South African Class 15C 4-8-2

South African Class 15C 4-8-2
& South African Class 15CB 4-8-2

Class 15C Big Bill, as delivered, c. 1930
Type and origin
Power type Steam
Designer South African Railways
Baldwin Locomotive Works
Builder Baldwin Locomotive Works
Serial number 58307, 58308, 58708-58717 [1]
Model Class 15C
Build date 1925-1926
Total produced 12
Specifications
Configuration 4-8-2 "Mountain"
Gauge 3 ft 6 in (1,067 mm) Cape gauge
Leading wheel
diameter
30 in (762 mm)
Driver diameter 57 in (1,450 mm) as built
60 in (1,520 mm) rewheeled
Trailing wheel
diameter
33 in (838 mm)
Wheelbase Total: 65 ft 3.1875 in (19.893 m)
Engine:
6 ft 10 in (2.083 m) bogie
15 ft 9 in (4.801 m) coupled
35 ft 8 in (10.871 m) total
Tender:
6 ft 2 in (1.880 m) bogie
20 ft 5 in (6.223 m) total
Length 73 ft 2.1875 in (22.306 m)
Height 12 ft 10 in (3.912 m) as built
12 ft 11.5 in (3.950 m) with 60" drivers
Frame Bar frame
Axle load As built:
17.65 long tons (17.9 t) on 1st & 3rd drivers, copper firebox
17.1 long tons (17.4 t) on 2nd & 3rd drivers, steel firebox
With 60" drivers:
17.95 long tons (18.2 t) on 3rd driver, copper firebox
17.4 long tons (17.7 t) on 2nd & 3rd drivers, steel firebox
Weight on drivers As built:
70.35 long tons (71.5 t) copper firebox
68.15 long tons (69.2 t) steel firebox
With 60" drivers:
71.4 long tons (72.5 t) copper firebox
69.2 long tons (70.3 t) steel firebox
Locomotive weight As built:
104.8 long tons (106.5 t) copper firebox
103.35 long tons (105.0 t) steel firebox
With 60" drivers:
105.85 long tons (107.5 t) copper firebox
104.4 long tons (106.1 t) steel firebox
Tender weight 68,888 lb (31.2 t) empty
69.4 long tons (70.5 t) w/o
Locomotive and tender
combined weight
As built:
214,596 lb (97.3 t) empty
174.2 long tons (177.0 t) w/o, copper firebox
172.75 long tons (175.5 t) w/o, steel firebox
With 60" drivers:
216,950 lb (98.4 t) empty
175.25 long tons (178.1 t) w/o, copper firebox
173.8 long tons (176.6 t) w/o, steel firebox
Tender type KT
* 2 axle bogies
* 34 in (864 mm) wheels
* Length 28 ft 8.25 in (8.744 m)
Fuel type Coal
Fuel capacity 14 long tons (14.2 t)
Water capacity 6,000 imp gal (27,000 l)
Boiler 6 ft 2.25 in (1.886 m) inside diameter
20 ft 0.5 in (6.109 m) inside length
8 ft 6 in (2.591 m) pitch as built
8 ft 7.5 in (2.629 m) pitch with 60" drivers
Boiler pressure 200 psi (1,380 kPa) as built
210 psi (1,450 kPa) with 60" drivers
Firegrate area 48 sq ft (4.459 m2)
Heating surface:
– Tubes
As built:
143 tubes 2.25 in (57.1 mm) diameter
30 tubes 5.5 in (140 mm) diameter
2,554 sq ft (237.274 m2)
Reboilered:
117 tubes 2.25 in (57.1 mm) diameter
34 tubes 5.5 in (140 mm) diameter
2,361 sq ft (219.344 m2)
– Flues 23 sq ft (2.137 m2)
– Firebox 200 sq ft (18.581 m2)
– Total 2,777 sq ft (257.992 m2) as built
2,584 sq ft (240.061 m2) reboilered
Superheater area 716 sq ft (66.519 m2) as built
570 sq ft (52.955 m2) reboilered
Cylinders Two
Cylinder size 24 in (610 mm) bore
28 in (711 mm) stroke
Valve gear Walschaerts
Performance figures
Tractive effort At 75% boiler pressure:
42,440 lbf (188.8 kN) as built
42,340 lbf (188.3 kN) with 60" drivers
Career
Operator(s) South African Railways [2]
Class Class 15C, Class 15CB
Number in class 12
Number(s) 2060–2071
Nicknames Big Bill
Delivered 1925-1926
First run 1925
Withdrawn 1976

The South African Class 15C 4-8-2 of 1925 is a South African steam locomotive from the South African Railways era.

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

Manufacturer

The Class 15C 4-8-2 Mountain type 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 type 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 in the range from 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 branchline locomotive as was usual practice.[3]

Modifications

They were delivered with 57 inches (1,450 millimetres) coupled 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) coupled 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 mainline passenger trains.[1][2]

Three of the Class 15CB and Class 15CA locomotives were later reboilered with boiler numbers in the range from 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 mainline 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]

Industrial service illustrated

The main picture shows a Class 15C, as delivered, c. 1930, while the following show two Class 15CB locomotives in industrial service after withdrawal from SAR service.

See also

References

  1. 1.0 1.1 1.2 1.3 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 978-0-7153-5427-8.
  2. 2.0 2.1 2.2 South African Railways and Harbours Locomotive Diagram Book, 2’0” & 3’6” Gauge Steam Locomotives, 15 August 1941, as amended
  3. 3.0 3.1 3.2 3.3 3.4 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.