General Purpose/High Explosive Bombs
The standard bombs used by the 8th Bomber Command from September 1942 were the five General Purpose types: the M30 100lb, M31 300lb, M43 500lb, M44 1000lb and M34 2000lb. Generally, 500lb, 1000lb, and 2000lb bombs were carried for industiral targets anf the other for airfields. The 8th Air Force used 1000lb and 2000lb bombs for attacks on sumarine pens but these had little effect on the vast concrete fortifications that sheltered the U-boats most of the damage was done to the surronding port area.
303rd BG Crew sitting on a 2000 lb bomb.
The General Purpose (GP) bombs used in the early missions were fitted with quarter second delay tail fuses with an extra tenth of a second fuse in the nose. In a report, in December 1942, after the raid on Lille, it was calculated that 30% of the bombs dropped had failed to explode because the arming mechanisms had frozen up after being exposed the damp conditions on the airfields overnight. Standard Operating Procedure was soon challanged so that fuses were installed just before take off. Eventually, to avoid accidents in landing, fuses were to be insered only when the bombs were securely fixed into the aircraft.
In 1943, a new set of GP bombs were produced: the M57 250lb, M64 500lb, M65 1000lb and M66 2000lb. These accounted for most of the bombs dropped in the final year of the war. In January 1945, experts recommended 250lb GP bombs to be used against synthetic oil plants, ammunition dumps and oil storage factilities. the 100lb bomb was recommended for attacking railway yards and runways.
Originally, the only incendiary bombs were available were the British 250lb and 500lb models filled with a rubber/gasoline mix, but in November 1942 the American M50A1 41lb magnesium bomb was added to the arsenal. It was packed in 100lb clusters which had a tendency to open prematurely, diperse too widely and cause damage to other planes in the formation. In Jnuary 1944, the US 8th Air Force used the 500lb M17 cluster which had better ballistics and a primecord release that could be set to give correct disbursement. This became the most favored and effectice incendiary bomb among the bomber Groups.
High explosive and incendiary bombs fell through the air in varing trajectories and thus an accurate attack with a mixed load was very difficult to aim. For this reason, timelag tables were esed to indicate the release interval times of the different types of bomb. Eventually, factors such as wind speed and altitude were also taken into account.