South African Class 7E1
|South African Class 7E1|
|Type and origin|
|Gauge||3 ft 6 in (1,067 mm) Cape gauge|
|Bogies||4.4 m (14 ft 5.2 in) wheelbase|
|Wheel diameter||1,220 mm (48 in)|
|Wheelbase||13.8 m (45 ft 3.3 in)|
|Length||18.43 m (60 ft 5.6 in)|
|Width||2.906 m (9 ft 6.4 in)|
|Height||4.18 m (13 ft 8.6 in) pantographs down|
|Axle load||21,000 kg (20.7 long tons)|
|Locomotive weight||125,500 kg (123.5 long tons)|
|Traction motors||Six HS 1054 GR|
|Transmission||16/94 Gear ratio|
|Maximum speed||100 km/h (62 mph)|
|Power output||Per motor:
515 kW (691 hp) 1 hour
500 kW (670 hp) continuous
3,150 kW (4,220 hp) 1 hour
3,000 kW (4,000 hp) continuous
|Tractive effort||450 kN (100,000 lbf) starting
319 kN (72,000 lbf) 1 hour
300 kN (67,000 lbf) continuous
|Locomotive brake||Air & Rheostatic |
|Train brakes||Air & Vacuum|
|Operator(s)||South African Railways
Transnet Freight Rail
|Class||Class 7E1 |
|Power class||25 kV AC|
|Number in class||50|
The South African Class 7E1 of 1980 is a South African electric locomotive from the South African Railways era.
In 1980 and 1981 the South African Railways placed fifty Class 7E1 electric locomotives with a Co-Co wheel arrangement in mainline service.
The 25 kV AC Class 7E1 electric locomotive was designed for the South African Railways (SAR) by Hitachi, while Dorbyl in South Africa supplied the mechanical components. The first two locomotives, numbered E7101 and E7102, were built by Hitachi in Japan in 1979, while forty-eight more were built by Dorbyl in South Africa between 1979 and 1981 and numbered in the range from E7103 to E7150.
Like Union Carriage and Wagon, neither Hitachi nor Dorbyl allocated builder’s numbers to the Class 7E1 locomotives it built for the SAR, but used the SAR unit numbers for their record keeping.
Since they were acquired solely for use on the Richards Bay coal line where they would always work in multiple, they were built with single cabs. Following the Class 9E that entered service in 1978, the Class 7E1 was the second single cab mainline electric locomotive to be acquired by the SAR. Until the Class 9E was introduced, all South African mainline electric locomotives were dual cab units.
The two sides of the Class 7E1 are sufficiently different in appearance that, when coupled end to end, a pair of them appears at first glance to be two different locomotive types. The left side is smooth, while the right has several large grilles.
Control of traction and rheostatic braking on the Class 7E1 is by stepless solid-state electronics. The electrical equipment was designed for high power factor operation, obtained by the switching in of power-factor correction capacitors. Unlike the Classes 7E and 7E2, where thyristors are used, these locomotives use silicon-diode rectifiers.
The Class 7E1 was placed in service on the 25 kV AC Ermelo-Richards Bay Coalink line, where they still work. In the period from the early 1990s until about 2007 various modifications to improve downhill braking capacity were done to the Coalink line Hitachi-designed locomotives. The first set of upgrades were done on the fifty Class 7E1 locomotives. They retained their Class 7E1 classification after modification.
The main picture shows number E7111’s right side, in SAR Gulf Red and yellow whiskers livery. Other liveries that were applied to the Class 7E1 are illustrated below.
No. E7137 in SAR Gulf Red and yellow whiskers livery at Vryheid, KwaZulu-Natal, 15 August 2007
No. E7118 in Spoornet blue with solid numbers in the Transnet Rail Engineering shops, Durban, 4 June 2010
No. E7145 in Spoornet blue with outline numbers at Richards Bay, KwaZulu-Natal, 14 August 2007
No. E7136 in Transnet Freight Rail livery, Durban, 14 June 2010
- Electric locomotive numbering and classification
- List of South African locomotive classes
- South African locomotive history
- Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 129–131. ISBN 0869772112.
- 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, 61.
- Jane's Train Recognition Guide