The 57mm Gun Motor Carriage, T48 is an American self-propelled gun halftrack developed in the 1940s. 962 specimens were produced and were originally planned for Britain to receive through lend-lease, with the intention of having them fight in the African front. By the time the T48s arrived in British hands, the campaign was over, and Britain had better vehicles suited to the role that the T48 was to fit. The British transferred 650 T48s to the Soviet Union under the Soviet Aid Program (under the name SU-57), 30 were kept and the rest returned to the US. All returned T48 GMCs except one were converted back into M3 halftracks.