Operation Matterhorn logistics

Operation Matterhorn was a military operation of the United States Army Air Forces in World War II involving the strategic bombing of industrial facilities in Japan, China and Southeast Asia by Boeing B-29 Superfortress bombers. The creation of bases for the B-29s in India, Ceylon and China and their maintenance was a logistical undertaking of enormous magnitude and difficulty.

The B-29s were based in India but staged through bases around Chengdu in China's Sichuan province. Operations were conducted from China because no other sites within range of Japan were in Allied hands in early 1944. Since the Japanese had cut the Burma Road in 1942, the only line of communications with China was over "the Hump", as the air ferry route to China was called. All the fuel, ammunition and supplies used by American forces in China had to be flown in over the Himalayas.

The B-29s required airbases with runways that were longer and stronger than those of smaller bombers. Five airfields in Bengal in India were upgraded to take them. Supplying fuel by rail would have placed too much strain on the railways, so a fuel pipeline to the airfields was laid from the port of Calcutta. The four B-29 airbases around Chengdu, along with five airstrips for fighters to defend them, were built by tens of thousands of Chinese laborers with hand tools. In November 1944, American bombers began raiding Japan from the Mariana Islands, and the B-29s left the logistically difficult and increasingly vulnerable bases in China in January 1945.