Bismarck Archipelago

The Bismarck Archipelago is located northeast of New Guinea and northwest of the Solomon Islands and shares the terrible jungle terrain of both. The total land area is about 19,000 square miles. There are superb anchorages at Seeadler Harbor and Rabaul, but only the latter had been developed to any extent by the end of 1941, with modest docking facilities and two airfields. There is also an anchorage at Kavieng, but it was overshadowed by Rabaul throughout the war.

Besides being jungle-clad, the islands are rugged, with several active or dormant volcanoes. The anchorage at Rabaul is a flooded caldera, and resurgent domes in the harbor area emitted quantities of steam and ash from time to time. Sulfurous fumes greatly reduced the habitability of the many underground fortifications build here by the Japanese during the war. There are no significant mineral resources on the islands.

New Britain is the largest island in the chain, with an area of 14,600 square miles.

Battle of the Bismarck Sea

The islands enclose a small body of water known as the Bismarck Sea.

Following the Japanese repulse at Wau in February 1943, the Japanese feared a counterattack against Lae, which had a garrison of just 3500 troops. General Imamura and Admiral Kusaka decided to move a force of 6900 soldiers from from Nakano's 51 Division from Rabaul to Lae to reinforce the garrison. The convoy would be timed to take advantage of bad weather for concealment, and a large number of fighters would be standing by to provide cover if necessary. The cargo was carefully distributed among the ships and combat-loaded for rapid unloading. All the transports carried numerous boats for unloading and the crews were under orders to ignore air raids while doing so. It was estimated that the troops could disembark in six hours and the supplied could be unloaded in 48 hours. Two earlier convoys had suffered an average 25% transport losses, but the Japanese were prepared to accept the loss of up to half the transports in this convoy.

By the end of February 1943, eight destroyers and eight transports were loaded and ready to go. In addition to 6912 toops, the ships were loaded with provisions and drums of aviation gasoline. Conditions were judged favorable on 28 February and the convoy set out, closely hugging the northern coast of New Britain and well concealed by poor weather. However, the Allies had anticipated such a move, and Allied code breakers were able to decrypt messages giving important details of the convoy operation. On the afternoon of 1 March the weather broke and the convoy was sighted by an Allied patrol aircraft. The convoy was picked up again the next morning, a force of 12 B-17 Flying Fortresses and 17 other bombers attacked at about 1015 from an altitude of 5000 feet. Kyokusei Maru was sunk and Teiyo Maru and Nojima were damaged in spite of the Japanese antiaircraft and fighter cover. Mikawa refused to call back the convoy, instead detaching Yukikaze and Asagumo to make a high speed run to Lae and deliver 950 survivors from the sunken transport.

The next day, just as the two destroyers were rejoining the convoy, Kenney threw in his Sunday punch. Although the convoy had cover from about 40 A6M Zeros, these were unable to cope with the 16 P-38 Lightnings, 13 Beaufighters, and masses of B-17s, A-20 Havocs, and B-25 Mitchells that came in at three different altitudes: the Lightnings at high altitude to engage the Zeros, the B-17s at medium altitude as they had the day before, and the other aircraft at very low altitude. For the first time, many of the low-level attackers were trained and equipped for skip bombing. Meanwhile, another 38 Allied fighters patrolled over Lae and prevented any Japanese fighters from joining the convoy from that airfield.

The Japanese ship captains ignored the Flying Fortresses and turned into the low-level attack, which they assumed was a torpedo attack. This left the ships highly vulnerable to being raked by the machine guns of the attacking aircraft, then skip bombed. The effect was devastating: 28 of the 37 500-pound bombs dropped by the first wave scored hits, and by the end of the day, all eight transports were sunk or crippled, along with four of the destroyers. Allied losses were just three Lightnings and two bombers out of 335 aircraft participating in the battle. The Japanese lost 25 aircraft.

That night, PT boats finished off the crippled Oigawa Maru. The next morning, another air strike finished off two crippled destroyers.

The Allies reasoned that the survivors could not be permitted to make it to shore to join the Lae garrison; and, since Japanese soldiers did not surrender, they would have to be killed. What followed was a sickening slaughter of survivors in the water or on boats by aircraft and PT boats. However, some 2734 men were rescued by Japanese destroyers and submarines, and a few hundred others escaped the slaughter to reach shore. One boatload of survivors drifted as far as Guadalcanal, where they were killed by an American patrol.

At least 3500 soldiers from Nakano's 51 Division were lost in the battle. The Japanese decided to risk no more convoys, and turned to barges and submarines to reinforce their garrisons in northeast New Guinea.

Japanese order of battle

Allied order of battle

References

Morison (1950)

Spector (1985)

The Pacific War Online Encyclopedia (c) 2007-2008 by Kent G. Budge. Index

Comment on this article