South African Class 15C 4-8-2

In 1925 the South African Railways placed two American built Class 15C steam locomotives with a 4-8-2 Mountain wheel arrangement in service. Another ten locomotives were ordered and delivered a year later.^[3]

Manufacturer

The Class 15C 4-8-2 steam locomotive was built by Baldwin Locomotive Works (BLW) in 1925 and 1926, conforming to South African Railways (SAR) requirements as far as practicable, but also incorporating the latest American railway engineering practices. These locomotives introduced several features which were new to the SAR at the time, such as top feeds to the boiler, self cleaning smokeboxes, Sellar’s drifting valves and grease lubrication. Their fireboxes were equipped with siphon tubes to support the brick arch and to improve circulation.^[1][3]

Its boiler was larger in proportion than that of any existing SAR locomotive and was also raised 10 inches (254 millimetres) higher than that of anything else in service at that time. The locomotive’s size quickly earned it the nickname "Big Bill", while its contemporary Class 16D 4-6-2 Pacific that arrived from the same builders in the same shipment was nicknamed "Big Bertha".^[3]

The first two locomotives, numbers 2060 and 2061, were erected at the Salt River shops and put to work on the line from Cape Town to Touws River. They performed well, were comparatively trouble free and good steamers, and capable of handling a heavy load exceeding that of any other locomotive that had been employed on this section to date. Because of the good results obtained from these two locomotives, an order was placed with Baldwin for another ten that were delivered in 1926, numbered 2062 to 2071.^[1]

Reclassification

Shortly after being placed in service, the Class 15C’s frames began to show evidence of cracking. A similar locomotive, differing mainly in the design of the frame under the firebox, was then ordered from the American Locomotive Company (ALCO). When the twenty-one ALCO builts were placed in service in 1926, they were classified as Class 15CA, with the "A" indicating the manufacturer ALCO. The Class 15C was then reclassified to Class 15CB, in this case with the "B" indicating the manufacturer Baldwin and not a branch line locomotive as was usual practice.^[3]

Modifications

They were delivered with 57 inches (1,450 millimetres) driving wheels and their boilers were set at an operating pressure of 200 pounds per square inch (1,380 kilopascals). All twelve were eventually rewheeled with 60 inches (1,520 millimetres) driving wheels and, to compensate for the loss of tractive effort due to the larger diameter drivers, their operating boiler pressure was increased to 210 pounds per square inch (1,450 kilopascals) by an adjustment of the setting of their safety valves. This modification enabled these mixed traffic locomotives to handle the fastest main line passenger trains.^[1][2]

Three of the Class 15CB and Class 15CA locomotives were later reboilered with boiler numbers 9504 to 9506, which were of similar dimensions, but with a different tube arrangement. Since these were not Watson Standard boilers, the locomotives were not reclassified.^[2]

Service

South African Railways

They were placed in service on the main line between Cape Town and Touws River and were later transferred to Bloemfontein, from where they worked south to Noupoort. A brief stint on the Natal north coast followed in the mid 1960s, after which they spent the rest of their SAR working lives in the eastern and western Transvaal. They were retired from SAR service in 1976.^[3]

Industrial

Eleven Class 15CB locomotives were sold into industrial service in 1976, with only the first built, number 2060, being retained by the SAR for preservation. By the late 1980s, therefore, at more than 60 years of age, eleven of the original twelve Class 15CB locomotives were still at work.^[4]

• Numbers 2061, 2065 and 2070 became South Witbank Coal Mine’s numbers 3, 2 and 1 respectively.
• Numbers 2062 and 2067 went to Tweefontein United Collieries.
• Numbers 2063 and 2064 went to Dunn’s Locomotive Works to be employed at Durban Navigation Collieries (Durnacol) in Natal. Number 2063 was subsequently resold to Rustenburg Platinum Mines, becoming their number 5, and 2064 was resold to Tavistock Colliery, becoming their number 3.
• Numbers 2066 and 2068 went to Tavistock Colliery, becoming their numbers 4 and 5 respectively.
• Numbers 2069 and 2071 went to Rustenburg Platinum Mines, becoming their numbers 3 and 4 respectively.

Gallery

The main picture shows ex SAR number 2071 on 31 March 1983, as Rustenburg Platinum Mines number 4.

See also

• South African Class 15 4-8-2
• South African Class 15A 4-8-2
• South African Class 15B 4-8-2
• South African Class 15CA 4-8-2
• South African Class 15E 4-8-2
• South African Class 15F 4-8-2
• Tender locomotive numbering and classification
• The 4-8-2 "Mountain"
• List of South African locomotive classes

References

1. ^ ^{a b c d} Holland, D.F. (1972). Steam Locomotives of the South African Railways, Volume 2: 1910-1955 (1st ed.). Newton Abbott, Devon: David & Charles. pp. 46-49. ISBN 0715354272. 
2. ^ ^{a b c} South African Railways and Harbours Locomotive Diagram Book, 2’0” & 3’6” Gauge Steam Locomotives, 15 August 1941, as amended
3. ^ ^{a b c d e} Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 10-11, 61-62, 66. ISBN 0869772112. 
4. ^ Durrant, A E (1989). Twilight of South African Steam (1st ed.). Newton Abbott, London: David & Charles. p. 88. ISBN 0715386387.