The TEP70 is a mainline passenger six-axle diesel locomotive with AC-DC electric transmission, produced in the USSR and Russia at the Kolomna Plant from 1973 to 2006. Since 2006, the TEP70BS locomotive, based on it, has been in production. The TEP70 family locomotives are single-section, dual-cab locomotives designed for hauling passenger trains on non-electrified railway sections with a 1520 mm gauge.
The TEP70 locomotives had a diesel engine power of 4000 hp and were primarily positioned as a replacement for the TEP60 series locomotives, which had a 3000 hp diesel engine, on the busiest non-electrified routes where the TEP60 locomotives were not powerful enough to haul long trains at the required speed. As of 2017, they remain the most widely used passenger diesel locomotives in Russia and several former USSR countries.