South African Class 11 2-8-2

CSAR Class 11 2-8-2
South African Class 11 2-8-2

Class 11 no. 933, ex CSAR no. 721, Sydenham, 1973

Type and origin Power type Steam Designer Central South African Railways (P.A. Hyde) Builder North British Locomotive Company Serial number 16207, 16250-16284 Model CSAR Class 11 Build date 1904 Total produced 36

Specifications Configuration 2-8-2 (Mikado) Driver 3rd coupled axle Gauge 3 ft 6 in (1,067 mm) Cape gauge Leading dia. 30 in (762 mm) Coupled dia. 48 in (1,219 mm) Trailing dia. 30 in (762 mm) Tender wheels 33 1⁄2 in (851 mm) as built 34 in (864 mm) retyred Wheelbase 55 ft 8 in (16,967 mm)  • Engine 29 ft 3 in (8,915 mm)  • Coupled 13 ft 1 1⁄2 in (4,000 mm)  • Tender 16 ft 9 in (5,105 mm)  • Tender bogie 4 ft 7 in (1,397 mm) Length: ​  • Over couplers 64 ft 4 1⁄2 in (19,622 mm) Height 12 ft 10 in (3,912 mm) Frame type Plate Axle load 15 LT 15 cwt (16,000 kg)  • Leading 6 LT 1 cwt (6,147 kg)  • 1st coupled 15 LT 4 cwt (15,440 kg)  • 2nd coupled 15 LT 12 cwt (15,850 kg)  • 3rd coupled 15 LT 15 cwt (16,000 kg)  • 4th coupled 15 LT 15 cwt (16,000 kg)  • Trailing 11 LT 7 cwt (11,530 kg)  • Tender bogie Bogie 1: 24 LT 4 cwt (24,590 kg) Bogie 2: 25 LT 3 cwt (25,550 kg)  • Tender axle 12 LT 11 cwt 2 qtr (12,780 kg) Adhesive weight 62 LT 6 cwt (63,300 kg) Loco weight 79 LT 14 cwt (80,980 kg) Tender weight 49 LT 7 cwt (50,140 kg) Total weight 129 LT (131.1 t) Tender type XM2 (2-axle bogies) XC, XC1, XE, XE1, XF, XF1, XF2, XJ, XM, XM1, XM2, XM3, XM4, XP1, XS permitted Fuel type Coal Fuel capacity 10 LT (10.2 t) Water cap 4,000 imp gal (18,200 l) Firebox type Belpaire  • Firegrate area 37 sq ft (3.4 m2) Boiler: ​  • Pitch 7 ft 2 in (2,184 mm)  • Diameter 5 ft 1 3⁄4 in (1,568 mm)  • Tube plates 18 ft 1⁄4 in (5,493 mm)  • Small tubes 121 2 1⁄4 in (57 mm)  • Large tubes 21: 5 1⁄2 in (140 mm) Boiler pressure 190 psi (1,310 kPa) Safety valve Ramsbottom Heating surface 1,971 sq ft (183.1 m2)  • Tubes 1,829 sq ft (169.9 m2)  • Firebox 142 sq ft (13.2 m2) Superheater: ​  • Heating area 331 sq ft (30.8 m2) Cylinders Two Cylinder size 20 in (508 mm) bore 26 in (660 mm) stroke Valve gear Walschaerts Valve type Piston Couplers Johnston link-and-pin AAR knuckle (1930s)

Performance figures Tractive effort 30,780 lbf (136.9 kN) @ 75%

Career Operators Central South African Railways South African Railways Freegold Tavistock Colliery Blue Circle Cement Class CSAR & SAR Class 11 Number in class 36 Numbers CSAR 700-735, SAR 912-947 Delivered 1904 First run 1904 Withdrawn 1975

The 2nd & 3rd coupled axles had flangeless wheels

The South African Railways Class 11 2-8-2 of 1904 was a steam locomotive from the pre-Union era in Transvaal Colony.

In 1904, the Central South African Railways placed 36 Class 11 steam locomotives with a 2-8-2 Mikado type wheel arrangement in service. When these locomotives were assimilated into the South African Railways in 1912, they were renumbered but retained their Class 11 classification.

Built by the North British Locomotive Company (NBL), the Class 11 was designed for goods train service on the Reef by P.A. Hyde, Chief Locomotive Superintendent of the Central South African Railways (CSAR) from 1902 to 1904. One locomotive, CSAR no. 700, was delivered early in 1904 for trial purposes. After successful trials, this locomotive was followed by a further 35 Class 11 locomotives which were delivered later that same year and numbered in the range from 701 to 735.

The Class 11 was designed by Hyde to take full advantage of the new 80 pounds per yard (40 kilograms per metre) track of the CSAR, which was gradually replacing the old 60 pounds per yard (30 kilograms per metre) sections on mainlines. Upon delivery, however, the class was found to be too heavy for a large part of the existing track and bridges on the line between Witbank and Germiston, where they were intended to work. It took nearly a year to carry out the programme of track and bridge strengthening and some of the new locomotives ended up being held in staging for all that time before the Chief Civil Engineer would allow them to run.

They were superheated, with Belpaire fireboxes. The cylinders were arranged outside the plate frames, with the 10 inches (254 millimetres) diameter outside admission piston valves arranged above the cylinders and actuated by Walschaerts valve gear. The drivers and intermediate coupled wheels were flangeless. The motion, axleboxes and several other details were identical or similar to equivalent parts of the Class 10, which was built at the same time by the same manufacturer, and their Type XM2 two-axle bogie tenders were identical.