Diesel-generator 21-26DG-01 including diesel engine 12ChN26/26, a modern 4-cycle 12-cylinder V-type engine, is intended for installation in mainline freight diesel locomotive 2TE25A (a.c.-a.c.; asynchronous drive) produced by AO “UK “Bryansky Engineering Plant”. Diesel locomotive 2TE25A is used for hauling trains weighing over 6500 tons on railways with gauge 1520 mm.