South African Class 8R 4-8-0

The South African Railways Class 8R 4-8-0 of 1930 was a steam locomotive.

South African Class 8R 4-8-0
Drawing of Class 8R no. 883
Type and origin Power type Steam Designer Cape Government Railways (H.M. Beatty) Builder American Locomotive Company Serial number ALCO 25454 Model CGR 8th Class (2-8-0) Build date 1902 Total produced 16 Rebuilder South African Railways Rebuild date 1930 Number rebuilt 1
Specifications Configuration: ​  • Whyte 4-8-0 (Mastodon)  • UIC 2'Dh2 Driver 2nd coupled axle Gauge 3 ft 6 in (1,067 mm) Cape gauge Leading dia. 28 ^1⁄2 in (724 mm) Coupled dia. 48 in (1,219 mm) Tender wheels 33 ^1⁄2 in (851 mm) as built 34 in (864 mm) retyred Wheelbase:  • Coupled 14 ft 6 in (4,420 mm)  • Tender 14 ft 5 in (4,394 mm)  • Tender bogie 5 ft (1,524 mm) Wheel spacing (Asymmetrical) 1-2: 4 ft 7 in (1,397 mm) 2-3: 4 ft 3 in (1,295 mm) 3-4: 5 ft 8 in (1,727 mm) Frame type Bar Axle load:  • Tender axle 9 LT 3 cwt 3 qtr (9,335 kg) average Tender weight 36 LT 15 cwt (37,340 kg) Tender type WG (2-axle bogies) WE, WG permitted Fuel type Coal Fuel capacity 6 LT (6.1 t) Water cap 3,080 imp gal (14,000 l) Firebox type Round-top Boiler: ​  • Tube plates 15 ft 2 ^1⁄2 in (4,636 mm) Safety valve Ramsbottom Heating surface 1,318 sq ft (122.4 m^2) Cylinders Two Cylinder size 18 ^1⁄2 in (470 mm) bore 24 in (610 mm) stroke Valve gear Stephenson Valve type Piston Loco brake Steam brake Train brakes Vacuum brake on tender Couplers AAR knuckle
Career Operators South African Railways Class Class 8R Number in class 1 Numbers 883 Delivered 1930 First run 1930 Withdrawn 1939

In 1901 and 1902, the Cape Government Railways placed sixteen 8th Class 2-8-0 Consolidation type steam locomotives in service. In 1912, when they were assimilated into the South African Railways, they were renumbered and reclassified to Class 8X. One of them was reboilered and converted to a 4-8-0 Mastodon type wheel arrangement in 1930 and reclassified to Class 8R.[1][2][3]

Manufacturers

H.M. Beatty

The first 8th Class 2-8-0 Consolidation type locomotive of the Cape Government Railways (CGR) was designed by H.M. Beatty, the Chief Locomotive Superintendent of the CGR from 1896 to 1910. Fourteen of these engines were built by the American Locomotive Company (ALCO) in 1902.[1][4][5]

They were conceived as mixed traffic locomotives, equally suitable for goods and passenger work, and had bar frames, narrow fireboxes, used saturated steam and had cylinders with overhead slide valves which were actuated by inside Stephenson valve gear. The Type WG bogie tender entered service with these engines.[1][3]

South African Railways

When the Union of South Africa was established on 31 May 1910, the three Colonial government railways (CGR, Natal Government Railways and Central South African Railways) 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. In 1912, these Consolidation types were designated Class 8X on the South African Railways (SAR).[2][6]

Wheel arrangement modification

In 1930, one of the Class 8X locomotives, SAR no. 883, was reboilered with a purpose-built boiler by SAR Chief Mechanical Engineer A.G. Watson. At the same time, it was equipped with superheating and piston-valve cylinders. The locomotive was converted to a 4-8-0 Mastodon type wheel arrangement by replacing the leading pony truck with a bogie in a belated attempt to rectify one of the shortcomings of the original Class 8 2-8-0 locomotive. To accommodate the four-wheeled bogie, the front of the bar frame was apparently modified to reposition the cylinders.[3][7][8]

The modified no. 883 was reclassified and became the sole Class 8R locomotive. No other such conversions were done, since the Class 8 family had already begun to be displaced by newer and more powerful locomotives and many would be withdrawn from service by the late 1930s.[7]

Service

Class 8R no. 883 was put to work in the Eastern Transvaal. Even though some did not consider the rebuilding a success, the engine remained in service for nine years until it was withdrawn from service in 1939.[3][8]

References

1. Holland, D.F. (1971). Steam Locomotives of the South African Railways. 1: 1859–1910 (1st ed.). Newton Abbott, Devon: David & Charles. pp. 61–63. ISBN 978-0-7153-5382-0.
2. 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)
3. Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 50–51. ISBN 0869772112.
4. Schenectady Consolidation for Cape Government Railways. Railway and Locomotive Engineering : A Practical Journal of Railway Motive Power and Rolling Stock. Volume XIV, No. 2, February 1901. 95 Liberty Street, New York. pp. 90-91. (Accessed on 13 December 2015)
5. Espitalier, T.J.; Day, W.A.J. (1944). The Locomotive in South Africa - A Brief History of Railway Development. Chapter II - The Cape Government Railways (Continued). South African Railways and Harbours Magazine, January 1944. pp. 9-12.
6. The South African Railways - Historical Survey. Editor George Hart, Publisher Bill Hart, Sponsored by Dorbyl Ltd., Published c. 1978, p. 25.
7. Dulez, Jean A. (2012). Railways of Southern Africa 150 Years (Commemorating One Hundred and Fifty Years of Railways on the Sub-Continent – Complete Motive Power Classifications and Famous Trains – 1860–2011) (1st ed.). Garden View, Johannesburg, South Africa: Vidrail Productions. p. 95. ISBN 9 780620 512282.
8. Holland, D. F. (1972). Steam Locomotives of the South African Railways. 2: 1910-1955 (1st ed.). Newton Abbott, Devon: David & Charles. p. 89. ISBN 978-0-7153-5427-8.