South African Class 8F 4-8-0

CGR 8th Class 4-8-0 1904
South African Classes 8F & 8FW 4-8-0

Class 8FW no. 1236 plinthed at De Aar, 27 May 2013

Type and origin ♠ Original locomotive, as built ♥ Superheated, inside admission valves, Class 8FW Power type Steam Designer Cape Government Railways (H.M. Beatty) Builder North British Locomotive Company Serial number 16161-16170 Model CGR 8th Class (4-8-0) Build date 1904 Total produced 10

Specifications Configuration 4-8-0 (Mastodon) Driver 2nd coupled axle Gauge 3 ft 6 in (1,067 mm) Cape gauge Leading dia. 28 1⁄2 in (724 mm) Coupled dia. 48 in (1,219 mm) Tender wheels 33 1⁄2 in (851 mm) as built 34 in (864 mm) retyred Wheelbase 46 ft 10 1⁄2 in (14,288 mm)  • 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 54 ft 2 1⁄4 in (16,516 mm) Height ♠♥ 12 ft 10 in (3,912 mm) Frame type Bar Axle load ♠ 11 LT 14 cwt (11,890 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)  • 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 bogie Bogie 1: 20 LT 14 cwt (21,030 kg) Bogie 2: 22 LT 7 cwt (22,710 kg)  • Tender axle 11 LT 3 cwt 2 qtr (11,350 kg) Adhesive weight ♠ 46 LT 16 cwt (47,550 kg) ♥ 48 LT 6 cwt (49,080 kg) Loco weight ♠ 59 LT 5 cwt (60,200 kg) ♥ 61 LT 1 cwt (62,030 kg) Tender weight 43 LT 1 cwt (43,740 kg) Total weight ♠ 102 LT 6 cwt (103,900 kg) ♥ 104 LT 2 cwt (105,800 kg) Tender type XF (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 3,000 imp gal (13,600 l) Firebox type Round-top  • Firegrate area ♠ 21.35 sq ft (1.983 m2) ♥ 21 sq ft (2.0 m2) Boiler: ​  • Pitch ♠♥ 7 ft 3 in (2,210 mm)  • Diameter ♠♥ 5 ft (1,524 mm)  • Tube plates ♠ 11 ft 1⁄4 in (3,359 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 pressure ♠♥ 180 psi (1,241 kPa) Safety valve Ramsbottom Heating surface ♠ 1,320.6 sq ft (122.69 m2) ♥ 1,081 sq ft (100.4 m2)  • Tubes ♠ 1,184 sq ft (110.0 m2) ♥ 950 sq ft (88 m2)  • Firebox ♠ 136.6 sq ft (12.69 m2) ♥ 131 sq ft (12.2 m2) Superheater: ​  • Heating area ♥ 214 sq ft (19.9 m2) Cylinders Two Cylinder size ♠ 18 1⁄2 in (470 mm) bore ♥ 20 in (508 mm) bore ♠♥ 24 in (610 mm) stroke Valve gear Stephenson Valve type ♠ Slide - ♥ Piston Couplers Johnston link-and-pin AAR knuckle (1930s)

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

Career Operators Cape Government Railways South African Railways Class CGR 8th Class SAR Classes 8F & 8FW Number in class 10 Numbers CGR 829-838 SAR 1234-1243 Delivered 1904 First run 1904 Withdrawn 1972

The leading coupled axle had flangeless wheels

The South African Railways Class 8F 4-8-0 of 1904 was a steam locomotive from the pre-Union era in the Cape of Good Hope.

In 1904, the Cape Government Railways placed its final batch of ten 8th Class 4-8-0 Mastodon type steam locomotives in service. In 1912, when they were assimilated into the South African Railways, they were renumbered and designated Class 8F.

The first 8th Class locomotive of the Cape Government Railways (CGR) was a 2-8-0 Consolidation type designed by H.M. Beatty, the CGR’s Chief Locomotive Superintendent from 1896 to 1910. It was later to become the Class 8X on the South African Railways (SAR). 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.

Orders for the last 8th Class locomotives for the CGR were placed with the North British Locomotive Company (NBL) in 1903. The ten locomotives were built and delivered in 1904, numbered in the range from 829 to 838 and allocated to the Western System of the CGR.

These ten locomotives were the final batch of CGR 8th Class locomotives to be built with a 4-8-0 Mastodon type wheel arrangement.

They were delivered with Type XF tenders with a coal capacity of 10 long tons (10.2 tonnes), a water capacity of 3,000 imperial gallons (14,000 litres) and a maximum axle load of 11 long tons 3 hundredweight 2 quarters (11,350 kilograms).

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. Even though 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 was only implemented with effect from 1 January 1912.