South African Class 15A 4-8-2
Encyclopedia
Between 1914 and 1925 the South African Railways placed one hundred and nineteen Class 15A steam locomotive
Steam locomotive
A steam locomotive is a railway locomotive that produces its power through a steam engine. These locomotives are fueled by burning some combustible material, usually coal, wood or oil, to produce steam in a boiler, which drives the steam engine...

s with a 4-8-2
4-8-2
Under the Whyte notation for the classification of steam locomotives, 4-8-2 represents the wheel arrangement of four leading wheels on two axles , eight powered and coupled driving wheels on four axles, and two trailing wheels on one axle...

 Mountain wheel arrangement in service, delivered in ten batches from three manufacturers.

Manufacturers

The Class 15 and Class 15A were the final development of the plate framed 4-8-2 Mountain locomotive designed by D.A. Hendrie, Chief Mechanical Engineer (CME) of the South African Railways (SAR) from 1910 to 1922. Of the whole Hendrie Mountain family, the Class 15A proved to be his most useful and most numerous group of locomotives.

The predecessor Class 15
South African Class 15 4-8-2
In 1914 the South African Railways placed ten Class 15 steam locomotives with a 4-8-2 Mountain wheel arrangement in service.-Manufacturer:The Class 15 was introduced by D.A...

 locomotives had one flaw, excessively long firetubes. When more were ordered, Hendrie improved the boiler by adding a combustion chamber and shortening the distance between tube plates from 21 in 9 in (6.63 m) to 19 feet (5.791 m) in the process. These locomotives were designated Class 15A and were built in ten batches by three manufacturers. Being wartime, initial production and delivery occurred in dribs and drabs.
  • Five were delivered by the North British Locomotive Company
    North British Locomotive Company
    The North British Locomotive Company was created in 1903 through the merger of three Glasgow locomotive manufacturing companies; Sharp Stewart and Company , Neilson, Reid and Company and Dübs and Company , creating the largest locomotive manufacturing company in Europe.Its main factories were...

     (NBL) in 1914, numbered 1571 to 1575.
  • Eight more were delivered by NBL, also in 1914, numbered 1781 to 1788. Like the Class 15, these first thirteen locomotives had narrow cabs, rear end running plates that curved down below their cabs and Belpaire firebox
    Belpaire firebox
    The Belpaire firebox is a type of firebox used on steam locomotives. It was invented by Alfred Belpaire of Belgium. It has a greater surface area at the top of the firebox, improving heat transfer and steam production...

    es, but unlike the Class 15, with a combustion chamber.
  • Ten more were delivered by NBL in 1915, numbered 1789 to 1798. While the first two batches were delivered with all coupled wheels flanged, beginning with this third batch the leading coupled wheels were flangeless to cope with the sharp curves on the Hex River Pass
    Hex River Pass
    Hex River Pass, Is situated in the Western Cape, province of South Africa, on the National road N1 road between De Doorns and Touws River.-Be Aware:* Driving Skill level: Novice* Road Condition: Tarred surface, sweeping turns...

    . These and subsequent locomotives also had rear end running plates continuing straight through underneath their cabs.
  • Six more were delivered by NBL in 1916, numbered 1799 to 1804.
  • Four more were delivered by NBL in 1917, numbered 1805 to 1808.
  • Twenty more were delivered by NBL in 1920, numbered 1809 to 1828. These twenty and all subsequent Class 15A locomotives were delivered with wider cabs.
  • Twenty were delivered by Beyer, Peacock and Company
    Beyer, Peacock and Company
    Beyer, Peacock and Company was an English railway Locomotive manufacturer with a factory in Gorton, Manchester. Founded by Charles Beyer and Richard Peacock, it traded from 1854 until 1966...

     in 1920, numbered 1839 to 1858.
  • Ten more were delivered by Beyer, Peacock in 1921, numbered 1961 to 1970.
  • Fifteen were delivered by NBL in 1921, numbered 2011 to 2025.
  • Twenty-one were delivered by J.A. Maffei in 1925, numbered 2080 to 2100.

Valve gear experiment

The last Class 15A locomotive, Maffei built number 2100, was fitted with Lentz Rotary Cam Poppet valve gear as an experiment, but this was soon replaced with Walschaerts valve gear and piston-valve cylinders, turning number 2100 into a standard Class 15A.

Watson Standard boilers

During the 1930s many serving locomotives were reboilered with a standard boiler type designed by A.G. Watson, CME of the SAR from 1929 to 1936, as part of his standardisation policy. Such Watson Standard reboilered locomotives were reclassified by adding an "R" suffix to their classification.

When Class 15A locomotives were reboilered with Watson Standard no. 2A boilers, they were therefore reclassified to Class 15AR. Early conversions were equipped with copper and later conversions with steel fireboxes. In the process they were also equipped with Watson cabs, with their distinctive slanted fronts compared to the conventional vertical fronts of their original cabs.

Since the only difference between the as delivered Class 15
South African Class 15 4-8-2
In 1914 the South African Railways placed ten Class 15 steam locomotives with a 4-8-2 Mountain wheel arrangement in service.-Manufacturer:The Class 15 was introduced by D.A...

 and Class 15A lay in the length of their boilers, Class 15 locomotives reboilered with Watson Standard boilers were also reclassified to Class 15AR.

An obvious visual difference between an original and a Watson Standard reboilered locomotive is usually a rectangular regulator cover just to the rear of the chimney on the reboilered locomotive. In the case of the Class 15A and Class 15AR two even more obvious visual differences are the Watson cab and the absence of the Belpaire firebox hump between the cab and boiler on the reboilered locomotives. In addition, during reboilering the early Class 15A models with curved down rear end running plates and narrow cabs were altered to straight rear end running plates with wider cabs.

The table shows the Class 15A running numbers, builders, years built, works numbers and eventual classifications.

Service

The Class 15A, one of the best classes of main line mixed traffic locomotives to see service in South Africa, was placed in service on the Cape main line to Kimberley
Kimberley, Northern Cape
Kimberley is a city in South Africa, and the capital of the Northern Cape. It is located near the confluence of the Vaal and Orange Rivers. The town has considerable historical significance due its diamond mining past and siege during the Second Boer War...

, where they formed the mainstay of motive power for many years. They ended up working in all parts of the country and proved to be reliable, free-steaming locomotives that ran up high mileage figures between major overhauls.

As the reboilered Class 15AR, many ended up working in the eastern Transvaal around Waterval Boven
Waterval Boven
Waterval Boven is a small town situated on the edge of the Escarpment on the banks of the Elands River above the 75m Elands Falls on the railway line from Pretoria to Maputo in Mpumalanga, South Africa. Hence the name which means "above the waterfall" in Dutch...

, in the western Transvaal, eastern Cape and the Orange Free State
Orange Free State
The Orange Free State was an independent Boer republic in southern Africa during the second half of the 19th century, and later a British colony and a province of the Union of South Africa. It is the historical precursor to the present-day Free State province...

. During the 1960s many were transferred to the Cape Midlands and used mainly on the section from Port Elizabeth to Klipplaat and in passenger service on the Uitenhage
Uitenhage
Uitenhage is a South African town with 275,185 inhabitants in the Eastern Cape Province. It is well known for the Volkswagen factory located there, which is the biggest car factory on the African continent. The town's name is pronounced by English speakers and in Afrikaans...

 suburban.

Near the end of their service lives in the early 1980s, they were all relegated to shunting work at centres all around the country, except for some that were hired out to Swaziland
Swaziland
Swaziland, officially the Kingdom of Swaziland , and sometimes called Ngwane or Swatini, is a landlocked country in Southern Africa, bordered to the north, south and west by South Africa, and to the east by Mozambique...

 and that were still employed in main line service on the Swaziland Railway
Swazi Rail
Swazi Rail ', also Swaziland Rail, is the official railway corporation of Swaziland.- Overview :Like the neighboring countries, its 301 km rail system uses the narrow Cape gauge of . SR provides only service for transportation of goods, not passengers...

, until they were eventually replaced by diesel traction and retired.

Gallery

The main picture shows reboilered NBL 1914 built Class 15A 1788 at Graaff Reinet on 4 April 1978.
  • Locomotives as built, with Belpaire fireboxes.


  • Ex narrow cab Class 15AR locomotives, reboilered with Watson Standard no. 2A boilers.


  • Ex wide cab Class 15AR locomotives, reboilered with Watson Standard no. 2A boilers.



See also

  • South African Class 15 4-8-2
    South African Class 15 4-8-2
    In 1914 the South African Railways placed ten Class 15 steam locomotives with a 4-8-2 Mountain wheel arrangement in service.-Manufacturer:The Class 15 was introduced by D.A...

  • South African Class 15B 4-8-2
    South African Class 15B 4-8-2
    Between 1918 and 1922 the South African Railways placed ten Class 15B steam locomotives with a 4-8-2 Mountain wheel arrangement in service.-Manufacturer:...

  • South African Class 15C 4-8-2
  • South African Class 15CA 4-8-2
    South African Class 15CA 4-8-2
    In 1926 the South African Railways placed twenty-three Class 15CA steam locomotives with a 4-8-2 Mountain wheel arrangement in service. Another sixty-one were ordered and delivered in 1929 and 1930.-Class 15C redesign:...

  • South African Class 15E 4-8-2
    South African Class 15E 4-8-2
    Between 1935 and 1937 the South African Railways placed forty-four Class 15E steam locomotives with a 4-8-2 Mountain wheel arrangement in service. -Manufacturers:...

  • South African Class 15F 4-8-2
    South African Class 15F 4-8-2
    The Class 15F was the most numerous steam locomotive class in South African Railways service. Between 1938 and 1946 two hundred and fifty-five of these steam locomotives with a 4-8-2 Mountain wheel arrangement were placed in service.-Manufacturers:...

  • Tender locomotive numbering and classification
  • Watson Standard boilers
  • The 4-8-2 "Mountain"
  • List of South African locomotive classes
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