South African Class 6E1, Series 11

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South African Class 6E1, Series 11
SAR Class 6E1 Series 11 E2185.jpg
No. E2185, the last Class 6E1, at Witbank, Transvaal, 7 October 1991
Type and origin
Power type Electric
Designer Union Carriage and Wagon
Builder Union Carriage and Wagon
Model UCW 6E1
Build date 1984-1985
Total produced 45
Rebuilder Transnet Rail Engineering
Rebuild date 2001-2005
Number rebuilt 45 to Class 18E, Series 1
 • AAR B-B
 • UIC Bo'Bo'
Gauge 3 ft 6 in (1,067 mm) Cape gauge
Wheel diameter 1,220 mm (48.0 in)
Wheelbase 11,279 mm (37 ft 0.1 in)
 • Bogie 3,430 mm (11 ft 3.0 in)
Pivot centres 7,849 mm (25 ft 9.0 in)
Panto shoes 6,972 mm (22 ft 10.5 in)
 • Over couplers 15,494 mm (50 ft 10.0 in)
 • Body 14,631 mm (48 ft 0 in)
Width 2,896 mm (9 ft 6.0 in)
 • Pantograph 4,089 mm (13 ft 5.0 in)
 • Body height 3,937 mm (12 ft 11.0 in)
Axle load 22,447 kg (49,487 lb)
Adhesive weight 89,788 kg (197,949 lb)
Loco weight 89,788 kg (197,949 lb)
Power supply Catenary
Current source Pantographs
Traction motors Four AEI-283AY
 • Rating 1 hour 623 kW (835 hp)
 • Continuous 563 kW (755 hp)
Gear ratio 18:67
Loco brake Air & Regenerative
Train brakes Air & Vacuum
Couplers AAR knuckle
Performance figures
Maximum speed 113 km/h (70 mph)
Power output:
 • 1 hour 2,492 kW (3,342 hp)
 • Continuous 2,252 kW (3,020 hp)
Tractive effort:
 • Starting 311 kN (70,000 lbf)
 • 1 hour 221 kN (50,000 lbf)
 • Continuous 193 kN (43,000 lbf) @ 40 km/h (25 mph)
Operators South African Railways
Class Class 6E1
Power class 3 kV DC
Number in class 45
Numbers E2141-E2185
Delivered 1984-1985
First run 1984
Last run 2005

The South African Railways Class 6E1, Series 11 of 1984 was an electric locomotive.

In 1984 and 1985, the South African Railways placed forty-five Class 6E1, Series 11 electric locomotives with a Bo-Bo wheel arrangement in mainline service.[1]


The 3 kV DC Class 6E1, Series 11 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).[2]

Forty-five locomotives were delivered in 1984 and 1985, numbered in the range from E2141 to E2185. These were the last Class 6E1 locomotives to be built. UCW did not allocate builder's numbers to the locomotives which it built for the SAR, but used the SAR unit numbers for their record keeping.[1]



Series 2 to 11 bogies
Bogie frame and wheels

The Class 6E1 was built with sophisticated traction linkages on their bogies. Together with the locomotive's electronic wheel-slip detection system, these traction struts, mounted between the linkages on the bogies and the locomotive body and colloquially referred to as grasshopper legs, ensure the maximum transfer of power to the rails without causing wheel-slip, by reducing the adhesion of the leading bogie and increasing that of the trailing bogie by as much as 15% upon starting off. This feature is controlled by electronic wheel-slip detection devices and an electric weight transfer relay, which reduce the anchor current to the leading bogie by as much as 50A in notches 2 to 16.[3]


The locomotive itself used air brakes, but it was equipped to operate trains with air or vacuum brakes. While hauling a vacuum braked train, the locomotive's air brake system would be disabled and the train would be controlled by using the train brakes alone to slow down and stop. While hauling an air braked train, on the other hand, the locomotive brakes would engage along with the train brakes. While working either type of train downgrade, the locomotive's regenerative braking system would also work in conjunction with the train brakes.[4]

When the locomotive was stopped, the air brakes on both bogies were applied together. The handbrake or parking brake, located in Cab no. 2, only operated on the unit's last axle, or no. 7 and 8 wheels.[4]


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 no. 2 end. A corridor 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. The locomotive has three small panels along the lower half of the body and a large hatch door on the roof access ladder side, and only one small panel and a large hatch door on the opposite side.[1]

Series identifying features[edit]

The Class 6E1 was produced in eleven series over a period of nearly sixteen years. While some of the 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 locomotives had their sandboxes mounted along the bottom edge of the locomotive body, with the sandbox lids fitting into recesses in the body.[1]

Series 8 and later locomotives could be distinguished from all older models by the large hatch door on each side, below the second small window to the right of the side door on the roof access ladder side, and below the first window immediately to the right of the door on the other side.[1][3]

Drainage holes on Series 9 to 11

The Series 9 to Series 11 locomotives were visually indistinguishable from each other, but could be distinguished from all earlier models by the rainwater drainage holes on their lower sides. These holes were usually covered by so-called buckets, but the covers were absent on a few locomotives. Another distinction was the end doors, which were recessed into the doorframes on Series 9 to Series 11 locomotives, compared to earlier models, which had their end doors flush with the doorframes. In addition, on Series 9 and later models, the split side window on the driver's assistant side was replaced by a single rectangular side window with rounded corners. Finally, unlike all earlier models, all four doors on Series 9 to Series 11 locomotives had rounded corners.[5]

Crew access[edit]

The Class 5E, 5E1, 6E and earlier 6E1 locomotives are notoriously difficult to enter from ground level, since their lever-style door handles are at waist level when standing inside the locomotive, making it impossible to open the door from outside without first climbing up high enough to reach the door handle while hanging on to the side handrails with one hand only. Crews therefore often chose to leave the doors ajar when parking and exiting the locomotives.[6]

Side doors with two interconnected latch handles on the outside, such as those which were introduced on the Class 7E1, with one outside handle mounted near floor level and the other at mid-door level, were also introduced on Class 6E1 locomotives, beginning with Series 9.[7]


The Class 6E1 family saw service all over both of the 3 kV DC mainline and branchline networks, the smaller Cape Western network between Cape Town and Beaufort West, and the larger network which covers portions of the Northern Cape, the Free State, Natal, Gauteng, North West Province and Mpumalanga.[8]

Rebuilding to Class 18E[edit]

Cab 1 of Class 18E no. 18-106, ex Class 6E1 no. E2174, Sentrarand, 22 September 2009

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 no. 1 end was stripped of all controls and the driver's front and side windows were blanked off to have a toilet installed, thereby forfeiting the locomotive's bi-directional ability.[8][9]

Brake rack in Class 18E no. 18-089

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 not a deciding factor, but was considered an additional benefit.[9]

While the earlier Class 6E1, Series 2 to 7 locomotives had been built with a brake system consisting of various valves, connected to each other with pipes, commonly referred to as a "bicycle frame" brake system, the Class 6E1, Series 8 to 11 locomotives were built with an air equipment frame brake system, commonly referred to as a brake rack. Since the design of the rebuilt Class 18E locomotives included the same brake rack, the rebuilding project was begun with the newer series 8 to 11 locomotives, to reduce the overall cost of rebuilding.[9]

The Class 6E1, Series 11 locomotives which were used in this project, were all rebuilt to Class 18E, Series 1 locomotives. All forty-five Series 11 locomotives were rebuilt by April 2005.[8][10]


  1. ^ a b c d e 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. ^ "UCW - Electric locomotives" (PDF). The UCW Partnership. Archived from the original (PDF) on 12 October 2007. Retrieved 30 September 2010. 
  3. ^ a b Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 128–129. ISBN 0869772112. 
  4. ^ a b Operation - South African Classes 6E, 6E1, 16E, 17E and 18E
  5. ^ 18-050 (ex Series 9 E2013) with recessed end door and rounded door corners
  6. ^ E1882 with high mounted door handle
  7. ^ 18-253 (ex Series 9 E2058) with two door handles
  8. ^ a b c Railways of Southern Africa Locomotive Guide, 2002 Edition, (Compiled by John N. Middleton), p57, as amended by Combined Amendment List 4, January 2009
  9. ^ 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
  10. ^ Information gathered from the rebuild files of individual locomotives at Transnet Rail Engineering's Koedoespoort shops