More than 50 different modifications and experimental vehicles based on the T-26 light infantry tank chassis were developed in the USSR in the 1930s, with 23 modifications going into series production. The majority were armoured combat vehicles: flame tanks, artillery tractors, radio-controlled tanks (teletanks), military engineering vehicles, self-propelled guns and armoured personnel carriers. They were developed at the Leningrad Factory of Experimental Mechanical Engineering (from 1935 known as the Factory No. 185 named after S.M. Kirov) by talented Soviet engineers P.N. Syachentov, S.A. Ginzburg, L.S. Troyanov, N.V. Tseits, B.A. Andryhevich, M.P. Zigel and others. Many Soviet tank engineers were declared "enemies of the nation" and repressed during Stalin's Great Purge from the middle