South African Class 1E

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South African Classes 1E and 1ES
SAR Class 1ES E145.jpg
Class 1ES no. E145 at Salt River, January 1975
Type and origin
Power type Electric
Designer Metropolitan-Vickers
Builder Swiss Locomotive and Machine
Metropolitan-Vickers
Werkspoor
Robert Stephenson & 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)
Adhesive weight 68,075 kg (150,080 lb)
Loco weight 68,075 kg (150,080 lb)
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 (c. 1930s-1950s)
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
Withdrawn c. 1990

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

Between 1925 and 1945, the South African Railways placed altogether 172 Class 1E electric locomotives in service, spread over seven orders. They were the first mainline electric locomotives to be introduced in South Africa.[1][2]

Railways electrification[edit]

In 1920, following a report and recommendations on electric traction by consulting engineers Merz and McClellan of London, the South African Parliament authorised the electrification of the lines between Durban and Pietermaritzburg in Natal and between Cape Town and Simon's Town on the Cape Peninsula, at a cost of £4,400,000.[1]

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]

After it was pointed out that the Natal traffic bottleneck was really above rather than below Pietermaritzburg, electrification in Natal eventually first took place between that city and Glencoe. It was a mountainous 171 miles (275 kilometres) single-track section which carried heavy mineral traffic towards the port of Durban on an alignment with severe gradients and tight curves, where the existing working by steam locomotives became too slow and inefficient to keep up with increasing traffic.[1][4]

Work commenced in 1922 and the first electric train on that section was run in November 1925. The section was in full electric operation by January 1927. Electrification of the Simon's Town line commenced in March 1927 and full electric operation was introduced during September 1928.[1]

Benefits[edit]

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 300 drivers and firemen to 170 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]

Colenso power station[edit]

The chosen overhead power supply was 3 kV DC, the highest direct current overhead voltage in use at the time. The Colenso power station was built by the SAR, specifically to power this line. The complete electrical system for the section consisted of the coal power station at Colenso, which generated three-phase 50 Hz current at 6.6 kV AC, stepped up and distributed at 88 kV AC to twelve automatic substations along the route. The substations were located at an average of about 15 miles (24 kilometres) apart and all but one were supplied at 88 kV by two separate three-phase transmission lines, while the one at Colenso was fed 6.6 kV AC directly from the power station.[1][5][6][7]

At the substations, the current was stepped down again to 6.6 kV AC, converted by synchronous motor generators to 3 kV DC and fed to the overhead catenary, for use by the electric locomotives. The overhead equipment consisted of a copper catenary which supported a copper contact wire by means of droppers. The track structures were steel lattice masts, erected on concrete foundations.[1][5][6][7]

Manufacturers[edit]

South Africa's first electric locomotive, the Class 1E, entered service in Natal in 1925. The locomotive was designed by Metropolitan-Vickers (Metrovick) of Manchester, while the mechanical parts of the unit were approved by Col F.R. Collins DSO, Chief Mechanical Engineer of the South African Railways (SAR). At the time, the first batch of 78 Class 1E, Series 1 locomotives constituted the largest order for a single type of electric locomotive to have been placed anywhere in the world. The eventual fleet of 172 locomotives was built for the SAR in seven series by four manufacturers over a period of twenty years.[1][4][8][9]

  • Series 1. The first sixty locomotives, numbered in the range from E1 to E60, were built by the Swiss Locomotive and Machine Works (SLM) in 1923 and 1924. The remaining eighteen Series 1 locomotives, numbered in the range from E61 to E78, were built by Metrovick in 1925.[10]
Series 2 builder's plate
  • Series 2. All seventeen locomotives, numbered in the range from E79 to E95, were built by Metrovick in 1925 and 1926 and entered service in 1927. These units were slightly heavier than those of Series 1.[10][11]
  • Series 3. Five locomotives, numbered in the range from E98 to E102, were built by Metrovick in 1936. The skipped numbers E96 and E97 were allocated to Class ES locomotives.[10]
  • Series 4. Twenty locomotives, numbered in the range from E103 to E122, were built by Metrovick in 1936.[10]
  • Series 5. Twenty-two locomotives, numbered in the range from E139 to E160, were built by SLM in 1938. The skipped numbers in the range from E123 to E138 were allocated to Classes ES1, ES, 2E, DS and DS1 locomotives.[10]
  • Series 6. Twenty locomotives, numbered in the range from E161 to E180, were built by the Nederlandsche Fabriek van Werktuigen en Spoorwegmaterieel (Werkspoor) in 1938.[10]
  • Series 7. Ten locomotives, numbered in the range from E181 to E190, were built by Robert Stephenson and Hawthorns (RSH) in 1944 and entered service in 1945. These units were built under austerity measures during the Second World War and, on account of wartime transport difficulties, were shipped in a disassembled condition. Body panels, frames and partitions were crated flat, together with bundles of tubing, copper bus-bar, coils of wire and cable, and general electrical equipment. The bogies were shipped partially assembled. The mechanical erection of these units was done by the Mechanical Engineer at the Pietermaritzburg shops, after which the units were towed to Danskraal for the assembly of electrical equipment.[10][11]

Characteristics[edit]

The locomotives were operated as single units on light local passenger trains, double-headed on mainline passenger trains and light goods trains, or triple-headed on heavy goods trains.[1]

Interior layout[edit]

The interior layout consisted of five compartments.[1]

  • The driving cabs at each end contained the control gear, meters, gauges, vacuum brake valves and other equipment and were connected by a side corridor, along the right side of the locomotive when looking towards Cab 1.[1]
  • The high tension compartment was in the middle of the locomotive and contained the high voltage control switches and resistances, accessed through a sliding door which was both mechanically and electrically interlocked to prevent it being opened while a pantograph was in contact with the overhead catenary.[1]
  • A machinery compartment behind each cab housed auxiliary gear such as two motor generator sets, one of 16 kilowatts (21 horsepower) and the other of 28 kilowatts (38 horsepower), each coupled to a blower fan on its shaft for ventilating the main motors. In addition, it contained a motor-driven rotary vacuum exhauster, air compressor, air reservoirs for the brakes, low-tension control contactors and resistances for the auxiliaries and battery, together with contactor gear for controlling the field of the larger motor generator.[1][3][12]

The sections of the roof above the compartments and the clerestory roof above the high tension compartment were removable to enable heavy machinery or control gear to be lifted out for repair.[1][3][12]

Orientation[edit]

These dual cab locomotives had four grilles below the four windows on the equipment side, and only two grilles below the centre two windows on the corridor side. When observing the locomotive from the side with four grilles, the no. 1 end would be to the left.[2]

Bogies[edit]

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. The bogie pivot centres were 6,604 millimetres (21 feet 8 inches) apart. One of the bottom pivot centres was fixed, while the other was free to move longitudinally to allow for any wear occurring in the articulated coupling between the two bogies.[1][3][9]

Traction motors[edit]

The four-pole traction motors each operated at 1.5 kV. They were electrically coupled in pairs, two in series across the 3 kV supply line.[1][3]

Braking[edit]

The locomotive used air brakes. Air connections between units were arranged in the main reservoir circuit, so that air could be supplied to another unit in the event of failure of its compressor. For train braking, it also 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. The usual speeds during regeneration were 14 and 28 miles per hour (23 and 45 kilometres per hour) for goods and passenger working, respectively. It was reportedly the first extensive use, in regular traffic, of electric locomotives equipped for multiple unit operation with regenerative braking.[1][3][4][9][11]

Sanding[edit]

Sanding was arranged for multiple control with electrically operated sand valves, to enable multiple unit coupled locomotives to sand simultaneously.[1]

Lighting[edit]

Lighting was supplied from a 110 V circuit, which was fed by the 16 kilowatts (21 horsepower) generator in parallel with 110 V lead acid batteries. The batteries were mounted in cases, hung underneath the locomotive body between the bogies. This generator also supplied power to the control circuits, exhauster, compressor and cab heaters.[1]

Service[edit]

SAR Class 1E E23 ID.JPG
1E Number Plate E155.jpg

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 (5,000,000 miles) during their service lives.[13][14]

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[edit]

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 fast passenger service on the mail trains, two Class 1E units, numbers E121 and E122, 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). This appeared to be the practical limit for this type of electric locomotive.[11][12]

Rebuilding[edit]

Altogether 35 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 identifiable by their front windows with slanted upper edges, compared to the rectangular shaped front windows of the Class 1E.[9]

In 1964, two of these Class 1ES locomotives were rebuilt to centre-cab Class ES shunting locomotives.[9]

Withdrawal[edit]

All the Class 1E and Class 1ES locomotives were withdrawn from service by 1990.[2]

Series-specific data[edit]

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 infobox table, 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.[2][10][15]

Illustration[edit]

The main picture shows a Class 1ES locomotive with its enlarged cab and slanted upper edge front windows, while the following pictures illustrate unmodified locomotives.

References[edit]

  1. ^ a b c d e f g h i j k l m n o p q r Espitalier, T.J.; Day, W.A.J. (1946). The Locomotive in South Africa - A Brief History of Railway Development. Chapter VII - South African Railways (Continued). South African Railways and Harbours Magazine, March 1946. pp. 205-208.
  2. ^ a b c d 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
  3. ^ a b c d e f g Mike's Railway History – A Look at Railways in 1935 & Before: South African Electrification (Accessed on 16 May 2016)
  4. ^ a b c SETS Library - SAR Class 1E Electric Locomotives (Accessed on 16 May 2016)
  5. ^ a b "South African Railways Power Plant". Electric Railway Journal. 60 (24): 914. 9 December 1922. Retrieved 15 September 2010. 
  6. ^ a b Brazil, H (1928). "The South African Railways Electrification". Electrical Substations. Edward Arnold & Co. p. 110. Retrieved 2010-01-12. 
  7. ^ a b Brazil, H (1928). "IX - Traction Substations". Electrical Substations. Edward Arnold and Co. p. 110. Retrieved 15 September 2010. 
  8. ^ "Natal Contract to British". Electric Railway Journal. 61: 107. 13 January 1923. Retrieved 15 September 2010. 
  9. ^ a b c d e Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. p. 125. ISBN 0869772112. 
  10. ^ a b c d e f g h 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. 
  11. ^ a b c d Espitalier, T.J.; Day, W.A.J. (1946). The Locomotive in South Africa - A Brief History of Railway Development. Chapter VII - South African Railways (Continued). South African Railways and Harbours Magazine, April 1946. pp. 294-296.
  12. ^ a b c Steam, Oil & Wires, vol 1, (Bernard Zurnamer), pp. 69-71.
  13. ^ December 1922 and March 1925 issues of the Metropolitan-Vickers Gazette
  14. ^ Electric Traction by A.T. Dover (1929)
  15. ^ SLM Lokomotiven 1871-1894 by Verein Rollmaterialverzeichnis Schweiz