South African Class 12 4-8-2
Encyclopedia
Between April 1912 and 1922 the South African Railways placed altogether forty-six Class 12 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 goods train service.

Manufacturers

The Class 12 was the first locomotive design to originate from the newly established South African Railways (SAR) in 1912. It was in effect an enlarged version of the already successful Class 3B
South African Class 3B 4-8-2
In 1912 the South African Railways took delivery of ten Class 3B steam locomotives with a 4-8-2 Mountain wheel arrangement that had been ordered by the Natal Government Railways the year before.-Manufacturer:...

, also designed by SAR Chief Mechanical Engineer (CME) D.A. Hendrie during his years on the Natal Government Railways, and was also built with plate frames, Walschaerts valve gear, superheaters 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.

Orders for the first eight locomotives in the Class were placed on 22 March 1911. They were built in two batches of four, the first of which was delivered from 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 April 1912, numbered 1494 to 1497. The second batch, numbered 1498 to 1501, followed shortly thereafter. These first eight locomotives had pilot bogies with a 6 feet (1.829 m) wheelbase.

These were followed by another eight in 1913, numbered 1502 to 1509, and ten more in 1915, numbered 1510 to 1519, all built by NBL. These and all subsequent Class 12 locomotives had pilot bogies with a 6 in 2 in (1.88 m) wheelbase.

In 1922 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...

 (BP) delivered the final twenty Class 12 locomotives, built in two batches of ten and numbered 1859 to 1878.

The builders, years built and works numbers are set out in the table.

Distinguishing features

The original Class 12 locomotives were equipped with a new Type MP1 tender, which marked the introduction of a standard type that, with few modifications, was eventually to be used on all the Hendrie-designed locomotives. During the 1920s many of the Class 12 locomotives had their original Type MP1 tenders replaced with Type MT tenders with a larger coal and water capacity.

The North British
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...

 built locomotives were very similar in appearance to the Class 3B, with running boards that curved down below the cab, while the Beyer, Peacock
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...

 built locomotives had larger and more spacious cabs and running boards that ran straight through to the rear buffer beams.

Watson standard boilers

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

All forty-six Class 12 locomotives were eventually reboilered with Watson Standard no. 2 boilers and reclassified to Class 12R. In the process they were also equipped with Watson cabs, with their distinctive slanted fronts compared to the vertical fronts of the original cabs and, in the case of the NBL built locomotives, with running boards that continued straight through underneath their cabs.

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 12 locomotives 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.

South African Railways

The Class 12 was designed for use in coal traffic on the line from Witbank
Witbank
Witbank , also known as eMalahleni is a city situated on the Highveld of Mpumalanga, South Africa, within the eMalahleni Local Municipality. The name Witbank is Afrikaans for White Ridge and is named after a white sandstone outcrop where wagon transport drivers rested...

 to Germiston. At the time they were introduced, they were the largest non-articulated locomotives in South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

 and, on railways of less than 1,435 millimetres (4 feet 8½ inches) Standard gauge, probably in the world.

They proved to be most successful in the service they had been designed for, handling loads of 1,400 tons and doing the return trip in one day. This compared favourably with the 2-6-6-0 and 2-6-6-2 Mallet locomotives which, while able to handle 1,600 tons, could not make a round trip in one day.

They were also used around Ladysmith in Natal. In the 1940s the Natal locomotives were relocated to the Orange Free State.

By the 1970s some were allocated to the Cape Midlands system, stationed at Sydenham in Port Elizabeth for use as dock shunters and for yard work in the New Brighton marshalling yards. In the Orange Free State some were shedded at Bloemfontein
Bloemfontein
Bloemfontein is the capital city of the Free State Province of South Africa; and, as the judicial capital of the nation, one of South Africa's three national capitals – the other two being Cape Town, the legislative capital, and Pretoria, the administrative capital.Bloemfontein is popularly and...

 and at Bethlehem, all in shunting service. The Transvaal had a large contingent, stationed at Springs, Germiston and Krugersdorp, also mainly used for shunting.

International

Ten Class 12R locomotives were briefly hired to the Zambian Railways during a peak in that country’s perpetual diesel motive power crisis in 1980, but were soon returned since the Zambian knowledge base on steam maintenance had virtually disappeared by then.

Industrial

For some reason few Class 12 locomotives ended up in industrial service, despite their evident suitability for such work. Only five were sold into private service.
  • NBL built 1510 went to Umgala Colliery at Utrecht
    Utrecht, KwaZulu-Natal
    Utrecht is a town in the foothills of the Balele Mountains, in the northwestern corner of KwaZulu-Natal, South Africa. Newcastle, Kwazulu-Natal's third-largest urban center, is 50 km from Utrecht...

     as number 7.
  • NBL built 1511 went to Middelplaas Manganese as number SL001.
  • NBL built 1515 went first to Tweefontein Colliery and later to Witbank Consolidated Coal Mine.
  • BP built 1863 and 1864 went to Middelplaas Manganese as numbers SL002 and SL003 respectively.

Gallery

The main picture shows NBL built Class 12R 1505 with a Type MP1 tender.


See also

  • South African Class 12A 4-8-2
    South African Class 12A 4-8-2
    Between 1919 and 1929 the South African Railways placed sixty-seven Class 12A steam locomotives with a 4-8-2 Mountain wheel arrangement in service.-Manufacturers:...

  • South African Class 12B 4-8-2
    South African Class 12B 4-8-2
    In 1920 the South African Railways placed thirty Class 12B steam locomotives with a 4-8-2 Mountain wheel arrangement in service.-Manufacturer:...

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