Pacific Theater · Mariana Islands · Chapter 8 of 9 · October 1944–August 1945
From the Marianas to Tokyo: The B-29 Bases and the Air War on Japan
Within months of their capture, the Marianas held the largest bomber bases in the world. From October 1944 B-29 Superfortresses flew from Saipan, Tinian and Guam to attack Japan, first by day and then by night with fire. In August 1945 two of them flew from Tinian with atomic bombs.
The B-29 Superfortress was the most expensive weapon program of the war, a pressurized, four-engine bomber that could fly higher and farther than any other. The Marianas gave it what bases in China could not: airfields within reach of Tokyo that could be supplied by sea. Over the next year the islands were turned into the base of the Twentieth Air Force’s XXI Bomber Command, and the war in the air over Japan was fought from them.
Key facts
Building the bases
Work began before the fighting ended. On Saipan, Aslito was rebuilt and lengthened as Isley Field. On Tinian, Navy Seabees built North Field and West Field, with six long runways between them, and taxiways and hardstands for hundreds of bombers. On Guam, North Field (later Andersen Air Force Base) and Northwest Field were carved out of the jungle on the northern plateau, and Harmon Field near the centre of the island. Coral was quarried and crushed for runway surfaces, and whole towns of Quonset huts rose for the air and ground crews.
Joltin' Josie
On 12 October 1944 the first B-29 to reach the Marianas, Joltin’ Josie, the Pacific Pioneer, landed at Isley Field with Brigadier General Haywood S. Hansell Jr., commander of XXI Bomber Command, aboard. The Army Air Forces magazine Brief reported that the war just about stopped in its tracks the day she arrived. The 73rd Bombardment Wing followed over the next weeks, and the crews flew practice missions against bypassed Japanese islands such as Truk and Iwo Jima.
San Antonio I
On 24 November 1944, 111 B-29s took off from Saipan for the first Marianas-based attack on Tokyo, Operation San Antonio I, led by Brigadier General Emmett O’Donnell in Dauntless Dotty. Their target was the Nakajima Musashino aircraft engine plant on the outskirts of the city. Seventeen aircraft turned back. Flying at high altitude, the bombers met the jet stream over Japan, winds of well over 100 miles an hour that scattered their bombs; only 24 bombed the plant, and 64 dropped on docks and urban areas. Two B-29s were lost to enemy action.
Through the winter Hansell’s high-altitude precision daylight raids achieved little against Japanese industry, because of the jet stream, cloud and the long, fuel-hungry flights. Japanese aircraft from Iwo Jima raided the bases on Saipan and destroyed several B-29s on the ground. Hansell was replaced in January 1945 by Major General Curtis LeMay, who had commanded the B-29s in China.
Gallery · 6 photographs · select to enlarge
B-29s in the Marianas
LeMay and the fire raids
LeMay changed the tactics. On the night of 9–10 March 1945 he sent more than 300 B-29s against Tokyo at low altitude, stripped of most of their guns to carry more incendiary bombs. The fires burned out about 16 square miles of the city and killed perhaps 80,000 to 100,000 people, most of them civilians, in what remains the deadliest air raid in history. Over the following months the B-29s burned most of Japan’s large and medium-sized cities and laid mines that closed its harbors.
The fire raids are among the most debated decisions of the war. Their defenders argued that Japan’s war industry was dispersed in homes and small workshops in the cities and that the raids shortened the war; their critics, then and since, that they deliberately killed civilians on an enormous scale. The figures are discussed in this site’s statistics chapter on the air war.
Iwo Jima
Iwo Jima lies about halfway between the Marianas and Tokyo. Japanese fighters and radar on the island threatened the bombers, and damaged B-29s had nowhere to land on the long flight home. The island was invaded in February 1945, and after its capture its airfields served as an emergency landing field for B-29s returning from Japan. Thousands of crewmen landed there who might otherwise have been lost at sea. The battle is told in this site’s Iwo Jima collection.
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The Marianas campaign in the Western Pacific, February 1944–August 1945
The atomic missions
In the spring of 1945 the 509th Composite Group, a special B-29 unit commanded by Colonel Paul Tibbets, moved to North Field on Tinian. In late July the cruiser Indianapolis delivered parts of the first atomic bomb to the island; she was sunk by a Japanese submarine on her way to the Philippines a few days later. The bombs were assembled on Tinian and loaded into the aircraft from specially dug pits.
At 0245 on 6 August 1945 Tibbets took off from North Field in the Enola Gay, carrying the uranium bomb known as Little Boy, and dropped it on Hiroshima at 0815 local time. On 9 August Major Charles Sweeney flew Bockscar from Tinian with the plutonium bomb Fat Man; clouds over the primary target, Kokura, sent him to Nagasaki. Japan announced its surrender on 15 August. The story of the bombs is told in the Manhattan Project collection.
Gallery · 6 photographs · select to enlarge
The bases and the bombers
Sources and further reading
- Craven and Cate, The Army Air Forces in World War II, vol. V, ch. 18, "Precision Bombardment Campaign" (HyperWar edition) — the first B-29s in the Marianas
- National Park Service, American Memorial Park: "Battle of Tinian"
- Air & Space Forces Magazine, "How the Superfortress Paced the Attack Against Japan"
- Pacific Wrecks: B-29 missions to Tokyo
- National Park Service, American Memorial Park — North Field and the atomic missions
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