Between July 1971 and March 1973, the South African Railways placed 125 Class 34-000 General Electric type U26C diesel-electric locomotives in service.

Other users are Kenya Railways who for some years also leased South African Class 34 U26C locomotives, and América Latina Logística (ALL) in Brazil.

At some stage during the mid-1980s, all Class 34-000, 34-400 and 34-500 locomotives had saddle filters installed across the long hood, mounted just to the rear of the screens behind the cab on the sides.

[7] To be usable on the iron ore line, Class 34-000 locomotives which ended up working there were modified to a similar fuel capacity.

[8] Class 34-000 locomotives that were allocated to the Sishen-Saldanha Orex line were often modified by having removable running board-mounted handrails installed.

[1] Since c. 2009, other mainline diesel-electric locomotive types also emerged from the Koedoespoort Transwerk shops with running board mounted handrails after major overhauls.

[9] Beginning in 2010, some Class 34-000 locomotives were equipped with electronic fuel injection and GE "Bright Star" control systems.

[2][12] In the 1990s many of the Class 34-000 units began to be repainted in the Spoornet orange livery with a yellow and blue chevron pattern on the buffer beams.