B-29 raids from China

In the first half of July 1944 American Boeing B-29 Superfortress bombers, flying from airfields around Chengdu in the Chinese province of Sichuan, reached Japan for only the second time in the war. On the night of 7–8 July more than a dozen aircraft of XX Bomber Command attacked targets on the island of Kyushu: the naval base at Sasebo, industrial plants at Nagasaki and Ōmura, and the steelworks at Yawata and Tobata. It was the first repeat of the raid that three weeks earlier had opened the strategic air offensive against the Japanese home islands.

Popular war chronologies sometimes state under 10 July 1944 that “Tokyo was bombed for the first time since the Doolittle Raid of April 1942”. That statement is wrong on two counts. First, no American aircraft bombed Tokyo in July 1944 – the capital lay far beyond the range of bombers based in China. Second, the first raid on Japan since the Doolittle Raid was the attack on the Yawata steelworks (today part of Kitakyushu) on the night of 15–16 June 1944, and the second was precisely the July raid on Sasebo and its surroundings. Tokyo first saw a B-29 overhead on 1 November 1944 (a lone reconnaissance aircraft), and the first bombing raid on the capital was carried out on 24 November 1944 by aircraft flying no longer from China but from the Mariana Islands. The date of 10 July does, however, relate to American plans: the commanding general of the Army Air Forces, General Henry Arnold, had demanded that a second, smaller raid on Japan take place “by 10 July”. So states the US official air force history (Craven and Cate, The Army Air Forces in World War II, vol. V), as do the studies based on it.

Operation Matterhorn

The B-29 was the most expensive American aviation project of the war: a four-engined bomber with pressurised cabins, remotely controlled defensive armament and the range to carry several tons of bombs more than 2,500 km. From the outset it was intended above all for the war against Japan. The problem was that in 1943 the Americans had no base from which they could reach the Japanese home islands. The Marianas remained in Japanese hands, and the only Allied territory at a suitable distance was China.

In April 1943 Arnold entrusted the preparation of the B-29 units to Brigadier General Kenneth Wolfe. In the autumn a plan was drawn up under the code name Matterhorn: the bombers were to be based in India, around Kharagpur in Bengal, where they could easily be supplied through the port of Calcutta, and were to use forward airfields in Sichuan for raids on Japan, Manchuria and Korea. The plan was approved at the Cairo Conference in November and December 1943. President Franklin Delano Roosevelt also saw it as a gesture towards Chiang Kai-shek: China, exhausted by seven years of war, was to see the Americans striking Japan directly.

An unusual command structure was created for the new bombers. In April 1944 the Joint Chiefs of Staff set up the Twentieth Air Force, which Arnold commanded personally from Washington as their executive agent. Theatre commanders – in China, Burma and India this was General Joseph Stilwell – were only to provide support, without any right to dispose of the B-29s. Arnold wanted in this way to prevent the bombers from being frittered away on tactical tasks, but at the same time he took personal responsibility for the results, which put constant pressure on the commanders in the field.

Airfields built by hand

The four bomber airfields around Chengdu – Xinjin, Guanghan, Qionglai and Pengshan – were built in the winter and spring of 1944 almost entirely by human muscle. According to the US official history, some 300,000 peasants conscripted by the provincial authorities and around 75,000 contract labourers worked on them, supervised by barely a dozen or so American engineers. There were no bulldozers or excavators. Earth was dug with hoes and carried away in baskets on shoulder poles, gravel from nearby rivers was moved in wheelbarrows, and the surface was compacted with stone rollers hauled by hundreds of people. Landowners received small compensation payments, and the tenants who farmed the land received nothing. The contract labourers earned barely enough to feed themselves. The first B-29 landed at Guanghan on 24 April, and all four airfields were completed by 10 May 1944.

An even greater problem than the runways was fuel. No overland route led to Sichuan – the Burma Road had been closed since 1942 – so every ton of petrol, bombs and spare parts had to be flown in from Assam over the eastern Himalayas, on the route the airmen called “the Hump”. Air Transport Command’s transport aircraft were not enough, so some B-29s were converted into flying tankers that carried fuel instead of bombs. The arithmetic was merciless: for one bomber to fly a combat mission from Chengdu, a B-29 had itself to cross the Himalayas several times. By the end of July twelve B-29s had crashed on the Hump, although most of the crews were rescued by Chinese civilians. When at the end of May 1944 Operation Ichi-Go, the Japanese offensive in China launched in April, entered a new phase and drove south from Wuhan, Stilwell diverted part of the tonnage allocated to the B-29s to General Claire Chennault’s Fourteenth Air Force, which was defending the front against the Japanese offensive.

Yawata – the first raid

XX Bomber Command flew its first combat mission on 5 June 1944 from its Indian bases, attacking the railway workshops in Bangkok. Ten days later, on the orders of Arnold, who wanted to synchronise the strike with the landing on Saipan, the bombers flew to Japan. The target was the Imperial Iron and Steel Works at Yawata on Kyushu, which produced about a quarter of Japan’s steel; the largest of its coke ovens was chosen as the aiming point. The round trip from Chengdu was more than 5,000 km, so it was decided to attack at night, with each aircraft bombing individually, aiming by radar.

Sixty-eight aircraft took off in the afternoon and reached Yawata around midnight on 15–16 June, hence both dates appear in the literature. Forty-seven bombers found the target area. One B-29 was shot down over Japan by a Kawasaki Ki-45 night fighter flown, according to American sources, by Warrant Officer Sadamitsu Kimura; twelve men died, including a correspondent of the weekly Newsweek. In all the operation cost seven bombers (most of them crashed on take-off, on landing or in the mountains) and 56 airmen. The result was negligible: aerial photographs showed that a single bomb had fallen within the works, damaging a power-station building more than a kilometre from the coke ovens. American press releases nevertheless presented the raid as the beginning of a new phase of the war, and the names of the Twentieth Air Force and XX Bomber Command were made public for the first time.

Sasebo, Nagasaki and Ōmura

Arnold wanted to prove to the Japanese and to his own public that Yawata had not been a one-off demonstration like the Doolittle Raid but the start of a campaign. He therefore demanded a small raid – about fifteen aircraft – on Japan by 10 July, a hundred-aircraft attack on Manchuria by the end of July, and a raid on the refineries at Palembang in Sumatra from airfields in Ceylon. Wolfe replied with a counter-proposal to reduce these forces, because he knew how much fuel was left at Chengdu. On 4 July Arnold recalled him to the United States, promoting him to major general and posting him to Air Materiel Command. Command passed temporarily to Brigadier General LaVerne Saunders, and was to be taken over permanently by General Curtis LeMay, transferred from the Eighth Air Force’s bombers in England.

The July raid was planned above all for psychological effect: the command assumed from the outset that the damage would be slight. The plan called for eighteen bombers to attack the naval base at Sasebo, three the Akunoura marine-engine works at Nagasaki, two the aircraft factory at Ōmura, and single aircraft the steelworks at Yawata and Tobata. According to the US official tally, putting twenty-odd B-29s over Japan required more than two hundred transport flights over the Himalayas. Twenty-eight bombers were sent from India to China; one burned out on the ground at Chakulia and two turned back. On the evening of 7 July seventeen bombers and two reconnaissance aircraft took off from Chengdu. Sasebo lay under cloud, so eleven bombers released their bombs by radar. None was lost over Japan, but the weather made it impossible to assess the results.

The Japanese response

For the Japanese high command the appearance of B-29s over Kyushu came as no surprise. The Japanese knew about the transfer of the bombers to India and China – their radio spoke of it openly, which defeated American attempts to conceal the preparations. Indeed, one of the aims of Operation Ichi-Go was to seize American airfields in China, although the offensive was directed against the Fourteenth Air Force’s forward bases in the east and south of the country, and Sichuan remained beyond its reach. The Japanese tried to harass the airfields around Chengdu with occasional night raids, to little effect.

In the home islands the authorities strengthened the air defences of Kyushu and northern Honshu, moving night-fighter and anti-aircraft units there. At the end of June 1944 Hideki Tōjō’s government adopted guidelines for evacuating schoolchildren from the big cities to the countryside; the mass departures of whole classes with their teachers began in August. The Japanese press reported the raids, emphasising the negligible damage and the number of attackers shot down. Yet the mere appearance of B-29s over Japan in June and July, at the same time as the fighting on Saipan, showed that the war was reaching a country that since 1942 had known it only from official communiqués.

The balance of the raids from China

In the end Operation Matterhorn failed to live up to the hopes placed in it. According to American figures, between June 1944 and January 1945 the bombers from China dropped only about 800 tons of bombs on targets in the Japanese home islands, while XX Bomber Command was absorbing nearly 15 per cent of all the tonnage flown over the Hump, which was also needed by the Chinese army and Chennault’s air force. The post-war analysis by the United States Strategic Bombing Survey concluded that the B-29s would have been better used against Japanese shipping or the refineries in the Dutch East Indies. The same authors acknowledged, however, that the raids raised Chinese morale, and that the experience gained in China – in the organisation of maintenance, in tactics and in new aiming methods – later proved useful in the Marianas.

The July raid on Sasebo was thus no turning point, but one of many attempts to show that the new and costly bomber could strike Japan on its own. What it revealed most clearly were the limits of that strategy: every combat sortie had to be paid for with dozens of supply flights, and the tempo of the air war was dictated not by bombers but by fuel drums.

Place in the war

On 29 July 1944 the bombers from Chengdu carried out their first large daylight raid – on the Shōwa steelworks at Anshan in Manchuria, one of the largest coke producers in the Japanese empire. That day one damaged B-29 made an emergency landing at Vladivostok; the Soviet Union, not then at war with Japan, interned the crew, and the impounded bombers were later used to copy the B-29 as the Tu-4. In August LeMay took over command in India; he reorganised training and tactics but could not overcome the supply limitations. In December B-29s from China firebombed warehouses in Hankou, foreshadowing the methods later used against Japan. In January 1945 XX Bomber Command left its bases in China, and in the spring its wing was transferred to the Marianas.

The real air offensive against Japan began from the islands captured in the summer of 1944 – Saipan, Tinian and Guam. From there, on 24 November 1944, B-29s bombed Tokyo for the first time, and on the night of 9–10 March 1945, now under LeMay’s command, they burned out a large part of the capital in the most destructive conventional air raid in history. It was also from the Marianas that the bombers took off which in August 1945 dropped the atomic bombs on Hiroshima and Nagasaki – the culmination of the whole air campaign against Japan.