The YA-12 light artillery tractors were developed by NATI Designers and
launched at the Yaroslavskiy Avtomobilniy Zavod YaAZ-Yaroslav Automobile
Plant. In 1943, the United States supplied a large quantity of the
U.S.-made GMC-4-71 four cylinder, two stroke, 110 horsepower engines
under lend-lease contract. Production started in 1943, and within 12
months a total of 285 units were built. In 1945, production of YA-11s
and 12s reached 1,270.