South African Class 8D 4-8-0

28+1⁄2 in (724 mm)Coupled dia.48 in (1,219 mm)Tender wheels33+1⁄2 in (851 mm) as built
34 in (864 mm) retyredWheelbase46 ft 10+1⁄2 in (14,288 mm) ​ • Engine23 ft 3 in (7,087 mm) • Leading6 ft (1,829 mm) • Coupled13 ft 6 in (4,115 mm) • Tender14 ft 7 in (4,445 mm) • Tender bogie4 ft 7 in (1,397 mm)Length:
​ • Over couplers54 ft 2+1⁄4 in (16,516 mm)Height♠ 12 ft 10 in (3,912 mm)
♥♣ 12 ft 8 in (3,861 mm)Frame typeBarAxle load♠ 11 LT 14 cwt (11,890 kg)
♥ 12 LT (12,190 kg)
♣ 12 LT 11 cwt (12,750 kg) ​ • Leading♠ 12 LT 9 cwt (12,650 kg)
♥♣ 12 LT 15 cwt (12,950 kg) • Coupled♠ 11 LT 14 cwt (11,890 kg) all
♥ 12 LT (12,190 kg) all • 1st coupled♣ 11 LT 18 cwt (12,090 kg) • 2nd coupled♣ 12 LT 11 cwt (12,750 kg) • 3rd coupled♣ 11 LT 19 cwt (12,140 kg) • 4th coupled♣ 11 LT 18 cwt (12,090 kg) • Tender bogieBogie 1: 17 LT 13 cwt (17,930 kg)
Bogie 2: 18 LT 16 cwt (19,100 kg) • Tender axle9 LT 8 cwt (9,551 kg)Adhesive weight♠ 46 LT 16 cwt (47,550 kg)
♥ 48 LT (48,770 kg)
♣ 48 LT 6 cwt (49,080 kg)Loco weight♠ 59 LT 5 cwt (60,200 kg)
♥ 60 LT 15 cwt (61,720 kg)
♣ 61 LT 1 cwt (62,030 kg)Tender weight36 LT 9 cwt (37,030 kg)Total weight♠ 95 LT 14 cwt (97,240 kg)
♥ 97 LT 4 cwt (98,760 kg)
♣ 97 LT 10 cwt (99,060 kg)Tender typeXE1 (2-axle bogies)
XC, XC1, XD, XE, XE1, XF, XF1, XF2, XJ, XM, XM1, XM2, XM3 permittedFuel typeCoalFuel capacity10 LT (10.2 t)Water cap.2,855 imp gal (13,000 L)Firebox:​ • TypeRound-top • Grate area♠ 21.35 sq ft (1.983 m²)
♥♣ 21 sq ft (2.0 m²)Boiler:
​ • Pitch♠♥♣ 7 ft 1 in (2,159 mm) • Diameter♠♥♣ 5 ft (1,524 mm) • Tube plates♠ 11 ft 1⁄2 in (3,366 mm)
♥♣ 11 ft 3⁄8 in (3,362 mm) • Small tubes♠ 205: 2 in (51 mm)
♥♣ 115: 2 in (51 mm) • Large tubes♥♣ 18: 5+1⁄2 in (140 mm)Boiler pressure180 psi (1,241 kPa)Safety valveRamsbottomHeating surface:​ • Firebox♠ 133 sq ft (12.4 m²)
♥♣ 131 sq ft (12.2 m²) • Tubes♠ 1,185 sq ft (110.1 m²)
♥♣ 950 sq ft (88 m²) • Total surface♠ 1,318 sq ft (122.4 m²)
♥♣ 1,081 sq ft (100.4 m²)Superheater:
​ • Heating area♥♣ 214 sq ft (19.9 m²)CylindersTwoCylinder size♠ 18+1⁄2 in (470 mm) bore
♥ 19 in (483 mm) bore
♣ 20 in (508 mm) bore
♠♥♣ 24 in (610 mm) strokeValve gearStephensonValve type♠ Slide - ♥♣ PistonCouplersJohnston link-and-pin
AAR knuckle (1930s)

Performance figures
Tractive effort	♠ 23,110 lbf (102.8 kN) @ 75% ♥ 24,370 lbf (108.4 kN) @ 75% ♣ 27,000 lbf (120 kN) @ 75%

Career
Operators	Cape Government Railways South African Railways
Class	CGR 8th Class, SAR Classes 8D & 8DW
Number in class	38
Numbers	CGR 366-384, 399, 783-794, 807-812 SAR 1192-1229
Delivered	1903
First run	1903
Withdrawn	1972

The leading coupled axle had flangeless wheels

The South African Railways Class 8D 4-8-0 of 1903 was a steam locomotive from the pre-Union era in the Cape of Good Hope.

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 38 8th Class 4-8-0 steam locomotives in service, six on the Western System, twenty on the Midland System and twelve on the Eastern System. In 1912, when they were assimilated into the South African Railways, they were renumbered and designated Class 8D.^[1][2][3]

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 be designated the South African Railways (SAR) Class 8X.^[2]

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. When designs were prepared at Salt River for a later order for more locomotives, the pony truck was replaced with a four-wheeled bogie.^[2]

These 38 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.^[1][2]

Builders

They were ordered from Neilson, Reid and Company in 1902 and were 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.^[2][4][5]

The locomotives were delivered with Type XE1 tenders and distributed between the CGR's Midland, Eastern and Western systems.

• Twenty were allocated to the Midland System, nineteen of them numbered in the range from 366 to 384 and the twentieth numbered 399.
• Twelve, numbered in the range from 783 to 794, went to the Eastern System.
• Six, numbered in the range from 807 to 812, went to the Western System.^[2][6]

Class 8 sub-classes

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.^[3][7][8]

In 1912, these 38 locomotives were renumbered in the range from 1192 to 1229 and designated Class 8D on the South African Railways (SAR).^[6]

These locomotives, together with the rest of the CGR's 8th Class 2-8-0 Consolidations and 8th Class 4-8-0 Mastodons as well as 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.^[9]

Modifications

Superheating

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+1⁄2 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.^[1][9]

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.^[9]

Fourteen were equipped with superheated boilers, 20 inches (508 millimetres) bore cylinders and inside admission piston valves, and were reclassified to Class 8DW.^[9]

Experimental chimney

In the early 1930s engine no. 1197 was fitted with an experimental chimney designed by Watson. A similar chimney, the shape of which earned it a nickname that referred to a night bucket, was also tested on Class 5B no. 726. This experiment did not result in further production.^[10]

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 branch lines. Their final days were spent in shunting service and they were all withdrawn by 1972.^[1]

Some were sold into industrial service after withdrawal, like no. 1211, which became Puffing Duggie at Grootvlei Proprietary Mines (GVPM).^[1][11]

Works numbers

The Class 8D and Class 8DW locomotive builders, works numbers, CGR to SAR renumbering and superheating modifications are listed in the table.^[3][4][5][9]

Class 8D 4-8-0 Builders, Works Numbers & Renumbering

Builder	Year	Works No.	CGR No.	CGR System	SAR No.	SAR Model
Neilson Reid	1903	6325	807	Western	1192	Class 8DW
Neilson Reid	1903	6326	808	Western	1193
Neilson Reid	1903	6327	809	Western	1194
Neilson Reid	1903	6328	810	Western	1195
Neilson Reid	1903	6329	811	Western	1196	Superheated
Neilson Reid	1903	6330	812	Western	1197	Class 8DW
Neilson Reid	1902	6284	366	Midland	1198	Class 8DW
Neilson Reid	1902	6285	367	Midland	1199
Neilson Reid	1902	6286	368	Midland	1200	Superheated
Neilson Reid	1902	6287	369	Midland	1201
Neilson Reid	1902	6288	370	Midland	1202	Class 8DW
Neilson Reid	1902	6289	371	Midland	1203
Neilson Reid	1902	6290	372	Midland	1204
Neilson Reid	1902	6291	373	Midland	1205	Class 8DW
Neilson Reid	1902	6292	374	Midland	1206	Class 8DW
Neilson Reid	1902	6293	375	Midland	1207	Class 8DW
Neilson Reid	1902	6294	376	Midland	1208	Class 8DW
Neilson Reid	1902	6295	377	Midland	1209
Neilson Reid	1903	6303	378	Midland	1210
Neilson Reid	1903	6304	379	Midland	1211	Class 8DW
Neilson Reid	1903	6305	380	Midland	1212	Class 8DW
Neilson Reid	1903	6308	381	Midland	1213	Superheated
NBL	1903	15833	382	Midland	1214	Superheated
NBL	1903	15834	383	Midland	1215
NBL	1903	15835	384	Midland	1216	Class 8DW
NBL	1903	15836	399	Midland	1217	Superheated
Neilson Reid	1902	6296	783	Eastern	1218
Neilson Reid	1902	6297	784	Eastern	1219	Class 8DW
Neilson Reid	1902	6298	785	Eastern	1220
Neilson Reid	1902	6299	786	Eastern	1221	Class 8DW
Neilson Reid	1903	6306	787	Eastern	1222
Neilson Reid	1902	6300	788	Eastern	1223	Superheated
Neilson Reid	1903	6307	789	Eastern	1224	Superheated
Neilson Reid	1902	6301	790	Eastern	1225	Superheated
Neilson Reid	1903	6331	791	Eastern	1226	Class 8DW
Neilson Reid	1903	6332	792	Eastern	1227
Neilson Reid	1903	6333	793	Eastern	1228
Neilson Reid	1903	6334	794	Eastern	1229	Superheated

Illustration

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

• 
  No. 1197 at East London with an experimental night bucket chimney, c. 1931
• 
  Still unmodified ex CGR (Eastern System) no. 788, SAR no. 1223, at Fort Beaufort, Eastern Cape, c. 1936
• 
  Ex CGR (Eastern System) no. 788, SAR no. 1223, here modified to superheating, c. 1970
• 
  Ex SAR Class 8DW no. 1211, GVPM Puffing Duggie, Chamdor, 2 February 2009

References

1. ^ ^{a b c d e} Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 48–49. ISBN 0869772112.
2. ^ ^{a b c d e f} Holland, D.F. (1971). Steam Locomotives of the South African Railways. Vol. 1: 1859–1910 (1st ed.). Newton Abbott, England: David & Charles. pp. 63–64. ISBN 978-0-7153-5382-0.
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, 42-43 (Reprinted in April 1987 by SATS Museum, R.3125-6/9/11-1000)
4. ^ ^{a b} Neilson, Reid works list, compiled by Austrian locomotive historian Bernhard Schmeiser
5. ^ ^{a b} North British Locomotive Company works list, compiled by Austrian locomotive historian Bernhard Schmeiser
6. ^ ^{a b} Holland, D. F. (1972). Steam Locomotives of the South African Railways. Vol. 2: 1910-1955 (1st ed.). Newton Abbott, England: David & Charles. p. 139. ISBN 978-0-7153-5427-8.
7. ^ The South African Railways - Historical Survey. Editor George Hart, Publisher Bill Hart, Sponsored by Dorbyl Ltd., Published c. 1978, p. 25.
8. ^ South Africa Act, 1909, enacted by the Parliament of the United Kingdom, 20 September 1909
9. ^ ^{a b c d e} South African Railways and Harbours Locomotive Diagram Book, 2'0" & 3'6" Gauge Steam Locomotives, 15 August 1941, as amended
10. ^ SAR Mechanical Department. Experimental Chimney. Class 5B Engine no. 726. SAR Mechanical Department Drawing Office Pretoria, Drawing L-7503, 7 October 1931.
11. ^ 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.

7' ¼" gauge4' 8½" gauge3' 6" gauge2' 6" gauge2' gauge