South African Class 24 2-8-4

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South African Class 24 2-8-4
SAR Class 24 3655 (2-8-4).JPG
3655 City of Cape Town leaving Monument station, 8 August 2010
Type and origin
Power typeSteam
DesignerSouth African Railways
(Dr. M.M. Loubser)
BuilderNorth British Locomotive Company
Order numberL976
Serial number26313-26412
ModelClass 24
Build date1949-1950
Total produced100
 • Whyte2-8-4 (Berkshire)
 • UIC1′D2′h2
Driver3rd coupled axle
Gauge3 ft 6 in (1,067 mm) Cape gauge
Leading dia.30 in (762 mm)
Coupled dia.51 in (1,295 mm)
Trailing dia.30 in (762 mm)
Tender wheels34 in (864 mm)
Minimum curve300 ft (91 m)
Wheelbase65 ft 3 in (19,888 mm)
 • Engine31 ft (9,449 mm)
 • Coupled13 ft 6 in (4,115 mm)
 • Trailing4 ft 6 in (1,372 mm)
 • Tender24 ft 7+14 in (7,499 mm)
 • Tender bogie8 ft 8 in (2,642 mm)
 • Over couplers74 ft 9+14 in (22,790 mm)
Height12 ft 10+78 in (3,934 mm)
Frame typeCast
Axle load11 LT 10 cwt (11,680 kg)
 • Leading8 LT (8,128 kg)
 • 1st coupled11 LT (11,180 kg)
 • 2nd coupled11 LT 10 cwt (11,680 kg)
 • 3rd coupled11 LT 9 cwt (11,630 kg)
 • 4th coupled11 LT 5 cwt (11,430 kg)
 • Trailing10 LT 2 cwt (10,260 kg) leading
9 LT 12 cwt (9,754 kg) trailing
 • Tender bogieBogie 1: 28 LT 1 cwt (28,500 kg)
Bogie 2: 28 LT 10 cwt (28,960 kg)
 • Tender axle9 LT 10 cwt (9,652 kg)
Adhesive weight45 LT 4 cwt (45,930 kg)
Loco weight72 LT 18 cwt (74,070 kg)
Tender weight56 LT 11 cwt (57,460 kg)
Total weight129 LT 9 cwt (131,500 kg)
Tender typeMY (Buckeye 3-axle bogies)
Fuel typeCoal
Fuel capacity9 LT (9.1 t)
Water cap4,520 imp gal (20,500 l)
Firebox typeRound-top
 • Firegrate area36 sq ft (3.3 m2)
 • ModelWatson Standard no. 1
 • Pitch8 ft (2,438 mm)
 • Diameter5 ft (1,524 mm)
 • Tube plates17 ft 9 in (5,410 mm) steel
17 ft 8+58 in (5,401 mm) copper
 • Small tubes76: 2+12 in (64 mm)
 • Large tubes24: 5+12 in (140 mm)
Boiler pressure200 psi (1,379 kPa)
Safety valveRoss-pop
Heating surface1,636 sq ft (152.0 m2)
 • Tubes1,497 sq ft (139.1 m2)
 • Arch tubes16 sq ft (1.5 m2)
 • Firebox123 sq ft (11.4 m2)
 • Heating area380 sq ft (35 m2)
Cylinder size19 in (483 mm) bore
26 in (660 mm) stroke
Valve gearWalschaerts
Valve typePiston
Loco brakeVacuum
CouplersAAR knuckle
Performance figures
Tractive effort27,600 lbf (123 kN) @ 75%
OperatorsSouth African Railways
ClassClass 24
Number in class100
First run1949

The South African Railways Class 24 2-8-4 of 1949 is a steam locomotive.

In 1949 and 1950, the South African Railways placed 100 Class 24 branch line steam locomotives with a 2-8-4 Berkshire type wheel arrangement in service.[1][2][3]


No. 3632 Tootsie at George, Cape Province, 29 September 1989
Preserved no. 3693 at Oudtshoorn, Cape Province, c. 1991. It was scrapped in 2016.
No. 3654 staged at Beaconsfield, Kimberley, 17 September 2009

By the late 1940s, the South African Railways (SAR) still had a comparatively large mileage of 45 pounds per yard (22 kilograms per metre) track. In South West Africa, where most of the locomotive fleet consisted of Classes 6, 7, GC and GCA, there were still hundreds of miles of 40+14 pounds per yard (20.0 kilograms per metre) track. Considering the increasing age of these locomotives, the options were either to relay these tracks with 60 pounds per yard (30 kilograms per metre) rail or to obtain new light branch line locomotives suitable for use on the existing track.[2]

The Class 24 2-8-4 Berkshire type branch line steam locomotive was designed by Dr. M.M. Loubser, Chief Mechanical Engineer (CME) of the SAR from 1939 to 1949. The locomotives were built by North British Locomotive Company (NBL) of Glasgow, who delivered 100 of them in 1949 and 1950, numbered in the range from 3601 to 3700. The cast engine main frames and the Buckeye bogies for the tenders were supplied by General Steel Castings of Eddystone, Pennsylvania.[1][2][4][5]

One of these locomotives, no. 3675, was the 2,000th locomotive to be built by NBL for the SAR and, to commemorate this milestone, a ceremony was conducted in Cape Town to name the locomotive Bartholomew Diaz after the Portuguese navigator Bartolomeu Dias who discovered the Cape of Good Hope in May 1488 and named it the Cape of Storms (Cabo das Tormentas). The ceremony was attended by the South African Minister of Transport and heads of departments of the SAR, as well as by the chairman and managing director of NBL.[1][5]


The Class 24 had a one-piece cast-steel main frame which was cast integrally with the cylinders, including the cylinder hind covers, smokebox support frame, stays and various brackets, all of which would normally be separate items riveted or bolted onto the frames. Advantages of this arrangement are reduced maintenance and less time spent in shops. It was the first South African steam locomotive to be built using this technique.[1][5]

They were built with Watson Standard no. 1 boilers, while their double hopper type ashpans were specially designed to clear the four-wheeled trailing bogies. Their specially designed Type MY tenders were similar in appearance to the Type MX and the North American Vanderbilt type tenders, with cylindrical water tanks. The tenders rode on three-axle Buckeye bogies to reduce the axle load and, along with the Type MX, became commonly known as Torpedo tenders.[1][2][3][6][7]

The piston valves were actuated by Walschaerts valve gear and the standard SAR type steam reversing gear was arranged on the right-hand side. The engine and tender were both equipped with vacuum brakes and the engine's two 21 inches (533 millimetres) diameter vacuum cylinders were arranged outside the engine's frame and under the running boards, one on either side. The valve gear, brake gear and coupled wheel hubs were soft grease lubricated, while the bronze axle boxes had hard grease lubrication. The leading and trailing bogies were fitted with roller bearing axle boxes while the tender's bogies used plain bearings.[2]


The Class 24 was built to replace the old Classes 6, 7 and 8 locomotives in branch line service on light rail. When they were introduced, an elaborate programme was drawn up to show on which systems and on what sections they were to be employed.[1][8]

Most of them went to the South West Africa System, where 55 of them would be in operation. From some time between 1955 and 1959, they were also employed on the Keetmanshoop-Walvisbaai section. They remained in that territory until 1961, when strengthening of the track and the complete dieselisation of the South West Africa System made them available to be employed elsewhere.[1][3][5]

Other branch lines to be served by the Class 24 include Breyten to Lothair, Nylstroom to Vaalwater, Port Elizabeth to Alexandra and George to Knysna. As a relatively powerful locomotive, they were also useful as suburban locomotives, a role they served in on the Springs-Nigel commuter line until electrification. Some eventually also worked on the Selati line in the Transvaal Lowveld. Heavy overhauls were done at Bloemfontein. The only province where they were unknown was Natal.[1][3][5][8]

The Calvinia and Sakrivier branches had been worked almost exclusively by Class 19C locomotives from about 1950, but from 1951 two Class 24s were also allocated to Beaufort West and sub-shedded at Hutchinson. After February 1963, this was reduced to one Class 24 locomotive until long after the branch was dieselised c. 1960, using Class 32-000 locomotives based at De Aar. For some six months in the latter half of 1969, the Calvinia and Sakrivier branches reverted to steam-only operation when there was a huge surge in ore traffic that required the drafting in of more Class 32-000 locomotives to the Port Elizabeth mainline. A pair of Class 24 locomotives temporarily worked those branches in 1969 and 1970 as relief engines during the diesel-electric locomotive shortage.[9]


The following is a list of 24 class that have survived into preservation. January 1, 2019

Number Works nmr. THF / Private Leaselend / Owner Current Location Outside South Africa Notes
3606 NBl 26318 THF Voorbaai Locomotive Depot
3608 NBL 26320 Private Calvinia Museum Calvinia Museum
3611 NBL 26323 Private TransNamib Ltd Keetmanshoop Locomotive Depot Namibia
3612 NBL 26324 Private TransNamib Ltd Keetmanshoop Locomotive Depot Namibia
3620 NBL 26332 Private Ian Welch & The Q Train Bellarine Railway[10] Australia Purchased by Main Line Steam Trust, Auckland, New Zealand in 1997,[11] sold to Cairns, Australia in 2001[12]
3631 NBL 26343 Private Ian Welch Bloemfontein Locomotive Depot
3632 NBL 26344 Private Ian Welch & Dylan Knott Voorbaai Locomotive Depot
3633 NBL 26345 Private SANRASM Hermanstad (station)
3635 NBL 26347 THF Voorbaai Locomotive Depot
3638 NBL 26350 Private National Parks Board Kruger National Park
3645 NBL 26357 THF Krugersdorp Locomotive Depot
3647 NBL 26359 Private Greg MC.lannan Germiston Locomotive Depot
3654 NBL 26366 THF Steamnet 2000 Kimberley Locomotive Depot
3655 NBL 26367 Private Grant Bradley Cape Town Station
3664 NBL 26376 THF Friends of the Rail Hermanstad (station)
3667 NBL 26379 THF Queenstown Locomotive Depot
3668 NBL 26380 THF Transnet Heritage Foundation Outiniqua Transport Museum Selected as Transnet Heritage Foundation representative of the class (National Collection)
3675 NBL 26387 THF Voorbaai Locomotive Depot
3688 NBL 26400 THF Sandstone Estate Bloemfontein Locomotive Depot
3689 NBL 26401 Private Michael Barclay Voorbaai Locomotive Depot
3690 NBL 26402 Private Ian Welch Bloemfontein Locomotive Depot


  1. ^ a b c d e f g h Holland, D. F. (1972). Steam Locomotives of the South African Railways. 2: 1910-1955 (1st ed.). Newton Abbott, England: David & Charles. pp. 105–107. ISBN 978-0-7153-5427-8.
  2. ^ a b c d e Espitalier, T.J.; Day, W.A.J. (1947). The Locomotive in South Africa - A Brief History of Railway Development. Chapter VII - South African Railways (Continued). South African Railways and Harbours Magazine, May 1947. pp. 403-404.
  3. ^ a b c d Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. p. 76. ISBN 0869772112.
  4. ^ North British Locomotive Company works list, compiled by Austrian locomotive historian Bernhard Schmeiser
  5. ^ a b c d e S.A.R. Class 24 2-8-4 South African Transport March 1971 pages 164-165
  6. ^ South African Railways & Harbours/Suid Afrikaanse Spoorweë en Hawens (15 Aug 1941). Locomotive Diagram Book/Lokomotiefdiagramboek, 3'6" Gauge/Spoorwydte. SAR/SAS Mechanical Department/Werktuigkundige Dept. Drawing Office/Tekenkantoor, Pretoria. pp. VIII, 46.
  7. ^ South African Railways & Harbours/Suid Afrikaanse Spoorweë en Hawens (15 Aug 1941). Locomotive Diagram Book/Lokomotiefdiagramboek, 2'0" & 3'6" Gauge/Spoorwydte, Steam Locomotives/Stoomlokomotiewe. SAR/SAS Mechanical Department/Werktuigkundige Dept. Drawing Office/Tekenkantoor, Pretoria. pp. VIII, 6a-7a, 28A, 46.
  8. ^ a b Durrant, A. E. (1989). Twilight of South African Steam (1st ed.). Newton Abbott, London: David & Charles. p. 106. ISBN 0715386387.
  9. ^ Soul of A Railway, System 1, Part 15: Calvinia, Sakrivier, Porterville and Saldanha branches by Charlie Lewis. Caption 22. (Accessed on 9 May 2017)
  10. ^ Loco’s nationwide road trip Narrow Gauge World issue 147 May 2020 page 15
  11. ^ Locomotives to New Zealand Continental Railway Journal issue 108 January 1997 page 517
  12. ^ Here & There Australian Railway Historical Society Bulletin issue 762 April 2001 page 153

External links[edit]

External video
video icon South African Steam: Pretoria area - Rovos Rail, THF Museum and 3664 rollover (16 March 1997) The video features a few trains on the same day in the Pretoria area. First we see Friends of the Rail's Class 24 no. 3664 heading out on the Hercules-Magaliesburg branch on a charter train. Whilst out at Meerhof, word came through that Rovos Rail were triple-heading their Pretoria train behind Class 6 no. 439 and Class 19D nos. 2701 and 2702, so I rushed down to Irene to see that. Later in the afternoon, one of the last THF Museum-run Magaliesburg trains departed with Class 15F no. 3040. Following that, we headed to Magaliesburg to follow the Friends of the Rail train back to Pretoria. Sadly, no. 3664 had not made it to Magaliesburg, having derailed and rolled over at Hekpoort. The remaining scenes feature the recovery crew's efforts to set no. 3664 upright again. (Time 14:51)
External video
video icon South African Steam: Class 24 No. 3664 - The Phoenix Rises (16 March to 31 May 1997) After her derailment and rollover at Hekpoort on 16 March 1997, Class 24 no. 3664 was recovered and returned to her home depot at Capital Park. Repairs began in earnest immediately. The tender, cab sides, cab roof, valve gear, wheels, bearings, cowcatcher, cylinder cladding and much more required repair or renewal. In just two months, 3664 was repaired and performed a line trial on a revenue freight train, before returning to the rails on a public train on 31 May 1997. (Time 12:26)
External video
video icon South African Steam: 3664 Restoration in the news (1997) SABC News story, covering the fall and rise of Class 24 no. 3664. (Time 1:17)
External video
video icon South African Steam: Steam to Cullinan - 24 3664 (28 June 1997) Class 24 no. 3664 on a return trip to Cullinan (Time 9:53)