Soviet locomotive class VM

VM or BM
VM or BM class diesel-electric locomotive
Type and origin Power type Diesel-electric Build date 1934
Specifications Configuration: ​  • UIC 2-Do-1+1-Do-2 Loco weight 2 x 123 tonnes (121 long tons; 136 short tons) Prime mover Two Soviet-built diesel engines MAN design RPM range Max. 400 rpm Transmission Diesel-electric 8 x 207 hp (154 kW) traction motors
Performance figures Power output 2 x 1,050 hp (780 kW) (diesel)
Career Number in class 1 pair

The VM or BM (Cyrillic script) was an experimental Soviet diesel-electric locomotive named after Vyacheslav Molotov (Russian: Вячеслав Молотов). It was a two-unit machine of 2-Do-1+1-Do-2 wheel arrangement and only one pair of locomotives was built.

Powertrain

The two diesel engines were of the six cylinder, four stroke type. They were Soviet-built and based on the MAN engine used in the Soviet E el-5 locomotive. The MAN engine was rated at 1,200 hp (890 kW) at 450 rpm but the Soviet engines were de-rated to 1,050 hp (780 kW) at 400 rpm. The traction motors were similar to those used in the Soviet E el-12 locomotive but the rating of each motor was increased from 190 hp (140 kW) to 207 hp (154 kW).