by Mark Lardas
As the Japanese air garrison grew weaker, Allied air strikes became bolder. Believing that Lakunai, Vunakanau, and Tobera were on the ropes, Comairsols turned attention onto Rapopo airfield and the warehouses around it, and on the remaining shipping in the harbor. Rapopo field was hit on February 14, 21, and 24. At the end of the third raid its runways were cratered and buildings were ruined. Large strikes hit the remaining shipping in the harbor on February 17 and 22. Six ships were sunk, most in Keravia Bay. The tonnage was half of what it had been in the January 17 attack. The ships still at Rabaul were smaller. On February 19 a massive airstrike was made on Rabaul city.
The Japanese kept challenging the Allied air raids, and kept losing aircraft. Even as late as February 19 35–50 Zeroes were scrambled to intercept that day’s raid. It was the last serious attempt to meet the Allies in the air. Imperial command decided to pull the plug two days later. A partial evacuation had started in January evacuating non-essential personnel, such as the “comfort girls.” On February 21 critical personnel including 350 ground personnel for the rikko units were shipped out. Most never reached Truk. The homebound ships were sunk by submarines and aircraft. No more freighters were sent to Rabaul.
Between February 19 and 23 all airworthy aircraft departed for Truk. In October, when the Allied air offensive started, there were 300 aircraft at Rabaul. Only 24 G4Ms, 40 A6Ms, 21 D3As, 4 D4Y1s, and 11 B5Ns flew home in February. Rabaul was on its own.
Oblivion: February 28–March 28, 1944
Following the departure of the Japanese air fleet from Rabaul the garrison was effectively isolated. Sea traffic, except for barges, ceased. The Allies had total control of the air and water in the seas around New Britain and New Ireland. If Comairsols aircraft failed to sink ships heading into or out of Rabaul, US submarines or even US Navy surface warships would.
The only way into and out of Rabaul was by air. Even that connection was tenuous. Allied airfields were beginning to ring Rabaul. If Rabaul were viewed as the center of a clock face, by late February the Allies had airfields from 3 o’clock (Nissan on the Green Islands) to 8 o’clock (Cape Gloucester). Japanese aircraft could still escape Allied fighters once away from the immediate vicinity of Rabaul by flying due north from Rabaul for an hour or so. Flying a straight-line path risked interception from the Green Islands. Once clear of the range of Allied fighters, aircraft could reach the dubious safety of Truk.
Flying into Rabaul was a different story. Multiple daily raids meant incoming Japanese aircraft were likely to arrive in the middle of a fighter sweep. Despite the risk, General Hideki Tojo, Japan’s Prime Minister, made his first (and only) visit to Rabaul in late February. He was accompanied by the Minister of the Navy, Admiral Yaichiro Shibata, and the Chief of the Imperial Japanese Navy General Staff, Osami Nagano. The three held meetings with Imamura and Kusaka to plan the future defense of Rabaul. There really was nothing the trio could tell Rabaul’s commanders, other than hold to the last, something Imamura and Kusaka intended even before the visit.
There were still a handful of Japanese aircraft at Rabaul, but far fewer than the Allies realized. Aerial reconnaissance photos taken on February 25 showed 33 aircraft. Most of these were unflyable wrecks. There were around ten flyable Zeroes still in the Gazelle Peninsula and a few bombers. All had been patched together from bits and pieces of other damaged aircraft. These were concealed in caves, and would take to the air singly, just to prove the Japanese were still there and still fighting. These efforts were meaningless pinpricks when related against the hundreds of Allied combat aircraft flying over Rabaul daily.
The Allies were throwing more aircraft into the fight each week, too. The Marines, always eager for a bigger role, discovered unused B-25s in the rear echelons. The USAAF was short of pilots and aircrew. Earlier, the Marines had created fighter squadrons to use Corsairs surplus to Navy needs. Now the Marines organized new Marine squadrons for the surplus Mitchells, providing pilots and crews for these PBJs – as the Marine Corps and Navy designated the B-25.
Rabaul was further isolated on February 29, 1944 when Allied forces landed on the Admiralty Islands. Airfields on Los Negros cut off Rabaul, and supported further Allied offensives. By August 1945 the Los Negros airfields had grown into a major complex. (USNHHC)
The attack on Rabaul was carried out systematically, with separate sections of the town targeted on each mission. The offensive started by attacking the waterfront areas, blazing after an attack by B-25s. (AC)
The ring around Rabaul closed a little tighter on February 29. On that day Allied forces landed on Los Negros Island in the Admiralties, a group of islands on the northwestern fringe of the Bismarck Sea. The first target was Momote aerodrome, a field painstakingly built by the occupying Japanese following their occupation of the Admiralties in 1942. It was captured on the day of landing. While the invasion of the Admiralties created another brick in the wall being built around Rabaul, isolating Rabaul was not the main reason for the invasion.
Seealder Harbor was the attraction. Although Rabaul was to be bypassed, the Allies still needed a naval base north of New Britain to support future operations against Japan. Seealder Harbor, 15 miles long and 4 miles wide, was not as good as Simpson Harbor, but it was good enough. The Japanese had 100,000 soldiers guarding Rabaul; their garrison at the Admiralties totaled around 3,000. The Allies soon had control of Los Negros and the eastern part of neighboring Manus Island. They also had control of the land around Seealder Harbor and held the two Japanese-built airfields. Momote airfield eventually became a major Allied airfield.
Meanwhile the Allied air campaign against Rabaul continued unabated and gained momentum. It took a week for the Allies to realize Japanese aircraft were no longer challenging air raids. When they did, the Allies’ emphasis shifted away from attacking the Gazelle Peninsula’s airfields. The new priorities were the stores held in Rabaul, barges and other remaining craft in Rabaul’s waters, and, finally, goods stockpiled in warehouses scattered throughout the Gazelle Peninsula.
The absence of Japanese air resistance left the Allies with a surplus of fighters. The solution was to use aircraft less capable of air-to-air combat as fighter-bombers. This had started earlier with P-39s, although they were used primarily as strafers. Starting on February 23, P-38s and P-40s added bomb racks and began carrying one 1,000lb or two 500lb bombs on each mission.
Mitchell and his staff divided Rabaul into 14 sectors, and broke each sector into two or three parts. A systematic bombing campaign was planned where each part would be attacked in turn until destroyed. Once this was done, the raids would concentrate on the next sector until Rabaul was completely flattened.
The campaign started March 1. Wave after wave of bombers would hit a designated part of Rabaul each day. B-24s would bomb at high altitude. Army B-25s and Marine PBJs conducted medium-altitude level bombing. SBDs attacked antiaircraft positions to suppress the only resistance the Japanese could still make. In assembly-line fashion Comairsols burned out Rabaul. An average of 85 tons of bombs was dropped on Rabaul each day. By March 10, only 12 days after the start of the campaign, 60 percent of Rabaul had been flattened. A week later, two-thirds of the town was gone. By April 20, only 122 buildings were still standing.
Nor was the harbor neglected. By March 1, the only ships still in Simpson Harbor or Blanche Bay were the ones sunk earlier. No new shipping visited. There were still plenty of barges scattered about the two bodies of water – over 500. These were used to carry supplies to minor Japanese garrisons elsewhere in New Britain and the Solomons, or to ferry material from New Ireland to New Britain. Comairsols turned its attention to these, sinking over 200 barges in February and March. By then the survivors were either scattered elsewhere or hidden in caves, coming out only at night.
Even before the bombing of Rabaul proper ceased, supply dumps, warehouses, repair shops, communications facilities, power plants, and sawmills in the rest of the Gazelle Peninsula were targeted. As late as January 1944, most of Rabaul’s
supplies and infrastructure were above ground; supplies were stored in unprotected warehouses or lightly built buildings or even tents. Supplies had flowed in faster than they could be properly stored throughout 1942 and the first half of 1943. So much had been brought in that the Japanese seized virtually every available existing building within the Gazelle Peninsula for their own use, and built 29 sawmills to create lumber for new structures from the native timber. At their peak they could produce 185,000 board-feet of lumber each week.
By October 1943 buildings aggregating 3 million square feet of area were within the city of Rabaul and another 1.7 million square feet of buildings scattered over the rest of the Gazelle Peninsula. These buildings and their contents began falling to bomb and blast from the inexorable Allied bombing campaign. Between January and March over 40 percent of the stockpiled food in Rabaul was destroyed by bombing, as was nearly one-third of the canteen and medical stores. Eighty percent of machinery in repair and machine shops was destroyed. One-third of the power plants were flattened. The Navy lost 750 tons of ammunition. The Army, better dispersed, only lost 5 percent of its ammunition. One-eighth of the gasoline stockpiled was similarly destroyed.
Throughout the campaign land-based Marine SBD Dauntless dive bombers bombed antiaircraft positions, suppressing their fire. After the Japanese withdrew aircraft from Rabaul, antiaircraft artillery was the only means of resistance left to the Japanese. (AC)
The “ace race” ended when Japanese aircraft departed, but fighter squadrons still supported the air offensive. These are Vought F4U-1A Corsair fighters of VF-17 in flight, in early March 1944. Aircraft 29 is flown by Ira Kepford, then the Navy’s leading ace, with 16 kills. (USNHHC)
Most of these losses occurred between January and the first two weeks of March. As early as November 1943 the Japanese had realized their vulnerability to aerial assault, and had begun dispersing supplies and facilities. Much of their stores of goods went underground. The volcanic rock of New Britain was easily carved yet extremely resistant to bombs. The Japanese had plenty of labor available for digging. The POWs and conscripted civilians that Japan had moved to Rabaul stopped making runways and started carving caves.
Between November and March a network of underground storage facilities sprouted beneath the Gazelle Peninsula’s surface. Warehouses moved underground, as did repair shops, communications facilities, barracks, and hospitals. Sometimes the facilities were rough, with bare rock walls. Other facilities, including command centers and radio rooms were paneled with wood ceilings, walls, and floors.
The Japanese built underground shelters for antiaircraft guns and spotlights, as well. After a position was hit, the gun or spotlight in it would be moved to a nearby location, where a cave would be dug. The item would wait in the cave until needed. It would then be rolled to position (typically rails were added), used briefly, and then rolled back to shelter. After a few minutes had passed, it would be deployed again.
Allied aircraft also hit the road network in the absence of other targets. As a result, most truck and automobile movement was done at night. Vehicles that had to travel during daylight hours followed roads concealed from air observation (13 percent of the road network was completely hidden and another 20 percent partially hidden) or along roads which had air lookouts every 500–1,000 yards. If an aircraft were spotted, the driver would be warned, and hide under cover until the danger had passed.
By March everything of value that remained in the Gazelle Peninsula, except food and fuel, had been moved underground. Food, especially rice and grains, quickly spoiled in the damp confines of the cave system. Rice was stored in open pits, concealed by vegetation. Fuel, similarly, was concealed by jungle.
Most of the stores the Allies did destroy were eradicated while still stored above ground. Had Mitchell shifted to bombing supplies a few weeks earlier than he did, up to half of all supplies, fuel, food, and ammunition on Rabaul would have been destroyed. Instead, the Japanese had sufficient supplies to last out the war.
The bombing campaign conducted in late February and March did not destroy the Rabaul garrison, or significantly reduce the fighting capabilities of Japanese ground forces or coastal defenses. What it did do was render Rabaul impotent. On March 9 unescorted bombing missions over Rabaul began. By the end of March Japanese forces in Rabaul could not project power further than their artillery could shoot and that only feebly. It ensured that even if Japan could reopen an air bridge or a sea route to Rabaul it would be a long time before it could be used as a base for offensive operations.
As March progressed, the chances of Japan reopening a road to Rabaul dimmed markedly. On March 8, the airfield at Nissan opened. This put Kavieng within range of Allied single-engine fighters. A Fifth Air Force raid had already devastated Kavieng in mid-February, all but closing it. On March 16, Nissan field mounted its first major raid against Kavieng. SBDs and TBFs escorted by Allied aircraft replicated the work they had been doing at Rabaul against a new target. Kavieng experienced the same treatment that Rabaul had suffered over the previous month.
The ability to cover Kavieng with Corsairs, Hellcats, Kittyhawks, and even Airacobras meant that Kavieng could no longer be used even to ferry aircraft to Rabaul. The only route left was a nonstop flight to or from Truk, with a long swim home if the engines failed during the journey. Soon half the Kittyhawks and most of the Airacobras were stationed at Nissan.
The final bricks in the wall being built around Rabaul were placed on March 20, when Allied troops landed on Emirau. This was a small island 100 miles northwest of Kavieng. It had two primary virtues: it could hold an airfield and was believed to have a very small Japanese garrison.
Originally Allied war plans had called for an invasion at Kavieng too. Its airfield would close the ring around Rabaul, and its harbor could substitute for Simpson Harbor. But Seealder Harbor, taken when the Admiralties were seized, was a perfectly adequate replacement for Simpson Harbor and was better placed than either Kavieng or Rabaul to support future Allied movement on the road to Japan. That left the airfield as a reason to land at Kavieng. Kavieng was heavily garrisoned, however. To take it would require committing two infantry divisions, the 3rd Marine Division and 40th Infantry Division, backed up by the 4th Marine Regiment.
The bombardment of Rabaul continued for two months, but by the third week much of the city had already been flattened. This attack took place on March 22. The eastern side of the city is destroyed, including the portion of the city containing the waterfront pictured in the previous Rabaul photo. (USNHHC)
The capture of Emirau on March 20 completed the isolation of Rabaul. Work on the airfield began at the end of March and the airfield was operational in early May. (AC)
The Green Islands showed that the main reason to take an island was to use it to hold an airfield. The whole Rabaul campaign demonstrated that physical occupation of a strongly held enemy position was unnecessary if air superiority could be achieved. At virtually the last minute the invasion of Kavieng was canceled, and Emirau substituted. Japanese garrisons at both Kavieng and Mussau (north of Emirau) were bypassed. The landing at Emirau was virtually unopposed.
Nimitz had ordered a bombardment of Kavieng’s port and airfield preparatory to a landing at Kavieng. The switch was made so late that the four old battleships assigned to do the bombardment were already in the area. In the belief that it would be a good diversion, the bombardment took place as planned on March 20. Meanwhile the 4th Marine Brigade was making an unopposed landing at Emirau. There were no Japanese on the island.
Airfield construction was begun on March 31. An emergency strip was available by April 14. The airfield was operational by May 2 – the leisurely pace a result of the winding down of the Rabaul campaign.
By March 31 there was no question that the Allies had succeeded in neutralizing Rabaul. Its air garrison had been reduced to a handful of aircraft. Rabaul city had been flattened. The garrison had turned into subterranean and nocturnal creatures. They lived and worked under
ground and generally emerged from their caves only at night.
Endgame: April 1944–August 1945
By mid-April 90 percent of the buildings in Rabaul had been destroyed. The Allies ended large-scale bombing raids for a lack of targets. They continued bombing the three largest Japanese airbases, Lakunai, Vunakanau, and Tobera, initially every week and then every other week, to make sure they could not be made operational. Rapopo and Keravat were recognized as abandoned, and rarely attacked after June 1944.
With a lack of conventional objectives, the Allied flyers sought more unusual targets. In June and July of 1944 they went after the crops the Japanese were raising. Mechanics fixed sprayers to Avenger torpedo bombers, and put 150-gallon fuel tanks into the bomb bay. These aircraft then flew over fields releasing diesel fuel on the plants, killing them. Similarly, Japanese attempts to harvest fish in the waters around Rabaul ended with their fishing boats attacked and sunk – along with anything else found still floating, right down to the smallest rowboat. These attacks were intended to force the Japanese to draw down stored food, since outside resupply was impossible.
Vunakanau was the biggest airfield in New Britain in September 1943. A year later it had been destroyed by Allied bombing. Every building was gone, its aircraft destroyed, and its concrete runway reduced to rubble. (AC)
There was also dusk-to-dawn harassment of Japanese airfields. A single medium bomber – a B-25 or more typically a Marine PBJ – would circle an airfield starting at sunset. It dropped a single 100lb bomb every five minutes or so. After 90 minutes, that aircraft would be relieved by a new one, and the process repeated. This bombing was intended to deprive the garrison of sleep. Plenty of Allied aircraft were available, and a single airfield could be covered for the night by fewer than a dozen bombers.