The landing on Biak

On the morning of 27 May 1944 American and Australian warships stood off the village of Bosnek on the south coast of the island of Biak. After three-quarters of an hour of naval bombardment and raids by bombers of the US Fifth Air Force, amphibious tractors carrying men of Major General Horace Fuller’s 41st Infantry Division headed for the shore. Biak, the largest of the Schouten Islands, lies at the entrance to Cenderawasih Bay (formerly Geelvink Bay), north of the western part of Dutch New Guinea. On the flat coastal plain west of Bosnek the Japanese had built three airfields – Mokmer, Borokoe and Sorido – and these were the objective of the landing. By evening there were some 12,000 Americans on the island, and the defenders had put up almost no resistance on the beaches. The real fighting began only in the following days, in front of the airfields.

The brief description of the day repeated in war chronologies – “Operation Horlicks begins, the Americans land on Biak in Dutch New Guinea; fierce Japanese resistance lasts until August” – is broadly accurate. The codename “Horlicks” is given mainly by English-language sources other than the US official history; in US Army documents the landing force was called the Hurricane Task Force, and the day of the landing was designated Z Day. It should also be noted that Biak was a developing air base rather than a major base: the Mokmer and Sorido strips were completed in April 1944, Borokoe became operational in early May, and after the Allied landing on Wakde on 17 May the Japanese commander halted work on the airfields and put his men to building fortifications. The island’s importance lay above all in what its airfields could become in Allied hands. Resistance did indeed last until August – the US official history regards the landing at Wardo Bay on 17 August as the last act of organised fighting, and isolated Japanese groups hid in the interior of the island for a long time afterwards.

After Hollandia: the jump west

The landing at Hollandia on 22 April 1944 had moved the New Guinea front hundreds of kilometres west and cut off the Japanese Eighteenth Army at Wewak. General Douglas MacArthur had no intention of stopping. His goal was the return to the Philippines, and for that he needed a chain of airfields from which bombers and fighters could cover each successive jump. Behind MacArthur the Admiralty Islands, where the fighting had ended on 18 May, were becoming a large fleet base. The airfields at Hollandia, on the other hand, proved less useful than expected – the terrain and weather around Lake Sentani did not allow runways for heavy bombers to be built quickly – and aircraft based there could not reach far enough west and north. Biak, some 520 kilometres north-west of Hollandia, had a flat plain with runways already built. Airfields on the island could also help the navy of Admiral Chester Nimitz, which was preparing a strike on the Marianas for mid-June: from Biak Allied aircraft could reconnoitre the seas west of the Marianas and attack the Japanese bases in Palau.

Land operations in this part of New Guinea were directed by General Walter Krueger, commander of the US Sixth Army, operating as Alamo Force. The original plan envisaged taking the coast near Sarmi, the island of Wakde and Biak in several stages; on 10 May MacArthur’s headquarters simplified it. First, on 17 May, the 163rd Infantry Regiment of the 41st Division landed on the New Guinea coast opposite Wakde, and on 18 May on the island itself. The small island with its airfield was taken in a few days of hard fighting, and its strip was soon receiving American aircraft – it became a forward airfield to cover the next jump. On the mainland, however, on the Tor river and around Lone Tree Hill, fighting with the Japanese 36th Division went on for weeks. Ten days after Wakde, on 27 May, the rest of the 41st Division was to land on Biak, some 290 kilometres further north-west.

Allied intelligence misjudged the strength of the defenders. MacArthur’s staff believed there were about 4,400 Japanese on Biak, including most of the 222nd Infantry Regiment of the 36th Division, of whom at most 2,500 were combat troops. An intercepted signal at the end of April had, it is true, given a figure of about 10,800 men on ration strength, but this was taken to be a planned rather than an actual strength. In reality, according to the US official history, the garrison numbered about 11,400 men, of whom roughly 4,000 were front-line soldiers. The planners expected the island to be taken within a week.

Colonel Kuzume’s defence

The island was defended by the Biak Detachment under Colonel Naoyuki Kuzume, commander of the 222nd Infantry Regiment. The regiment had previously served in China and was one of the best units in western New Guinea. Kuzume had about 3,400 men of the regiment, a company of Type 95 Ha-Go light tanks from the 36th Division, field and anti-aircraft artillery, and numerous airfield construction units. Some 1,500 sailors under Rear Admiral Sadatoshi Senda, mostly from rear-echelon formations, also came under his operational command. Kuzume armed his service troops and labourers as far as his stocks allowed and used them as auxiliary infantry. There were also several hundred forced labourers on the island from Java and British India, brought in by the Japanese for construction work.

Kuzume did not try to defend the coast. He knew he could not hold a long shoreline, and he assumed the Americans’ objective would be the airfields. He therefore sited his strongest positions where he could deny their use for as long as possible: on the coral terraces and ridges rising above Mokmer. The key to the defence was the so-called West Caves – three large sumps in the coral bedrock, linked by underground passages, able to hold about a thousand men and surrounded by bunkers and firing positions. Two other centres of resistance were set up along the coastal road from Bosnek to the airfields: on the steep ridge between the villages of Ibdi and Parai (later called the “Ibdi Pocket” by the Americans) and in the East Caves above the village of Mokmer, from where observers could see the whole coast as far as the western end of the airfield. Historians often point to Biak as the first such clear case in which the Japanese defence deliberately gave up fighting on the beach in favour of a defence in depth, in caves and on the hills; the Japanese later used similar tactics on Peleliu, Iwo Jima and Okinawa.

This decision did not mean, however, that on 27 May the Japanese were waiting ready in their positions. In early May the headquarters of the Japanese Second Area Army had warned Kuzume that the Allies would strike at the Schouten Islands, and after the Wakde landing the colonel stopped work on the airfields and began feverishly fortifying the island. On 9 May Imperial General Headquarters moved the main line of defence in this direction further west, to the Sorong–Halmahera line; Biak and Manokwari thus became forward outposts to which no reinforcements were intended to be sent. According to the US official history, the Biak Detachment was not ready on the day of the landing: units were dispersed, some of the artillery was not yet in position, and troops were being held as a mobile reserve. The chief of staff of the Second Area Army, Lieutenant General Takazō Numata, happened to be on the island on an inspection. He stayed on Biak until 15 June and from the first day effectively took over the direction of the defence; according to the same history, many of the changes to Kuzume’s original plans were probably made on his orders.

Z Day: current, smoke and an empty shore

The Hurricane Task Force assembled in Humboldt Bay near Hollandia and, after brief rehearsals, sailed on the evening of 25 May. The landing force was carried by, among others, 5 fast transports, 8 large LST landing ships, 8 smaller LCTs and 15 LCI infantry landing craft; on board were also amphibious tractors and DUKW amphibians, needed to cross the coral reef fringing the shore. The naval forces were commanded by Rear Admiral William Fechteler. They were covered by two heavy cruisers, three light cruisers and 21 destroyers, including the Australian cruisers HMAS Australia and HMAS Shropshire. The convoy steamed at only 8.5 knots and made no attempt to zigzag; even so, it seems, Japanese aircraft did not detect it.

Before dawn on 27 May the ships ran into a strong westward current. The hydrographic charts had not allowed for it, and the convoy arrived off Bosnek a quarter of an hour early. At 6.29 a.m. Fechteler gave the order to begin the operation. The naval bombardment and air strikes went according to plan, and almost no one replied from the shore. But the current was carrying the transports further west, and smoke and dust from the bombardment obscured the coastline. The first waves of amphibious tractors with the 2nd Battalion, 186th Infantry Regiment reached the shore at 7.15 a.m. – on schedule, but in the wrong place: in a mangrove swamp almost three kilometres west of the designated beaches. For about half an hour the officers controlling the boats turned successive waves back east, towards the correct beaches and the two jetties at Bosnek. The jetties were secured only after 8 a.m.

The Japanese did not exploit the confusion. The commander of the 186th Regiment, Colonel Oliver Newman, seeing that most of his men had landed far to the west, proposed exchanging tasks with the 162nd Regiment, which was to advance on the airfields; Fuller refused and ordered him to keep to the plan. The US official history later regards this as a missed opportunity – the intermingling of units cost several hours. By noon the 186th Regiment had taken its designated beachhead around Bosnek and explored the jungle-covered ridge behind the village, which was full of small caves. Most proved empty. The Japanese platoon on the ridge above Bosnek mostly committed suicide, and American patrols dispersed the rest.

The 162nd Infantry Regiment began landing after 9 a.m. and at once set off west along the coastal road towards the airfields. Beyond the village of Ibdi the coral ridge came right down to the sea and dropped in a sheer cliff about 60 metres high; the road ran beneath it along a narrow strip of beach for almost two kilometres. This defile, later called the Parai Defile, did not appear on any map. A few Japanese riflemen in caves in the cliff halted the march there; M4 Sherman tanks of the 603rd Tank Company and rocket-firing LCIs shelled the positions, and at 3 p.m. the battalion passed through the defile and took Parai. In the evening two battalions dug in near Parai and further along the shore, about two kilometres from the village of Mokmer, beyond which the first airfield began.

Unloading was halted at 5.15 p.m., half an hour ahead of plan, for fear of air raids. By then about 12,000 troops had come ashore, along with 12 medium tanks, several dozen guns – 155 mm and 105 mm howitzers and 75 mm pack howitzers – about 500 vehicles and about 3,000 tons of supplies. Japanese aircraft appeared in the afternoon: four bombers with a fighter escort attacked the landing ships at the jetties and the beaches, but none of their bombs exploded. Anti-aircraft fire shot down all four bombers; one, as it fell, grazed an American submarine chaser, killing two sailors. According to the US official history the raid cost the Allies 3 killed and 14 wounded. The first Japanese counter-attack came on the night of 27/28 May: men of the 3rd Battalion, 222nd Regiment made a bayonet charge on American artillery batteries near Ibdi and fought until dawn before withdrawing.

The trap at Mokmer

The quiet first day bred complacency. On 28 May the 3rd Battalion, 162nd Regiment passed through the village of Mokmer and came out onto the plain in front of the airfield – straight into fire from the ridges and from the East Caves, which dominated the road. The Japanese cut off the battalion and attacked it from several sides. In the evening, when holding on any longer threatened to destroy the unit, the Americans withdrew along the shore under cover of tanks, and some of the men were taken off the beach by amphibious tractors.

On the morning of 29 May the Japanese attacked the 2nd Battalion, 162nd Regiment, about a kilometre east of Mokmer. The infantry was supported by Type 95 tanks – light, nine-ton vehicles with a 37 mm gun. Facing them were Shermans with 75 mm guns. A single armour-piercing round stopped each Japanese tank, and the infantry following them was broken up by machine-gun and mortar fire; a second wave of three tanks shared the fate of the first. The US official history calls this engagement the first tank battle of the war in the South West Pacific Area – so the phrase “the first tank battle in the Pacific”, found in some accounts, is a simplification. Despite this success, pressure from the Japanese, who were working round the battalion along the ridges, was so strong that the command withdrew the 162nd Regiment’s units from Mokmer – by land and by sea – all the way back to Ibdi, behind the Parai Defile.

Long weeks

The plan to take the island in a week fell apart in the first few days. Fuller asked for reinforcements and received the 163rd Infantry Regiment from Wakde, and then the 34th Regiment of the 24th Infantry Division. The 186th Regiment worked round the ridges across the plateau and on 7 June reached the sea at Mokmer airfield, but the strip lay under fire from the West and East Caves and the engineers could not repair it. The air forces did not wait: on 2 June the Americans occupied the nearby islet of Owi and built airfields on it, from which bombers and fighters were soon operating.

MacArthur’s headquarters, meanwhile, had already publicly announced victory on Biak, and the slow progress irritated both it and Krueger. On 14 June Krueger relieved Fuller of command of the task force and sent Lieutenant General Robert Eichelberger, commander of I Corps, to the island. Fuller, offended, asked to be relieved of command of his division as well, and his request was granted. Eichelberger changed the plan: instead of storming the airfields from the sea, he ordered that the hills from which they were being fired on be cleared first. The 186th Regiment attacked the West Caves from the north. On the night of 21/22 June Kuzume burned the colours of the 222nd Regiment and ordered his remaining men to break out of the caves; according to American accounts he committed seppuku, while according to Japanese ones he was killed or took his own life a few days later. The West Caves were taken on 27 June, and the Ibdi Pocket, the last major centre of resistance along the road from Bosnek, fell only on 22 July, after a heavy-bomber raid.

Biak also provoked an unexpected reaction from the Japanese fleet. The Imperial Navy concluded that Allied airfields on the island would threaten the “decisive battle” with the American fleet that it was preparing (Plan A-Go), and on 30 or 31 May the Combined Fleet ordered an infantry brigade to be shipped to Biak from the Philippines. This operation, named Kon, failed twice – on 3 June the force turned back because Japanese airmen wrongly reported Allied carriers off Biak, and on the night of 8/9 June Allied cruisers and destroyers drove off the Japanese destroyers carrying troops, which cast off the barges they were towing and fled north-west. For a third attempt even the super-battleships Yamato and Musashi were assigned, but it was called off when American carriers struck the Marianas on 11 June. The ships gathered for Biak joined the main force, which a few days later lost the Battle of the Philippine Sea.

Place in the war

Biak cost far more than had been expected. According to the US official history, whose author cautions that exact figures cannot be established, the Hurricane Task Force lost about 400 killed and 2,000 wounded between 27 May and 20 August, and more than 7,000 men were put out of action by sickness, above all fevers of undetermined origin and an epidemic of scrub typhus that broke out on Owi in July. According to the same source about 4,700 Japanese were killed and 220 taken prisoner; about 600 forced labourers from Java and British India were also freed. Other accounts give somewhat different figures, especially for Japanese losses, because some of the defenders died of hunger and wounds in the interior of the island.

Strategically Biak fulfilled its purpose, though late. According to the US official history, none of the island’s airfields was ready in time to support the landing in the Marianas in mid-June, as had been intended. They proved very valuable later, however: from there aircraft covered the landing on Noemfoor in July and MacArthur’s further jumps west, towards the Vogelkop Peninsula and Morotai, and in September the landing of Nimitz’s fleet in the Palau Islands. The Japanese attempt to save the island showed how closely the Imperial fleet was tied to the defence of western New Guinea – and how easily the American strike on Saipan took that choice away from it.

Biak also foreshadowed a way of fighting that the Americans would encounter many more times. Instead of defending the beaches, the Japanese let the enemy ashore and fought from caves and hills, out of reach of naval gunfire, forcing the infantry to take each position one by one. On Peleliu, Iwo Jima and Okinawa the same method proved even more costly. For MacArthur the island was one of the last stages of the advance along New Guinea, which in September 1944 brought his forces to Morotai and in October to the Philippines.