T-20 armored tractor Komsomolets (Bronirovannyy gusenichnyy tyagach Komsomolets T-20, armored caterpillar-track tractor T-20) was designed in 1936 at the Ordzhonikidze Moscow Plant no.37. They were manufactured during 1937-1941 at Factory no. 37, as well as at STZ and GAZ.
The tractor was designed to tow light artillery pieces such as the 45mm anti-tank gun and the 120mm heavy mortar. The tractor could tow the weapons themselves plus a small quantity of ammunition, usually towed in a limber, along with up to six crewmen. Occasionally, two limbers were towed to increase the ammunition supply.
The forward compartment provided space for the driver and vehicle commander. It was fully armored and had a ball-mounted DT machinegun. The rear compartment held the gun crews, seated back-to-back in outward-facing bench seats. A canvas top could be erected for protection in poor weather.
An expedient variant was built in 1941, the ZiS-30, mounting the ZIS-2 57mm anti-tank gun.