South African Class 24 2-8-4


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 branch line steam locomotives with a 2-8-4 Berkshire type wheel arrangement in service.

Manufacturer

By the late 1940s, the South African Railways still had a comparatively large mileage of 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 track. Considering the increasing age of these locomotives, the options were either to relay these tracks with rail or to obtain new light branch line locomotives suitable for use on the existing track.
The Class 24 2-8-4 Berkshire type branch line steam locomotive was designed by Dr. M.M. Loubser, Chief Mechanical Engineer of the SAR from 1939 to 1949. The locomotives were built by North British Locomotive Company of Glasgow, who delivered one hundred 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.
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 Bartolomeu Dias after the Portuguese navigator who discovered the Cape of Good Hope in May 1488 and named it the Cape of Storms . 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.

Characteristics

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.
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.
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 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.

Service

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.
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.
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.
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 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 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.

Preservation

The following is a list of 24 class that have survived into preservation. January 1st 2019
NumberWorks nmr.THF / PrivateLeaselend / OwnerCurrent LocationOutside South Africa?
3606NBl 26318THFVoorbaai Locomotive Depot
3608NBL 26320PrivateCalvinia MuseumCalvinia Museum
3611NBL 26323PrivateTransNamib LtdKeetmanshoop Locomotive DepotNamibia
3612NBL 26324PrivateTransNamib LtdKeetmanshoop Locomotive DepotNamibia
3620NBL 26332PrivateIan Welch & The Q TrainThe Bellarine RailwayAustralia
3631NBL 26343PrivateIan WelchBloemfontein Locomotive Depot
3632NBL 26344PrivateIan Welch & Dylan KnottVoorbaai Locomotive Depot
3633NBL 26345PrivateSANRASMHermanstad
3635NBL 26347THFVoorbaai Locomotive Depot
3638NBL 26350PrivateNational Parks BoardKruger National Park
3645NBL 26357THFKrugersdorp Locomotive Depot
3647NBL 26359PrivateGreg MC.lannanGermiston Locomotive Depot
3654NBL 26366THFSteamnet 2000Kimberley Locomotive Depot
3655NBL 26367PrivateGrant BradleyCape Town Station
3664NBL 26376THFFriends of the RailHermanstad
3667NBL 26379THFQueenstown Locomotive Depot
3668NBL 26380THFTransnet Heritage FoundationOutiniqua Transport MuseumSELECTED AS TRANSNET HERITAGE FOUNDATION REPRESENTATIVE OF THE CLASS
3675NBL 26387THFVoorbaai Locomotive Depot2000 LOCOMOTIVE BUILT BY NBL FOR
3688NBL 26400THFSandstone EstateBloemfontein Locomotive Depot
3689NBL 26401PrivateMichael BarclayVoorbaai Locomotive Depot
3690NBL 26402PrivateIan WelchBloemfontein Locomotive Depot

Illustration

The main picture shows no. 3655, the City of Cape Town, leaving Monument station in Cape Town on 8 August 2010. This locomotive was rechristened Jenny in 2011 in honour of the late Jenny Pretorius, a much respected South African steam preservationist.