New Britain

Besides being jungle-clad, the island is 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.

Rabaul was seized by the Japanese on 23 January 1942 and rapidly developed into a major base. By 1943 the garrison numbered 80,000 to 90,000 men, mostly deployed around the Gazelle Peninsula, with about 7500 troops defending the 3900 foot (1200 m) airstrip on Cape Gloucester on the western end of the island.

The New Britain Campaign

MacArthur had called for an offensive against Rabaul almost from the time he arrived in Australia. However, Allied planners chose instead to first encircle the base from east and west. As the war progressed, and it became clear how formidable a fortress the Japanese had made of Rabaul, the Allies contented themselves with smashing the base from the air, then bypassing it by seizing control of the Vitiaz and Dampier Straits between Cape Gloucester and the Huon Peninsula of New Guinea. By December 1943 the Allied airfields in the Markham and Ramu Valleys, west of Lae on New Guinea, were fully operational and 5 Air Force was able to guarantee air superiority over western New Britain.

Arawe. As part of the encirclement strategy, landings were made along the western half of New Britain, beginning with 112 Cavalry Regiment at Arawe on 15 December 1943. Arawe was located on the south coast of New Britain about 60 miles (100 km) from Cape Gloucester. It boasted a small anchorage, suitable only for shallow-draft vessels; a plantation; and an unused airstrip. The anchorage was the main objective, since MacArthur claimed it would be useful as a base for PT boats (in spite of objections from the PT commander), but the real purpose of the landings at Arawe was to provide a diversion.

Arawe had been serviced the day before the landings by 5 Air Force, which dropped 433 tons of bombs on the area. The troopers had had no prior training in amphibious assault and had just ten days to rehearse at Goodenough Island. The landing force consisted of LSD Carter Hall, APDs Humphreys and Sands, and Australian LSI Westralia escorted by destroyers and given air cover by Navy Black Cats. Landings commenced at 0330 and Pilelo Island, covering the main channel into the anchorage, was seized almost at once. However, a second landing group found itself at the head of a cove covered by cliffs where the Japanese had sited several machine guns. The navy commander had declined to bombard the area, in hopes of achieving surprise, but the Japanese had detected the activities of American amphibious scouts in the area and were fully alerted. Twelve of the fifteen landing boats were destroyed but most of the men were able to swim back to sea to be picked up by SC-699. The main landing force was equipped with LVTs and was supported by a raid by B-25s from Dobodura. The troops were ashore by 0723 and quickly secured the beachhead. A strike by 8 Vals and 56 Zeros from Rabaul broke through the 16 defending P-38s but inflicted no damage.

By nightfall over 1900 troops were ashore, but the supply echelons arriving in the following days came under heavy air attack. 5 Air Force was occupied elsewhere and the warships were forced to rely on their own antiaircraft for protection. A coastal transport was sunk and seven other ships were damaged, but this did not prevent the supply ships from landing 6287 tons of supplies and 451 guns and vehicles in the next three weeks. By contrast, just 35 troops were killed ashore. A weak counterattack by Japanese support troops on 25 December was easly repelled.

Cape Gloucester. The landings at Cape Gloucester were carried out by 1 Marine Division (Rupertus) on 26 December 1943. Here the terrible terrain proved more of an enemy than the Japanese The airfield was overlooked by jungle-covered mountains and most of the shore was mangrove swamp. Aerial reconnaissance had carefully mapped the offshore reefs but failed to detect the swamp. Three separate reconnaissances by Alamo Scouts identified two small landing beaches about five miles (8 km) from the airfield that were weakly defended and could be approached through gaps in the reefs.

Allied order of battle, 26 December 1943

Japanese order of battle

Air support was provided by AIRSOLS strikes against Rabaul, a carrier strike against Kavieng, and 5 Air Force strikes against Cape Gloucester itself. The Japanese nonetheless got enough scout planes into the air to detect the convoy, but Kusaka guessed it was headed towards the beachhead at Arawe, and most of the Japanese air power was directed there: The diversion worked.

The preliminary bombardment began at 0600, and white phosphorus bombs were used for the first time. The first wave was ashore by 0805 and immediately began moving through the jungle. By the end of the day, some 13,000 troops and 7600 tons of supplies were ashore. The Japanese responded with a strike at 1430 by 20 Vals and 50 to 60 fighters. These were detected 60 miles (100 km) out by destroyer radar, but the four squadrons of P-38s providing air cover missed the interception. The Japanese sank destroyer Brownson with heavy loss of life and badly damaged Shaw with near misses that sprayed the hull with shrapnel. Subsequent attacks did little damage and heavy weather from 29 December onward put a halt to enemy air activity.

The same weather meant wretched conditions for the ground troops. However, the discovery of a small beach further west that was suitable for landing supplies relieved some of the logistical pressure. Marine engineers and 19 Construction Battalion were able to construct roads and bridges to support the advance. This was fortunate as the monsoon set in on 28 December, with rain as heavy as 16 inches per day, which made the existing coastal road impassable. The Marines slogged ahead and the airfield was captured on 30 December after a sharp fight. A more difficult objective was the hills overlooking the anchorage at Borgen Bay. It took the Marines two weeks just to move into position through the jungle, and on 13 January 1944 the Marines commenced their attack on Hill 660. Tanks were unable to move up to support, but the Marines crawled up a near-vertical slope to surprise the Japanese and clear the hills on 14 January 1944. Thereafter, Japanese counterattacks against the beachhead were sporadic and ineffective. Some 3100 Japanese were killed at a cost to the Marines of 248 killed and 772 wounded. Some 25 deaths were due to falling trees in the swamps, whose roots were loosened by the heavy rain and the artillery barrage.

The terrible weather conditions proved more memorable for many Marines than the Japanese resistance. Hot food was impossible to prepare in the downpour, and Marines hoarded the waxed paper and cardboard from K ration containers as a source of fuel for heating coffee. Anything made of leather quickly developed a layer of blue mold that had to be scraped off every day. It was impossible for the Marines to keep their feet dry, and trench foot became a serious problem.

Allied units would continue to probe up the island as the Japanese withdrew into their fortress for the remainder of the war.

MacArthur believed the Cape Gloucester landings were necessary to secure Dampier Strait between New Britain and New Guinea and helped close the noose on Rabaul. However, Morison has argued that the landings were unnecessary, since the Japanese force at Cape Gloucester had no artillery with which to close Dampier Strait, and Vitiaz Strait between Finschhafen and Rooke Island was a better channel for shipping in any case. However, this was not obvious at the time.

References

Morison (1950)

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

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