South African Class 8D 4-8-0

This article is about one of several different Cape Government Railways locomotive types to be designated "8th Class". For other CGR 8th Class locomotives, see Cape Government Railways 8th Class locomotives.

CGR 8th Class 4-8-0 1903
South African Classes 8D & 8DW 4-8-0

300px CGR 8th Class no. 788, SAR Class 8D no. 1223, Bloemfontein, 22 March 1970

Type and origin ♠ Original locomotive, as built ♥ Superheated, outside admission valves ♣ Superheated, inside admission valves, Class 8DW Power type Steam Designer Cape Government Railways (H.M. Beatty) Builder Neilson, Reid and Company North British Locomotive Company Serial number NR 6284-6301, 6303-6308, 6325-6334 NBL 15833-15836 Model CGR 8th Class (4-8-0) Build date 1902-1903 Total produced 38

Specifications Configuration 4-8-0 (Mastodon) Driver axle 2nd coupled axle Gauge 3 ft 6 in (1,067 mm) Cape gauge Leading dia Coupled dia 48 in (1,219 mm) Tender wheels as built 34 in (864 mm) retyred Wheelbase  • Engine 23 ft 3 in (7,087 mm)  • Leading 6 ft (1,829 mm)  • Coupled 13 ft 6 in (4,115 mm)  • Tender 14 ft 7 in (4,445 mm)  • Tender bogie 4 ft 7 in (1,397 mm) Length:  • Over couplers Height ♠ 12 ft 10 in (3,912 mm) ♥♣ 12 ft 8 in (3,861 mm) Frame type Bar Axle load ♠ ♥ ♣  • Leading ♠ ♥♣  • 1st coupled ♣  • 2nd coupled ♣  • 3rd coupled ♣  • 4th coupled ♣  • Tender bogie Bogie 1: Bogie 2:  • Tender axle Adhesive weight ♠ ♥ ♣ Loco weight ♠ ♥ ♣ Tender weight Loco & tender weight ♠ ♥ ♣ Tender type XE1 (2-axle bogies) XC, XC1, XD, XE, XE1, XF, XF1, XF2, XJ, XM, XM1, XM2, XM3 permitted Fuel type Coal Fuel capacity 10 LT (10.2 t) Water cap Boiler:  • Pitch ♠♥♣ 7 ft 1 in (2,159 mm)  • Diameter ♠♥♣ 5 ft (1,524 mm)  • Tube plates ♠ ♥♣  • Small tubes ♠ 205: 2 in (51 mm) ♥♣ 115: 2 in (51 mm)  • large tubes ♥♣ 18:  • Firebox type Round-top Boiler pressure 180 psi (1,241 kPa) Safety valve Ramsbottom Firegrate area ♠ 21.35 sq ft (1.983 m2) ♥♣ 21 sq ft (2.0 m2) Heating surface ♠ 1,318 sq ft (122.4 m2) ♥♣ 1,081 sq ft (100.4 m2)  • Tubes ♠ 1,185 sq ft (110.1 m2) ♥♣ 950 sq ft (88 m2)  • Firebox ♠ 133 sq ft (12.4 m2) ♥♣ 131 sq ft (12.2 m2) Superheater:  • Heating area ♥♣ 214 sq ft (19.9 m2) Cylinders Two Cylinder size ♠ bore ♥ 19 in (483 mm) bore ♣ 20 in (508 mm) bore ♠♥♣ 24 in (610 mm) stroke Valve gear Stephenson Valve type ♠ Slide - ♥♣ Piston Couplers Bell link-and-pin AAR knuckle (c. 1930s-1950s)

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 thirty-eight 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 reclassified to Class 8D.

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.

File:H.M. Beatty.jpg

H.M. Beatty

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.

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.

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.

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

• Twenty were allocated to the Midland System, with 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.

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 required careful planning and was only implemented with effect from 1 January 1912.

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

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.

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 to 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.

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.

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

The Class 8D and Class 8DW locomotive builders, works numbers, CGR to SAR renumbering and superheating modifications are listed in the table.

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

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 were sold into industrial service after withdrawal, like no. 1211, which became Puffing Duggie at Grootvlei Proprietary Mines (GVPM).

Illustration

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

• SAR Class 8D 1223 (4-8-0) CGR 788.jpg

  Still unmodified ex CGR (Eastern System) no. 788, SAR no. 1223, at Fort Beaufort, Eastern Cape, circa 1936

• Class 8D no. 1223.jpg

  Ex CGR (Eastern System) no. 788, SAR no. 1223, here modified to superheating, c. 1970

• Class8DWno1211.jpg

  Ex SAR Class 8DW no. 1211, GVPM Puffing Duggie, Chamdor, 2 February 2009