Ordnance Department incendiary bomb development

Nor was the distinction between plan and reality confined to the training activities of the Chemical Warfare Service. After responsibility for the development, procurement, and storage of incendiary bombs was transferred from the Ordnance Department in the fall of 1941, the CWS undertook a program for which no peacetime plans had been drawn, a program that developed into one of the most important wartime efforts. The assignment of the biological warfare mission to the CWS shortly before the outbreak of war led to large-scale research and development in this new field of endeavor. 

The Ordnance Department was aware of these facts when it began development of 4-pound magnesium bombs. It planned a substitute bomb having the same dimensions and incendiary filling as the M50, but with a steel case in place of magnesium. It sent the plans and models of the substitute bomb, called the M54, to the CWS when that service took over responsibility for incendiaries, and the bomb was completed by the technical staff at Edgewood. 

The Ordnance Department began development of the first American adapter. The CWS inherited the item when it accepted responsibility for incendiary bombs. The device was made up of two end plates, two longitudinal bars, and four steel straps, and it held together thirty-four bombs. The adapter was designated as Model M5, the entire cluster of bombs as the AN-M6. A larger adapter, holding 128 bombs, was developed shortly afterward. This adapter was standardized as the M6, the cluster as the AN-M7. 

The general causes of the explosion were plain enough. The CWS had taken over a partially developed bomb from the Ordnance Department and under pressure from the War Department had put it into production without adequate lead time. In doing this the CWS did not insist that loading contractors construct explosive proof buildings and use the best safety procedures in filling the bombs. Actually no one knew exactly what the best procedures were, as is indicated by the fact that the War Department had previously classified incendiaries as pyrotechnics instead of explosives. In fact, one of the explosions had occurred at the loading plant at Huntsville Arsenal. ... 

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