South African Class 7E3, Series 1 - AbsoluteAstronomy.com

Between 1983 and 1984 the South African Railways placed sixty Class 7E3, Series 1 electric locomotive

Electric locomotive

An electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or an on-board energy storage device...

s with a Co-Co wheel arrangement in main line service. Circa 2000 sixteen of these dual cab locomotives were rebuilt to single cab locomotives and reclassified to Class 7E4

South African Class 7E4

In 1983 and 1984 the South African Railways placed sixty Class 7E3, Series 1 electric locomotives with a Co-Co wheel arrangement in main line service. These were followed by another twenty-five Class 7E3, Series 2 locomotives in 1984 and 1985...

Manufacturer

The Class 7E3, Series 1 25 kV AC electric locomotive was designed for the South African Railways (SAR) by Hitachi

Hitachi

Hitachi is a multinational corporation specializing in high-technology.Hitachi may also refer to:*Hitachi, Ibaraki, Japan*Hitachi province, former province of Japan*Prince Hitachi and Princess Hitachi, members of the Japanese imperial family...

and built in South Africa by Dorbyl, who also supplied the mechanical components. Sixty locomotives were delivered by Dorbyl between 1983 and 1984, numbered E7216 to E7275.

Like Union Carriage and Wagon (UCW), Dorbyl did not allocate builder’s numbers to the locomotives it built for the SAR. While the usual practice by most other locomotive builders was to allocate builder’s numbers or works numbers to record the locomotives built by them, Dorbyl simply used the SAR running numbers for their record keeping.

Features

On the Class 7E3, Series 1, control of traction and rheostatic braking 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.

These dual cab locomotives have a roof access ladder on one side only, just to the right of the cab access door. The roof access ladder end is marked as the number 1 end. Series 1 and Series 2 locomotives are visually indistinguishable from each other, but the two sides of the locomotives are sufficiently different in appearance that a pair of them coupled at the same end appears at first glance to be two different locomotive types. The roof access ladder side is smooth, while the other side has several large grilles.

Modifications and reclassifications

In the period from the early 1990s until about 2007 various modifications to improve downhill braking capacity were done to the Coalink line’s Hitachi designed locomotives. The first set of upgrades were done on the fifty Class 7E1

South African Class 7E1

Between 1980 and 1981 the South African Railways placed fifty Class 7E1 electric locomotives with a Co-Co wheel arrangement in main line service.-Manufacturers:...

locomotives.

Class 7E4

Circa 2000 seventeen Class 7E3 locomotives, sixteen Series 1, numbers E7260 to E7275, and one Series 2, number E7276, underwent significant modifications. This included the installation of Hitachi micro-processor controls with improved rheostatic brakes and the conversion from double cab to single cab, since the cab space was required for some of the new equipment that was installed. These modified single cab locomotives were reclassified to Class 7E4

South African Class 7E4

Class 7E5

The conversions to Class 7E4 were costly, however, and it was decided to modify further Class 7E3 locomotives to a lesser extent, gaining almost the same benefits at a lower cost since they remained as double cab locomotives. In total about fifty locomotives of both series were upgraded in this manner. These were reclassified to Class 7E5, although externally they were still identical to the Class 7E3.

Class 7E6

Following some systems failures on the upgraded Class 7E5 locomotives, a further variation in the modifications was applied to the remaining Class 7E3 locomotives that had not yet been upgraded. These locomotives were then reclassified to Class 7E6. Eventually all the Class 7E5 locomotives were also modified once again to meet the Class 7E6 specifications.

Revert to Class 7E3

Since by October 2007 all these locomotives were fully upgraded and, apart from the single cab Class 7E4 conversions, once again identical, they reverted to their original Class 7E3 classifications. Although E7216 to E7259 are all officially Class 7E3, Series 1 once again, many of these forty-four locomotives still bore markings to identify them as either Class 7E5 or Class 7E6. The single cab locomotives, however, remained classified as Class 7E4.

Service

Since 1978, 25 kV AC was introduced on all new main line electrification projects bar one, the one exception being the Orex iron ore line from Sishen to Saldanha, where 50 kV AC is used. The Class 7E3, Series 1 locomotives all serve on the 25 kV AC Coalink line between Ermelo via Vryheid to the Richards Bay Coal Terminal

Richards Bay Coal Terminal

The Richards Bay Coal Terminal , located in the Richards Bay harbour, is the largest coal export facility in Africa. The Chinese port of Qinhuangdao maintains the largest coal exporting terminal in the world, at 209 Million tons compared to Richards Bay with 91 Million tons.Potential throughput is...

Liveries

The main picture shows E7253 in Spoornet blue livery with solid numbers, inscribed "7E6".