The raid on Palembang

On the afternoon of 10 August 1944, 54 American Boeing B-29 Superfortress bombers of XX Bomber Command took off from the British airfield of China Bay near Trincomalee in Ceylon. Their target was the refinery at Pladjoe (today Plaju) near Palembang on Sumatra, in the Japanese-occupied Dutch East Indies. The raid, code-named Boomerang, took place on the night of 10–11 August. That same night another group of B-29s, flying from airfields in China, bombed Nagasaki – the two targets were some 4,800 kilometres apart. It was the only attack by American strategic bombers on the Palembang refineries in the whole war.

It was a night-time radar attack carried out at the limit of the bombers’ range, and the mines dropped into the river by which the oil was shipped out had more important effects than the bombs themselves.

Sumatran oil

For Japan, the capture of the oilfields of the Dutch East Indies was one of the main aims of the war in the Pacific. Palembang, with its two large refineries – Pladjoe, which before the war belonged to Royal Dutch Shell, and Sungai Gerong, owned by the American Standard Oil – was taken by the Japanese in mid-February 1942 with a parachute drop and an attack from the sea, in the course of the Dutch East Indies campaign. Dutch engineers managed to destroy some of the installations, but production had resumed by the end of 1942.

In the spring of 1944 Allied intelligence estimated that Pladjoe processed more than 20 million barrels of oil a year, supplying some 22 per cent of Japan’s fuel oil and as much as 78 per cent of its aviation spirit. The official history of the US Army Air Forces points out, however, that these were intelligence estimates, and that how much fuel actually reached the fronts was determined by an increasingly depleted tanker fleet. Oil from Palembang went down to the sea along the Musi River – all the refinery’s exports passed along it.

The air defence of Palembang, which was the responsibility of the Japanese army, was strengthened at the beginning of 1944. The 9th Air Division was formed at that time, with three anti-aircraft artillery regiments, a battalion of automatic cannon, a barrage balloon regiment and two army fighter regiments under its command.

The Matterhorn compromise

The attack on Palembang was part of the Matterhorn plan from the outset – the strategic offensive by B-29 bombers from bases in India and forward airfields in China. At the turn of 1943 and 1944 some American planners wanted to use the new bombers mainly against shipping and the oilfields of South-East Asia, others against the industry of the Japanese home islands. The Palembang refineries were accepted as a target by the Allied chiefs of staff at the Cairo Conference, and in the schedule approved in April 1944 by the US Joint Chiefs of Staff Palembang was the only important oil target. According to the official history of the Army Air Forces, this was a compromise between those who favoured strikes on Japan and those who wanted first to cut it off from fuel.

As the B-29s could not reach Sumatra from India, the strike was to be made from Ceylon. In March 1944 work began on rebuilding four airfields there, but it fell behind schedule and in the end it was decided to prepare only one – China Bay, with 56 hardstands and a fuelling system borrowed from another theatre. After the first B-29 raid on Japan in June 1944, General Henry H. Arnold, who commanded the Twentieth Air Force directly, demanded that the command in India press simultaneously against several targets, including sending at least fifty bombers against Palembang as soon as the airfield in Ceylon was ready. The dispute over these demands, part of the background to the B-29 raids from China, cost the commander of XX Bomber Command, Brigadier General Kenneth Wolfe, his post. His temporary successor, Brigadier General LaVern Saunders, postponed Palembang to August so as to strike first at the steelworks at Anshan.

Meanwhile, in June several American intelligence and analysis bodies concluded that, given the changes in the Pacific and the losses of the Japanese merchant fleet, the Pladjoe refinery had lost its first-rank importance. Bomber Command would gladly have dropped a mission that diverted forces from the main campaign against the Japanese steel industry, but the Joint Chiefs of Staff upheld the order. When it became clear that China Bay would be ready on 4 August, Arnold set a deadline of 15 August; the date of the attack was fixed for 10 August.

The original intention of a daylight precision raid by the command’s entire strength – 112 aircraft – was abandoned, because from a single airfield they would have had to be dispatched in waves, risking heavy losses. In the end a night attack aimed by radar and taking advantage of favourable winds was adopted. The primary target was the Pladjoe refinery, the secondary the refinery at Pangkalan, and the last resort a cement works near Padang. Some of the aircraft were to drop naval mines into the Musi. According to the official history, the round trip was 3,855 miles (about 6,200 km) to Palembang and 4,030 miles (about 6,500 km) to the mining areas on the river, so each bomber carried only about a ton of bombs or mines, but with full tanks. The mission is sometimes described as the longest non-stop bombing raid of the war up to that time; XX Bomber Command later flew even longer missions from India to Singapore.

The British supplied the fuel and covered the cost of extending the airfield under reverse Lend-Lease, and the Royal Air Force placed practically the whole base at the Americans’ disposal. Admiral James Somerville’s Eastern Fleet set up an elaborate air–sea rescue system – submarines, a cruiser, destroyers, smaller vessels and aircraft stationed along the return route.

The night of 10–11 August

On the afternoon of 9 August, 56 bombers flew in from Bengal to China Bay, where a control team from XX Bomber Command brought them in and parked them without radio contact. At 4.45 p.m. the next day the first B-29 took off, and within 84 minutes 54 aircraft were airborne; one, which soon turned back with a leaking engine, took off again after repairs. The bombers flew singly, on a straight course to the island of Siberut just south of the equator, and from there turned east over Sumatra.

More than a dozen aircraft failed to reach the target for various reasons. Two bombed Pangkalan Brandan, one the airfield at Jambi, and 39 reached the Palembang area. The city was blacked out, the target was partly obscured by cloud, and the only bomber equipped with illuminating flares did not reach the refinery. Thirty-one aircraft bombed Pladjoe by radar or visually through gaps in the cloud. Crews reported explosions and fires, but their observations were fragmentary, and the photographs taken during the raid were too poor to assess the results.

The mining went better. According to the official history, eight bombers of the 462nd Bombardment Group went down below the cloud base to about 300 metres and dropped 16 mines into the Musi in a good pattern. The bombers met anti-aircraft fire and – for the first time in their service – ground-launched rockets. The crews counted 37 Japanese fighters, some of which pursued them for about 560 kilometres, but no B-29 was hit.

The greatest worry was the return flight on the last of the fuel. Several aircraft turned back without dropping their bombs because they would otherwise have run out of petrol. Only one bomber ditched, about 140 kilometres from China Bay and some distance off the return route. Its crew managed to send an SOS; after an intensive search, on the morning of 12 August aircraft and the British destroyer HMS Redoubt found the raft thanks to the signal from a portable emergency transmitter. One of the gunners was killed in the ditching; the rest of the crew were rescued.

Nagasaki the same night

For psychological reasons, the Palembang mission was timed to coincide with a night attack on Nagasaki, which in 1944 – with its shipyards, docks and armaments works – ranked high on the list of urban-industrial targets. Of the 33 bombers sent from Bengal to China, 31 reached the forward airfields (one crashed on the way, killing two airmen). Twenty-nine aircraft took off from Chengdu, each carrying a load of incendiary and fragmentation bombs; two turned back, three attacked alternative targets and 24 bombed Nagasaki, mostly by radar, as cloud was thickening over the city. It was the first time that XX Bomber Command, which had previously dropped only high-explosive bombs, used incendiaries against a Japanese city, but according to later intelligence assessments the damage was not significant. The defences proved weak; a gunner in one of the B-29s shot down a Japanese fighter, the command’s first officially credited aerial victory.

Results

Operationally, the mission was a success: it was planned and executed efficiently, and the only loss was the bomber that ditched. Its strategic effects, however, were negligible. Reconnaissance photographs were taken only on 19 September, when it was already difficult to assess the damage; they showed that the raid had certainly destroyed only one small building at Pladjoe, and several others were judged probably hit. The official history of the Army Air Forces concludes that Washington’s insistence on a mission that, in the conditions of the time, could not produce decisive results showed a lack of flexibility in setting priorities.

The mines achieved more. According to post-war studies, they sank three ships totalling some 1,770 tons in the Musi and damaged four more, and for about a month, until the channel was cleared, the Japanese were unable to ship oil down the river.

XX Bomber Command itself judged the mission not worth the cost, and on 24 August, even before the damage had been assessed, it proposed abandoning China Bay as a staging base. Washington agreed on 3 October. No B-29 ever took off from Ceylon again, and the authors of the official history called the building of the airfield for one fruitless mission a “glaring example of the wastefulness of war”.

Significance

The Palembang raid showed both that the B-29s could safely cover thousands of kilometres over the sea and that XX Bomber Command, which a few weeks earlier had been struggling with basic technical problems, was capable of complex operations. The mines dropped into the Musi were a first foretaste of the role the B-29s later played in mining Japanese waters: in the spring and summer of 1945 bombers from the Marianas mined the ports and straits of the home islands, almost paralysing coastal shipping. The Marianas themselves – on that same day, 10 August 1944, the end of the fighting on Guam was announced – soon became the main B-29 base, and the value of the forward airfields in China and the bases in Ceylon rapidly diminished.

The Palembang refineries returned to the target list a few months later, this time for the carrier aircraft of the British fleet. After smaller strikes on Sumatra at the end of 1944, under Operation Meridian aircraft from carriers commanded by Admiral Philip Vian attacked Pladjoe on 24 January 1945 and the Sungai Gerong refinery on 29 January, causing serious damage to both. The Japanese general responsible for the refineries testified after the war that these attacks had caused far greater losses than the raid of August 1944, and according to the British official history the refineries were working at a third of their capacity at the end of March 1945. By then American submarines and aircraft had so thinned out the Japanese tanker fleet that oil from Sumatra and Borneo was reaching Japan ever more rarely – which ultimately sealed the fuel starvation of the navy and air forces in the last year of the war.