In 1947 and 1948, the South African Railways placed twenty-eight Class 3E electric locomotives with a Co+Co wheel arrangement in mainline service.

[1] The South African Railways (SAR) placed orders for the design and construction of the 3 kV DC Class 3E electric locomotive with Metropolitan-Vickers (Metrovick) in 1944.

Although the locomotive was designed by Metrovick who also supplied the electrical equipment, its construction was subcontracted to Robert Stephenson and Hawthorns.

Subsequent electric locomotive models like the Classes 4E, 5E and 6E used separate steam wagons on passenger service during the winter months.

In the picture alongside showing rarely seen snow on the ground along the Johannesburg-Pretoria line on the Transvaal Highveld, the roof jumper connections between the suburban coaches and next to the unit's headlight are visible.

It was designed for both goods and passenger working on the Western Transvaal System, where higher speeds were possible on track with less severe curvature than on the lower Natal mainline.