South African Class 15B 4-8-2

The South African Railways Class 15B 4-8-2 of 1918 was a steam locomotive.

Between 1918 and 1922, the South African Railways placed thirty Class 15B steam locomotives with a 4-8-2 Mountain type wheel arrangement in service.^[1][2][3]

Manufacturer

The Class 15B was ordered at a time when further orders of the earlier Class 15 models were unobtainable from manufacturers in the United Kingdom as a result of wartime disruption in Europe. The first batch of ten Class 15B 4-8-2 steam locomotives for the South African Railways (SAR) was therefore ordered from the Montreal Locomotive Works (MLW) in Canada, who undertook to supply engines of equivalent power, wheelbase and weight, but built to their own design. They were built and delivered in 1918, numbered in the range from 1829 to 1838. A second batch of twenty locomotives was ordered from the same builders and delivered in 1922, numbered in the range from 1971 to 1990.^[1][2][3]

Characteristics

They were built to the general specifications of the Class 15, but with 4 inches (102 millimetres) thick bar frames instead of plate frames and some other typical North American features, and they were equipped with Belpaire fireboxes with combustion chambers. Many of the parts of these engines were similar to those of the Class 14C, which was built by the same manufacturers in that same year.^[1][2]

Modifications

Cylinder bushing

The first ten locomotives were modified on similar lines as the earlier versions of the Class 14C. As they went in for major overhauls, they had their cylinders bushed to reduce the bore from the as-built 22 to 21 ³⁄₄ inches (559 to 552 millimetres). At the same time, their operating boiler pressure was adjusted upwards from 185 to 190 pounds per square inch (1,276 to 1,310 kilopascals) to keep their tractive effort more or less unaffected by the reduction in piston diameter.^[2][4]

Watson Standard boilers

Class 15B

Class 15R

Class 15BR

During the 1930s, many serving locomotives were reboilered with a standard boiler type, designed by A.G. Watson, CME of the SAR at the time, as part of his standardisation policy. Such Watson Standard reboilered locomotives were reclassified by adding an "R" suffix to their classification.^[3][4]

Eventually all thirty Class 15B locomotives were reboilered with Watson Standard no. 2A boilers and reclassified to Class 15BR. The number plate of no. 1972, as illustrated, had the "B" omitted in error.^[2][4]

Only slight modifications were found necessary to accept the Watson Standard boilers. With the new boilers, the side running boards and platforms were attached to the engine frames, instead of to the boilers as in the original design. In the reboilering process, the boiler pitch was raised from 7 feet 9 inches (2,362 millimetres) to 8 feet 1 ¹⁄₂ inches (2,476 millimetres), which raised the chimney height from 12 feet 10 inches (3,912 millimetres) to 13 feet ³⁄₄ inch (3,981 millimetres). As also happened with the Class 14C, this exceeded the loading gauge height of 13 feet (3,962 millimetres) above the railhead, the only two locomotive types where the height restriction had been exceeded by 1945.^[2][4]

Their original Belpaire boilers were fitted with Ramsbottom safety valves, while the Watson Standard boiler was fitted with Pop safety valves. 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, to enable easier access to the firebox stays.^[4]

An 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 15B and Class 15BR, 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.^[3][4]

Service

South African Railways

The Class 15B was placed in service in the eastern Orange Free State, but eventually spent most of their working lives in the Cape Midland, working south from Noupoort to Cradock and across to De Aar. When the Class 15F started taking over in that area, they were gradually relocated to Cape Town, from where they worked goods and passenger trains to the north. They also worked across Sir Lowry's Pass to Caledon and Bredasdorp in the Overberg and on the Bitterfontein line via Malmesbury and Klawer.^[1][3]

Some were shedded at Worcester and at Ashton for shunting. The usual way of exchanging the Ashton shunter every fortnight was for it to be used on the local passenger train, which was normally hauled by a Garratt. They were withdrawn by 1976.^[5]

Caminhos de Ferro de Moçambique

In March and July 1973, twelve Class 15BR locomotives were sold in two batches to Caminhos de Ferro de Moçambique (CFM), the Mozambique Railways, which mainly used them for shunting at Lourenco Marques and occasionally on freight service to Swaziland. The SAR engine numbers of these locomotives were 1836, 1974, 1981, 1983, 1984 and 1986, sold in March 1973, and 1829, 1831, 1838, 1976, 1977 and 1985, sold in July 1973. The CFM renumbered the March batch to 421, 426 and 422 to 425, and the July batch to 427 to 432. This renumbering sequence could, however, not be ascertained with certainty.^[5]

Industrial

Six Class 15BR locomotives were sold into industrial use.^[5]

• Numbers 1972 and 1980 went to Tweefontein United Collieries.^[5]
• Numbers 1973, 1975, 1982 and 1990 went to the Randfontein Estates Gold Mine (REGM).^[5]

Illustration

The main picture shows Class 15BR no. 1982 at Bonnievale in February 1974, on the Saturdays-only Worcester-Riversdale passenger train. The following pictures show SAR no. 1838 as built, with a Belpaire firebox, and REGM no. R7, ex SAR Class 15BR no. 1990, with a Watson Standard boiler and round-top firebox, photographed on the Doornkop branch while heading a mine manager's tour of the REGM system on 14 September 1997.

• 
  SAR no. 1838 as built with Belpaire firebox
• 
  REGM no. R7 on the Doornkop branch

References

Wikimedia Commons has media related to South African Class 15B (4-8-2).

Locomotives of South Africa
Steam	7' ¼" gauge East London 0-4-0VB Table Bay 0-4-0ST Table Bay 0-4-0T Table Bay 0-4-0WT 4' 8½" gauge Cape 0-4-0T Blackie Cape 0-4-2 Cape 2-4-0T CGR 0-4-0ST Aid Natal 0-4-0ST Durban Natal 0-4-0WT Natal Natal 4-4-0T Perseverance 3' 6" gauge Tank engines CGR 0-4-0ST 1873 CGR 0-4-0ST 1874 CGR 0-4-0ST 1881 CGR 0-4-0ST 1881 Coffee Pot CGR 0-6-0ST CGR 0-6-0T CGR 2-6-0ST 1900 CGR 2-6-0ST 1902 CGR 1st Class 0-4-0ST 1875 CGR 1st Class 0-4-0ST 1876 CGR 1st Class 2-6-0ST CGR 1st Class 4-4-0T CGR 2nd Class 4-4-0T CGR 3rd Class 2-6-0T CGR Railmotor CSAR Class C CSAR Class E CSAR Rack 4-6-4RT CSAR Railmotor Durban's Congella Durban's Edward Innes Durban's John Milne Durban's Sir Albert Port Elizabeth 0-4-0ST Kowie Railway 0-6-0T Kowie Railway 4-4-0T Metropolitan & Suburban 4-6-2T NGR 2-6-0T Durban & Pietermaritzburg NGR Class I 2-6-2T NGR Class K 0-4-0ST NGR Class K 0-6-0ST NGR Class K 2-6-0T NZASM 10 Tonner NZASM 13 Tonner NZASM 14 Tonner NZASM 18 Tonner NZASM 19 Tonner NZASM 32 Tonner NZASM 40 Tonner PPR 26 Tonner PPR 35 Tonner Portuguese SAR Class A SAR Class B SAR Class C SAR Class C1 SAR Class C2 SAR Class D SAR Class E SAR Class F SAR Class G SAR Class H SAR Class H1 SAR Class H2 SAR Class J SAR Class K SAR Railmotor SAR Dock 0-4-0ST SAR Dock 0-4-0T SWA 2-8-0T 3' 6" gauge Tender engines CGR 1st Class 2-6-0 1876 BP CGR 1st Class 2-6-0 1876 Kitson CGR 1st Class 2-6-0 1879 CGR 1st Class 2-6-0 1891 CGR 1st Class 4-4-0 CGR 1st Class 4-4-0TT CGR 2nd Class 2-6-2TT CGR 3rd Class 4-4-0 1883 CGR 3rd Class 4-4-0 1884 CGR 3rd Class 4-4-0 1889 CGR 3rd Class 4-4-0 1898 CGR 3rd Class 4-4-0 1901 CGR 3rd Class 4-4-0 1903 CGR 4th Class 4-4-2 CGR 4th Class 4-6-0TT 1880 CGR 4th Class 4-6-0TT 1882 CGR 4th Class 4-6-0TT 1882 Joy CGR 4th Class 4-6-0TT 1884 CGR 5th Class 4-6-0 1890 CGR 5th Class 4-6-0 1891 NGR Havelock NGR Class I SAR Class Exp 1 SAR Class Exp 2 SAR Class Exp 3 SAR Class Exp 4 SAR Class Exp 5 SAR Class Exp 6 SAR Class S SAR Class S1 SAR Class S2 SAR Class 1 SAR Class 1A SAR Class 1B SAR Class 2 SAR Class 2C SAR Class 3 SAR Class 3A SAR Class 3B SAR Class 4 SAR Class 4A SAR Class 5 SAR Class 5A SAR Class 5B SAR Class 6 SAR Class 6A SAR Class 6B SAR Class 6C SAR Class 6D SAR Class 6E SAR Class 6F SAR Class 6G SAR Class 6H SAR Class 6J SAR Class 6K SAR Class 6L SAR Class 6Y SAR Class 6Z SAR Class 7 SAR Class 7A SAR Class 7B SAR Class 7C SAR Class 7D SAR Class 7E SAR Class 7F SAR Class 8 SAR Class 8A SAR Class 8B SAR Class 8C SAR Class 8D SAR Class 8E SAR Class 8F SAR Class 8R SAR Class 8X SAR Class 8Y SAR Class 8Z SAR Class 9 SAR Class 10 SAR Class 10A SAR Class 10B SAR Class 10C SAR Class 10D SAR Class 11 SAR Class 12 SAR Class 12A SAR Class 12B SAR Class 13 SAR Class 14 SAR Class 14A SAR Class 14B SAR Class 14C 1st SAR Class 14C 2nd SAR Class 14C 3rd SAR Class 14C 4th SAR Class 15 SAR Class 15A SAR Class 15B SAR Class 15C SAR Class 15CA SAR Class 15E SAR Class 15F SAR Class 16 SAR Class 16A SAR Class 16B SAR Class 16C SAR Class 16D SAR Class 16DA 1928 SAR Class 16DA 1930 SAR Class 16E SAR Class 17 SAR Class 18 SAR Class 19 SAR Class 19A SAR Class 19B SAR Class 19C SAR Class 19D SAR Class 20 SAR Class 21 SAR Class 23 SAR Class 24 SAR Class 25 SAR Class 25NC SAR Class 26 SAR Katanga SWA 2-8-0 3' 6" gauge Articulated engines CGR Fairlie CGR Kitson-Meyer SAR Class FC SAR Class FD SAR Class GA SAR Class GB SAR Class GC SAR Class GCA SAR Class GD SAR Class GDA SAR Class GE SAR Class GEA SAR Class GF SAR Class GG SAR Class GH SAR Class GK SAR Class GL SAR Class GM SAR Class GMA SAR Class GO SAR Class HF SAR Class KM SAR Class MA SAR Class MB SAR Class MC SAR Class MC1 SAR Class MD SAR Class ME SAR Class MF SAR Class MG SAR Class MH SAR Class MJ SAR Class MJ1 SAR Class U 2' 6" gauge Cape Copper John King & Miner Cape Copper Britannia Cape Copper Caledonia Cape Copper Clara Cape Copper Condenser Cape Copper Scotia Namaqua Copper Pioneer Walvis Bay 2-4-2T Hope 2' & 600mm gauges ACR Class NG-G16A CGR NG 0-4-0T CGR NG 0-6-0T CGR NG 4-6-2T CGR Type A 2-6-4T CGR Type C 0-4-0T NGR Class N 4-6-2T SAR Dutton SAR NG 0-4-0T SAR Class NG1 SAR Class NG2 SAR Class NG3 SAR Class NG4 SAR Class NG5 SAR Class NG6 SAR Class NG7 SAR Class NG8 SAR Class NG9 SAR Class NG10 SAR Class NG-G11 SAR Class NG-G12 SAR Class NG-G13 SAR Class NG-G14 SAR Class NG15 SAR Class NG-G16 SWA Class Ha SWA Class Hb SWA Class Hc SWA Class Hd SWA Jung SWA Zwillinge
Electric	Amcoal Class E38 SAR Class ES SAR Class ES1 SAR Class Exp-AC SAR Class 1E SAR Class 2E SAR Class 3E SAR Class 4E SAR Class 5E s1 SAR Class 5E s2 SAR Class 5E s3 SAR Class 5E1 s1 SAR Class 5E1 s2 SAR Class 5E1 s3 SAR Class 5E1 s4 SAR Class 5E1 s5 SAR Class 6E SAR Class 6E1 s1 SAR Class 6E1 s2 SAR Class 6E1 s3 SAR Class 6E1 s4 SAR Class 6E1 s5 SAR Class 6E1 s6 SAR Class 6E1 s7 SAR Class 6E1 s8 SAR Class 6E1 s9 SAR Class 6E1 s10 SAR Class 6E1 s11 SAR Class 7E SAR Class 7E1 SAR Class 7E2 s1 SAR Class 7E2 s2 SAR Class 7E3 s1 SAR Class 7E3 s2 Spoornet Class 7E4 SAR Class 8E SAR Class 9E s1 SAR Class 9E s2 SAR Class 10E SAR Class 10E1 s1 Spoornet Class 10E1 s2 SAR Class 10E2 SAR Class 11E SAR Class 12E Spoornet Class 14E Spoornet Class 14E1 TFR Class 15E Spoornet Class 16E Spoornet Class 17E Spoornet Class 18E s1 TFR Class 18E s2 TFR Class 19E TFR Class 20E TFR Class 21E TFR Class 22E
Gas-electric	SAR Gas-electric
Diesel	3' 6" gauge Diesel-electric PRASA Class Afro 4000 SAR Class DS SAR Class DS1 SAR Class 31-000 SAR Class 32-000 SAR Class 32-200 SAR Class 33-000 SAR Class 33-200 SAR Class 33-400 SAR Class 34-000 SAR Class 34-200 SAR Class 34-400 SAR Class 34-500 SAR Class 34-600 SAR Class 34-800 SAR Class 34-900 SAR Class 35-000 SAR Class 35-200 SAR Class 35-400 SAR Class 35-600 TFR Class 35-800 SAR Class 36-000 SAR Class 36-200 SAR Class 37-000 Spoornet Class 39-000 TFR Class 39-200 TFR Class 43-000 TFR Class 44-000 2' gauge Diesel-electric SAR Class 91-000 3' 6" gauge Diesel-hydraulic SAR Class 61-000 3' 6" gauge Electro-diesel Spoornet Class 38-000
List of South African locomotive classes South African locomotive numbering and classification

South African steam locomotive tenders
Cape gauge	Type CL Type CZ Type ET Type ET1 Type EW Type EW1 Type EW2 Type FT Type GT Type HT Type JT Type JT1 Type JV Type KT Type LP Type MP Type MP1 Type MR Type MS Type MT Type MT1 Type MT2 Type MX Type MY Type MY1 Type SH Type SK Type TJ Type TL Type TM Type WE Type WG Type X-17 Type X-20 Type XC Type XC1 Type XD Type XE Type XE1 Type XF Type XF1 Type XF2 Type XJ Type XM Type XM1 Type XM2 Type XM3 Type XM4 Type XP1 Type XS Type YB Type YC Type YE Type YE1 Type ZA Type ZB Type ZC Type ZE
List of South African locomotive classes South African locomotive history