South African Class 23 4-8-2

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The South African Railways Class 23 4-8-2 of 1938 is a South African steam locomotive from the South African Railways era.

In 1938 and 1939 the South African Railways placed one hundred and thirty-six Class 23 steam locomotives in service. The Class 23 was the last and the largest 4-8-2 Mountain type locomotive to be designed by the South African Railways.^[1][2][3]

Manufacturers

The Class 23 4-8-2 Mountain type steam locomotive was designed by W.A.J. Day, Chief Mechanical Engineer (CME) of the South African Railways (SAR) from 1936 to 1939. It was intended as a general utility locomotive capable of operating on 80 pounds per yard (40 kilograms per metre) rail, and was built in two batches by Berliner Maschinenbau and Henschel and Son in Germany. The original order in 1938 was for twenty locomotives, of which Berliner built seven, numbered in the range from 2552 to 2558, and Henschel thirteen, numbered in the range from 2559 to 2571.^[1][4][5]

The urgency brought about by the rapidly deteriorating political climate in Europe at the time led to a further one hundred and sixteen locomotives being ordered even before the first batch could be delivered and tested. Of these, Henschel built eighty-five, numbered in the range from 3201 to 3285, and Berliner thirty-one, numbered in the range from 3286 to 3316. The last locomotive of this second order was delivered in August 1939, just one month before the outbreak of World War II.^[1][4][6]

Locomotive number 3301 received an out of sequence works number, Berliner 10816 instead of 11000, since works number 11000 was reserved for a new 4-6-2 Pacific type locomotive for the German State Railways. The table shows the Class 23 engine numbers, builders and works numbers. On the builders’ works lists all the locomotives are recorded as having been built in 1938.^[1][2][5]

Design considerations

Watson Standard boiler

As originally designed, the locomotive would have had 66 inches (1,676 millimetres) coupled wheels, which would have required a newly designed boiler to accommodate the extra length brought about by the longer coupled wheelbase. The increasing political turmoil in Europe and the resulting urgency, however, prohibited time being spent on designing a new boiler. As a result, the existing Watson Standard no. 3B boiler was incorporated in the design, with an extra long smokebox to partially compensate for the shorter boiler. This boiler was one of the range of standard type boilers designed by Day’s predecessor as CME, A.G. Watson, as part of the latter’s standardisation policy.^[1]

Coupled wheel diameter

In order to enable them to negotiate 300 feet (91.4 metres) radius curves, the leading coupled wheels were given a 1 inch (25 millimetres) side-play. In addition, largely also as a result of the decision to use the shorter Watson Standard boiler, it was decided to reduce the coupled wheel diameter from 66 inches (1,676 millimetres) to 63 inches (1,600 millimetres), which shortened the coupled wheelbase and would further ease passage on sharp curves.^[1][4]

These decisions appear to have been taken at quite a late stage, since the cylinders were cast to suit the larger wheel diameter. To compensate for the decreased wheel diameter, the maximum boiler pressure was raised to 225 pounds per square inch (1,550 kilopascals), at the time the highest yet used on the SAR.^[3]

Tender

Since these locomotives were intended for working in the Karoo where good quality water is a scarce resource, they were equipped with very large tenders with a high water capacity that rode on six wheeled bogies. They were the largest tenders to have been used in South Africa up to that time and as designed, they would have had a water capacity of 10,000 imperial gallons (45,000 litres).^[1][4]

Axle load restrictions, however, led to the water capacity being reduced to 9,200 imperial gallons (42,000 litres) for the first order of twenty locomotives. This was increased to 9,500 imperial gallons (43,000 litres) for the second order of one hundred and sixteen. Four vacuum cylinders operated clasp brakes on all tender wheels.^[1][4]

Streamlining

During the 1930s the streamlining of locomotives was fashionable in Europe and the United States of America. It was proposed to adopt streamlining on some of the Class 23 locomotives, but investigation showed that it would increase the cost by £500 per locomotive and increase the weight by approximately 2 long tons (2.0 tonnes). Those factors, coupled to the negligible performance benefit of streamlining at normal goods train speeds as well as the reduced accessibility of working parts on a streamlined locomotive, led to this idea being abandoned.^[1][4]

Service

In general appearance and power the Class 23 locomotive is very similar to the Class 15E and 15F. In their first few years of service the Class 23 fleet formed the bulk of the motive power on the lines from Touws River to Beaufort West and from De Aar to Welverdiend via Kimberley and Klerksdorp.^[4]

The arrival of the new Class 25 and Class 25NC in 1953 caused them to be transferred to Bloemfontein, to work from there to Kimberley to the west and Kroonstad to the north.^[4]

Due to metal fatigue cracks that developed in their 5 inches (127 millimetres) thick rolled steel bar frames, they were withdrawn from mainline service considerably earlier than the similar Class 15F. They were all retired by 1983, many of them in the process donating their large Type EW tenders to increase the range of the Class 15F. At least one of these tenders, that of number 3209, was later rebuilt to a water-only tender.^[3][4]

Illustration

The main picture shows Berliner-built number 2556, which was plinthed next to the High School in Gideon Joubert Park in Touws River on occasion of that Railway town’s centenary in 1977. It was officially presented to the town by SAR chief executive Dr. Kobus Loubser on 24 September 1977.^[7]

• 

  Berliner-built no. 3300 at Koppies, Orange Free State, between Sasolburg and Kroonstad, 6 October 1989

• 

  Henschel-built no. 3282 "Vrystaat" on the Orange Express, stopped at Perdeberg on the line between Petrusburg and Kimberley

• 

  No. 3209’s Type EW tender, rebuilt to a water-only tender, at Worcester, Western Cape, 20 October 2009

References

Wikimedia Commons has media related to South African Class 23 (4-8-2).

Locomotives of South Africa Steam 7' ¼" gauge East London Harbour 0-4-0 Table Bay Harbour 0-4-0ST Table Bay Harbour 0-4-0T Table Bay Harbour 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 Coffee Pot CGR 0-6-0ST 1902 CGR 0-6-0T 1876 Back-to-Back 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 1876 CGR 1st Class 4-4-0T 1875 CGR 2nd Class 4-4-0T 1882 CGR 3rd Class 2-6-0T CGR Railmotor CSAR Class C CSAR Class E CSAR Rack CSAR Railmotor DSWA Eight-Coupled Tank 2-8-0T Durban's Congella Durban's Edward Innes Durban's John Milne Durban's Sir Albert Port Elizabeth Harbour 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 14 Tonner NZASM 18 Tonner NZASM 19 Tonner NZASM 32 Tonner NZASM 40 Tonner PPR 26 Tonner PPR 35 Tonner Portuguese SAR 0-4-0ST 1903 SAR 0-4-0T no. 69 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 Clayton Railmotor 3' 6" gauge Tender engines CGR 1st Class 2-6-0 1876 Beyer, Peacock 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 1879 CGR 1st Class 4-4-0TT 1881 CGR 2nd Class 2-6-2TT 1875 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 1884 CGR 5th Class 4-6-0 1890 CGR 5th Class 4-6-0 1891 DSWA Eight-Coupled Tender 2-8-0 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 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 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 Red Devil 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 0-6-0T 1871 Cape Copper Britannia Cape Copper Caledonia Cape Copper Clara Class Cape Copper Condenser Cape Copper Scotia Class Namaqua Copper Pioneer 2' & 600mm gauges ACR Class NG-G16A CGR NG 0-6-0T CGR NG 4-6-2T CGR Type A 2-6-4T CGR Type C 0-4-0T DSWA Class Ha DSWA Class Hb DSWA Class Hc DSWA Class Hd DSWA Jung DSWA Zwillinge NGR Class N 4-6-2T SAR NG 0-4-0T 1899 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 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 SAR Class 8E SAR Class 9E s1 SAR Class 9E s2 SAR Class 10E SAR Class 10E1 s1 SAR Class 10E2 SAR Class 11E SAR Class 12E Spoornet Class 7E4 Spoornet Class 10E1 s2 Spoornet Class 14E Spoornet Class 14E1 Spoornet Class 16E Spoornet Class 17E Spoornet Class 18E s1 TFR Class 15E TFR Class 18E s2 TFR Class 19E TFR Class 20E TFR Class 21E TFR Class 22E 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 SAR Class 36-000 SAR Class 36-200 SAR Class 37-000 Spoornet Class 39-000 TFR Class 35-800 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 Rail transport in South 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