South African Class 4A 4-8-2
Encyclopedia
In 1913 and 1914 ten Class 4A steam locomotives with a 4-8-2
Mountain wheel arrangement were placed in service by the South African Railways.
(NBL) for a further ten locomotives of this type. They were delivered in 1913 and 1914 and became the Class 4A.
having to be replaced with piston valves and Walschaerts valve gear. Like their two forerunners, they were excellent steamers and, with the modifications, gave a much better performance.
When all ten Class 4A locomotives were eventually reboilered with Watson Standard no. 2 boilers, they were therefore reclassified to Class 4AR. 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.
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, but this was not always the case, as illustrated in the gallery below. In the case of the Class 4AR an even more obvious visual difference is the Watson cab.
, but when more powerful locomotives became available they were transferred to the Karoo
, working between Touws River and Kimberley and also northward from Kimberley to Mafeking. They were then transferred to the Reef, from where they regularly served on the Zeerust, Breyten
and Volksrust
lines while also being employed in a variety of suburban and local train workings.
During the Second World War Class 4A number 1554 was equipped with temporary protective armour to serve as the locomotive of an armoured train that was based at Mapleton Camp. The photograph alongside shows the locomotive and armoured train being inspected during 1942 by the Honourable F.C. Sturrock, M.P., South Africa’s Minister of Transport at the time.
The last Class 4AR was withdrawn from shunting operations on the West Reef in 1974. Some remained working in industrial service for several more years, the last one being finally retired from Apex Colliery in 1983.
in Southern Rhodesia
(now Zimbabwe) through Bechuanaland Protectorate (now Botswana) to Mafeking in the Cape Province.
Like the SAR Class 4A, the RR Class 10 had combustion chambers, the only RR locomotive class with this feature.
train, taking water at Hutchinson in the Karoo on 11 November 1916.
In the pictures of reboilered Class 4AR locomotives below, one locomotive has the rectangular regulator cover just to the rear of the chimney, while the other, Class 4AR 1554, has a bolted on cover plate flush with the boiler cladding instead. Both have Watson cabs, while the pictures of Class 4A locomotives display their original cabs with conventional vertical fronts.
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 were placed in service by the South African Railways.
Manufacturer
The Class 4 Mountain locomotive was designed as a heavy mixed traffic locomotive by H.M. Beatty, the last Chief Locomotive Superintendent of the Cape Government Railways (CGR), at the Salt River shops. Soon after the South African Railways (SAR) was established in 1912, an order was placed with North British Locomotive CompanyNorth 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) for a further ten locomotives of this type. They were delivered in 1913 and 1914 and became the Class 4A.
Improvements
The Class 4A locomotive was an improved version of the predecessor Class 4. It had a superheater added, which further resulted in the Stephenson valve gearStephenson valve gear
The Stephenson valve gear or Stephenson link or shifting link is a simple design of valve gear that was widely used throughout the world for all kinds of steam engine. It is named after Robert Stephenson but was actually invented by his employees....
having to be replaced with piston valves and Walschaerts valve gear. Like their two forerunners, they were excellent steamers and, with the modifications, gave a much better performance.
Watson Standard boilers
In the 1930s many serving locomotives were reboilered with a standard boiler type designed by then Chief Mechanical Engineer (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.When all ten Class 4A locomotives were eventually reboilered with Watson Standard no. 2 boilers, they were therefore reclassified to Class 4AR. 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.
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, but this was not always the case, as illustrated in the gallery below. In the case of the Class 4AR an even more obvious visual difference is the Watson cab.
Service
Their first ten years of service were spent working both passenger and goods trains on various sections of the Cape main line. At first they worked out of Cape TownCape Town
Cape Town is the second-most populous city in South Africa, and the provincial capital and primate city of the Western Cape. As the seat of the National Parliament, it is also the legislative capital of the country. It forms part of the City of Cape Town metropolitan municipality...
, but when more powerful locomotives became available they were transferred to the Karoo
Karoo
The Karoo is a semi-desert region of South Africa. It has two main sub-regions - the Great Karoo in the north and the Little Karoo in the south. The 'High' Karoo is one of the distinct physiographic provinces of the larger South African Platform division.-Great Karoo:The Great Karoo has an area of...
, working between Touws River and Kimberley and also northward from Kimberley to Mafeking. They were then transferred to the Reef, from where they regularly served on the Zeerust, Breyten
Breyten
Breyten is a small farming town in Mpumalanga, South Africa and is situated at the foot of Klipstapel, the highest point on the watershed between the westward flowing Vaal River system and the eastward flowing Olifants and Komati River systems...
and Volksrust
Volksrust
Volksrust is a town in the Mpumalanga province of South Africa on the KwaZulu-Natal provincial border. The town has important beef, dairy, maize, sorghum, wool and sunflower seed industries. It was established near to where the Battle of Majuba, wherein the Transvaal won its independence back...
lines while also being employed in a variety of suburban and local train workings.
During the Second World War Class 4A number 1554 was equipped with temporary protective armour to serve as the locomotive of an armoured train that was based at Mapleton Camp. The photograph alongside shows the locomotive and armoured train being inspected during 1942 by the Honourable F.C. Sturrock, M.P., South Africa’s Minister of Transport at the time.
The last Class 4AR was withdrawn from shunting operations on the West Reef in 1974. Some remained working in industrial service for several more years, the last one being finally retired from Apex Colliery in 1983.
Rhodesian Railways
A lighter version of the Class 4A was built by NBL for the Rhodesian Railways (RR). It became the RR Class 10 and was used on the long section south of BulawayoBulawayo
Bulawayo is the second largest city in Zimbabwe after the capital Harare, with an estimated population in 2010 of 2,000,000. It is located in Matabeleland, 439 km southwest of Harare, and is now treated as a separate provincial area from Matabeleland...
in Southern Rhodesia
Southern Rhodesia
Southern Rhodesia was the name of the British colony situated north of the Limpopo River and the Union of South Africa. From its independence in 1965 until its extinction in 1980, it was known as Rhodesia...
(now Zimbabwe) through Bechuanaland Protectorate (now Botswana) to Mafeking in the Cape Province.
Like the SAR Class 4A, the RR Class 10 had combustion chambers, the only RR locomotive class with this feature.
Gallery
The main picture shows SAR Class 4A 1559, as built, on the Cape Town-JohannesburgJohannesburg
Johannesburg also known as Jozi, Jo'burg or Egoli, is the largest city in South Africa, by population. Johannesburg is the provincial capital of Gauteng, the wealthiest province in South Africa, having the largest economy of any metropolitan region in Sub-Saharan Africa...
train, taking water at Hutchinson in the Karoo on 11 November 1916.
In the pictures of reboilered Class 4AR locomotives below, one locomotive has the rectangular regulator cover just to the rear of the chimney, while the other, Class 4AR 1554, has a bolted on cover plate flush with the boiler cladding instead. Both have Watson cabs, while the pictures of Class 4A locomotives display their original cabs with conventional vertical fronts.
See also
- South African Class 4 4-8-2South African Class 4 4-8-2In 1911 the Cape Government Railways placed two steam locomotives with a 4-8-2 Mountain wheel arrangement in service. A year later, when they were assimilated into the South African Railways, they were renumbered and classified as Class 4.-Manufacturer:...
- Tender locomotive numbering and classification
- Watson Standard boilers
- The 4-8-2 "Mountain"
- List of South African locomotive classes