The South African Railways Class 15A 4-8-2 of 1914 was a steam locomotive. Between 1914 and 1925, the South African Railways placed 119 Class 15A steam locomotives with a

4-8-2 Under the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of four leading wheels, eight powered and coupled driving wheels and two trailing wheels. This type of steam locomotive is commonly known as t ...

Mountain type wheel arrangement in service, delivered in ten batches from three manufacturers.Espitalier, T.J.; Day, W.A.J. (1945). ''The Locomotive in South Africa - A Brief History of Railway Development. Chapter VII - South African Railways (Continued).'' South African Railways and Harbours Magazine, August 1945. pp. 593-594.

Manufacturers

The Classes 15 and 15A were the final development of the plate-framed 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 was the most numerous and proved to be his most useful.

The predecessor Class 15 locomotives had one flaw, their excessively long fire tubes. When more locomotives of the type were ordered, Hendrie improved the boiler by adding a combustion chamber in the firebox, which shortened the distance between tube plates from to . When the first five of these redesigned locomotives were delivered in 1914, they were designated Class 15A. Altogether 119 were ultimately 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 The North British Locomotive Company (NBL, NB Loco or North British) was created in 1903 through the merger of three Glasgow locomotive manufacturing companies; Sharp, Stewart and Company (Atlas Works), Neilson, Reid and Company (Hyde Park Wor ...

(NBL) in July 1914, numbered in the range from 1571 to 1575.North British Locomotive Company works list, compiled by Austrian locomotive historian Bernhard Schmeiser * Eight more were delivered by NBL, also in 1914, numbered in the range from 1781 to 1788. Like the Class 15, these first thirteen locomotives had narrow cabs, rear end running boards which curved down below their cabs and

Belpaire firebox The Belpaire firebox is a type of firebox used on steam locomotives. It was invented by Alfred Belpaire of Belgium in 1864. Today it generally refers to the shape of the outer shell of the firebox which is approximately flat at the top and squa ...

es, but unlike the Class 15, the firebox had a combustion chamber. * Ten more were delivered by NBL in 1915, numbered in the range from 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 is a pass on the N1 national road, between De Doorns and Touws River in the Western Cape province of South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country i ...

. These and subsequent locomotives had rear end running boards which continued straight through underneath their cabs. * Six more were delivered by NBL in 1916, numbered in the range from 1799 to 1804. * Four more were delivered by NBL in 1917, numbered in the range from 1805 to 1808. * Twenty more were delivered by NBL in 1920, numbered in the range from 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 was an English railway locomotive manufacturer with a factory in Openshaw, Manchester. Founded by Charles Beyer, Richard Peacock and Henry Robertson, it traded from 1854 until 1966. The company exported locomotives, ...

in 1920, numbered in the range from 1839 to 1858.Beyer, Peacock and Company production list, excluding Garratts, Customer List V1 04.08.02 * Ten more were delivered by Beyer, Peacock in 1921, numbered in the range from 1961 to 1970. * Fifteen were delivered by NBL in 1921, numbered in the range from 2011 to 2025. * Twenty-one were delivered by J.A. Maffei in 1925, numbered in the range from 2080 to 2100.

Characteristics

The locomotives had thick plate frames and piston valves, actuated by Walschaerts valve gear.

Firebox

To reduce the weight on the trailing wheels, steel fireboxes were originally used instead of copper. Some locomotives in Natal had been fitted with steel fireboxes years previously and the results were fairly good, but wherever water supplies were of poor quality, steel fireboxes gave a lot of trouble and necessitated the introduction of water treatment plants to prevent corrosion. This reintroduction of steel fireboxes eventually led to its widespread use on all the larger locomotive types, but it also forced the SAR to adopt locomotive water treatment as a general policy.Espitalier, T.J.; Day, W.A.J. (1945). ''The Locomotive in South Africa - A Brief History of Railway Development. Chapter VII - South African Railways (Continued).'' South African Railways and Harbours Magazine, July 1945. p. 516. The first five locomotives of 1914 were delivered with steel fireboxes. In the case of the Classes 15 and 15A, it was still early days for water treatment and enough trouble was experienced to result in their steel fireboxes being replaced with copper fireboxes. Hendrie followed a conservative policy in this respect and the majority of the rest of the Class 15A fleet were originally fitted with copper fireboxes. Steel fireboxes were only to be fitted in large numbers by his successor, Colonel F.R. Collins DSO, and only the last batch of 1925, supplied by Maffei, were delivered with steel fireboxes.

Valve gear experiment

The last Class 15A locomotive, Maffei-built no. 2100, was fitted with Lentz Rotary Cam Poppet valve gear as an experiment, but this was later replaced with

Walschaerts valve gear The Walschaerts valve gear is a type of valve gear used to regulate the flow of steam to the pistons in steam locomotives, invented by Belgium, Belgian railway mechanical engineering, engineer Egide Walschaerts in 1844. The gear is sometimes name ...

and piston-valve cylinders, thereby turning no. 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.South African Railways & Harbours/Suid Afrikaanse Spoorweë en Hawens (15 Aug 1941). ''Locomotive Diagram Book/Lokomotiefdiagramboek, 3'6" Gauge/Spoorwydte''. SAR/SAS Mechanical Department/Werktuigkundige Dept. Drawing Office/Tekenkantoor, Pretoria. p. 43.South African Railways & Harbours/Suid Afrikaanse Spoorweë en Hawens (15 Aug 1941). ''Locomotive Diagram Book/Lokomotiefdiagramboek, 2'0" & 3'6" Gauge/Spoorwydte, Steam Locomotives/Stoomlokomotiewe''. SAR/SAS Mechanical Department/Werktuigkundige Dept. Drawing Office/Tekenkantoor, Pretoria. pp. 6a-7a, 41, 43. 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, while the cab platform was extended over the front end of the tender underframe. Many of the reboilered engines were later fitted with Type MR or Type MT tenders. Since the only difference between the as-delivered Class 15 and Class 15A lay in the length of their boilers and whether they were built with or without combustion chambers, both models were reclassified to Class 15AR when they were reboilered with Watson Standard boilers. In the case of the Class 15A engines, reboilering replaced their combustion-chambered Belpaire boilers with less efficient Watson Standard boilers without combustion chambers and it was found that the rebuilds were inferior steamers compared with their non-rebuilt sister engines.Soul of A Railway, System 1, Part 1: Cape Town prior to the Second World War. Caption 6.
(Accessed on 26 November 2016) Their original Belpaire boilers were fitted with Ramsbottom safety valves, while the Watson Standard boiler was fitted with Pop safety valves. Another obvious 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 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 boards and narrow cabs were altered to straight rear end running boards with Watson cabs.

Service

The Class 15A, one of the best classes of mainline mixed traffic locomotives to see service in South Africa, was placed in service on the Cape mainline to

Kimberley Kimberly or Kimberley may refer to: Places and historical events Australia * Kimberley (Western Australia) ** Roman Catholic Diocese of Kimberley * Kimberley Warm Springs, Tasmania * Kimberley, Tasmania a small town * County of Kimberley, a ...

where they formed the mainstay of motive power for many years. The engine was a good utility type and gave a good account of itself on goods and passenger working alike. It is noted for reducing the running time of the ''Union Limited'' by 2½ hours in March 1922. When they were superseded on this section by more powerful types, they ended up working in all parts of the country and proved to be reliable, free-steaming locomotives which 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 (officially known as Emgwenya) 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 n ...

, in the Western Transvaal, Eastern Cape and the

Orange Free State The Orange Free State ( nl, Oranje Vrijstaat; af, Oranje-Vrystaat;) was an independent Boer sovereign republic under British suzerainty in Southern Africa during the second half of the 19th century, which ceased to exist after it was defeat ...

. During the 1960s, many were transferred to the Cape Midland and used mainly on the section from Port Elizabeth to Klipplaat and in passenger service on the

Uitenhage Uitenhage ( ; ), officially renamed Kariega, is a South African town 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. Along with the city of Port El ...

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 which were hired out to

Swaziland Eswatini ( ; ss, eSwatini ), officially the Kingdom of Eswatini and formerly named Swaziland ( ; officially renamed in 2018), is a landlocked country in Southern Africa. It is bordered by Mozambique to its northeast and South Africa to its no ...

and which were still employed in mainline service on the Swaziland Railway until they were eventually replaced by diesel traction and retired. By the time they were withdrawn after more than sixty years in service, many of these locomotives had completed three million miles of heavy-duty mainline work.Soul of A Railway, System 3, Part 13: The Original Midland Main Line, Part 1, PE to Graaff-Reinet. Caption 48.
(Accessed on 19 February 2017)

Works numbers

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

Preservation

Illustration

The main picture shows reboilered 1914-built Class 15A no. 1788 at Graaff Reinet on 4 April 1978. Differences between the various locomotive models are illustrated in the pictures below. ;Locomotives as built, with Belpaire fireboxes. File:SAR Class 15A 1791 Capital Park 230378.jpg, Class 15A no. 1791 (1915 NBL narrow cab) at Capital Park, 23 March 1978 File:SAR Class 15A 1970 De Aar 130479.jpg, Class 15A no. 1970 ''Milly'' (1921 BP wide cab) at

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 ...

, 13 April 1979 File:Class 15A no. 2100 Lenz.jpg, Class 15A no. 2100 (1925 Maffei with Lentz Rotary Cam Poppet valve gear) at Paardeneiland, c. 1930 ;Ex narrow cab Class 15AR locomotives, reboilered with Watson Standard no. 2A boilers. File:SAR Class 15AR 1575 Rosmead 210479.jpg, No. 1575 (NBL 1914) at Rosmead, Cape Province, 21 April 1979 File:SAR Class 15AR 1804 New Brighton 160479.jpg, No. 1804 (NBL 1916) at New Brighton,

Port Elizabeth Gqeberha (), formerly Port Elizabeth and colloquially often referred to as P.E., is a major seaport and the most populous city in the Eastern Cape province of South Africa. It is the seat of the Nelson Mandela Bay Metropolitan Municipality, Sou ...

, 16 April 1979 File:SAR Class 15AR 1805 Graaff-Reinet 040478.jpg, No. 1805 (NBL 1917) at

Graaff Reinet Graaff-Reinet is a town in the Eastern Cape Province of South Africa. It is the oldest town in the province. It is also the sixth-oldest town in South Africa, after Cape Town, Stellenbosch, Simon's Town, Paarl and Swellendam. The town was the c ...

, Cape Province, 4 April 1978 ;Ex wide cab Class 15AR locomotives, reboilered with Watson Standard no. 2A boilers. File:SAR Class 15AR 1811 Sydenham 300379.jpg, No. 1811 (NBL 1919) at

Sydenham Sydenham may refer to: Places Australia * Sydenham, New South Wales, a suburb of Sydney ** Sydenham railway station, Sydney * Sydenham, Victoria, a suburb of Melbourne ** Sydenham railway line, the name of the Sunbury railway line, Melbourne ...

, 30 March 1979 File:SAR Class 15AR 1855 Klipplaat 160479.jpg, No. 1855 (BP 1920) at Klipplaat,

Cape Province The Province of the Cape of Good Hope ( af, Provinsie Kaap die Goeie Hoop), commonly referred to as the Cape Province ( af, Kaapprovinsie) and colloquially as The Cape ( af, Die Kaap), was a province in the Union of South Africa and subsequen ...

, 16 April 1979 File:Class 15AR 2100 (4-8-2).JPG, No. 2100 (Maffei 1925), the last Class 15A, at Queenstown, 26 April 2013

References

{{Steam locomotive tenders

1820 Events January–March *January 1 – Nominal beginning of the Trienio Liberal in Spain: A constitutionalist military insurrection at Cádiz leads to the summoning of the Spanish Parliament (March 7). *January 8 – General Maritime T ...

4-8-2 locomotives 2D1 locomotives NBL locomotives Beyer, Peacock locomotives Maffei locomotives Cape gauge railway locomotives Railway locomotives introduced in 1914 1914 in South Africa