South African Class 10B 4-6-2

The South African Class 10B 4-6-2 of 1910 is a South African steam locomotive from the pre-Union era in the Transvaal.

In March 1910 the Central South African Railways placed ten Class 10-2 steam locomotives with a 4-6-2 Pacific wheel arrangement in service, of which five were built with and five without superheaters. In 1912, when the five superheated locomotives were assimilated into the South African Railways, they were renumbered and reclassified to Class 10B. During 1912 the South African Railways placed five more Class 10B locomotives in service.^[4][5][6][7]

Manufacturers

Ten heavy 4-6-2 Pacific type passenger locomotives, designed by Central South African Railways (CSAR) Chief Mechanical Engineer (CME) G.G. Elliot and based on the Class 10 design of his predecessor, CSAR Chief Locomotive Superintendent P.A. Hyde, were ordered from the North British Locomotive Company (NBL) and delivered in 1910. They had Belpaire fireboxes and Walschaerts valve gear and were delivered in two variants, five of them using saturated steam while the rest were superheated with Schmidt type superheaters. They were all classified as Class 10-2 by the CSAR, numbered in the range from 665 to 674, and entered service in March 1910.^[6][4]

South African Railways

The Union of South Africa was established on 31 May 1910, in terms of the South Africa Act, enacted by the Parliament of the United Kingdom. One of the clauses in the Act required that the three Colonial Government railways, the Cape Government Railways, the Natal Government Railways and the CSAR, also be united under one single administration to control and administer the railways, ports and harbours of the Union. While the South African Railways (SAR) came into existence in 1910, the actual classification and renumbering of all the rolling stock of the three constituent railways required careful planning and was only implemented with effect from 1 January 1912.^[5][8]

When they were assimilated into the SAR in 1912, the five saturated steam locomotives numbered in the range from 665 to 669 were reclassified as Class 10A, while the five superheated steam locomotives numbered in the range from 670 to 674 were designated Class 10B and renumbered in the range from 752 to 756.^[4][5]

During 1911 the CSAR had ordered a further five superheated Class 10B locomotives from Beyer, Peacock and Company. These were delivered to the SAR in 1912 and numbered in the range from 757 to 761, with their engine numbers out of sequence with their builder’s works numbers.^[6][5]

Characteristics

These locomotives were similar to the CSAR Class 10, except that their boilers were arranged 7.5 inches (191 millimetres) further forwards and their firebox throats and back plates were sloped instead of being vertical. Like the Class 10, they had 62 inches (1,570 millimetres) coupled wheels, the largest yet used in South Africa.^[4]

While the Class 10 had outside admission valves, the Class 10B used inside admission piston valves. The valve gear was reversed by means of a vertical steam reversing engine placed on the right-hand running board in line with the steam dome. Two Trevithick exhaust steam feedwater heaters were mounted on the running boards on either side of the smokebox, and a Weir’s feedwater pump was mounted on the left-hand side of the firebox. The feedwater heaters and the feedwater pump were removed after a few years since the feedwater heaters proved to be troublesome.^[4][9]

Watson standard boilers

During the 1930s many serving locomotives were reboilered with a standard boiler type designed by then 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.^[3][6]

Five of the Class 10B locomotives were eventually reboilered with Watson Standard no. 1 boilers and reclassified to Class 10BR.^[3][6]

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. In the case of the Class 10BR locomotives an even more obvious visual difference was the absence of the Belpaire firebox hump between the cab and boiler on the reboilered locomotives.^[3]

The table displays the locomotive builders, works numbers, CSAR to SAR renumbering and the Watson Standard boiler reclassification for the Class 10B and 10BR locomotives.^[4][5]

Service

The Class 10B was placed in service hauling passenger trains out of Johannesburg. Most of their working lives were, however, spent on the Cape Midlands system, where they were used on the mainline out of Port Elizabeth. Two of them worked as station pilots at Kimberley, but in 1960 they joined the rest of the Class that were by then working the suburban between Port Elizabeth and Uitenhage.^[6]

In later years they also served on the Reef’s suburban routes while a few were used in the same service around Cape Town, until they were eventually relegated to shunting work. They were scrapped in 1974.^[6]

Versions illustrated

The main picture shows a CSAR Class 10-2, later SAR Class 10B, as delivered with feedwater heaters, while the 1930s picture below shows one with the feedwater heaters removed.

• 

  Belpaire firebox Class 10B on a passenger train, c. 1930

• 

  Class 10BR no. 758 at the Old Uitenhage Station Museum

See also

• List of South African locomotive classes
• South African Class 10 4-6-2
• South African Class 10A 4-6-2
• South African Class 10C 4-6-2
• South African Class 10D 4-6-2
• South African locomotive history
• Tender locomotive numbering and classification
• The 4-6-2 "Pacific"
• Watson Standard boilers

References

Wikimedia Commons has media related to: South African Class 10B (4-6-2)

Locomotives of South Africa Steam Brunel gauge HBEL 0-4-0 HBTB 0-4-0T HBTB 0-4-0WT HBTB 0-4-0ST Broad gauge CGR Aid CGR Blackie CGR 0-4-2 CGR 2-4-0T NRC Durban NRC Natal NRC Perseverance Cape gauge Tank CGR Coffee Pot CGR 040 1873 CGR 040 1874 CGR 060 1876 CGR 060 1902 CGR 260 1900 CGR 260 1902 CGR 1st 040 1875 CGR 1st 440 1875 CGR 1st 040 1876 CGR 1st 260 1876 CGR 2nd 1882 CGR 3rd 1900 CGR RM CSAR C CSAR E CSAR Rack CSAR RM Dbn Congella Dbn Edward Innes Dbn John Milne Dbn Sir Albert HBPE 040 Kowie 060 Kowie 440 M&S 462 NGR Dbn & Pmb NGR I 262 NGR K 040 NGR K 060 NGR K 260 NZASM 10T NZASM 14T NZASM 18T NZASM 19T NZASM 32T NZASM 40T PPR 26T PPR 35T SAR RM SAR 0-4-0ST SAR 040 69 SAR A SAR B SAR C SAR C1 SAR C2 SAR D SAR E SAR F SAR G SAR H SAR H1 SAR H2 SAR J SAR K SWA 2-8-0T Cape gauge Tender CGR 1st 260 1876 BP CGR 1st 260 1876 K CGR 1st 260 1879 CGR 1st 440 1879 CGR 1st 1881 CGR 1st 1891 CGR 2nd 1875 CGR 3rd 1883 CGR 3rd 1884 CGR 3rd 1889 CGR 3rd 1898 CGR 3rd 1901 CGR 3rd 1903 CGR 4th 1880 CGR 4th 1882 CGR 4th 1884 CGR 4th 1897 CGR 5th 1890 CGR 5th 1891 NGR Havelock NGR I 260 Exp-1 Exp-2 Exp-3 Exp-4 Exp-5 Exp-6 SAR S SAR S1 SAR S2 SAR 1 SAR 1A SAR 1B SAR 2 SAR 2C SAR 3 SAR 3A SAR 3B SAR 4 SAR 4A SAR 5 SAR 5A SAR 5B SAR 6 SAR 6A SAR 6B SAR 6C SAR 6D SAR 6E SAR 6F SAR 6G SAR 6H SAR 6J SAR 6K SAR 6L SAR 6Y SAR 6Z SAR 7 SAR 7A SAR 7B SAR 7C SAR 7D SAR 7E SAR 7F SAR 8 SAR 8A SAR 8B SAR 8C SAR 8D SAR 8E SAR 8F SAR 8X SAR 8Y SAR 8Z SAR 9 SAR 10 SAR 10A SAR 10B SAR 10C SAR 10D SAR 11 SAR 12 SAR 12A SAR 12B SAR 13 SAR 14 SAR 14A SAR 14B SAR 14C SAR 15 SAR 15A SAR 15B SAR 15C SAR 15CA SAR 15E SAR 15F SAR 16 SAR 16A SAR 16B SAR 16C SAR 16D SAR 16DA SAR 16E SAR 17 SAR 18 SAR 19 SAR 19A SAR 19B SAR 19C SAR 19D SAR 20 SAR 21 SAR 23 SAR 24 SAR 25 SAR 25NC SAR 26 SWA 2-8-0 Cape gauge Articulated CGR Fairlie CGR Kitson-Meyer SAR FC SAR FD SAR GA SAR GB SAR GC SAR GCA SAR GD SAR GDA SAR GE SAR GEA SAR GF SAR GG SAR GH SAR GK SAR GL SAR GM SAR GMA SAR GO SAR HF SAR KM SAR MA SAR MB SAR MC SAR MC1 SAR MD SAR ME SAR MF SAR MG SAR MH SAR MJ SAR MJ1 SAR U 2ft 6in gauge CCC 1871 CCC Britannia CCC Caledonia CCC Clara CCC Condenser CCC Scotia NCC Pioneer 2ft & 600mm gauges ACR NG-G16A CGR NG 060 CGR NG 462 CGR A CGR C NGR N SAR 040 1899 SAR NG1 SAR NG2 SAR NG3 SAR NG4 SAR NG5 SAR NG6 SAR NG7 SAR NG8 SAR NG9 SAR NG10 SAR NG-G11 SAR NG-G12 SAR NG-G13 SAR NG-G14 SAR NG15 SAR NG-G16 SWA Ha SWA Hb SWA Hc SWA Hd SWA Jung SWA Zwillinge Diesel -electric SAR DS SAR DS1 SAR 31-000 SAR 32-000 SAR 32-200 SAR 33-000 SAR 33-200 SAR 33-400 SAR 34-000 SAR 34-200 SAR 34-400 SAR 34-500 SAR 34-600 SAR 34-800 SAR 34-900 SAR 35-000 SAR 35-200 SAR 35-400 SAR 35-600 SAR 36-000 SAR 36-200 SAR 37-000 SN 39-000 TFR 39-200 TFR 43-000 SAR 91-000 Afro4000 -hydraulic SAR 61-000 Electro-diesel SN 38-000 Electric SAR ES SAR ES1 Exp-AC SAR 1E SAR 2E SAR 3E SAR 4E SAR 5E-S1 SAR 5E-S2 SAR 5E-S3 SAR 5E1-S1 SAR 5E1-S2 SAR 5E1-S3 SAR 5E1-S4 SAR 5E1-S5 SAR 6E SAR 6E1-S1 SAR 6E1-S2 SAR 6E1-S3 SAR 6E1-S4 SAR 6E1-S5 SAR 6E1-S6 SAR 6E1-S7 SAR 6E1-S8 SAR 6E1-S9 SAR 6E1-S10 SAR 6E1-S11 SAR 7E SAR 7E1 SAR 7E2-S1 SAR 7E2-S2 SAR 7E3-S1 SAR 7E3-S2 SN 7E4 SAR 8E SAR 9E-S1 SAR 9E-S2 SAR 10E SAR 10E1-S1 SAR 10E1-S2 SAR 10E2 SAR 11E SAR 12E SN 14E SN 14E1 TFR 15E SN 16E SN 17E SN 18E-S1 TFR 18E-S2 TFR 19E TFR 20E TFR 21E E38 List of South African locomotive classes Rail transport in South Africa