South African Class 8D 4-8-0

South African Class 8D 4-8-0
& South African Class 8DW 4-8-0
ex CGR 8th Class 4-8-0

Ex CGR 8th Class no. 788, SAR Class 8D no. 1223, Bloemfontein, 22 March 1970
Type and origin
Power type Steam
Designer Cape Government Railways
Builder Neilson, Reid and Company
North British Locomotive Company
Serial number NR 6284-6301, 6303-6308, 6325-6334[1]
NBL 15833-15836[2]
Model CGR 8th Class (4-8-0)
Build date 1902-1903[1][2]
Total produced 38
Specifications
Configuration 4-8-0 "Mastodon"
Gauge 3 ft 6 in (1,067 mm) Cape gauge
Leading wheel
diameter		 28.5 in (724 mm)
Driver diameter 48 in (1,220 mm)
Wheelbase Total: 46 ft 10.5 in (14.288 m)
Engine:
6 ft (1.829 m) bogie
13 ft 6 in (4.115 m) coupled
23 ft 3 in (7.087 m) total
Tender:
4 ft 7 in (1.397 m) bogie
14 ft 7 in (4.445 m) total
Length 54 ft 2.25 in (16.516 m)
Height As built:
12 ft 10 in (3.912 m)
Superheated & Class 8DW:
12 ft 8 in (3.861 m)
Frame Bar frame
Axle load As built:
11.7 long tons (11.9 t) per driver
Superheated:
12 long tons (12.2 t) per driver
Class 8DW:
12.55 long tons (12.8 t) on 2nd driver
Weight on drivers 45.8 long tons (46.5 t) as built
48 long tons (48.8 t) superheated
48.3 long tons (49.1 t) Class 8DW
Locomotive weight 59.25 long tons (60.2 t) as built
60.75 long tons (61.7 t) superheated
61.05 long tons (62.0 t) Class 8DW
Tender weight 44,032 lb (20.0 t) empty
43.05 long tons (43.7 t) w/o
Locomotive and tender
combined weight		 117,376 lb (53.2 t) empty
102.3 long tons (103.9 t) as built
103.8 long tons (105.5 t) superheated
104.1 long tons (105.8 t) Class 8DW
Tender type XF - XC, XC1, XD, XE, XE1, XF, XF1, XF2, XJ, XN, XN1, XM2, XM3 permitted
* 2 axle bogies
* 34 in (864 mm) wheels
* Length 22 ft 2.5 in (6.769 m)
Fuel type Coal
Fuel capacity 10 long tons (10.2 t)
Water capacity 3,000 imp gal (14,000 l)
Boiler As built:
5 ft (1.524 m) inside diameter
11 ft 0.5 in (3.366 m) inside length
7 ft 1 in (2.159 m) pitch
Superheated & Class 8DW:
5 ft (1.524 m) inside diameter
11 ft 0.375 in (3.362 m) inside length
7 ft 1 in (2.159 m) pitch
Boiler pressure 180 psi (1,240 kPa)
Firegrate area 21 sq ft (1.951 m2)
Heating surface:
– Tubes		 As built:
205 tubes 2 in (50.8 mm) diameter
1,185 sq ft (110.090 m2)
Superheated & Class 8DW:
115 tubes 2 in (50.8 mm) diameter
18 tubes 5.5 in (140 mm) diameter
950 sq ft (88.258 m2)
– Firebox 133 sq ft (12.356 m2) as built 130 sq ft (12.077 m2) superheated & Class 8DW
– Total 1,318 sq ft (122.446 m2) as built
1,081 sq ft (100.428 m2) superheated & Class 8DW
Superheater type Not equipped as built
Superheater area 214 sq ft (19.881 m2) superheated & Class 8DW
Cylinders Two
Cylinder size As built: 18.5 in (470 mm) bore
Superheated: 19 in (483 mm) bore
Class 8DW: 20 in (508 mm) bore
All: 24 in (610 mm) stroke
Valve gear Stephenson
Performance figures
Tractive effort At 75% boiler pressure:
23,100 lbf (102.8 kN) as built
24,370 lbf (108.4 kN) superheated
27,000 lbf (120.1 kN) Class 8DW[3]
Career
Operator(s) Cape Government Railways
South African Railways
Class CGR 8th Class
SAR Class 8D, Class 8DW
Number in class 38
Number(s) CGR 366-384, 399, 783-794, 807-812
SAR 1192-1229[4][5]
Delivered 1903
First run 1903
Withdrawn 1972[6]

The South African Class 8D 4-8-0 of 1903 is a South African steam locomotive from the pre-Union era in the Cape Colony.

In 1903, when the first batch of 8th Class 4-8-0 Mastodon type locomotives had been tried and proven successful, the Cape Government Railways placed another thirty-eight 8th Class 4-8-0 steam locomotives in service, six on the Cape Western System, twenty on the Cape Midland System and twelve on the Cape Eastern System. In 1912, when they were assimilated into the South African Railways, they were renumbered and reclassified to Class 8D.[4][6][7]

Manufacture

Evolution

The first 8th Class locomotive of the Cape Government Railways (CGR) was a 2-8-0 Consolidation type designed by H.M. Beatty, the Chief Locomotive Superintendent of the CGR from 1896 to 1910. It was later to become the South African Railways (SAR) Class 8X. While these first Schenectady and ALCO built 2-8-0 locomotives were being subjected to exhaustive testing on all types of traffic and under varying conditions, some trouble was experienced with the leading two-wheeled pony truck and, when designs were prepared at Salt River for a later order for more locomotives, it was replaced with a four-wheeled bogie.[7]

These thirty-eight locomotives were the second batch of CGR 8th Class locomotives to be built with a 4-8-0 Mastodon type wheel arrangement. In spite of the difference in wheel arrangement, the CGR’s new post-7th Class Consolidations and Mastodons were all grouped together into the 8th Class.[7][6]

Builders

They were ordered from Neilson, Reid and Company in 1902 and delivered in four batches in 1903. While they were being built, Neilson, Reid amalgamated with Dübs and Company and Sharp, Stewart and Company to form the North British Locomotive Company (NBL). As a result, the last four of these locomotives were delivered as having been built by NBL at the Hyde Park shops of the former Neilson, Reid.[7]

The locomotives were distributed between the CGR’s Midland, Eastern and Western systems as follows:

Class 8 sub-classes

The Union of South Africa was established on 31 May 1910 in terms of the South Africa Act, 1909, enacted by the Parliament of the United Kingdom. One of the clauses in the Act required that the three Colonial Government railways, the CGR, the Natal Government Railways and the Central South African Railways, also be united under one single administration to control and administer the railways, ports and harbours of the Union. While the 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][9]

In 1912 these thirty-eight locomotives were renumbered in the range from 1192 to 1229 and reclassified to Class 8D on the SAR.[5]

These locomotives, together with the rest of the CGR’s 8th Class 2-8-0 Consolidations and 8th Class 4-8-0 Mastodons and the Class 8-L1 to 8-L3 4-8-0 Mastodon locomotives from the Central South African Railways (CSAR), were grouped into ten different sub-classes by the SAR. The 4-8-0 locomotives became SAR Classes 8 and 8A to 8F and the 2-8-0 locomotives became Classes 8X to 8Z.[3]

Modification

During A.G. Watson’s term as the Chief Mechanical Engineer of the SAR from 1929 to 1936, many of the Class 8 to Class 8F locomotives were equipped with superheated boilers, larger bore cylinders and either inside or outside admission piston valves. The outside admission valve locomotives had their cylinder bore increased from 18.5 inches (470 millimetres) to 19 inches (483 millimetres) and retained their existing SAR classifications, while the inside admission valve locomotives had their cylinder bore increased to 20 inches (508 millimetres) and were reclassified by having a "W" suffix added to their existing SAR classifications.[3][6]

Of the Class 8D locomotives, nine were equipped with superheated boilers, 19 inches (483 millimetres) bore cylinders and outside admission piston valves while retaining their Class 8D classification.[3]

Fourteen were equipped with superheated boilers, 20 inches (508 millimetres) bore cylinders and inside admission piston valves, and were reclassified to Class 8DW.[3]

The Class 8D and Class 8DW locomotive builders, works numbers, CGR to SAR renumbering and superheating modifications are shown in the table.[1][2][3][4]

Service

In SAR service, the 4-8-0 Class 8 family of locomotives served on every system in the country and in the 1920s became the mainstay of motive power on many branchlines. Their final days were spent in shunting service and by 1972 they were all withdrawn, some being sold into industry, like number 1211 which became "Puffing Duggie" at Grootvlei Proprietary Mines (GVPM).[6][10]

Modifications illustrated

The main picture shows reboilered and modified SAR Class 8D no. 1223 at the Bloemfontein locomotive depot on 22 March 1970. The same locomotive is depicted below before the modification.

See also

References

  1. ↑ 1.0 1.1 1.2 Neilson, Reid works list, compiled by Austrian locomotive historian Bernhard Schmeiser
  2. ↑ 2.0 2.1 2.2 North British Locomotive Company works list, compiled by Austrian locomotive historian Bernhard Schmeiser
  3. ↑ 3.0 3.1 3.2 3.3 3.4 3.5 South African Railways and Harbours Locomotive Diagram Book, 2’0” & 3’6” Gauge Steam Locomotives, 15 August 1941, as amended
  4. ↑ 4.0 4.1 4.2 4.3 Classification of S.A.R. Engines with Renumbering Lists, issued by the Chief Mechanical Engineer’s Office, Pretoria, January 1912, pp. 9, 12, 15, 42-43 (Reprinted in April 1987 by SATS Museum, R.3125-6/9/11-1000)
  5. ↑ 5.0 5.1 5.2 Holland, D.F. (1972). Steam Locomotives of the South African Railways, Volume 2: 1910-1955 (1st ed.). Newton Abbott, Devon: David & Charles. p. 139. ISBN 978-0-7153-5427-8.
  6. ↑ 6.0 6.1 6.2 6.3 6.4 Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 48–49. ISBN 0869772112.
  7. ↑ 7.0 7.1 7.2 7.3 7.4 Holland, D.F. (1971). Steam Locomotives of the South African Railways, Volume 1: 1859-1910 (1st ed.). Newton Abbott, Devon: David & Charles. pp. 63–64. 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.
  9. ↑ South Africa Act, 1909, enacted by the Parliament of the United Kingdom, 20 September 1909
  10. ↑ Middleton, John N. (2002). Railways of Southern Africa Locomotive Guide - 2002 (as amended by Combined Amendment List 4, January 2009) (2nd, Dec 2002 ed.). Herts, England: Beyer-Garratt Publications. pp. 14, 19.