Between 1959 and 1961, the South African Railways placed 135 Class 5E1, Series 1 electric locomotives with a Bo-Bo wheel arrangement in mainline service.

[1][2] The first series of the 3 kV DC Class 5E1 electric locomotive was designed and built for the South African Railways (SAR) by Metropolitan-Vickers (Metrovick) at its Bowesfield Works.

Apart from the bogies, an externally visible difference from the Class 5E is the size and location of the small access panels on the lower body sides.

The axle-hung traction motors of all earlier SAR electric locomotives up to and including the Class 5E1, Series 1, were suspended on the axles by means of plain oil-lubricated bearings consisting of bronze shells with white metal linings.

With the introduction of the more powerful Class 5E1, Series 1, considerable trouble was experienced due to flaking of the white metal linings as a result of the increased intensity of the pressure on these bearings.

Since satisfactory results were obtained, it was decided to equip the traction motors of the subsequent UCW built Series 2 and later locomotives with roller-type suspension bearings.

[6] Prior to 1960, green was the traditional colour for electric locomotives, with yellow whiskers and side-stripes being added in the late 1950s.

When the SAR celebrated 100 years of railways in South Africa in 1960, new colour schemes were adopted for passenger stock as well as electric and diesel-electric locomotives.

The yellow side-stripes were initially applied to the full body-length of electric locomotives, but these were later curtailed to just beyond the cab-sides, with the number plates on the sides enclosed in three-stripe wings.

[7] The early deliveries of Series 1 units still entered service in the bottle green and yellow whiskers livery with red cowcatchers.

The units were delivered in plain green or red and the yellow whiskers were added in South Africa during their erection.

By 1981 they were all back in pool service and were gradually repainted to Gulf Red and whiskers again as they were shopped for major overhauls.