South African Class S 0-8-0

South African Railways Class S

Company type	Steam locomotive
Industry	Railway transportation
Predecessor	Downgraded mainline locomotives used for shunting
Founded	1929
Founder	Colonel F.R. Collins DSO (designer)
Headquarters	South Africa
Products	Class S 0-8-0 steam shunting locomotives
Parent	South African Railways

Overview

The South African Railways Class S 0-8-0 steam locomotive was introduced in 1929.

During that year, the South African Railways commissioned a total of fourteen specialized shunting locomotives, designated as Class S, featuring an 0-8-0 wheel configuration. These engines were specifically designed for yard duties and heavy shunting tasks. The third coupled axle was equipped with flangeless wheels to facilitate smoother navigation through tight curves.

Background

Historically, South African railways primarily relied on downgraded mainline locomotives for shunting duties. Despite the extensive volume of shunting operations, the steam era saw a surprisingly small number of locomotives specifically designed for this purpose on the South African Railways (SAR), totaling only 151 units out of a peak steam fleet that approached nearly 2,800 locomotives.

When SAR eventually introduced locomotives built expressly for shunting, it followed the American convention of employing tender locomotives rather than adopting the European preference for tank engines in such roles.

Manufacturer

Col F.R. Collins DSO

Although some Class A tank locomotives were converted into Class 17 tank-and-tender shunters, the surge in rail traffic across South Africa—and notably on the Witwatersrand—during the 1920s necessitated continued use of heavy mainline engines for shunting tasks. Consequently, Colonel F.R. Collins DSO, Chief Mechanical Engineer of SAR, developed the specifications for the Class S 0-8-0 tender-type steam shunting locomotive.

In 1928, fourteen units were constructed in Germany by Henschel and Son according to SAR's design requirements. Delivered in 1929 and numbered between 360 and 373, these locomotives were optimized for low-speed operation within sharply curved yard environments. This design eliminated the need for leading or trailing wheels—features essential on mainline locomotives to enhance stability at high speeds. Additionally, maximizing the locomotive's adhesive weight by concentrating it on the coupled wheels was a key objective.

Characteristics

The Class S engines featured superheating technology and were constructed with bar frames. They utilized Walschaerts valve gear paired with piston valves. Each locomotive was equipped with a Type GT tender, which held 8 long tons (8.1 tonnes) of coal and 6,000 imperial gallons (27,300 litres) of water, with a maximum axle load of 15 long tons 19 hundredweight 2 quarters (16,230 kilograms). To enhance visibility for the crew when looking backward, the upper sides of the tender’s coal bunker were recessed inward and the water tank’s top was curved.

Initially, these locomotives operated at a boiler pressure of 216 pounds per square inch (1,489 kilopascals), producing a tractive effort of 45,500 pounds-force (202 kilonewtons) at 75% boiler pressure. However, due to tendencies toward wheel slip, their operating pressure was lowered in 1933 to 170 pounds per square inch (1,172 kilopascals), which reduced tractive effort accordingly to 35,890 pounds-force (159.6 kilonewtons) at the same percentage of boiler pressure.

South African Railways

Originally, the Class S locomotives were deployed in the Orange Free State and Natal regions; however, they were soon reassigned to Transvaal, where they remained for the majority of their operational lifespan. In Transvaal, these engines provided reliable service across various yard locations. Ultimately, the Class S became predominantly associated with Western Transvaal, being based at facilities such as Germiston, Kaserne, Krugersdorp, Springs, and Beaconsfield in Kimberley. A single unit was stationed at Volksrust. Most of the fleet spent their entire careers operating out of Braamfontein.

Industrial

The Class S locomotives were retired from SAR operations in 1976. The following year, four units were sold to Dunn's and subsequently relocated to multiple industrial sites.

• Locomotive No. 362 was transferred to Apex Mines at Greenside and renumbered as no. 6.
• No. 365 was assigned to Tweefontein United Colliery before moving on to Enyati Colliery.
• No. 367 served Apex Mines under no. 5 and later moved to Grootvlei Proprietary Mines in Springs, initially designated as no. 3 Big Mac before being renumbered to no. 2.
• No. 369 went to Grootvlei Proprietary Mines (GVPM), first carrying the number 2 with the nickname King Kong, and subsequently renumbered as no. 1.

Preservation

Number	Works Number	THF / Private Owner	Leased / Current Owner	Present Location	Outside South Africa	Notes
360	HENSC 21071	THF		Krugersdorp Locomotive Depot

Illustration

• 
  No. 362 at Braamfontein in August 1973
• 
  GVPM no. 2 King Kong, photographed on 23 April 1979