The South African Railways Class 5A 4-6-2 of 1903 was a steam locomotive from the pre-

Union Union commonly refers to: * Trade union, an organization of workers * Union (set theory), in mathematics, a fundamental operation on sets Union may also refer to: Arts and entertainment Music * Union (band), an American rock group ** ''Un ...

era in the

Cape of Good Hope The Cape of Good Hope ( af, Kaap die Goeie Hoop ) ;''Kaap'' in isolation: pt, Cabo da Boa Esperança is a rocky headland on the Atlantic coast of the Cape Peninsula in South Africa. A common misconception is that the Cape of Good Hope is t ...

. In 1903, the

Cape Government Railways The Cape Government Railways (CGR) was the government-owned railway operator in the Cape Colony from 1874 until the creation of the South African Railways (SAR) in 1910. History Private railways The first railways at the Cape were privately own ...

placed two Karoo Class steam locomotives with a Pacific type wheel arrangement in passenger service. In 1912, when they were assimilated into the South African Railways, they were renumbered and designated Class 5A.Espitalier, T.J.; Day, W.A.J. (1944). ''The Locomotive in South Africa - A Brief History of Railway Development. Chapter II - The Cape Government Railways'' (Continued). South African Railways and Harbours Magazine, February 1944. pp. 97-101.Classification of S.A.R. Engines with Renumbering Lists, issued by the Chief Mechanical Engineer's Office, Pretoria, January 1912, pp. 8, 12, 14, 34 (Reprinted in April 1987 by SATS Museum, R.3125-6/9/11-1000)

Design

The Karoo Class of the Cape Government Railways (CGR) was the first tender locomotive with a Pacific type wheel arrangement to be introduced in Africa. It was the logical development of the CGR 6th Class Prairie type which later became the Class 6Y on the South African Railways (SAR).

Cape Town Cape Town ( af, Kaapstad; , xh, iKapa) is one of South Africa's three capital cities, serving as the seat of the Parliament of South Africa. It is the legislative capital of the country, the oldest city in the country, and the second largest ...

, it was acquired to cope with the increasing weight of passenger trains on the one-in-eighty gradients between

Beaufort West Beaufort West (Afrikaans: ''Beaufort-Wes''; Xhosa: ''eBhofolo'') is a town in the Western Cape province in South Africa. It is the largest town in the arid Great Karoo region, and is known as the "Capital of the Karoo". It forms part of the Beauf ...

and

De Aar De Aar is a town in the Northern Cape province of South Africa. It has a population of around 42,000 inhabitants. It is the second-most important railway junction in the country, situated on the line between Cape Town and Kimberley. The junctio ...

. The locomotive had a bar frame,

Stephenson 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 various kinds of steam engines. It is named after Robert Stephenson but was invented by his employees. ...

and used saturated steam. At the time, there was a general belief that any appreciable raising of the boiler pitch would result in a top-heavy locomotive. Since Beatty was very cautious about raising the boiler's centre line to more than twice the rail gauge, or , and in this case also to accommodate the large diameter coupled wheels, he resorted to cutting the boiler shell and installing specially shaped pockets to obtain the required clearance.

Manufacturer

In 1903, two of these locomotives were built by

Kitson and Company Kitson and Company was a locomotive manufacturer based in Hunslet, Leeds, West Yorkshire, England. Early history The company was started in 1835 by James Kitson (businessman), James Kitson at the Airedale Foundry, off Pearson Street, Hunslet, ...

, immediately after building the two 6th Class Prairie locomotives since their works numbers follow in sequence. They were numbered 903 and 904, but were not allocated class numbers by the CGR and instead became known as the

Karoo The Karoo ( ; from the Afrikaans borrowing of the South Khoekhoe !Orakobab or Khoemana word ''ǃ’Aukarob'' "Hardveld") is a semi-desert natural region of South Africa. No exact definition of what constitutes the Karoo is available, so its ext ...

Class after the region of the Western System which they were designed to work in. Kitson’s later used the Karoo design as basis for a batch of Pacific type locomotives which it built for the

Midland Railway of Western Australia The Midland Railway of Western Australia (MRWA) was a railway company that built and operated the Midland line in Western Australia. It was listed on the London Stock Exchange. Although having its headquarters in London, it had no association ...

Characteristics

One of the most striking features of the Karoo Class was the length of its boiler, which was accentuated by the extended smokebox. The length of the smokebox was over and the distance between the boiler's tube-plates was . The engine used Richardson slide valves, arranged above the cylinders and actuated by the Stephenson motion and rocker shafts. The eccentrics were fitted to the trailing coupled wheel axle, which resulted in exceptionally long valve connecting rods of .

South African Railways

When the

Union of South Africa The Union of South Africa ( nl, Unie van Zuid-Afrika; af, Unie van Suid-Afrika; ) was the historical predecessor to the present-day Republic of South Africa. It came into existence on 31 May 1910 with the unification of the Cape, Natal, Trans ...

was established on 31 May 1910, the three Colonial government railways (CGR,

Natal Government Railways The Natal Government Railways (NGR) was formed in January 1877 in the Colony of Natal. In 1877, the Natal Government Railways acquired the Natal Railway Company for the sum of £40,000, gaining the line from the Point to Durban and from Durban ...

and

Central South African Railways The Central South African Railways (CSAR) was from 1902 to 1910 the operator of public railways in the Transvaal Colony and Orange River Colony in what is now South Africa. During the Anglo-Boer War, as British forces moved into the territory of ...

) were united under a single administration to control and administer the railways, ports and harbours of the Union. Although the South African Railways and Harbours came into existence in 1910, the actual classification and renumbering of all the rolling stock of the three constituent railways were only implemented with effect from 1 January 1912.''The South African Railways - Historical Survey''. Editor George Hart, Publisher Bill Hart, Sponsored by Dorbyl Ltd., Published c. 1978, p. 25. In 1912, these two locomotives were renumbered 721 and 722 and designated Class 5A on the SAR.South African Railways and Harbours Locomotive Diagram Book, 2'0" & 3'6" Gauge Steam Locomotives, 15 August 1941, as amended

Service

In service, the Class 5A locomotives performed excellently. Beatty's annual report for 1905 stated that they ran before a failure occurred, that failure being a hot box. They spent most of their working lives in the Karoo until they were displaced by larger locomotives. They were then placed in suburban service working out of Cape Town, where they remained until they were withdrawn from service c. 1940.

Illustration

File:SAR Class 5A (4-6-2).jpg, Working a suburban train, c. 1930 File:CGR Karoo Class no. SAR 721.jpg, Ex CGR Karoo Class no. 903, SAR Class 5A no. 721, Paardeneiland, Cape Town, c. 1940

References

{{Steam locomotive tenders

1290 Year 1290 ( MCCXC) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar. Events By place Europe * July 10 – King Ladislaus IV (the Cuman) is assassinated at the castle of Köröss ...

4-6-2 locomotives 2′C1′ n2 locomotives Kitson locomotives Cape gauge railway locomotives Railway locomotives introduced in 1903 1903 in South Africa Scrapped locomotives