Air raids on Rabaul

On 12 October 1943 the largest formation the Allies had yet sent against a single target in the Pacific appeared over Rabaul on New Britain. General George Kenney, commander of the Allied air forces in the South-West Pacific, threw 349 aircraft against the main Japanese base in the region – in his own words, “everything I had that was in commission and could fly that far”. Medium bombers and Australian Beaufighters strafed and bombed the airfields, and heavy bombers struck at the shipping in the harbour. So began a series of massed raids which over the following months, together with carrier strikes and attacks by aircraft from the Solomon Islands, paralysed Rabaul and allowed the Allies to bypass it.

War chronologies state that on this day Operation Cartwheel “began the bombing campaign against Rabaul”. That needs qualifying: Allied aircraft had been bombing Rabaul since January 1942, almost from the moment the Japanese took it – but these were small raids, often at night, flown by a handful of machines or a dozen or so. What began on 12 October was the massed offensive, planned as support for the forthcoming invasion of Bougainville.

The fortress on New Britain

The Japanese took Rabaul on 23 January 1942, overwhelming its small Australian garrison. Within a year and a half they had turned the former capital of the Australian mandated Territory of New Guinea into their largest base south of the equator. The spacious, sheltered harbour of Simpson Harbour could hold dozens of ships; the Allies called it “the Pearl Harbor of the South Pacific”. Around the town there were four airfields – Lakunai and Vunakanau, built by the Australians, and the new Rapopo and Tobera – while a fifth, Borpop, lay across the strait on New Ireland. According to American figures, the harbour and airfields were protected by several hundred anti-aircraft guns, and radar gave the defenders between half an hour and an hour’s warning of a raid.

Rabaul housed the headquarters of General Hitoshi Imamura’s Eighth Area Army, which commanded the land forces in New Guinea and the Solomon Islands, and of Vice Admiral Jin’ichi Kusaka’s South-East Area Fleet, to which the 11th Air Fleet was subordinate. From here convoys left for Lae and Wewak; from here aircraft took off to attack Guadalcanal, New Georgia and the Allied bases in New Guinea; from here sailed the destroyers that by night supplied and evacuated the garrisons in the Solomons. In the autumn of 1943 several tens of thousands of Japanese soldiers and sailors were stationed in and around Rabaul – by some estimates nearly a hundred thousand.

Capture or bypass

Rabaul had been the main objective of the Allied counter-offensive in the South-West Pacific from the start. General Douglas MacArthur’s Elkton Plan, reworked in the spring of 1943 into Operation Cartwheel, envisaged two converging advances: MacArthur’s forces along the coast of New Guinea and onto western New Britain, and Admiral William Halsey’s forces up the chain of the Solomon Islands. At the end of both roads lay the capture of Rabaul.

During the summer of 1943, however, the conviction grew in Washington that storming a heavily garrisoned fortress would cost too much. General George Marshall’s staff officers proposed that Rabaul be cut off and neutralised from the air. MacArthur at first protested, arguing that a base with such a harbour would be needed for further operations, but in August the Quebec Conference approved the new concept. Rabaul was no longer to be captured; air power was to destroy its aircraft and ships, and the ground forces were to seize bases around it and close it in a ring. In the Solomons the same method had proved itself in August, when the Americans bypassed Kolombangara and landed on Vella Lavella.

For the autumn of 1943 the plan provided for two steps that required Rabaul to be neutralised. Halsey was to land at Empress Augusta Bay on Bougainville on 1 November, and MacArthur at the western end of New Britain at the end of the year. In the Solomons the fighting for the New Georgia group was just ending: during the night of 6–7 October, after the naval Battle of Vella Lavella, the Japanese evacuated their last garrison from that island. In New Guinea the Australians, after the landing near Lae and the capture of the town in September, had landed near Finschhafen and taken the town on 2 October. Kenney, who had moved almost all his combat aircraft to forward airfields – Dobodura was the main heavy-bomber base, and Port Moresby had turned from a front-line foothold into a rear base – could at last strike Rabaul on a large scale. P-38 fighters, staging through Kiriwina in the Trobriand Islands, were able to escort the bombers all the way.

The raid of 12 October

The first great raid was planned as an all-out strike. According to the US official history, it involved 87 B-24 Liberator heavy bombers, 114 B-25 Mitchell medium bombers, 12 Beaufighters of the Royal Australian Air Force and 125 P-38 Lightning fighters, plus a dozen or so weather and photographic reconnaissance aircraft. The long flight over sea and jungle took its toll: some fifty machines had to turn back because of mechanical failures and accidents.

The Mitchells came in first. Nine squadrons of B-25s, converted into heavily armed strafers, raced low over the waters of St George’s Channel to avoid detection by radar and coastwatchers, and turned inland at the mouth of the Warangoi River. Skimming the treetops, they raked the aircraft parked on Vunakanau and Rapopo airfields with cannon and machine-gun fire and showered them with light parachute fragmentation bombs – a weapon Kenney’s airmen had already used to good effect in New Guinea. The Japanese were taken by surprise and offered almost no resistance to the first attack.

The Australians were less fortunate. Their Beaufighters, delayed on take-off from Dobodura by the clouds of dust thrown up by the Mitchells, failed to meet their escort and had to fight their way through Japanese fighters before strafing Tobera airfield. Last of all the Liberators appeared over Simpson Harbour, each carrying six 1,000-pound bombs, and attacked the ships in the harbour. According to the US Marine Corps official history, the Allies lost five aircraft that day; John Miller, in the Army’s official history, gives four.

Reports and reality

The crews returned with a sense of great success. One Liberator squadron reported 48 hits from 48 bombs dropped, and the first, hastily compiled tally spoke of 177 Japanese aircraft destroyed and numerous ships sunk. Analysis of aerial photographs lowered these figures, but even so they remained far higher than the reality.

The official history of the US Marine Corps, written after the war with the use of Japanese documents, judges these reports to have been “exceptionally optimistic”. According to Japanese figures, two interceptors were shot down that day and 45 aircraft destroyed or damaged on the ground. In the harbour a transport of about 6,000 tons and several smaller vessels were sunk, and three destroyers and many small ships were damaged. These were serious losses, but not crushing ones. John Miller assesses the raid in similar terms: Allied estimates, especially of shipping losses, were exaggerated, although some Japanese aircraft were indeed destroyed. The Japanese command later admitted that this and the subsequent October raids became “a great obstacle to the conduct of operations”.

The gap between reports and the enemy’s actual losses was not peculiar to Kenney. All the airmen of this war, Japanese no less than American, counted the same burning aircraft several times over in the confusion of battle and took every explosion in a harbour for a sinking ship. Over Rabaul, however, the scale of the phenomenon was exceptional: the Marine Corps official history notes that the discrepancy between the reports and the Japanese figures recurred with every subsequent raid. Miller concludes that the attacks did not wreak the havoc Kenney’s airmen claimed, but they did destroy many aircraft and deprived the air forces at Rabaul of the ability to conduct purely offensive operations.

October over Rabaul

The weather thwarted the plan to repeat the blow quickly. On 13 October a squadron of Australian Beaufort torpedo bombers attacked Rabaul, but a large expedition – some 70 heavy bombers and 100 fighters – was turned back by storms. The Japanese made use of the respite: their aircraft from Rabaul attacked Oro Bay on 15 and 17 October and the Finschhafen beachhead on 17 and 19 October. On 18 October Kenney sent out another armada, but over the Solomon Sea the weather broke again and only 54 Mitchells reached the target, attacking Tobera and Rapopo airfields and the harbour beneath a cloud ceiling of about 60 metres. The airmen reported 10–12 aircraft shot down and 41 destroyed on the ground; the Japanese admitted the loss of three fighters and a small submarine chaser.

On 23, 24 and 25 October further raids of about a hundred aircraft each flew against Rabaul. The crews claimed more than 175 Japanese aircraft destroyed or badly damaged; according to the Marine Corps official history, the Japanese admitted to roughly two-fifths of that number – which still meant a loss the 11th Air Fleet could not quickly make good. On 29 October 46 Liberators escorted by 57 Lightnings bombed Vunakanau. Poor weather forecasts led to the cancellation of the attacks planned for the last two days of the month, immediately before the landing on Bougainville.

Operation RO and the November strikes

The Japanese command had no intention of giving up Rabaul without a fight. Admiral Mineichi Koga, who had taken command of the Combined Fleet after Yamamoto’s death, decided to reinforce the base with carrier aircraft. Under Operation RO, at the turn of October and November, he transferred the air groups of the carriers Zuikaku, Shōkaku and Zuihō from Truk to Rabaul – 173 aircraft, including 82 fighters, with the best-trained pilots the navy still had.

Kenney’s airmen felt their presence at once. On 2 November, the day after the American landing on Bougainville, about 75 Mitchells escorted by 80 Lightnings attacked the harbour and the anti-aircraft batteries. They met – as Miller recorded – the fiercest opposition the Fifth Air Force encountered in the whole war. Nine bombers and 10 fighters were lost; among the dead was Major Raymond Wilkins, posthumously awarded the Medal of Honor.

Meanwhile Koga sent Vice Admiral Takeo Kurita’s force of heavy cruisers from Truk to Rabaul to smash the ships covering the Bougainville beachhead. Halsey had no surface forces of equal strength to hand, so he threw against it the only thing he had: Rear Admiral Frederick Sherman’s carriers Saratoga and Princeton. A carrier strike on so heavily defended a base was a great risk. On the morning of 5 November 97 of Sherman’s aircraft, followed an hour later by 27 of Kenney’s Liberators escorted by 58 Lightnings, damaged six of the seven cruisers in the harbour, among them Atago, Maya, Takao and Mogami. The next day most of the Japanese ships left for Truk. On 11 November aircraft from Sherman’s carriers and from Rear Admiral Alfred Montgomery’s new carriers – Essex, Bunker Hill and Independence – struck again: the destroyer Suzunami was sunk and the cruiser Agano torpedoed, while a Japanese counter-attack on Montgomery’s carriers cost the attackers 35 aircraft without scoring a single hit. Koga soon withdrew what was left of the carrier air groups from Rabaul; Operation RO had cost them more than half their aircraft and many experienced pilots.

Place in the war

The raid of 12 October opened a campaign that within a few months stripped Rabaul of its importance. The October and November strikes did not destroy the base, but they covered the landing on Bougainville and drove the Japanese fleet out of it. From December, when airfields began operating in the Torokina beachhead, Rabaul was attacked daily by aircraft from the Solomons, and at the end of the year MacArthur’s troops landed in western New Britain, at Arawe and at Cape Gloucester. In February 1944, after the American strike on Truk, the Japanese withdrew their last combat aircraft from Rabaul; the capture of the Admiralty Islands and Emirau closed the ring.

Rabaul was never captured. Its garrison – by various estimates from about 70,000 to more than 100,000 men – survived until the end of the war cut off from Japan, tending gardens and digging tunnels, and surrendered only in September 1945. Bypassing the fortress instead of storming it at great cost in blood became the model for the rest of the war in the Pacific: from then on the Allies captured only the islands they needed for airfields and bases, leaving strong Japanese garrisons behind them.