet the resistance continued. It would have been suicidal to force an entry to dig the defenders out. So a ruse of an escape route was provided and some of the defenders elected to risk it. However the route was well covered with fire power arid any real escape was unlikely. One Jap was caught in the cross fire of two machine guns and was shot 60 times. But as long as Japs remained alive in their fortress they remained as a threat to the security of our position on the strip below. A few-attempts at burning them out was made by pouring gasoline down the cracks in the roof of the cavern but the defenders seemed able to cope with the effects. But lastly, after getting exasperated with this stubborn resistance, a super demolitions charge was devised. The' engineers provided 1500 pounds of dynamite and a Jap reserve of 50 barrels of 100 octane gasoline was tapped, and while machine gun fire kept the Japs under cover, the barrels of gas and the dynamite In barrels, each fitted with electric primers, were lowered with slings to the entrances of the cavern. The whole, setoff in one simultaneous blast of fire and concussion, ended that part of the war instantaneously!

Organized resistance was declared ended on the 20th day of July, almost two months after the start of a "four day job." But the approximation of this date, some say, lay in the report that the Jap officer, Colonel Kazumi, 221st Jap Infantry Regiment, in command, had committed Harikari in traditional decorum. However, in the following months, till September 20th, patrols of both sides were still active to the count of 1,043 Japs killed and 412 captured. This count was increased as battalions were dispatched to secondary landings on the opposite side of the island to cut off Jap attempts to escape in barges and other rescue craft.

With escapes cut off, there remained hundreds to carry on in hope and hiding to be hunted down by our patrols. With one of these hunted bands is a character subject of much speculation and rumor. On the days preceding our landings, a Japanese admiral came as part of an inspecting staff. While many of the inspecting party were reported to have escaped by seaplane, the admiral "missed the boat." And in many of the escape attempts that were intercepted by our secondary landing operations at the opposite side of the island, the bail that led our troops to the spot was the admiral's frantic radio pleas to the homeland for help. So far as can be ascertained from captured Japs, to this day the admiral is, sick and lonely, wondering around the island with his small band of bearers and guards. Apparently it can be presumed he has been deserted and left to meet his fate and join his ancestors along with the 6,996 others accounted for in death at the time of this, the 23rd December 1944.