South African Class 10 4-6-2

From Wikipedia, the free encyclopedia
Jump to: navigation, search
South African Class 10 4-6-2
ex CSAR Class 10 4-6-2
SAR Class 10 738 (4-6-2) ex CSAR 656.jpg
SAR no. 738 (ex CSAR no. 656) at Sydenham Loco depot, 4 September 1966
Type and origin
Power type Steam
Designer Central South African Railways
Builder North British Locomotive Company
Serial number 16194-16203, 16226-16230 [1][2]
Model CSAR Class 10
Build date 1904
Total produced 15
Configuration 4-6-2 "Pacific"
Gauge 3 ft 6 in (1,067 mm) Cape gauge
Leading wheel
28.5 in (724 mm)
Driver diameter 62 in (1,570 mm) as built
63 in (1,600 mm) no. 745
Trailing wheel
33 in (838 mm)
Wheelbase Total: 56 ft 4 in (17.170 m)
6 ft (1.829 m) bogie
10 ft 10 in (3.302 m) coupled
30 ft 2 in (9.195 m) total
4 ft 7 in (1.397 m) bogie
16 ft 9 in (5.105 m) total
Length 64 ft 6.75 in (19.679 m)
Height 12 ft 10 in (3.912 m) as built
12 ft 11 in (3.937 m) no. 745
Frame Plate frame
Axle load 15.5 long tons (15.7 t) on 2nd & 3rd drivers
Weight on drivers 46 long tons (46.7 t)
Locomotive weight 72.75 long tons (73.9 t)
Tender weight 48,144 lb (21.8 t) empty
49.35 long tons (50.1 t) w/o
Locomotive and tender
combined weight
122.1 long tons (124.1 t)
Tender type XM2 - XC, XC1, XD, XE, XE1, XF, XF1, XF2, XJ, XM, XM1, XM2, XM3, XM4, XP1, XS permitted, MP1 on no. 746 only
* 2 axle bogies
* 34 in (864 mm) wheels
* Length 25 ft 11.625 in (7.915 m)
Fuel type Coal
Fuel capacity 10 long tons (10.2 t)
Water capacity 4,000 imp gal (18,000 l)
Boiler 4 ft 6.75 in (1.391 m) inside diameter
18 ft 6.5 in (5.652 m) inside length
7 ft 4 in (2.235 m) pitch
Boiler pressure 190 psi (1,310 kPa)
Firegrate area 35 sq ft (3.252 m2)
Heating surface:
– Tubes
92 tubes 2.25 in (57.1 mm) diameter
18 tubes 5.25 in (133 mm) diameter
1,463 sq ft (135.917 m2)
– Firebox 125 sq ft (11.613 m2)
– Total 1,588 sq ft (147.530 m2)
Superheater area 384 sq ft (35.675 m2)
Cylinders Two
Cylinder size 19.5 in (495 mm) bore
28 in (711 mm) stroke
Valve gear Walschaerts
Performance figures
Tractive effort 24,470 lbf (109 kN) at 75% pressure
Operator(s) Central South African Railways
South African Railways
Class CSAR & SAR Class 10 [3]
Number in class 15
Number(s) CSAR 650-664, SAR 732-746 [4]
Delivered 1904
First run 1904
Retired 1972

The South African Class 10 4-6-2 of 1904 is a South African steam locomotive from the pre-Union era in the Transvaal.

In 1904 the Central South African Railways placed fifteen Class 10 steam locomotives with a 4-6-2 Pacific type wheel arrangement in service. In 1912, when they were assimilated into the South African Railways, they were renumbered but retained their Class 10 classification.[4][5]


Fifteen 4-6-2 Pacific type passenger locomotives, designed by Central South African Railways (CSAR) Chief Locomotive Superintendent P.A. Hyde, were ordered from the North British Locomotive Company (NBL) and delivered in 1904, numbered in the range from 650 to 664. They had plate frames, wide Belpaire fireboxes, outside admission piston valves and Walschaerts valve gear, and were superheated. They were classified as Class 10 by the CSAR.[5][6]


At the time, the Class 10 was of an extremely advanced design. At 7 feet 4 inches (2.235 metres) above rail level, its boiler centre line was higher than that of any other locomotive in service in South Africa at the time.[5]

They were to form the basis for further development of the Pacific type that was to become the standard express passenger steam locomotive type in South Africa. They were handsome locomotives and their appearance was enhanced by the use of planished steel plates to cover the boiler and cylinder lagging, and they were equipped with two whistles of different tones and a steam turbine generator to power the "Edwards" headlight.[7]

South African Railways[edit]

The Union of South Africa was established on 31 May 1910, in terms of the South Africa Act, enacted by the Parliament of the United Kingdom. One of the clauses in the Act required that the three Colonial Government railways, the Cape Government Railways, the Natal Government Railways and the CSAR, also be united under one single administration to control and administer the railways, ports and harbours of the Union. While the South African Railways (SAR) came into existence in 1910, the actual classification and renumbering of all the rolling stock of the three constituent railways required careful planning and was only implemented with effect from 1 January 1912.[4][8]

When these locomotives were assimilated into the SAR in 1912, they retained the Class 10 classification, but were renumbered in the range from 732 to 746.[4][5][6]


Two of the locomotives were later modified by the SAR. Number 745 was equipped with 1 inch (25.4 millimetres) larger diameter tyres on its coupled wheels, while number 746 was altered to suit a Type MP1 tender as well as the other listed permissible tender types. While the Type MP1 tender had the same coal capacity as the Type XM2 that the locomotives were delivered with, it had a 250 imperial gallons (1,100 litres) larger water capacity.[3]

The rest of the fleet remained unmodified and, unlike their Class 10A, 10B and 10C successors, were never reboilered with Watson Standard boilers.[3]


The Class 10 was designed for use on the newly laid 80 pounds per yard (40 kilograms per metre) track of the CSAR, and it was placed in service hauling the fast passenger trains out of Johannesburg to Volksrust on the Natal line and to Klerksdorp on the Cape line. In later years some were relocated to work in the Noupoort area, while the rest were relegated to suburban work on the lines from Germiston to Kliprivier and the Springs-Nigel-Heidelberg branch, or for pick-up work on the Braamfontein-Klerksdorp line.[5][6]

In 1961 they went to Port Elizabeth, initially to be used on the Uitenhage suburban and finally as shunting engines, until they were scrapped between 1971 and 1972 after 68 years in service.[5][6]

Sides illustrated[edit]

The main picture and the following show both sides of the Class 10 locomotive.

See also[edit]


  1. ^ North British Locomotive Company works list, compiled by Austrian locomotive historian Bernhard Schmeiser
  2. ^ North British Locomotive Co. (from J. Lambert)
  3. ^ a b c South African Railways and Harbours Locomotive Diagram Book, 2’0” & 3’6” Gauge Steam Locomotives, 15 August 1941, p12, as amended
  4. ^ a b c d Classification of S.A.R. Engines with Renumbering Lists, issued by the Chief Mechanical Engineer’s Office, Pretoria, January 1912, pp. 9, 12, 14, 34 (Reprinted in April 1987 by SATS Museum, R.3125-6/9/11-1000)
  5. ^ a b c d e f Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 51–52. ISBN 0869772112. 
  6. ^ a b c d Durrant, A E (1989). Twilight of South African Steam (1st ed.). Newton Abbott, London: David & Charles. p. 8. ISBN 0715386387. 
  7. ^ Holland, D.F. (1971). Steam Locomotives of the South African Railways, Volume 1: 1859-1910 (1st ed.). Newton Abbott, Devon: David & Charles. pp. 129–130. ISBN 978-0-7153-5382-0. 
  8. ^ The South African Railways - Historical Survey. Editor George Hart, Publisher Bill Hart, Sponsored by Dorbyl Ltd., Published c. 1978, p. 25.