South African Class 5 4-6-2

The South African Railways Class 5 4-6-2 of 1912 was a steam locomotive.

In 1912, four Enlarged Karoo Class 4-6-2 Pacific type passenger steam locomotives, which had been ordered by the Cape Government Railways the year before, were placed in service by the newly established South African Railways. The locomotives were therefore numbered directly onto the South African Railways roster and designated Class 5.^[1][2][3][4]

Manufacturer

The Cape Government Railways (CGR), Natal Government Railways (NGR) and Central South African Railways (CSAR) had all prepared designs and placed orders for new locomotives shortly prior to 1912, when the South African Railways (SAR) locomotive classification and renumbering scheme was implemented.^[1]

H.M. Beatty

The CGR's Enlarged Karoo, designed by H.M. Beatty, the Cape Government Railways Chief Locomotive Superintendent, and built by Vulcan Foundry of Newton-le-Willows, was one of the locomotive types which were designed and ordered before the SAR was established and which ended up being delivered to the newly established national railways of the Union of South Africa. The locomotives were designated Class 5 and numbered in the range from 780 to 783. They entered service during November 1912.^[1][2][3]

Characteristics

The Class 5 was a larger and heavier version of the Class 5B, with a higher pitched boiler, Belpaire firebox, larger diameter leading and coupled wheels and larger cylinders.^[4]

The cylinders were arranged outside the bar frames, with balanced Richardson type D slide valves arranged above the cylinders and actuated by Stephenson valve gear through rocker shafts. The hind frame of the engine was of the plate type and was widened out to receive the Belpaire firebox, which itself was a notable departure from the usual practice of the CGR to use round-topped fireboxes.^[2]

Watson Standard boilers

In the 1930s, many serving locomotives were reboilered with a standard boiler type, designed by then Chief Mechanical Engineer A.G. Watson as part of his standardisation policy. Such Watson Standard reboilered locomotives were reclassified by adding an "R" suffix to their classification.^[4][5]

During 1935, only one of the Class 5 locomotives, no. 781, was reboilered with a Watson Standard no. 1 boiler and reclassified to Class 5R. The most obvious difference between the Class 5 and Class 5R is the absence of the Belpaire firebox hump between the cab and boiler on the reboilered locomotive.^[2][4][5]

During the reboilering process, the engine was also equipped with a superheater and underwent several other modifications. It was fitted with larger bore cylinders, similar to those of the Class 15B, with piston valves and by-pass valves. The diameter of the coupled wheels was increased from 61 to 62 inches (1,549 to 1,575 millimetres).^[2][4][5]

The hind end of the frame was redesigned and the bridle casting was removed and replaced by a frame plate, riveted to the main bar frame and carried through to the hind buffer beam. A new steel casting, extending across and over the main frame, added rigidity and served as a support for the boiler at the throat plate. A new design of drag box was installed. While the trailing Bissel truck remained unaltered, its side control was re-designed and a new compensating beam and support pivot was fitted.^[2]

To compensate for the increased axle loads, the diameter of the driving axle was increased from 8 to 8 ¹⁄₂ inches (203 to 216 millimetres), while that of the other two coupled wheel axles was increased from 7 ¹⁄₂ to 8 inches (191 to 203 millimetres). Grease-lubricated axle boxes were fitted to all coupled wheels and new coupling and connecting rods of a heavier design were installed. All these alterations had the result that the boiler pitch was raised from 7 feet 5 inches (2,261 millimetres) to 8 feet (2,438 millimetres) and the weight of the engine was increased from 68 long tons 5 hundredweight (69,350 kilograms) to 72 long tons 9 hundredweight (73,610 kilograms). The overall length of the engine and tender was increased by 1 ³⁄₈ in (35 mm).^[2][5]

Their original boilers were fitted with Ramsbottom safety valves, while the Watson Standard boiler was fitted with Pop safety valves. Even though the boiler pressure setting of the reboilered engine was lowered from 200 to 190 pounds per square inch (1,379 to 1,310 kilopascals), the tractive effort increased from 24,860 to 25,750 pounds-force (111 to 115 kilonewtons) at 75% of boiler pressure.^[1][2][5]

Service

The engines were placed in service on mainline passenger service between Cape Town and Touws River, where they remained until the loads became too heavy for them. From about 1928, they were used on secondary services, chiefly being employed to haul suburban passenger trains from Cape Town to the Strand and Stellenbosch.^[1]

The three Class 5 locomotives were withdrawn from service by 1942, but the sole Class 5R remained in service for another 27 years. For most of its working life, it was employed in suburban service in Cape Town, where it gained fame for the unusual achievement of being an individual locomotive which worked the same train, the Strand Express, for more than thirty years. It was only withdrawn occasionally for maintenance in the locomotive depot or for heavy repairs in the shops. During this time, it regularly attained a speed of 60 miles per hour (97 kilometres per hour) while en route between Cape Town and Bellville. It was sub-shedded at Sir Lowry's Pass and always had regular drivers.^[6]

When the Strand line was electrified in the mid-1960s, engine no. 781 was transferred to the Eastern Transvaal System as a shunting engine at Nylstroom, and later to Capital Park in Pretoria. From there, it was transferred to the Western Transvaal System and it was also briefly stationed at Springs on the East Rand. It spent its last years in service as station pilot at Germiston, until it was retired in 1969.^[4][6]

After withdrawal from service, it was returned to the Salt River Shops in Cape Town for use in the training of apprentice fitters, until it was moved to De Aar to be maintained for preservation.^[6]

Illustration

The main picture shows Class 5R no. 781, retired at De Aar in 1978, while the following illustrate the differences in appearance due to modifications during the lifespan of the Class.

The last picture, of the reboilered no. 781, dates to the 1950s, by which time the original enormous headlight had been replaced.

• 
  Vulcan Foundry works picture of no. 780
• 
  No. 783 passing the junction at Woltemade No. 3, c. 1930
• 
  No. 782 with driver M. Mileham and stoker Treadaway, c.1930
• 
  Class 5R no. 781 with driver Sonny Best, c.1950

References

Wikimedia Commons has media related to South African Class 5 (4-6-2).

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