In 1990, Spoornet took delivery of three prototype Class 14E dual voltage electric mainline locomotives with a Bo-Bo wheel arrangement.

[1] In January 1984, the South African Railways (SAR) invited tenders for six prototype Class 14E locomotives.

These were required to be dual voltage 3 kV DC and 25 kV AC locomotives with self steering bogies and fully suspended AC traction motors, with a 3,800 kilowatts (5,100 horsepower) power output plus some 400 kilowatts (540 horsepower) to be available for train services such as heating.

The 3 kV DC and 25 kV AC dual voltage Class 14E electric locomotive, the first dual voltage locomotive in South Africa, was designed by the 50 c/s Group consisting of SA Ateliers de Constructions Electriques de Charleroi (ACEC) of Belgium, AEG-Telefunken and Siemens of Germany, Alstom-Atlantique of France and Brown Boveri of Switzerland.

[4] All earlier South African electric locomotives, with the exception of the Orex Line's Class 9Es, ran on spoked wheels using spur gears.

This gear ratio had the result that, while the three prototypes were very fast, they struggled to pick up a load.

On occasion, the Class 14E locomotives were employed to haul the Blue Train all the way along the Cape Town-Pretoria route across the 25 kV AC stretch between Beaufort West and Kimberley, but this task was usually performed by selected Class 14E1 locomotives.