South African Class 7E4

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South African Class 7E4

Class 7E4 no. E7274.jpg

No. E7274 c. 2000
Type and origin
Power type Electric
Designer Hitachi
Builder Transwerk
Model Hitachi 7E4
Build date 2000-2003
Total produced 17
Specifications
Configuration:
   AAR C-C
   UIC Co'Co'
  Commonwealth Co-Co
Gauge 3 ft 6 in (1,067 mm) Cape gauge
Wheel diameter 1,220 mm (48.0 in)
Wheelbase 13,460 mm (44 ft 1.9 in)
   Bogie 4,060 mm (13 ft 3.8 in)
Pivot centres 10,200 mm (33 ft 5.6 in)
Panto shoes 12,075 mm (39 ft 7.4 in)
Length:
  Over couplers 18,430 mm (60 ft 5.6 in)
  Body 17,480 mm (57 ft 4.2 in)
Width 2,906 mm (9 ft 6.4 in)
Height:
  Pantograph 4,180 mm (13 ft 8.6 in)
  Body height 3,941 mm (12 ft 11.2 in)
Axle load 21,420 kg (47,220 lb)
Adhesive weight 123,500 kg (272,300 lb)
Loco weight 123,500 kg (272,300 lb)
Electric system/s 25 kV AC/50 Hz
Current pickup(s) Pantographs from catenary
Traction motors Six HS-1054-GR
  Rating 1 hour 525 kW (704 hp)
  Continuous 500 kW (670 hp)
Gear ratio 16:94
Loco brake Air & Rheostatic
Train brakes Air & Vacuum
Couplers AAR knuckle
Performance figures
Maximum speed 100 km/h (62 mph)
Power output:
  1 hour 3,150 kW (4,220 hp)
  Continuous 3,000 kW (4,000 hp)
Tractive effort:
  Starting 450 kN (100,000 lbf)
  1 hour 319 kN (72,000 lbf)
  Continuous 300 kN (67,000 lbf)
Career
Operators South African Railways
Spoornet
Transnet Freight Rail
Class Class 7E4
Number in class 17
Numbers E7260-E7276
NicknamesMacGyver
Delivered 2001
First run 2001

The Spoornet Class 7E4 of 2001 is a South African electric locomotive.

Contents

In 1983 and 1984, the South African Railways placed sixty Class 7E3, Series 1 electric locomotives with a Co-Co wheel arrangement in mainline service. These were followed by another twenty-five Class 7E3, Series 2 locomotives in 1984 and 1985. Beginning in 2000, Spoornet rebuilt seventeen of these dual-cab locomotives to single-cab locomotives and reclassified them to Class 7E4. [1]

South Africa Republic in the southernmost part of Africa

South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by 2,798 kilometres (1,739 mi) of coastline of Southern Africa stretching along the South Atlantic and Indian Oceans; to the north by the neighbouring countries of Namibia, Botswana, and Zimbabwe; and to the east and northeast by Mozambique and Eswatini (Swaziland); and it surrounds the enclaved country of Lesotho. South Africa is the largest country in Southern Africa and the 25th-largest country in the world by land area and, with over 57 million people, is the world's 24th-most populous nation. It is the southernmost country on the mainland of the Old World or the Eastern Hemisphere. About 80 percent of South Africans are of Sub-Saharan African ancestry, divided among a variety of ethnic groups speaking different African languages, nine of which have official status. The remaining population consists of Africa's largest communities of European (White), Asian (Indian), and multiracial (Coloured) ancestry.

Electric locomotive locomotive powered by electricity

An electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or on-board energy storage such as a battery or a supercapacitor.

Manufacturers

The 25 kV AC Class 7E3 electric locomotives were designed for the South African Railways (SAR) by Hitachi and built in South Africa by Dorbyl, who also supplied the mechanical components. [2] [3]

Hitachi Japanese multinational engineering and electronics company

Hitachi, Ltd. is a Japanese multinational conglomerate company headquartered in Chiyoda, Tokyo, Japan. It is the parent company of the Hitachi Group and forms part of the DKB Group of companies. Hitachi is a highly diversified company that operates eleven business segments: Information & Telecommunication Systems, Social Infrastructure, High Functional Materials & Components, Financial Services, Power Systems, Electronic Systems & Equipment, Automotive Systems, Railway & Urban Systems, Digital Media & Consumer Products, Construction Machinery and Other Components & Systems.

Sixty Series 1 locomotives were delivered by Dorbyl in 1983 and 1984, numbered in the range from E7216 to E7275, and twenty-five Series 2 locomotives in 1984 and 1985, numbered in the range from E7276 to E7300. Like Union Carriage and Wagon, Dorbyl did not allocate builder’s numbers to the locomotives it built for the SAR, but used the SAR unit numbers for their record keeping. [2]

Modification and reclassification

In the period from the early 1990s until about 2007, various modifications to improve downhill braking capacity were done to the Coalink line's Hitachi-designed locomotives. The first set of upgrades was done on the fifty Class 7E1 locomotives. [1]

South African Class 7E1 class of 50 South African electric locomotives

The South African Railways Class 7E1 of 1980 is an electric locomotive.

Beginning in 2000, seventeen Class 7E3 locomotives, sixteen Series 1, numbered in the range from E7260 to E7275, and one Series 2, no. E7276, underwent significant modifications. This included the installation of Hitachi micro-processor controls with improved rheostatic brakes, auxiliary inverters designed and built by Fuji Electric, Thelma and Cutler-Hammer rheostat grids, fans by Donkin Fans in Port Elizabeth, and conversion from double-cab to single-cab since the no. 2 end cab space was required for some of the new equipment which was installed. These single-cab locomotives were reclassified to Class 7E4 and the first of them entered service early in 2001. [1] [4]

Fuji Electric company

Fuji Electric Co., Ltd., operating under the brand name FE, is a Japanese electrical equipment company, manufacturing pressure transmitters, flowmeters, gas analyzers, controllers, inverters, pumps, generators, ICs, motors, and power equipment.

Features

Appearance

The two sides of the locomotive are sufficiently different in appearance that a pair of them, coupled end to end, appears at first glance to be two different locomotive types. The left side is smooth while the right side has several large grilles. [2]

Pantographs

The locomotive's pantograph placement is unusual in not being equidistant from the locomotive ends. The contact shoe centre of the front pantograph is 6,155 millimetres (20 feet 2.32 inches) from the longitudinal centre of the locomotive, while that of the rear pantograph is 5,920 millimetres (19 feet 5.07 inches) from the longitudinal centre. [2]

Brakes

Control of traction and rheostatic braking on the Class 7E4 is by stepless solid-state electronics. The electrical equipment was designed for high power factor operation, obtained by the switching in of power-factor correction capacitors. [3]

Unlike the Classes 7E and 7E2 Series 1 and 2, where thyristors are used, these locomotives use silicon-diode rectifiers. [5]

Bogies

Like the Class 7E, the Class 7E4 was built with sophisticated traction linkages on the 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. [3]

Service

Since 1978, 25 kV AC was introduced on all new mainline electrification projects bar one, the exception being the Orex iron ore line from Sishen to Saldanha, where 50 kV AC is used. The Class 7E4 locomotives all serve on the 25 kV AC Coalink line from Ermelo via Vryheid to the Richards Bay Coal Terminal. [1] [3]

Livery

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. [1] [6] [7]

While it is doubtful that the intention was to have a Class 7E4 in blue train livery for blue train hauling on the Richards Bay line, the ones photographed, numbers E7272, E7274 and E7275, were nevertheless painted in Spoornet’s maroon era Blue Train livery after being rebuilt, possibly to make them easier to identify at a glance. [7]

Illustration

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References

  1. 1 2 3 4 5 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, 61.
  2. 1 2 3 4 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
  3. 1 2 3 4 Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 129–131. ISBN   0869772112.
  4. Information obtained from Transnet engineers and drivers
  5. Jane's Train Recognition Guide
  6. E1973 in blue based on orange livery
  7. 1 2 E1951 in blue based on maroon livery