South African Class 19C 4-8-2

In 1935 the South African Railways placed fifty Class 19C steam locomotives with a 4-8-2 Mountain wheel arrangement in service.^[1][4]

Manufacturer

When the need for more branch line locomotives became apparent in 1934, tenders were invited by the South African Railways (SAR) for another fifty Class 19B locomotives with Walschaerts valve gear. When the tenders were received it was found that the North British Locomotive Company (NBL) of Glasgow, Scotland, had also tendered for a locomotive with Rotary Cam Poppet valve gear.^[1][4]

Even though this would increase the cost per locomotive by £200, Chief Mechanical Engineer (CME) A.G. Watson decided to adopt it in view of the good reports he had received concerning Poppet valve gear. This variation on the design led to these locomotives being classified as Class 19C when they were delivered in 1935.^[1][4]

All fifty Class 19C locomotives were erected at the Salt River shops, numbered 2435 to 2484, and many remained stationed at Cape Town while being subjected to exhaustive testing.^[1]

The photograph alongside shows a Class 19C locomotive after a record speed test run, during which the locomotive achieved a speed of 67 miles per hour (108 kilometres per hour). CME A.G. Watson is standing sixth from left in the group in front of the locomotive, with hat in hand.

Characteristics

Watson Standard boilers

The Class 19C was delivered with a Watson Standard no. 1A boiler, one of the range of a standard boiler type designed by Watson as part of his standardisation policy. It had a larger superheater than the Class 19B and was equipped with the altered cab with the sloping front design that, like the Watson Standard boiler, was to become standard on later SAR steam locomotive classes.

In a break with prior custom, to facilitate easier removal of the boiler for repairs, the ash pan and running boards were affixed to the locomotive frame instead of to the boiler.^[5]

Fireboxes

Some were built with steel fireboxes for use in those areas where good or treated water was readily available, while others were still equipped with copper or composite fireboxes for use in areas with poor water quality.^[3]

Copper or composite fireboxes are considerably more expensive to manufacture and repair than steel boxes. It was only by the late 1960s, when severe corrosion was no longer a big problem as a result of the availability of water treatment throughout the country, that copper and composite fireboxes were no longer considered necessary.^[6]

Balancing

The balancing of these locomotives represented another advance on former practices. Until then, locomotives had been balanced to an extent of 50% to 70% of their reciprocating parts, and fully as regards their revolving parts.^[1]

On the Class 19C the proportion of reciprocating parts balanced was reduced to 20%, which resulted in a big decrease of vertical hammer blow to not more than 0.9 long tons (0.91 tonnes) on any wheel at 50 miles per hour (80 kilometres per hour). Similar balancing metods on subsequent new locomotives enabled the SAR to adopt axle loads exceeding those permitted on many other railways of the world for comparable weight of rail.^[1]

Service

The Class 19C was designed for main line as well as branch line service. They initially worked in the Witwatersrand area, the Eastern Cape and Western Cape. The Poppet valves made the Class 19C a very free-running locomotive, although it required special maintenance techniques.^[4][5]

As a result the whole class was allocated to the Western Cape during World War II, based at the Paardeneiland shed in Cape Town. From here they worked on branch lines such as those from Cape Town to Saldanha, along the long branch line via Klawer to Bitterfontein, and across Sir Lowry's Pass to Caledon and Protem in the Overberg.^[4][5][7][8]

In later years, around 1970, a few were stationed at Bloemfontein from where they worked the line to Aliwal North. They were withdrawn from service in 1978.^[4]

One, number 2439, was preserved but none of them were sold into industry, firstly because of the special maintenance required for the Poppet valves, and secondly because Cape Town was a long distance away from any potential industrial operators, which would increase the cost of relocation.^[5]

Gallery

The main picture shows Class 19C 2439 on the line between Humefield and Klipplaat on 1 October 1989.

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 19D 4-8-2
• 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 e f g} Holland, D.F. (1972). Steam Locomotives of the South African Railways, Volume 2: 1910-1955 (1st ed.). Newton Abbott, Devon: David & Charles. pp. 68–71. ISBN 0715354272. 
2. ^ North British Locomotive Company works list, compiled by Austrian locomotive historian Bernhard Schmeiser
3. ^ ^{a b} South African Railways and Harbours Locomotive Diagram Book, 2’0” & 3’6” Gauge Steam Locomotives, 15 August 1941, as amended
4. ^ ^{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, 69-72. ISBN 0869772112. 
5. ^ ^{a b c d} Durrant, A E (1989). Twilight of South African Steam (1st ed.). Newton Abbott, London: David & Charles. pp. 63-64. ISBN 0715386387. 
6. ^ SAR Code of Practice No. 7 (Boilers), Part 3A.811 dated May 1968 - Procedure to be followed when copper plates of complete copper or composite fireboxes require to be renewed
7. ^ Warrenton, Town, SAR Class 19D no. 2688
8. ^ SAR Class 19C 4-8-2 (with MX tender) Locomotive