South African Class 6E1, Series 5

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South African Class 6E1, Series 5
SAR Class 6E1 Series 5 E1629 Purple.JPG
No. E1629 at Koedoespoort, Pretoria, Gauteng, 8 October 2009, in brand new Shosholoza Meyl passenger livery
Power type Electric
Designer Union Carriage and Wagon
Builder Union Carriage and Wagon
Model UCW 6E1
Build date 1974-1976
Total produced 100
Rebuilder Transwerk
Rebuild date 1978
Number rebuilt 1 to experimental AC
UIC classification Bo-Bo
Gauge 3 ft 6 in (1,067 mm) Cape gauge
Bogies 3.430 m (11 ft 3 in) wheelbase
Wheel diameter 1,220 mm (48 in)
Wheelbase 11.279 m (37 ft 0.1 in)
Length 15.494 m (50 ft 10 in)
Width 2.896 m (9 ft 6 in)
Height 4.089 m (13 ft 5 in) pantographs down
Axle load 22,226 kg (21.9 long tons)
Locomotive weight 88,904 kg (87.5 long tons)
Current collection
Traction motors Four AEI 283 AZ
Transmission 18/67 gear ratio
Top speed 113 km/h (70 mph)
Power output Per motor:
623 kW (835 hp) 1 hour
563 kW (755 hp) continuous
2,492 kW (3,342 hp) 1 hour
2,252 kW (3,020 hp) continuous
Tractive effort 311 kN (70,000 lbf) starting
221 kN (50,000 lbf) 1 hour
193 kN (43,000 lbf) continuous at 40 km/h (25 mph)
Locomotive brake Regenerative
Train brakes Air & Vacuum
Operator(s) South African Railways
Transnet Freight Rail
Class Class 6E1
Power class 3 kV DC
Number in class 99
Number E1546-E1599, E1601-E1645 [1]
Delivered 1974-1976
First run 1974

The South African Class 6E1, Series 5 of 1974 is a South African electric locomotive from the South African Railways era.

Between 1974 and 1976 the South African Railways placed one hundred Class 6E1, Series 5 electric locomotives with a Bo-Bo wheel arrangement in mainline service. One of them was later withdrawn from revenue service for use as an experimental 25 kV AC locomotive.[1][2][3]


The 3 kV DC Class 6E1, Series 5 electric locomotive was designed and built for the South African Railways (SAR) by Union Carriage and Wagon (UCW) in Nigel, Transvaal, with the electrical equipment supplied by the General Electric Company (GEC).[4]

One hundred locomotives were delivered between 1974 and 1976, numbered in the range from E1546 to E1645. UCW did not allocate builder’s numbers to the locomotives it built for the SAR and used the SAR running numbers for their record keeping.[1]



The Class 6E1 was built with sophisticated traction linkages on their bogies and with stabilisers mounted between the linkages on the bogies and the locomotive body. Together with its electronic wheelslip detection system, these traction linkages and stabilisers ensure the maximum transfer of power to the rails without causing wheelslip.[2]


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 2 end. A passage along the centre of the locomotive connects the cabs, which are identical apart from the fact that the handbrake is located in cab 2. A pantograph hook stick is stowed in a tube mounted below the lower edge of the locomotive body on the roof access ladder side.[1]


The locomotive is controlled via resistors over which the voltage is dropped in a configuration of series and parallel electrical circuits. The circuit breakers that switch these circuits work under very high power and voltage and are all pneumatically operated for insulation purposes. Compressed air is required to open or close the switch actions and air is also used for the weak field cam switch that also switches under very high currents.[5]

Upon starting off and in the low notches the major part of the voltage is dropped over the banks of resistors and all four traction motors are in series. As the driver notches up, some of the resistor banks are cut out via the pneumatically operated switches and the voltage increases across the traction motors. The more resistors that are cut out as the driver notches higher, the more power is developed by the traction motors. At around 22 to 28 kilometres per hour (14 to 17 miles per hour) the locomotive switches to a parallel combination, where the two traction motors per bogie are in a series electrical circuit while the two bogies are in parallel electrical circuit. Eventually, when all resistors are cut out, the locomotive is operating in full-field.[5]

Series identifying features[edit]

SAR Class 6E1 Series 5 E1597 ID.JPG

The Class 6E1 was produced in eleven series over a period of nearly sixteen years, with altogether nine hundred and sixty units placed in service, all built by UCW. This makes the Class 6E1 the most numerous single locomotive class ever to have seen service in South Africa and serves as ample proof of a highly successful design.[1][2]

While some Class 6E1 series are visually indistinguishable from their predecessors or successors, some externally visible changes did occur over the years. Series 1 locomotives had their sandboxes mounted on the bogies, while Series 2 to 11 had their sandboxes mounted along the bottom edge of the locomotive body, with the sandbox lids fitting into recesses in the body.[1]

The Series 3 to Series 5 locomotives are visually indistinguishable from each other, the only externally visible difference being the narrower stirrup middle step below the side doors of the first fifty Series 3 locomotives, those in the number range from E1296 to E1345.[1][2][6][7]


The Class 6E1 family saw service all over both of the Transnet Freight Rail (TFR) 3 kV DC mainline and branchline networks, the smaller Cape Western network between Cape Town and Beaufort West and the larger network that covers portions of the Northern Cape, the Free State, Natal, Gauteng, North West Province and Mpumalanga.[3]

Test bed for 25 kV AC research[edit]

Class Experimental AC no. E1600

One of the one hundred Series 5 units, no. E1600, was withdrawn from revenue service in 1978, rebuilt as a test-bed for 25 kV AC electrification and reclassified to Class Experimental AC. This was done while the electrification of the four isolated 25 kV routes was in progress. E1600 was never returned to revenue service. The four 25 kV AC routes are:[2]

Reclassification and rebuilding[edit]

Reclassification to Class 16E[edit]

During 1990 and 1991 Spoornet semi-permanently coupled several pairs of otherwise largely unmodified Class 6E1 locomotives, reclassified them to Class 16E and allocated a single running number to each pair, with the individual locomotives in the pairs inscribed "A" or "B". The aim was to accomplish savings on cab maintenance by coupling the locomotives at their number 1 ends, abandoning the number one end cabs in terms of maintenance and using only the number two end cabs.[3]

Two known Series 5 locomotives, numbers E1549 and E1607, were part of such Class 16E pairs and became Class 16E numbers 16-319B and 16-335A respectively.[3]

Rebuilding to Class 18E[edit]

Cab 1 of Class 18E no. 18-698, ex Class 6E1 no. E1553, Beaufort West, 29 May 2013

Beginning in 2000, Spoornet began a project to rebuild Series 2 to 11 Class 6E1 locomotives to Class 18E, Series 1 and Series 2 at the Transnet Rail Engineering (TRE) workshops at Koedoespoort. In the process the cab at the number 1 end was stripped of all controls and the driver's front and side windows were blanked off in order to have a toilet installed, thereby forfeiting the loco's bi-directional ability.[3][8]

Since the driving cab's noise level had to be below 85 decibels, cab 2 was selected as the Class 18E driving cab primarily based on its lower noise level compared to cab 1, which is closer and more exposed to the compressor's noise and vibration. Another factor was the closer proximity of cab 2 to the low voltage switch panel. The fact that the handbrake was located in cab 2 was considered an additional benefit.[8]

The Class 6E1, Series 5 locomotives that were used in this project were all rebuilt to Class 18E, Series 2 locomotives. Their numbers and renumbering details are shown in the table.[8]

Liveries illustrated[edit]

All the Class 6E1, Series 5 locomotives were delivered in the SAR Gulf Red and yellow whiskers livery. The main picture shows no. E1629 in the Shosholoza Meyl livery of the Passenger Rail Agency of South Africa (PRASA). Illustrated below are some of the other liveries that Series 5 locomotives served in.

See also[edit]


  1. ^ a b c d e f g 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
  2. ^ a b c d e Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 128–129. ISBN 0869772112. 
  3. ^ a b c d e f 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. 50, 57, 60. 
  4. ^ "UCW - Electric locomotives". The UCW Partnership. Archived from the original on 12 October 2007. Retrieved 30 September 2010. 
  5. ^ a b Operation - South African Classes 6E, 6E1, 16E, 17E and 18E
  6. ^ E1345 with narrow stirrup
  7. ^ E1346 with wide stirrup
  8. ^ a b c Information gathered from the rebuild files of individual locomotives at Transnet Rail Engineering’s Koedoespoort shops, or obtained from John Middleton as well as several Transnet employees