South African Class 1E

South African Classes 1E and 1ES

Class 1ES no. E145 at Salt River, Cape Town, January 1975
Type and origin
Power type Electric
Designer Metropolitan-Vickers
Builder Swiss Locomotive and Machine Works
Metropolitan-Vickers
Werkspoor
Robert Stephenson and Hawthorns
Serial number SLM 2875-2934, 3655-3676
WS 747-766
RSH 7181-7190
Model Metrovick 1E
Build date 1923-1944
Total produced 172
Rebuilder South African Railways
Number rebuilt 35 to Classes 1ES and ES
Specifications
AAR wheel arr B-B
UIC class Bo'Bo'
Gauge 3 ft 6 in (1,067 mm) Cape gauge
Wheel diameter 1,219 mm (48.0 in)
Minimum curve 91.45 m (300 ft)
Wheelbase 9,423 mm (30 ft 11.0 in)
 • Bogie 2,819 mm (9 ft 3.0 in)
Pivot centres 6,604 mm (21 ft 8.0 in)
Panto shoes 8,039 mm (26 ft 4.5 in)
Length:
 ​
 • Over couplers 13,310 mm (43 ft 8.0 in)
 • Over beams 12,395 mm (40 ft 8.0 in)
Width 2,800 mm (9 ft 2.2 in)
Height:
 ​
 • Pantograph 3,962 mm (13 ft 0 in)
 • Body height 3,480 mm (11 ft 5.0 in)
Axle load 17,018.75 kg (37,519.9 lb) max
Adhesive weight 68,075 kg (150,080 lb) w/o
Loco weight 68,075 kg (150,080 lb) w/o
Power supply Catenary
Current collection Pantographs
Traction motors Four MV 182R
 • Rating 1 hour 224 kW (300 hp)
Gear ratio 17:75
MU working 4 maximum
Loco brake Air, Rheostatic & Regenerative
Train brakes Air & Vacuum
Couplers Bell link-and-pin
AAR knuckle
Performance figures
Maximum speed 72 km/h (45 mph)
Power output:
 ​
 • 1 hour 896 kW (1,202 hp)
Tractive effort:
 ​
 • Starting 176 kN (40,000 lbf)
 • 1 hour 94 kN (21,000 lbf)
 • Continuous 73 kN (16,000 lbf)
Career
Operators South African Railways
Class Class 1E, Class 1ES
Power class 3 kV DC
Number in class 172
Numbers E1-E95, E98-E122, E139-E190
Delivered 1925-1945
First run 1925

The South African Railways Class 1E of 1925 is an electric locomotive.

Between 1925 and 1945, the South African Railways placed altogether one hundred and seventy-two Class 1E electric locomotives in service, spread over seven orders. They were the first mainline electric locomotives to be introduced in South Africa.[1]

Electrification in Natal

South Africa's first electric locomotive, the Class 1E, entered South African Railways (SAR) service in Natal in 1925. It was designed and ordered for the electrification of the Glencoe to Pietermaritzburg section, a mountainous single track line which carried heavy mineral traffic towards the port of Durban, on an alignment with severe gradients and tight curves. When the existing working by steam locomotives became too slow and inefficient to keep up with increased traffic, electrification of this 171 miles (275 kilometres) section was decided upon to increase the capacity of the line.[2]

Benefits of electrification

An important consideration in deciding upon the economics of electrification was the potential saving in wage-bills. Electrification would reduce the required crew roster from three hundred drivers and firemen to one hundred and seventy drivers and assistants. In addition, it was expected that a large reduction in overtime would be accomplished by increasing the average train speeds from steam traction’s 8 miles per hour (13 kilometres per hour) to electric traction’s 21 miles per hour (34 kilometres per hour) on the Glencoe to Pietermaritzburg section, with slightly higher future speeds anticipated. It was further estimated that the total capacity of the line would be increased by sixty per cent.[3]

At the time, there were two routes between Pietermaritzburg and Durban. The newer route with its 1 in 66 (1½%) gradients was chosen for electrification over the older route with its 1 in 33 (3%) gradients. Between Cato Ridge and Durban, electrification necessitated the doubling of the track and the construction of ten tunnels, as well as the construction of long stretches of cutting and embankment across difficult terrain.[3]

Colenso power station

The Colenso power station was built by the SAR, specifically to power this line. The power which was generated at Colenso, was distributed at 88 kV to twelve substations along the route, where it was converted to 6.6 kV and then to 3 kV DC by synchronous motor generators, for use by the Railways.[4][5][6]

Manufacturers

Class 1E Series 2 builder’s plate

At the time, the first batch of seventy-eight Series 1 locomotives constituted the largest order for a single type of electric locomotive to have been placed anywhere in the world.[7]

Designed by Metropolitan-Vickers (Metrovick), they were built for the SAR in seven series by four manufacturers over a period of twenty years. A total of one hundred and seventy-two Class 1E locomotives were delivered between 1925 and 1945.[8]

Characteristics

Like the subsequent Classes 2E, 3E and 4E, the Class 1E had bogie mounted draft gear. It had a Bo+Bo wheel arrangement with an articulated inter-bogie linkage, therefore no train forces were transmitted directly to the locomotive body.[8]

The batteries were mounted in cases, hung underneath the locomotive body, while sections of the roof above the three compartments were removable to enable heavy machinery or control gear to be lifted out for repair.[3]

Power supply

The chosen overhead power supply was 3 kV DC, the highest direct current overhead voltage in use at the time, while the traction motors operated at 1.5 kV. The four traction motors were electrically coupled in pairs, two in series across the 3 kV supply line.[3]

Orientation

These dual cab locomotives have four grilles below the four windows on one side, and only two grilles below the centre two windows on the other side. When observing the locomotive from the side with four grilles, the number 1 end would be to the left.[1]

Interior layout

The interior layout consisted of five compartments, a driving cab at each end with a connecting corridor along one side of the locomotive, the high tension compartment in the middle of the locomotive, and a machinery compartment behind each cab. The latter two compartments housed auxiliary gear such as two motor generator sets, one of 16 kilowatts (21 horsepower) and the other of 28 kilowatts (38 horsepower), each with a blower fan on its shaft for ventilating the main motors. In addition, it contained the vacuum exhauster, air compressor, air reservoirs for the brakes, low-tension control apparatus for the auxiliaries and battery, together with contactor gear for controlling the field of the larger motor generator.[3][10]

Regenerative braking

The locomotives made use of regenerative braking, which enabled higher speeds to be allowed on down grades, while reducing the dependence on the train's vacuum or air braking system and with the collateral benefit of savings in electricity consumption. It was reportedly the first extensive use, in regular traffic, of electric locomotives equipped for multiple unit operation with regenerative braking.[2][3][8]

Service

While they were employed mainly in Natal, some later also worked on the Witwatersrand and eventually also in the Western Cape. Some of them covered more than 8,000,000 kilometres (4,970,970 miles) during their service lives.[11][12]

Early models bore number plates inscribed in English only. By 1938, when the Series 5 locomotives were placed in service, Afrikaans had been accepted as South Africa’s second official language and new locomotives bore bilingual number plates.

Modification

They served in both goods and passenger service. Since their top speed of 72 kilometres per hour (45 miles per hour) was considered too slow for passenger service, two Class 1Es were modified in 1936, by changing their gear ratio to enable them to run at speeds of up to 90 kilometres per hour (56 miles per hour).[10]

Altogether thirty-five of the Class 1E locomotives were eventually withdrawn from mainline service, modified and reclassified to Class 1ES, for use as shunting locomotives. The modifications included alteration of the resistance grids in the electrical circuit and enlarged and widened cabs, but the gear ratios were not altered. Apart from the wider cabs, the modified Class 1ES locomotives were visually identifiable by their front windows with slanted upper edges, compared to the rectangular shaped front windows of the Class 1E.[8]

In 1964, two of these Class 1ES locomotives were rebuilt to centre-cab Class ES shunting locomotives.[8]

Retirement

All the Class 1E and Class 1ES locomotives were retired by 1990.[1]

Series-specific data

The Class 1E builders, works numbers, years of construction and modifications to Classes ES and 1ES are listed in the table. The axle load and adhesive weight, as shown under "Specifications" in the table above, may be considered as average figures for the Class 1E, since these weights varied between the seven locomotive series. In respect of the Series 1 to 6 locomotives, the actual load per axle of each bogie and the total locomotive mass are included in the table below.[1][9][13]

Illustration

The main picture shows a Class 1ES locomotive with its enlarged cab and slanted upper edge front windows, while the following pictures illustrate some of the liveries which Class 1E locomotives served in.

References

  1. 1 2 3 4 South African Railways Index and Diagrams Electric and Diesel Locomotives, 610 mm and 1065 mm Gauges, Ref LXD 14/1/100/20, 28 January 1975, as amended
  2. 1 2 SETS - SAR Class 1E Electric Locomotives
  3. 1 2 3 4 5 6 Mike’s Railway History – A Look at Railways in 1935 & Before: South African Electrification
  4. ↑ "South African Railways Power Plant". Electric Railway Journal 60 (24): 914. 9 December 1922. Retrieved 15 September 2010.
  5. ↑ Brazil, H (1928). "The South African Railways Electrification". Electrical Substations. Edward Arnold & Co. p. 110. Retrieved 2010-01-12.
  6. ↑ Brazil, H (1928). "IX - Traction Substations". Electrical Substations. Edward Arnold and Co. p. 110. Retrieved 15 September 2010.
  7. ↑ "Natal Contract to British". Electric Railway Journal 61: 107. 13 January 1923. Retrieved 15 September 2010.
  8. 1 2 3 4 5 Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. p. 125. ISBN 0869772112.
  9. 1 2 3 4 5 6 7 8 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. 4, 50.
  10. 1 2 Steam, Oil & Wires, vol 1, (Bernard Zurnamer), pp69-71
  11. ↑ December 1922 and March 1925 issues of the Metropolitan-Vickers Gazette
  12. ↑ Electric Traction by A.T. Dover (1929)
  13. ↑ SLM Lokomotiven 1871-1894 by Verein Rollmaterialverzeichnis Schweiz
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