The A-3149 (LS-750) and A-3171 (LS-800) were diesel-electric switching locomotives built between November 1949 and June 1951, by the Lima-Hamilton Corporation of Lima, Ohio, U.S.A..

It was later upgraded to 800 hp (600 kW) by changing fuel rack settings.

Both models used the same turbocharged Hamilton T69SA four-stroke, six cylinder inline diesel engine, a Westinghouse generator and 4 Westinghouse traction motors.

The 23 A-3171’s were sold to just two railroads, the Chicago, Rock Island and Pacific bought 2, and Chicago River and Indiana (a subsidiary of the New York Central System, CR&I class DES-19a) bought 21.

The last extant A-3149, former Cincinnati Union Terminal 25, is operated by the Whitewater Valley Railroad