page_title: South African Class 3 4-8-2
section_title: Characteristics
hierarchical_section_title: South African Class 3 4-8-2 / Characteristics
caption_attribution_description: English: Hendrie's steam reverser on Class 1A 4-8-0 (ex Natal Government Railways)
context_page_description: The South African Railways Class 3 4-8-2 of 1909 was a steam locomotive from the pre-Union era in the Colony of Natal.
  In 1909, the Natal Government Railways placed the world’s first true Mountain type locomotive in service when five Class B 4-8-2 tender locomotives were commissioned. Another 25 were placed in service in 1911. In 1912, when they were assimilated into the South African Railways, they were renumbered and designated Class 3. The Mountain wheel arrangement went on to become the most numerous steam locomotive wheel configuration in use in South Africa.
context_section_description: The locomotives were equipped with Pyle National Electric headlights. They were the world's first true Mountain type tender locomotives, having been designed and built with a 4-8-2 wheel arrangement with the firebox positioned to the rear of the driving wheels. Earlier Natal 4-8-2 locomotives were modified from a different original wheel arrangement.
  The boilers which were used on these locomotives were, at the time, the largest in South Africa. Like the altered NGR Class B of 1906 on which it was based, these loco­motives used saturated steam and had plate frames. They used Walschaerts valve gear with flat "D" gunmetal type valves, which were arranged above the cylinders and controlled by the Hendrie-designed steam reversing gear. Since they were built without superheaters, the bore of their slide valves were ¹⁄₂ inch (12.7 millimetres) larger than those on the altered Class B of 1906 to compensate for the additional weight of the locomotive.
  The boiler, of which the barrel was ¹¹⁄₁₆ inch (17 millimetres) thick, was fitted with four Ramsbottom safety valves, 3 ¹⁄₂ inches (89 millimetres) in diameter. It was fed by two injectors, arranged on the underside of the footplate at the sides, with the combination valves placed on the back of the firebox. The Belpaire firebox was constructed with a forward "rake" of the throat and back plates to keep the distance between the boiler's tube plates reasonably short at 18 feet 6 inches (5,639 millimetres). It had a finger bar firegrate which was operated by hand lever from the cab.
caption: Hendrie's steam reversing gear
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