South African Class 6E1, Series 8

Manufacturer

The 3 kV DC Class 6E1, Series 8 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).

Between 1979 and 1981, 105 locomotives were delivered, numbered in the range from E1896 to E2000. UCW did not allocate builder’s or works numbers to the locomotives it built for the SAR, but used the SAR unit numbers for their record keeping.

Bogies

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.

Brakes

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.

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.

Orientation

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 on the roof access ladder side, and only one small panel on the opposite side.

Series identifying features

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.

Series 8 is the only Class 6E1 series with unique visual distinguishing features. It can be distinguished from all earlier series by its 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 side door on the other side. It can also be distinguished from all subsequent series by the absence of rainwater drainage holes along the lower body sides.

Crew access

The Class 5E, 5E1, 6E and 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 choose to leave the doors ajar when parking and exiting the locomotives.

Series 8 and some late model Series 7 locomotives were equipped with doors on which the outside door latch handle is mounted near floor level, with a simple drawer pull type handle at mid-door level.

Service

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.

Reclassification to Class 16E

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 locomotive 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 no. 1 ends, abandoning the no. 1 end cabs in terms of maintenance and using only the no. 2 end cabs. Most were later either disbanded, with the locomotives reverting to Class 6E1 and regaining their original numbers, or getting rebuilt to Class 18E.

Ten known Series 8 locomotives were part of such Class 16E pairs.

Modification to Class 17E

Class 17E locomotives were modified and reclassified from Class 6E1 Series 7, 8 or 9 locomotives during 1993 and 1994. Key modifications included improved regenerative braking and wheel-slip control, to improve their reliability on the steep gradients and curves of the Natal mainline. Unlike the unmodified but reclassified Class 16E locomotives, the Class 17Es retained their original unit numbers after reclassification.

A stumbling block was that the regeneration equipment at many of the sub-stations along the route was unreliable, and since there was no guarantee that another train would be in the same section to absorb the regenerated energy, there was always the risk that line voltage could exceed 4.1 kV, which would make either the sub-station or the locomotive trip out. As a result, the subsequent rebuilt Class 18E locomotives were not equipped with regenerative braking.

Fifty-five known Series 8 locomotives were modified and reclassified to Class 17E. Their unit numbers are listed in the table below.

Rebuilding to Class 18E

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 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.

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.

While the earlier Class 6E1, Series 2 to 7 locomotives had been built with a brake system which consisted of various valves, connected to each other with pipes and 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.

Bar two, all the Class 6E1, Series 8 locomotives which were used in this rebuilding project were rebuilt to Class 18E, Series 1 locomotives. The known numbers and renumbering details are listed in the table.

The Blue Train

In the SAR and Spoornet eras, when the official liveries were Gulf Red and yellow whiskers for the SAR, and initially orange and later maroon for Spoornet, many selected electric locomotives and some diesel-electrics were painted blue for use with the Blue Train, but without altering the layout of the various paint schemes. Blue Train locomotives were therefore blue with yellow whiskers in the SAR era, blue with the Spoornet logo and the name "SPOORNET" in Spoornet’s orange era, and blue with the Spoornet logo, but without the name "SPOORNET", in Spoornet’s maroon era. Later, in Spoornet’s blue era, there was no need for a separate Blue Train livery, while in the Transnet Freight Rail (TFR) era, one Class 14E and the surviving Class 14E1 electric locomotives were eventually repainted in blue during 2012, for use with the Blue Train.

All but eight Class 6E1, Series 8 locomotives were delivered in the SAR Gulf Red and yellow whiskers livery. The eight exceptions, numbers E1950 to E1957, were delivered in blue with yellow whiskers, for use with the Blue Train between Cape Town and Beaufort West in the Cape Western region.

Four of these blue locomotives were damaged on 24 April 1997, when trains number 81007 and 18008, two Trans-Karoo passenger trains, collided at Gouda. One known additional Series 8 locomomotive, no. E1973, was then repainted in Spoornet’s orange era Blue Train livery. The four damaged locomotives were later replaced by eight Class 6E locomotives, which were repainted in blue.

Of the four damaged blue locomotives, numbers E1953 and E1956 were scrapped, while numbers E1954 and E1955 were rebuilt to the first two Class 18E locomotives in 2000 and 2001, numbered 18-001 and 18-002 respectively.

The main picture shows both versions of the Spoornet Blue Train livery. The leading locomotive, no. E1973, is in the orange era livery with the name "SPOORNET" below the emblem on the side, while the trailing locomotive, no. E1951, is in the maroon era livery without the name "SPOORNET" below the emblem on the side.

Illustration

The main picture shows no. E1973 in Spoornet's orange era Blue Train livery, approaching Bellville from Stikland on 17 November 2006. Illustrated below are some of the other liveries in which Class 6E1, Series 8 locomotives served.