South African Class 10D 4-6-2

The South African Railways Class 10D 4-6-2 of 1910 was a steam locomotive from the pre-Union era in Transvaal.

CSAR Class 10 4-6-2 1910
South African Class 10D 4-6-2
CSAR no. 1002, SAR no. 779, c. 1910
Type and origin
Power typeSteam
DesignerCentral South African Railways
BuilderAmerican Locomotive Company
Serial number46715
ModelCSAR Class 10
Build date1910
Total produced1
Specifications
Configuration:
 • Whyte4-6-2 (Pacific)
 • UIC2'C1'h2
Driver2nd coupled axle
Gauge3 ft 6 in (1,067 mm) Cape gauge
Leading dia.28+12 in (724 mm)
Coupled dia.62 in (1,575 mm)
Trailing dia.33 in (838 mm)
Tender wheels33+12 in (851 mm)
Wheelbase55 ft (16,764 mm) ​
 • Engine29 ft 8 in (9,042 mm)
 • Leading6 ft (1,829 mm)
 • Coupled11 ft 2 in (3,404 mm)
 • Tender16 ft 8 in (5,080 mm)
 • Tender bogie5 ft 4 in (1,626 mm)
Length:
 • Over couplers62 ft 7 in (19,075 mm)
Height12 ft 9+716 in (3,897 mm)
Frame typeBar
Axle load16 LT 10 cwt (16,760 kg) ​
 • Leading10 LT 19 cwt (11,130 kg)
 • 1st coupled16 LT (16,260 kg)
 • 2nd coupled16 LT 10 cwt (16,760 kg)
 • 3rd coupled16 LT 3 cwt (16,410 kg)
 • Trailing12 LT 8 cwt (12,600 kg)
 • Tender axle11 LT 13 cwt 1 qtr (11,850 kg) av.
Adhesive weight48 LT 13 cwt (49,430 kg)
Loco weight72 LT (73,160 kg)
Tender weight46 LT 13 cwt (47,400 kg)
Total weight118 LT 13 cwt (120,600 kg)
Tender type2-axle bogies
Fuel typeCoal
Fuel capacity10 LT (10.2 t)
Water cap.4,000 imp gal (18,200 L)
Firebox:
 • TypeBelpaire
 • Grate area35 sq ft (3.3 m2)
Boiler:
 • Pitch7 ft 8 in (2,337 mm)
 • Diameter5 ft 34 in (1,543 mm)
 • Tube plates18 ft 38 in (5,496 mm)
 • Small tubes132: 2+14 in (57 mm)
 • Large tubes18 5+14 in (133 mm)
Boiler pressure170 psi (1,172 kPa)
Safety valveRamsbottom
Heating surface:
 • Firebox133 sq ft (12.4 m2)
 • Tubes1,848 sq ft (171.7 m2)
 • Total surface1,981 sq ft (184.0 m2)
Superheater:
 • TypeCole
 • Heating area353 sq ft (32.8 m2)
CylindersTwo
Cylinder size21 in (533 mm) bore
28 in (711 mm) stroke
Valve gearWalschaerts
Valve typePiston
Valve travel5+12 in (140 mm)
Valve lap1 in (25 mm)
Valve lead14 in (6 mm)
CouplersJohnston link-and-pin
Performance figures
Tractive effort25,390 lbf (112.9 kN) @ 75%
Career
OperatorsCentral South African Railways
South African Railways
ClassCSAR Class 10, SAR Class 10D
Number in class1
NumbersCSAR 1002, SAR 779
Delivered1910
First run1910
Withdrawn1931
The 2nd coupled axle had flangeless wheels

In 1910, the Central South African Railways placed one American-built Class 10 4-6-2 Pacific type steam locomotive in service. When the South African Railways classification and renumbering took place in 1912, this locomotive was designated the sole member of Class 10D.[1][2][3][4]

Manufacturer

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One 4-6-2 Pacific type passenger locomotive was ordered by the Central South African Railways (CSAR) from the American Locomotive Company (ALCO) in 1910. It was built to very much the same specifications as that of the CSAR Class 10-2 of that same year, which was designed by CSAR Chief Mechanical Engineer (CME) G.G. Elliot.[2][4][5]

The locomotive was slightly more powerful than the Class 10-2 and was designated Class 10 by the CSAR, with engine number 1002, along with the fifteen CSAR Class 10 4-6-2 locomotives which had been built by the North British Locomotive Company in 1904.[1][2][4][6]

Characteristics

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The cylinders were arranged outside the 4 inches (102 millimetres) thick bar frames, while the piston valves, arranged above the cylinders, were actuated by Walschaerts valve gear. Reversing was effected by means of a screw gear. The locomotive had a Belpaire firebox and, instead of the usual deep bridle casting, was built with a shallow casting and frame under the firebox. This permitted all firebox stays to be removed without lifting the boiler from the frame.[2]

 
Cole type superheater header

The locomotive was superheated, using the Cole double-header superheater system. The Cole superheater was somewhat similar to the Schmidt superheater system, except that the Cole type had two headers arranged at either side of the smokebox instead of one at the top.[7]

Each of the eighteen 5+14 inches (133 millimetres) diameter boiler flues contained four lengths of seamless steam pipes of 1+12 inches (38 millimetres) outside diameter, arranged in double pairs which were connected at the back ends by return bends and with the two pairs connected to each other at the front by another return bend. This forced the steam to traverse the entire four pipe lengths before entering the steam chests. The two free front ends of each such foursome of pipes were bent around to meet the steam headers. This design of superheater produced a superheat of from 175 to 250 degrees Fahrenheit (79 to 121 degrees Celsius) above saturation temperature.[7]

South African Railways

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When the Union of South Africa was established on 31 May 1910, the three Colonial government railways (Cape Government Railways, Natal Government Railways and CSAR) were united under a single administration to control and administer the railways, ports and harbours of the Union. Although the South African Railways and Harbours came into existence in 1910, the actual classification and renumbering of all the rolling stock of the three constituent railways were only implemented with effect from 1 January 1912.[3][8]

In 1912, the sixteen CSAR Class 10 locomotives were renumbered on the South African Railways (SAR) roster. The fifteen older British-built locomotives retained their Class 10 designation on the SAR roster, but the ALCO-built engine was designated the sole member of Class 10D and renumbered 779.[2][3][9]

Service

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The Class 10D was placed in service on fast passenger work in the Transvaal and later in the Orange Free State. It spent its last working years at Bloemfontein until it was withdrawn from service in 1931 and scrapped.[1][4]

 
Class 10D 779 (4-6-2) - Ex CSAR 1002, on a SAR Museum Playing Card

References

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  1. ^ a b c Holland, D.F. (1971). Steam Locomotives of the South African Railways. Vol. 1: 1859–1910 (1st ed.). Newton Abbott, England: David & Charles. pp. 138–139. ISBN 978-0-7153-5382-0.
  2. ^ a b c d e Espitalier, T.J.; Day, W.A.J. (1945). The Locomotive in South Africa - A Brief History of Railway Development. Chapter VI - Imperial Military Railways and C.S.A.R. (Continued). South African Railways and Harbours Magazine, March 1945. p. 183.
  3. ^ a b c Classification of S.A.R. Engines with Renumbering Lists, issued by the Chief Mechanical Engineer's Office, Pretoria, January 1912, pp. 9, 12, 15, 35 (Reprinted in April 1987 by SATS Museum, R.3125-6/9/11-1000)
  4. ^ a b c d Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. p. 53. ISBN 0869772112.
  5. ^ "Powerful Freight and Passenger Locomotives for a Narrow Gauge Railway". American Engineer and Railroad Journal: 192–194. May 1910. Retrieved 31 December 2012.
  6. ^ Durrant, AE (1989). Twilight of South African Steam (1st ed.). Newton Abbott: David & Charles. pp. 8–10. ISBN 0715386387.
  7. ^ a b Espitalier, T.J.; Day, W.A.J. (1944). The Locomotive in South Africa - A Brief History of Railway Development. Chapter III - Natal Government Railways (Continued). South African Railways and Harbours Magazine, August 1944. pp. 591-594, 599.
  8. ^ The South African Railways - Historical Survey. Editor George Hart, Publisher Bill Hart, Sponsored by Dorbyl Ltd., Published c. 1978, p. 25.
  9. ^ Holland, D. F. (1972). Steam Locomotives of the South African Railways. Vol. 2: 1910-1955 (1st ed.). Newton Abbott, England: David & Charles. p. 140. ISBN 978-0-7153-5427-8.