When the Japanese forces attacked Pearl Harbor on December 7, 1941, it was only the beginning of a series of Japanese victories. They also continued to win the Battle of Wake Island against the US, the Attack on the Prince of Wales, the Repulse against the British Royal Navy, and The Battle of Sunda Strait against the Allied forces.

But, it was not until the Battle of the Coral Sea and Battle of Midway that the seemingly unstoppable Imperial Japanese Navy (IJN) was finally slowed down. So how did they

Japanese Plan

In late 1942, a series of victories from the Allied forces weakened Japan so that they could lose control of the South West Pacific, specifically on the island of New Guinea.

Japanese forces on the island desperately needed supplies and reinforcements; otherwise, it would be a sure victory for the western forces. So, they decided to send around 7,000 soldiers as reinforcements and a considerable amount of supplies from Rabaul to Lae through a convoy. This was a dangerous plan since the Allied air forces were expected to obliterate the convoy once they were found. Regardless, it was a risk that they had to and were willing to take.

Unknown to the Japanese, their radio communications about the planned convoy had been intercepted and deciphered by codebreakers, and they were well aware of its arrival date and destination. Consequently, the Royal Australian Air Force (RAAF) and the United States Air Force (f0rmerly called Army Air Corps) prepared to prevent the Japanese convoy from reaching Lake.

The joint air forces figured out the convoy’s location through reconnaissance aircraft. They launched a series of land-based heavy, medium, and light bombers and torpedo boats, all of which would attempt to stop and obliterate the convoy.

The commanders conducted a series of mock-up battles so inexperienced pilots could practice the attack. They knew that their complex plan with coordinated attacks had exact timing for it to work, and they could not afford to make mistakes.

Meanwhile, the Japanese convoy consisted of eight destroyers and troop transports, escorted by 100 fighter aircraft overhead. They left Rabaul on February 28, 1943, and were expected to reach Lake on March 3.

Unleashing the Havoc

The weather was poor that day, allowing the convoy to hide from the observing eyes of the Allied reconnaissance aircraft. On March 2, however, the skies became apparent, and a USAAF Liberator spotted the convoy. This prompted General Whitehead, US battle commander, to launch eight B-17s and twenty more. In addition, another eleven of these Flying Fortresses were launched, causing damage to the enemy convoy.

By the end of March 2, the Japanese group approached the waters within the range of all Allied planes, where all havoc was waiting for them. A RAAF Catalina followed the convoy throughout the night, reporting its location to ensure that the Allied attack began as soon as possible the next day.

March 3 came, and the clear skies helped the aerial attack. The morning began with attacking the fighter bases at Lae to limit Japanese defenses, all while 90 aircraft took off to strike at the convoy. They were relentlessly attacked by the day by RAAF and USAAF B-17 Flying Fortresses, P-38 Lightning, B-25 Mitchells, Beaufighters, and A-20 Bostons.

Japanese transport was under aerial attack in the Bismarck Sea on March 3, 1943. (Unknown author, Public domain, via Wikimedia Commons)

As the aircraft approached, skimming the surface, the convoy mistook the Beaufighters for Beauforts carrying torpedoes. So it turned towards them to deny them the broadside profile needed for a torpedo attack, but these were Beaufighters armed not with torpedoes but with guns and cannons.

The Beaufighter was a heavy fighter made to shoot down bombers and carried four 20mm cannons in the nose and six .30 cal machine guns in the wings. The 13 Beaufighers now had a perfect setup for a nose-on strafing run on the destroyers escorting the convoy. The result was carnage as the 20mm cannons raked the destroyers from bow to stern, chewing up Japanese sailors in open pit anti-aircraft mounts. The destroyers also had no actual armor plate, so the cannon and machine gun fire ripped through several decks killing the crews: with shots and metal splinters. In a matter of minutes, all the Japanese destroyers were smoking wrecks with their anti-aircraft guns silenced.

Then B-25s and A-20s came in at low altitudes as well. They had developed and practiced a skip bombing technique where they would release their bombs at less than 100 feet close to the target and watch them skip and hop over the wave to strike the sides of the ships. Failing in that, the bombs might sink and explode beneath the vessel, caving in their sides. 17 of 28 bombs hit their targets; the cargo ships packed to the decks with 7,000 Japanese troops.

The B-17s were at the medium bombing altitude, while the P-38 Lightnings flew above, taking down the escort fighter planes.

Wave after wave came in using this profile, B-17s bombing from 8,000 feet and low-level strafing and skip bombing attacks by medium bombers.

By the morning of March 4, only four mangled destroyers remained running for their lives, stuffed with some 2,000 survivors they had rescued from the transports.

Costly Defeat

Flight lieutenant 260353 R. F. (Torchy) Uren, No. 30 Squadron RAAF, in the cockpit of his Beaufighter aircraft, takes a drink from a water bottle after leaving the target area during the Bismarck Sea battle. (Dami n Parer, Public domain, via Wikimedia Commons)

Still in the water were some 1,000 Japanese soldiers and sailors bobbing on the surface. Worried that the remaining survivors would be rescued or make it to shore in New Guinea, the allies sent PT Boats and medium bombers to survey the ocean with orders to shoot survivors in the water in rafts or clinging to wreckage. These orders did not sit well with the crews, but they understood why. They were stopping the Japanese army’s invasion of New Guinea, and if 1,000 Japanese troops made it ashore, they represented a fighting force that Japan could recover, rearm and send back into the fight.

In the interior of New Guinea were tribes of headhunters who were also cannibals. The Australians had administrative control over the island before the war. They had managed to get the tribes not to kill and eat any Europeans that might fall into their hands, and Christian missionaries were among the tribes trying to convert them. Now the Australians went to the tribes again with photos of Japanese soldiers and told them it was permitted to hunt, kill and eat them if they found them. It is not known how many of the survivors made it ashore. Still, decades later, a photographic expedition made contact with one of the tribes and found several of them wearing bits and pieces of tattered Japanese army uniforms.

The Battle of the Bismarck Sea cost the Japanese forces twenty fighters, eight transports, four destroyers, and about 3,000 men. On the other hand, the Allies lost but two bombers, four fighters, and 13 soldiers.

Following this disastrous defeat, the Japanese military sent a memo ordering various army units to teach their soldiers how to swim.