When the line between Durban and Pietermaritzburg in Natal was the first South African line to be electrified, the South African Railways ordered the first 78 units of the four-axle Class 1E, which at the time was the largest order for an electric locomotive worldwide. Due to the large numbers, the locomotives were partly built in Switzerland by SLM and in England by Metropolitan-Vickers. They were modern engines with two two-axle bogies with all axles powered independently. For the first time, a DC voltage of 3,000 volts was used, which is why the bogies were connected in series and the motors were therefore operated with 1,500 volts. The locomotives were intended for all types of trains and could be used in multiple.

From the beginning the plan was to use between one and three locomotives, depending on the weight, route profile and required speed of the trains. The ultimately 172 pieces in seven series came mainly from the manufacturers mentioned. In 1938 the sixth series of 20 locomotives from Werkspoor in the Netherlands followed, and in 1944 the last ten of the seventh series from Robert Stephenson and Hawthorns. Due to the circumstances of the war, the latter were delivered in parts and assembled in South Africa. The 1E had a very long life, lasting until about 1990. As early as 1936, two units were equipped with a different transmission for 90 km/h or 56 mph, but they remained prototypes. Some locomotives have been converted to shunting locomotives over time and designated as Class 1ES. A total mileage of more than five million miles is stated for some engines.

The 5E and 5E1, developed in England, are considered the best-known South African electric locomotives. A total of 160 5E were built in three series by English Electric and the Vulcan Foundry. Since they were often used in multiple, they had gangway doors on the front sides. The first received the nickname “Klein Mamba” (“Little Mamba”) because of their coloring. The rest were also called “Balstamper” (“ball tamper”) because of their poor running characteristics. The improved 5E1 was developed by Metropolitan-Vickers. A total of 690 were built in five series, the first of which were built at Metropolitan-Vickers and the rest at the Union Carriage & Wagon Works.

At the end of the seventies, the SAR had the 50c/s Group develop the class 7E for the lines newly electrified with 25 kV alternating current. This consortium consisted of companies from Belgium, Germany, France and Switzerland and specialized in building locomotives for the modern 50 Hertz system. The 100 locomotives were built by Union Carriage & Wagon in South Africa. They became the first thyristor-controlled locomotives in South Africa and replaced the last class 25NC steam locomotives.

After 100 locomotives of the actual 7E, 50 7E1s followed, the electrical part of which was developed by Hitachi and contained solid state converters. They were built by Dorbyl in South Africa and only had one cab because they were normally only used in multiple.

From 1982 onwards, 65 7E2s were built, most of which again corresponded to the 7E. The 85 7E3, which were built from 1983, again came from Hitachi and Dorbyl. In contrast to the 7E1, they again had two cabs. Some of these were significantly modernized from 2001 onwards in the area of electrics and electronics, resulting in the different classes 7E4, 7E5 and 7E6. These were later brought up to the same standard and renamed 7E3 again.

For the iron ore export line between Sishen and Saldanha, class 15E electric locomotives were built since 2009. Like the 9E from the 1970s, which was also only used there, they are designed for the system used there with 50,000 volts of alternating current. This is used in order to require fewer feed-in points for the large total outputs required. The locomotives were developed by Mitsui and built at the Union Carriage & Wagon Works with Toshiba electronics.

The ore trains consist of 342 cars with a payload of 100 tons each, which consist of three sections of 114 wagons each and a total of 41,400 tons. There were originally a total of nine to twelve locomotives distributed between the sections, which were divided into class 15E electric locomotives and various GE diesel locomotives, as the power grid did not allow for completely electric drive. Over time, the number of electric locomotives was increased and at the same time the number of diesel locomotives was reduced, so that there are now five 15E units.