South African Class F 4-6-4T

South African Class F 4-6-4T
Central South African Railways Class F no. 260
South African Railways Class F no. 78
Power type Steam
Designer Central South African Railways
Builder Vulcan Foundry
Serial number 1908-1915
Model CSAR Class F
Build date 1904
Total produced 8
Configuration 4-6-4T "Hudson"
Gauge 3 ft 6 in (1,067 mm) Cape gauge
Leading wheel
diameter		 30 in (762 mm)
Driver diameter 54 in (1,370 mm)
Trailing wheel
diameter		 30 in (762 mm)
Wheelbase 34 ft 1 in (10.389 m) total
6 ft 4 in (1.930 m) pilot
11 ft (3.353 m) drivers
6 ft 4 in (1.930 m) trailing
Length 41 ft 5.75 in (12.643 m)
Height 12 ft 7.5625 in (3.850 m)
Frame Bar frame
Axle load 13 long tons (13.2 t) per driver
Weight on drivers 39 long tons (39.6 t)
Locomotive weight 79 long tons (80.3 t)
Fuel type Coal
Fuel capacity 3 long tons (3.0 t)
Water capacity 1,800 imp gal (8,200 l)
Boiler 5 ft (1.524 m) int dia
12 ft 7 in (3.835 m) int length
7 ft 0.5 in (2.146 m) pitch
Boiler pressure 200 psi (1,380 kPa)
Firegrate area 21.75 sq ft (2.021 m2)
Heating surface:
Tubes		 205 tubes 2 in (50.8 mm) ext dia
1,350 sq ft (125.419 m2)
Heating surface:
Firebox		 131 sq ft (12.170 m2)
Heating surface:
Total		 1,481 sq ft (137.589 m2)
Cylinders Two
Cylinder size 18 in (457 mm) bore
26 in (660 mm) stroke
Valve gear Stephenson
Tractive effort 23,410 lbf (104.1 kN) at 75% boiler pressure
Career Central South African Railways
South African Railways
Class Class F
Number in class 8
Number CSAR 260-267, SAR 78-85[1][2][3]
Nicknames Chocolate Box
Delivered 1904[1]
First run 1904
Withdrawn 1931[4]
Disposition Retired

In 1904 the Central South African Railways placed eight Class F tank steam locomotives with a 4-6-4T wheel arrangement in service. In 1912, when these locomotives were assimilated into the South African Railways, they were renumbered but retained their Class F classification.[1][2]

Contents

Manufacturer

The first two locomotive types to be designed for the Central South African Railways (CSAR) by P.A. Hyde, who had been appointed as Chief Locomotive Superintendent of the CSAR upon its inception on 1 July 1902, were placed in service in 1904. These were the Class 9 “Pacific” type passenger locomotive and the Class F 4-6-4T “Hudson” type tank steam locomotive.[1]

Orders for these two classes were placed simultaneously with Vulcan Foundry of Newton-le-Willows in England. The eight Class F locomotives were delivered in 1904, numbered 260 to 267.[1]

Characteristics

Since the Class F and the Class 9 were designed and built simultaneously, there were many similarities between them. Apart from the tank locomotive’s slightly smaller driving wheels, 54 inches (1,370 millimetres) on the Class F compared to 57 inches (1,450 millimetres) on the Class 9, many parts including their boilers were made interchangeable. They had bar frames, Stephenson valve gear and used saturated steam.[1][4]

Renumbering

When the three colonial railroads were amalgamated into the South African Railways (SAR) in 1912, these locomotives retained their Class F classification, but were renumbered 78 to 85.[2][3][4]

Service

At the time that the Class F locomotives were ordered, the suburban services on the Reef were being worked by the 46 Tonner Class B tank locomotives that had been inherited from the Nederlandsche-Zuid-Afrikaansche Spoorwegmaatschappij (NZASM) via the Imperial Military Railways (IMR). Since the loads were fast becoming too heavy for them, the Class F was designed and ordered as a replacement, intended for the suburban services between Springs and Randfontein.[1][4]

Hyde considered the Class F and the Class 9 as two of his most successful designs for the CSAR. The tank locomotives were very attractive in appearance, with double red lining on their black livery and the tradition of polished copper-capped chimneys, brass domes and boiler bands that was continued on the CSAR after the IMR era. They were always maintained in immaculate condition while in service and became affectionately known as the “Chocolate Boxes”.[1][4]

The last of the Class F was withdrawn from service by 1931.[4]

Gallery

The main picture is a Vulcan Foundry builder’s photograph of Class F number 260.

See also

References

  1. ^ a b c d e f g h Holland, D.F. (1971). Steam Locomotives of the South African Railways, Volume 1: 1859-1910 (1st ed.). Newton Abbott, Devon: David & Charles. pp. 127-129. ISBN 0715353829. 
  2. ^ a b c Classification of S.A.R. Engines with Renumbering Lists, issued by the Chief Mechanical Engineer’s Office, Pretoria, January 1912, pp. 7, 11, 13, 19-20 (Reprinted in April 1987 by SATS Museum, R.3125-6/9/11-1000)
  3. ^ a b Holland, D.F. (1972). Steam Locomotives of the South African Railways, Volume 2: 1910-1955 (1st ed.). Newton Abbott, Devon: David & Charles. p. 136. ISBN 0715354272. 
  4. ^ a b c d e f Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. p. 30. ISBN 0869772112.