South African Class ES
Class ES shunting locomotive, circa 1936
|Type and origin|
|Designer||South African Railways|
|Builder||South African Railways
Swiss Locomotive & Machine Works
|Serial number||See table|
|Total produced||2 Series 1, 1935
10 Series 2, 1938
10 Series 3, 1951
4 industrial, 1952 & 1957
2 Series 4, 1964
|Rebuilder||South African Railways|
|Number rebuilt||Two ex Class 1E|
|Gauge||3 ft 6 in (1,067 mm) Cape gauge|
|Bogies||2,819 mm (9 ft 2.98 in) wheelbase|
|Wheel diameter||1,219 mm (47.99 in)|
|Minimum curve||91.45 m (300 ft)|
|Wheelbase||9,423 mm (30 ft 10.98 in)|
|Length||13,310 mm (43 ft 8.02 in)|
|Width||2,800 mm (9 ft 2.24 in)|
Series 1 & 2: 3,478 mm (11 ft 4.93 in)
Series 3 & 4: 3,618 mm (11 ft 10.44 in)
Series 1 & 2: 3,859 mm (12 ft 7.93 in)
Series 3 & 4: 4,026 mm (13 ft 2.50 in)
|Axle load||17,018 kg (16.7 long tons)|
|Locomotive weight||68,075 kg (67 long tons)|
|Traction motors||Four MV 182R|
|Transmission||17/75 gear ratio|
|Maximum speed||40 km/h (25 mph)|
|Power output||224 kW (300 hp) 1 hour per motor
896 kW (1,202 hp) 1 hour total
|Tractive effort||176 kN (40,000 lbf) starting
94 kN (21,000 lbf) 1 hour
73 kN (16,000 lbf) continuous
|Train brakes||Air & Vacuum|
|Operator(s)||South African Railways
|Power class||3 kV DC|
|Number in class||28|
E500 & E501 (ex E96 & E97)
E503-E512 (ex E124-E133
|First run||1936 |
In 1936 the South African Railways built two Class ES centre-cab electric shunting locomotives with a Bo-Bo wheel arrangement, based on the Class 1E mainline electric locomotive. Between then and 1964, more were acquired until a total of twenty-four Class ES locomotives were eventually in service. Four more were built new for industry in 1952 and 1957.
In 1935 a design for a centre-cab electric shunting locomotive, based on the South African Class 1E mainline locomotive that was originally designed by Metropolitan-Vickers (Metrovick), was prepared by A.G. Watson, Chief Mechanical Engineer (CME) of the South African Railways (SAR) from 1929 to 1936.
For the South African Railways
The first two Class ES locomotives were built new in the Pietermaritzburg shops of the SAR. These two were initially numbered E96 and E97, but they were later renumbered to E500 and E501. They entered service in 1936 as South Africa's first purpose-built electric shunting locomotives.
Over the next twenty-eight years more of these locomotives were built and by 1964 twenty-four Class ES locomotives had been placed in service by the SAR. As can be expected in a locomotive type that was built over a period of almost three decades, there are differences in exterior appearance between locomotives.
- Two batches of ten were built by the Nederlandsche Fabriek van Werktuigen en Spoorwegmaterieel (Werkspoor).
- Series 2, numbers E124 to E133, were delivered in 1937 and were later renumbered in the range from E503 to E512.
- Series 3, numbers E515 to E524, were delivered in 1951.
- Series 4, numbers E525 and E526, the last two, were rebuilt from Class 1E locomotives in the SAR shops in 1964.
For Driefontein gold mine
In 1952 two Class ES locomotives were built new for the Driefontein Consolidated Gold Mine (Dries) by Werkspoor, numbered 1 and 2. Another two were delivered new to the mine in 1957, numbered 3 and 4, also built by Werkspoor.
The "S" in the locomotive’s class designation identifies it as a shunting locomotive, designed for and usually limited to yard work.
With a maximum safe speed of 40 kilometres per hour (25 miles per hour), they ran on an overhead power supply of 3 kV DC, the highest direct current overhead voltage in use at the time they were placed in service. Their traction motors, connected in series on each bogie, operated on 1.5 kV DC.
Although the class ES was initially largely confined to service in Natal, members of the class became quite common working on the Western Transvaal System in later years, mainly being employed around the Witwatersrand. Beginning in 1983, they were eventually replaced by the Class 8E, also a centre-cab shunting locomotive.
The main picture shows one of the first Class ES locomotives to be built, circa 1936. Until the 1960s they had a bottle green livery with red buffer beams. Some of the liveries that were applied to Class ES locomotives are illustrated in the pictures below.
- South African Railways Index and Diagrams Electric and Diesel Locomotives, 610mm and 1065mm Gauges, Ref LXD 14/1/100/20, 28 January 1975, as amended
- Middleton, John N. (2002). Railways of Southern Africa Locomotive Guide - 2002 (as amended by Combined Amendment List 4, January 2009) (2nd, Dec 2002 ed.). Herts, England: Beyer-Garratt Publications. pp. 51, 63.
- Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 134–135. ISBN 0869772112.
- "Natal Contract to British". Electric Railway Journal 61: 107. 13 January 1923. Retrieved 15 September 2010.
- SETS - SAR Class 1E Electric Locomotives