South African Class 19D 4-8-2

Between 1937 and 1949 the South African Railways placed two hundred and thirty-five Class 19D steam locomotives wirh a 4-8-2 Mountain wheel arrangement in service. Between 1951 and 1953 thirty-three more were built for other operators like the Rhodesian and Angolan railways and the Nkana and Wankie mines.^[7]

Manufacturers

The Class 19D 4-8-2 steam locomotive was the final development of the Class 19 series of locomotives. At the request of Colonel F.R. Collins, Chief Mechanical Engineer (CME) of the South African Railways (SAR) from 1922 to 1929, the original basic design of the Class 19 was done in the late 1920s by Test Engineer M.M. Loubser, himself later to serve as the CME from 1939 to 1949. The final development was done in 1937 by W.A.J. Day, CME from 1936 to 1939. The Class 19D was built in batches by several locomotive manufacturers in Germany, Czechoslovakia and the United Kingdom.^[7][8]

• The first forty were built in Germany in 1937, twenty by Friedrich Krupp AG in Essen, numbered 2506 to 2525, and twenty by the Borsig Lokomotiv Werke in Hennigsdorf, Berlin, numbered 2526 to 2545.
• In 1938 a further ninety-five locomotives were ordered, built by three manufacturers. Škoda Works in Czechoslovakia built fifteen, numbered 2626 to 2640, Krupp built forty, numbered 2641 to 2680, and Borsig built forty, numbered 2681 to 2720.
• Locomotive building was interrupted by World War II and post-war locomotive procurement saw German suppliers being replaced by British ones. In 1947 the first fifty post-war Class 19D locomotives were delivered by Robert Stephenson and Hawthorns (RSH) of Darlington, England, numbered 2721 to 2770.
• The final batch of fifty Class 19D locomotives for the SAR were delivered in 1949 by the North British Locomotive Company (NBL) of Glasgow, Scotland, numbered 3321 to 3370.^[6]
• Between 1951 and 1953 Henschel and Son built twenty-one more for the Rhodesian Railways (RR), and altogether twelve more were built for the Angolan railway and for industry.^[5][7]

The Class 19D, nicknamed "Dolly", was very similar to its predecessor Class 19C, but W.A.J. Day specified piston valves and Walschaerts valve gear instead of RC Poppet valve gear. The cylinders were redesigned with straighter steam ports, while the valve gear itself was revamped with a longer steam lap and greater travel. In all other respects they were identical to the Class 19C.^[7][9][10]

The table shows the Class 19D running numbers, builders, years built and works numbers.^[2][3][4][6]

Characteristics

Watson Standard boilers

The Class 19D was delivered with a Watson Standard no. 1A boiler, one of the range of standard type boilers designed by Day’s predecessor as CME, A.G. Watson, as part of his standardisation policy. It was also equipped with a Watson cab with its distinctive slanted front.^[2][6][10]

Domeless boilers

Despite the specifications the first batch of Class 19D locomotives, built by Krupp and Borsig and delivered in 1937 and 1938, came in two variations. The Krupp built locomotives were delivered with domeless boilers while the Borsig built locomotives conformed to specifications with domed boilers.^[2][10]

While the domeless boilers did not conform to the specified Watson Standard no. 1A boiler as far as the dome was concerned, they were accepted nevertheless, probably since all their other dimensions were identical to that of the Watson Standard boiler. It appears that Krupp had decided on their own accord that a dome was not necessary since there was no regulator in the dome, but merely a standpipe.^[2]

They substituted it with a manhole cover on which the two safety valves were mounted, while the steam was collected through a battery of collecting pipes situated high up in the boiler in a similar manner to that which was used in the Class 16E. All of the subsequent Class 19D orders were delivered with domed Watson Standard no. 1A boilers.^[2]

The Watson Standard boilers are interchangeable between locomotives and, in the process of locomotives undergoing major overhauls, these domeless boilers migrated between locomotives during subsequent years. As a result locomomotives from the other builders and even some Class 19C locomotives eventually ended up with domeless boilers.^[10][11]

Tenders

Over the eleven years during which the Class 19D was being produced for the SAR, some alterations occurred.

• The pre-war locomotives as well as the first post-war order from RSH were all equipped with Type MR tenders, a type that first saw service in 1912.
• All the post-war locomotives came equipped with vacuum brake systems.
• The final batch from NBL had Type MX Vanderbilt tenders with cylindrical water tanks that ran on three axle Buckeye bogies. These became commonly known as "Torpedo" tenders.^[2][10][12]

During the service life of the Class 19D, several tender exchanges occurred in order to best equip a locomotive for the region it was allocated to and the type of service it was to be employed in. In line service, type MX Vanderbilt tenders were usually preferred for their larger coal and water capacities. The result was that by the time the Class 19D was withdrawn from service circa 1980, many had exchanged their Type MR tenders for Type MX Vanderbilt tenders and vice versa.^[2]

Red Devil predecessor

As a trial run before SAR mechanical engineer David Wardale was granted permission to proceed to rebuild a Class 25NC 4-8-4 to the Class 26 "Red Devil" in 1979, he was allowed to carry out modifications to a Class 19D locomotive. The locomotive selected for the experiment was Krupp built number 2644, a particularly poor-steaming member of the Class at the time.^[7]

A gas producer combustion system (GPCS) and dual Lempor exhaust were installed along with some other small improvements. The Lempor had a four jet blastpipe with extended petticoats to provide truer ejector proportions. To accommodate the arrangement, the smokebox was extended by 300 millimetres (11.8 inches), and steam flow in the cylinders was improved by streamlining the edges of the piston valves, which were each equipped with an additional valve ring to reduce leakage. The firebox was modified to the GPCS system wherein principal combustion is effected using secondary air introduced above the firebed through ducts in the firebox sides, while primary air was restricted through dampers and a redesigned grate.^[7]

Firebox turbulence was created by steam jets and clinkering was inhibited by introducing exhaust steam under the grate. Sanding was improved and de-sanding jets were installed to clean the rails after the locomotive had passed.^[7]

The modifications improved the locomotive’s steaming rate and enabled it to achieve significantly higher power and significantly lower fuel consumption than other unmodified Class 19D locomotives, the coal savings and increased output being in the order of 20% to 25%. The success of this experiment convinced the SAR management at the time of the viability of the project which culminated in the Class 26 Red Devil.^[7][10][13]

Service

South African Railways

The Class 19D was the most numerous South African branch line locomotive and, at two hundred and thirty five built, was only twenty less in number than the Class 15F main line locomotive, the most numerous South African steam class. The Class 19D was very versatile and saw main and branch line service all over South Africa with the exception of the Western Cape, where the Class 19C was used.^[7]

Tasks varied from main line local and international passenger trains en route between South Africa and Northern Rhodesia (Zambia) via Bechuanaland (Botswana) and Southern Rhodesia (Zimbabwe), hauled by Class 19D locomotives on the section between Warrenton and Mafeking, to secondary and branch line duties and, in later years, as shunters.^[7][14]

On occasion South African Class 19D locomotives worked through from Mafikeng in South Africa via Botswana all the way to Bulawayo in Zimbabwe. SAR Class 19D locomotives were also hired out for shunting work, to the RR for use at Beit Bridge and to Mozambique for use at Lourenco Marques (Maputo).^[7]

They served until right at the end of the South African steam era and were amongst the last steam locomotives to be replaced by electric and diesel-electric traction.^[7][15]

Other operators

Other Southern African railroads and some industries also purchased locomotives built to the Class 19D design.

• Henschel and Son built twenty-one for RR, their Class 19 and Class 19D, with tenders similar to the SAR "Torpedo" type but with plate instead of Buckeye bogies. One of these, the sole RR Class 19D number 336, was built in 1953 as a condensing locomotive.^[5][7]
• Six were built for the Caminho de Ferro de Benguela (CFB or Benguela Railway) in Angola.
• Two were built by Henschel for the Nkana copper mines in Northern Rhodesia (Zambia), numbered 337 and 338 in the RR number range.
• Four were built without superheaters for Wankie Colliery in Rhodesia.^[5][7]

When these foreign versions are included, a total of two hundred and sixty eight locomotives were built to the Class 19D design, making them even more numerous than the Class 15F.^[7]

Industrial

As they were being retired, several Class 19D locomotives were sold into industrial service. By the late 1980s, some of them were already at work at Dunn’s, Saiccor, Loraine Gold Mine and Bamangwato Concessions in Botswana, and more were to follow.^[7]

Images

The main picture shows Rovos Rail’s "Bianca", Borsig built number 2702 with a domed boiler and a Type MX Vanderbilt tender.

See also

• South African Class 19 4-8-2
• South African Class 19A 4-8-2
• South African Class 19B 4-8-2
• South African Class 19C 4-8-2
• South African Class 26 4-8-4
• Tender locomotive numbering and classification
• Watson Standard boilers
• The 4-8-2 "Mountain"
• List of South African locomotive classes

References

1. ^ ^{a b c d} Friedrich Krupp AG, Essen Listen-Verwaltung: Stw - works list as supplied by Piotr Staszewski
2. ^ ^{a b c d e f g h i} Holland, D.F. (1972). Steam Locomotives of the South African Railways, Volume 2: 1910-1955 (1st ed.). Newton Abbott, Devon: David & Charles. pp. 93–96. ISBN 0715354272. 
3. ^ ^{a b} Škoda-Werke, Plzen (Pilsen), Czecholsovakai works list, as supplied by Piotr Staszewski
4. ^ ^{a b} North British Locomotive Company works list, compiled by Austrian locomotive historian Bernhard Schmeiser
5. ^ ^{a b c d} Henschel & Son works list, compiled by Dietmar Stresow
6. ^ ^{a b c d} South African Railways and Harbours Locomotive Diagram Book, 2’0” & 3’6” Gauge Steam Locomotives, 15 August 1941, as amended
7. ^ ^{a b c d e f g h i j k l m n o p} Durrant, A E (1989). Twilight of South African Steam (1st ed.). Newton Abbott, London: David & Charles. p. 104. ISBN 0715386387. 
8. ^ Information supplied by R.S. Loubser, son of M.M. Loubser
9. ^ Naboomspruit Municipal Offices, SAR Class 19D No 2534
10. ^ ^{a b c d e f} Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 10-11, 72-73. ISBN 0869772112. 
11. ^ Potgietersrus, Town, SAR Class 19D no. 2541
12. ^ Barkly East, Town Centre, Class 19D no 2510
13. ^ The Ultimate Steam Page
14. ^ Warrenton, Town, SAR Class 19D no. 2688
15. ^ Jan Kempdorp; Town Centre; SAR Class 19D no 2656
16. ^ Friends of the Rail – Preserving South African Railway Heritage

External links