Between September 1976 and June 1978, the South African Railways placed one hundred Class 35-600 General Motors Electro-Motive Division type GT18MC diesel-electric locomotives in branch line service.

[1][2] The Class 35-600 type GT18MC diesel-electric locomotive was designed by General Motors Electro-Motive Division (GM-EMD) and built in two batches for the South African Railways (SAR) by General Motors South Africa (GMSA) in Port Elizabeth.

The GM-EMD Class 35-600s were designed for light rail conditions and they work on most branch lines in the central, eastern, northern and northeastern parts of the country.

In the 1990s many of them began to be repainted in the Spoornet orange livery with a yellow and blue chevron pattern on the buffer beams.

In the late 1990s many were repainted in the Spoornet blue livery with outline numbers on the long hood sides.