SAR class 91

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SAR class 91
SAR Class 91-000 91-002.JPG
Numbering: 91-001 - 91-020
Number: 20th
Manufacturer: General Electric
Year of construction (s): 1973, 1974
Type : Bo'Bo '
Gauge : 610 mm
Length over coupling: 10,580 mm
Height: 3,632 mm
Width: 2,564 mm
Trunnion Distance: 5,232 mm
Bogie axle base: 2,108 mm
Service mass: 44 t
Friction mass: 44 t
Wheel set mass : 11 t
Top speed: 50 km / h
Installed capacity: 520 kW
Driving wheel diameter: 838 mm
Fuel supply: 1,600 liters of diesel
Motor type: D-379
Motor type: 1 × 8-cylinder V-engine with exhaust gas turbocharger
Power transmission: electric
Number of traction motors: 4th
Train brake: Suction air brake

Vehicles of Class 91 of the South African Railways (SAR) are diesel-electric locomotives for 610-mm narrow gauge. In 1973 and 1974 General Electric delivered a total of 20 UM6B machines , which are the first and, to date, the only non-steam-powered locomotives that SAR has procured for this gauge.

The locomotives are a variant of the GE U6B type , which had been developed for gauges from 914 mm, and new bogies had to be constructed for use on the even narrower track : because the motors, which are parallel to the axles, are no longer between the two due to the narrow track the wheels fit, they are shifted to the center of the bogie and protrude from the wheel plane on one side.

Another difference to the U6B type is the short "nose" in front of the driver's cab, which is visually matched to the driver's cabs of the larger diesel locomotives on the railway.

The locomotives are among the world's largest and most powerful for the 610 mm gauge. The width of 2564 mm is more than four times the track width, and with a height of 3632 mm the machines tower above all the wagons they pull (for comparison: a standard-gauge locomotive with these proportions would have a width of around 5.8 m and a height from about 8.3 m).


Freight train with UM6B near Kruitsfontain in March 2009.

All 20 locomotives were initially stationed in Port Elizabeth , from where they were used on the route to Avontuur , particularly for limestone trains between Loerie and Chelsea Station. They replaced the steam locomotives of classes NGG 13 and 16 ; most of which were laid on narrow gauge lines in Natal . In the 1990s, two Class 91 locomotives were also leased to the Alfred County Railway for the railway line from Port Shepstone to Harding in KwaZulu-Natal.

Because the SAR's 610 mm networks were not connected to one another, the locomotives could be placed on Cape Gauge bogies and run on Cape Gauge routes on their own. However, since the closure of the last 610 mm line in Natal, this is no longer necessary.

The locomotives are mostly used in multiple units; three locomotives in front of a freight train are not unusual.


Locomotive 91-014 fell down a slope after a derailment and was completely destroyed in the process. 91-009 overturned after a derailment and was also badly damaged. Because there are enough locomotives due to the reduced volume of traffic, it has not yet been repaired. The remaining locomotives are stationed in a depot near Humewood train station in Port Elisabeth.

See also


  • Leith Paxton, David Bourne: Locomotives of the South African Railways. A Concise Guide. C. Strui (Pty) Ltd., Cape Town 1985, ISBN 0-86977-211-2 .
  • John N. Middleton: Railways of Southern Africa. Locomotive guide. 5th edition. Beyer-Garratt Publications, Rickmansworth 1994, ISBN 0-620-18548-1 .

Web links

Commons : SAR Class 91  - Collection of Images, Videos and Audio Files
Commons : Railroad  - Collection of images, videos and audio files