Equipped with a 155 mm M2 gun, it was designed to replace the earlier M12 gun motor carriage. Its prototype designation was the T38, but this was changed to the M40 in March 1945.[citation needed]
After World War II, the M40 was used by the British Army, who designated it 155 mm SP, M40 and called it Cardinal in the tradition of using ecclesiastical names for self-propelled (SP) artillery, such as Deacon, Priest, Bishop and Sexton.[citation needed]
Gun section
A complete gun section consisted of one M40 GMC and one M4A1 high speed tractor towing a 4-wheel, 8-ton M23 ammunition trailer. Each battery had four gun sections. The M4A1/M23 combination replaced the earlier M30 cargo carrier.[2]
Variants
The Army planned to use the same T38 chassis for a family of SP artillery:
Cargo carrier T30 – despite several being built, its production was cancelled in December 1944 to make more chassis available for GMCs