Widely unknown, the Soviet Union received some 7,500 track-laying tractors through Lend-Lease during WW2, the three main producers being Caterpillar, International and Allis-Chalmers. The mass of the crawlers were delivered from 1943 on and were of the medium type, roughly 5,000, among them 2,100 Allis-Chalmers HD-7W as well as several hundred Caterpillar D-6 and International TD-14.
The Hd-7W was in fact a decreased version of the HD-10W, running on narrower 18in. tracks and driven by a 3cyl. General Motors RC3-71 diesel engine. The 60 hp gave him a top speed of 8mph and enough drawbar pull for the Russian 152mm ML-20 howitzer.
The Red Army instantly deployed the crawlers to their own heavy artillery units as well as to those of their Polish allies, as shown here.
An interesting sidenote by Arvo L.Vecamer : A Lend-Lease convoy leaving Seattle for Vladivostok in January 1944 carried no less than 2,000 (!) Allis-chalmers tractors to the Russian ally.