Battle of Milne Bay 1942

Importance of Milne Bay

In June 1942, the Allies decided to build an air base at Milne Bay, on the south-eastern tip of Papua.

The Japanese had occupied Rabaul on nearby New Britain since January 1942. They then occupied the northern coast of New Guinea in March. After defeating the Japanese in the Battle of the Coral Sea in May 1942, the Allies were expecting another assault on Port Moresby.

General Douglas MacArthur, Allied Commander-in-Chief of the South-West Pacific Area, had ordered new airstrips. These would be operational bases for aircraft patrols and bombing raids. Merauke in Dutch New Guinea and Milne Bay were chosen as strategic sites.

Milne Bay was also valuable to the Japanese. Control of Milne Bay would give them a significant base close to Port Moresby for future attacks. It would also mean that the Allies could not use it.

Milne Bay map

Building the air base

Allied troops arrived at Milne Bay on 25 June 1942 to begin construction.

Australian forces were:

• two-and-a-half companies from the 55th Infantry Battalion
• the 9th Battery of the 2/3rd Light Anti-Aircraft Regiment.

The United States (US) forces were:

• an anti-aircraft platoon from the 101st Coast Artillery Battalion
• 2 guns from the 23rd Heavy Anti-Aircraft Battery,
• engineers from the 46th and 96th engineer battalions.

The US Army engineers were responsible for constructing airstrips and wharves. Other troops had to build:

• taxi strips
• aircraft dispersal areas
• wharves
• accommodation.

The Australians were responsible for the construction of accommodation, roads and bridges. The first Australian engineer unit, the 24th Field Company, didn't arrive at Milne Bay until July 1942.

The shortage of engineers meant many other troops, including infantry, had to be used in construction roles.

The few existing bridges had to be rebuilt to take the weight of military traffic. The roads were dirt tracks that needed improving. During the heavy rains of the wet season, roads quickly became deep, almost impassable mud channels.

Troops and local labourers began clearing land for the 3 airstrips and the military base. Land for the airstrips was cleared by hand, removing coconut plantations and dense jungle.

A veteran recalled that, with no machetes, they had to use bayonets to cut the tall kunai grass (cogon grass). Around 5,000 coconut palms had to be removed for the site of the second airstrip (Strip 2). Papuans worked as labourers during construction.

Australian reinforcements

By the end of August 1942, nearly 9,000 Allied personnel were based at Milne Bay.

There were around 7,500 Australians, including about 4,500 men from the 7th Infantry Brigade and the 18th Infantry Brigade.

The 7th Brigade were largely inexperienced Militia (reserve) units. About half the men of the 18th were veterans of the Siege of Tobruk, and the other half were reinforcements.

The 9th Battery gunners of the 2/3rd Light Anti-Aircraft Regiment were joined by the 4th Battery of the 101st Anti-Tank Regiment and 6th Battery of the 2/2nd Heavy Anti-Aircraft Regiment.

Around 600 servicemen from No 75 Squadron RAAF and No 76 Squadron RAAF were also stationed at Milne Bay.

Major General Cyril Clowes was commander of the Australian forces at Milne Bay, soon known as 'Milne Force'. From 12 August, Milne Force became part of New Guinea Force, under the overall command of Lieutenant General Sydney Rowell.

Soldiers from the Militia units knew an attack would come. They were buoyed by the arrival of the experienced 18th Brigade soldiers. Private James 'Jim' Watt of the 61st Battalion recalled:

We thought they were saviours … We felt that these fellows from the Middle East, they must be great fighters, and they were good fighters too as it turned out … We were very thrilled, “Gee whiz, the 18th Brigade has come along.” … They looked as though they could have knocked over the Japanese quite easily without our help.

[Interview with James 'Jim' Watt, 2003, Australians at War Film Archive.]

Conditions for soldiers

Milne Bay was shaped like a semi-ellipse … Heavily wooded mountains pressed in from three sides, leaving only a narrow coastal strip, soggy with sago and mangrove swamps; bush-covered except where a few coconut plantations stood in orderly rows. On the north shore the mountains came down almost to the sea leaving only a ledge which was rarely more than a mile wide and in places narrowed to a few hundred yards … On the southern shore the mountains rose steeply and again there was a narrow strip of flat land edging the sea, with mangrove swamps and native coconut plantations … The place was notorious for torrential rains during the months just beginning and was a malarial pest-hole.

[McCarthy, Dudley (1959), Second World War Official History.]

The Milne Bay area receives an average of 5,000 mm (200 inches) of rainfall per year. With rain, the coastal plains of Milne Bay turned to mud. The men slept in rain-soaked tents on muddy ground. The few roads became impassable to vehicles.

Malaria was endemic in Milne Bay. Disease was one of the most serious threats to the capability of Allied forces in New Guinea and Papua.

Precautions to prevent malaria were inadequate at first. Australian troops wore shorts and short-sleeved shirts, which did not prevent mosquito bites. Many had come ashore without mosquito nets for sleeping. And the anti-malarial drug, quinine, was in short supply. Some troops were advised only to begin quinine a week after landing, but by then they were infected.

Guarding against malaria became a much higher priority later. A daily dose of atabrine (anti-malarial medication) was made compulsory for Australian troops.

Those stationed at Milne Bay felt that 'even Hell would be preferable' because at least there they would be dry. Sergeant Harold 'Lofty' McCosker described the conditions:

It was wet when we got there. It rained almost continuously during the whole of that operation. You never went anywhere where you were walking in mud that wasn’t over the top of your boots and very frequently up to your knees.

[Interview with Harold 'Lofty' McCosker, 2003, Australians at War Film Archive.]

For pilots, the muddy conditions were difficult and dangerous. The interlocking steel matting (Marston mat) of the airstrip sank into the mud when wet. Mud would kick up onto the plane's flaps, and the force would break them. Aircraft had to land with flaps up, making it harder to slow down.

Pilot Officer Bruce 'Buster' Brown of No 75 Squadron RAAF said that it was 'probably the worst airstrip I've ever operated off in my life and ever likely to.' He recalled the danger of landing:

Col Lindeman, a pilot in 76 Squadron, was taking off one day and just like a car slipping on a slippery road, he started to slide and, of course, you have no control whatsoever, and unfortunately he went right through a Hudson that was parked on the side being worked on because it was unserviceable and unfortunately there were two deaths of ground crew who were working on that Hudson.

[Bruce Edward 'Buster' Brown, 75 Squadron RAAF, 1989 interview.]

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Preparing for attack

With the Japanese relatively close at Rabaul, the Allies knew that their presence at Milne Bay would be discovered. They expected an attack at any time.

The Milne Bay area was first observed by the Japanese on 11 July 1942. The Japanese discovered the Allied air base at Milne Bay on 4 August 1942 and made their first air raid on it that day.

The Japanese planned a larger attack to seize Milne Bay. But after the Allied landings on Guadalcanal Island on 7 August 1942, they postponed their attack.

When the Japanese made a second air raid on Milne Bay on 11 August, RAAF aircraft and anti-aircraft guns engaged enemy aircraft.

On 22 August, the recently arrived Major General Clowes assumed command.

The next day, 23 August, Clowes dispersed his forces around Milne Bay, anticipating the enemy's most likely landing points. Without naval support, coastal guns or searchlights, Clowes could only respond to a landing when it happened.

On 23 August, one of the coastwatchers reported landing barges heading towards Milne Bay. On 25 August, another coastwatcher reported landing barges on the south-west of the island.

Bad weather had prevented Allied aircraft from attacking the Japanese as they landed. On 26 August Nos 75 and 76 Squadrons Kittyhawks destroyed many of the barges.

Lieutenant Chikanori Moji, 5th Kure Special Naval Landing Force, described the Japanese base after the RAAF raids:

In the darkness it presented a spectacle of ruin.

[Moji, quoted in Baker and Knight, Milne Bay 1942, p 190.]

Aircraft reconnaissance that day reported a Japanese force of cruisers and transports approaching Milne Bay. Clowes prepared to defend the air base at Milne Bay.

Fighting around the mission

Just before midnight on 26 August 1942, around 2,000 Japanese marines landed at Milne Bay. They believed that only a few infantry companies protected the area. This was a serious intelligence failure on the part of the Japanese.

Japanese forces landed about 11 km east of the Allied airfields. With daylight, the RAAF Kittyhawks had attacked their landing forces, barges and supplies, and destroyed radio equipment. Without barges, Japanese troops had to move overland.

The first enemy engagement was with the 61st Battalion around KB Mission. KB Mission, between Rabi and Ahioma, was a religious missionary centre. The missionaries helped the Allied troops during the war.

Fighting continued overnight and into the next day. The combined 61st and 25th battalions pushed into Japanese positions in the evening of 27 August. But with exhausted troops and strong Japanese resistance, the Australian forces withdrew.

On 28 August, the 2/10th Battalion moved up towards KB Mission. Fierce fighting, helped by the 2 small tanks the Japanese had brought ashore, pushed Allied troops towards Gili Gili and the airstrips.

By 29 August, Japanese troops reached the edge of No 3 Strip. Troops of the 25th and 61st, with support from the the 9th Battery of the 2/5th Field Regiment and the US 709th Anti-Aircraft Battery, turned back a Japanese attack on the airstrip.

Patrols, skirmishes and air attacks continued through 29 and 30 August. Australian patrols found the Japanese tanks bogged and abandoned. They also found evidence of war atrocities against Australian servicemen and Papuans.

Milne Force decisions

Several factors made it difficult for Clowes to command Milne Force.

He had only one hand-drawn map to make decisions, and it was inaccurate.

He did not know how many Japanese had landed – first overestimates were 5,000 – or whether more would land later. This made it difficult to know when to deploy his reserve troops.

Communication with troops in the field was very difficult. And moving troops in muddy conditions was slow and drained their energy.

The Japanese also had a significant advantage over the Allies. They controlled the harbour at night, allowing them to move their supplies and troops more easily.

Adding to his woes, General MacArthur's headquarters was pressuring Clowes to provide detailed daily updates. This was necessary because, at the same time, the Allies were fighting the Japanese in Buna, Gona and Isurava on the Kokoda Track.

Defending No 3 Strip

Japanese troops suffered heavy casualties from air attacks and ground fighting. They were bombed and attacked with machine-gun fire by the Kittyhawks of No 75 and No 76 Squadrons RAAF.

The Japanese had attacked the airstrip and been repulsed. Now the 61st and 25th battalions, and the 2nd Battalion of the 46th Engineer Regiment were in defence. They were armed with artillery, mortars and machine guns.

Bren gunner, Private John Duncan of the 61st Battalion, remembered:

When they built the number three airstrip, the American CeeBees [Construction Battalions] built it, they pushed all the coconut trees and everything to our side so there was about an 8-foot wall of coconut trees and dirt, which we were behind. The poor old Japs had to cross on cleared ground, and it was the 3-Inch Mortar Platoon who had cases and cases of ammunition.

[Interview with John Duncan, 2003, Australians at War Film Archive.]

The attack came at 3 am on 31 August. Three waves of Japanese troops launched themselves across the open ground of the airstrip towards the defenders.

Coming under very heavy machine-gun, artillery and mortar fire, Japanese losses were high. The Japanese tried moving around the end of the airstrip. But they were met with heavy fire from the 61st Battalion.

Around dawn, the Japanese withdrew.

Sergeant Harold 'Lofty' McCosker described the attack:

At about 3 am … there was a gong sounded on the eastern side of No 3 Strip, and our people sent up flares … there was a great group of Japanese. The battalions defending … had sighted in weapons, Vickers machine guns and Bren guns … for across lines of fire. The artillery had registered in on that position, and the mortars of 2 battalions had done the same. As soon as the flares went up and the Japs were seen, all hell broke loose. All the automatic weapons opened up. The mortars opened up, and the artillery did the same … They basically walked into a solid wall of flying metal. They stopped. They went back. They re-formed. They attacked a second time. They attacked a third time, and exactly the same thing occurred. They just walked into a wall of death, and they were slaughtered.

[Interview with Harold 'Lofty' McCosker, 2003, Australians at War Film Archive.]

Allied counterattack

Around 9 am on 31 August, Clowes launched a counterattack.

Clowes sent the 2/12th Battalion to the KB Mission after the retreating Japanese forces. The men of the 9th Battalion were positioned around the airstrip and the mission.

That evening, around 300 Japanese encountered the 9th and 2/12th battalions. After fierce fighting and many losses, the Japanese fell back.

The next day, the 2/12th pushed further down the coast with air support from the RAAF Kittyhawks. The Japanese had abandoned their mission and were holding on for evacuation.

The 2/9th Battalion landed at KB Mission to relieve the 2/12th Battalion and push toward Goroni. On 3 September, the men encountered strong Japanese resistance at Elevada Creek. The Japanese used the difficult terrain to their advantage, with the Australians losing 34 men.

It was in fighting on 4 September that Lance Corporal John French earned his Victoria Cross.

A forward company of the 2/9th Battalion had struck a strong Japanese defensive post. They attacked but were held back by 3 machine-gun positions. French attacked and destroyed 2 guns with grenades and then attacked the last with his Thompson machine gun. French was killed, but his courageous actions enabled the attack to succeed.

By the end of 4 September, the Japanese forces had only 50 fully fit soldiers, and most commanders had been killed.

The Japanese evacuated the last of their survivors on the night of 6 September 1942. It had been 12 days since they landed. This came after fierce fighting and determined Allied defence.

Losses at Milne Bay

Australian forces at Milne Bay sustained 377 battle casualties, including 172 killed or missing in action. Several captured men had been killed by the Japanese with bayonets.

The Japanese death toll was at least 700, and around 1,300 were evacuated.

Japanese forces killed many Papuans during the fighting. Some were tortured for refusing to help the Japanese.

The Allied supply ship SS Anshun was sunk in Milne Bay on 6 September. The attack took place on the same night as the Japanese evacuation. It was sunk by the Imperial Japanese Navy ships Tenryu and Arashi.

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After the battle

Milne Bay was the Japanese forces' first land defeat since they joined the war. It showed that the Japanese could be beaten, which boosted the troops' morale.

At the same time as Milne Bay, the Japanese were also fighting in Guadalcanal and New Guinea.

The Allies developed Milne Bay as a major operational base. They used it to support the counteroffensive in Papua and New Guinea.

Milne Bay was part of an Allied supply route that ran to Oro Bay, south of Buna, using Australian and US vessels.

In late 1942, the Allies used this route to move artillery and tanks in Operation Lilliput. From December 1942, Operation Lilliput moved more than 60,000 tons of supplies and 3,802 troops from Milne Bay to Oro Bay. This contributed to victory at the Battle of Buna-Gona.

Alleged war crimes

Australian troops found evidence that Japanese forces had committed war crimes against soldiers and civilians. None of the 36 Australians taken prisoner survived, and at least 59 civilians were killed.

Evidence was submitted to the Tokyo War Crimes Tribunal in 1947, but no Japanese personnel were prosecuted.