South African Class S2 0-8-0

South African Class S2 0-8-0

300px No. 3728 in the Table Bay yard, Cape Town, August 1973

Type and origin Power type Steam Designer South African Railways Builder Friedrich Krupp AG Serial number 2966-3065 Model Class S2 Build date 1952-1953 Total produced 100

Specifications Configuration 0-8-0 "Eight-coupled" Gauge 3 ft 6 in (1,067 mm) Cape gauge Driver diameter 48 in (1,219 mm) Wheelbase Total: 51 ft 2.625 in (15,611 mm) Engine: 12 ft 9 in (3,886 mm) Tender: 8 ft 8 in (2,642 mm) bogie 24 ft 7.25 in (7,499 mm) total Length 67 ft 9.25 in (20,657 mm) Height 12 ft 6.625 in (3,826 mm) Frame Cast frame Axle load 12.77 long tons (13.0 t) on 2nd driver Adhesive weight 50.65 long tons (51.5 t) Loco weight 50.65 long tons (51.5 t) Tender weight 105,784 lb (48.0 t) empty 53.4 long tons (54.3 t) w/o Loco & tender weight 105,784 lb (48.0 t) empty 104 long tons (105.7 t) w/o Tender type MY1 Torpedo * 3 axle Buckeye bogies * 34 in (864 mm) wheels Fuel type Coal Fuel capacity 8 long tons (8.1 t) Water cap 4,200 imp gal (19,000 L) Boiler 4 ft 6.875 in (1,394 mm) inside diameter 13 ft 3.625 in (4,054 mm) inside length 8 ft 4 in (2,540 mm) pitch Boiler pressure Firegrate area 30 sq ft (2.787 m2) Heating surface 1,092 sq ft (101.450 m2)  • Tubes 91 tubes 2 in (51 mm) diameter 30 tubes 5.5 in (140 mm) diameter 979 sq ft (90.952 m2)  • Firebox 113 sq ft (10.498 m2) Superheater:  • Heating area 330 sq ft (30.658 m2) Cylinders Two Cylinder size 18 in (457 mm) bore 26 in (660 mm) stroke Valve gear Walschaerts

Performance figures Tractive effort 25,600 lbf (114 kN) at 75% pressure

Career Operators South African Railways Class Class S2 Number in class 100 Numbers 3701-3800 Delivered 1952-1953 First run 1952 Withdrawn 1985

The South African Railways Class S2 0-8-0 of 1952 is a steam locomotive.

In 1952 and 1953 the South African Railways placed one hundred Class S2 shunting steam locomotives with a 0-8-0 wheel arrangement in service.

Design specifications

By 1952 the need arose for shunting locomotives with a light axle load for harbour work, where most of the trackwork was laid with light rail. Under the direction of L.C. Grubb, Chief Mechanical Engineer (CME) of the South African Railways (SAR) from 1949 to 1954, specifications were prepared for a light locomotive with the 0-8-0 wheel arrangement that had already been proven successful with the Class S and Class S1 shunting engines. In order to keep the total weight of the engine and tender down to approximately 100 long tons (100 tonnes), it was to be equipped with the Watson Standard no. 1 boiler, the smallest of the standard boilers.

Manufacturer

When tenders were called for, a number of firms responded, but all except one stated that it would not be possible to construct the locomotive within the stipulated weight. Only the firm of Friedrich Krupp AG of Essen in Germany undertook to build the locomotives to the required specifications.

When design work commenced after the signing of the contract, however, it was discovered that the other tendering firms had been correct and that the locomotives could not be built within the specified weight limit if the specifications were to be adhered to. It was eventually agreed that Krupp should design a suitable smaller boiler that would bring the locomotive’s weight down to a level that would be in line with the stipulated maximum. The end result was an engine that had the appearance of a Cape gauge locomotive with a Narrow gauge boiler, particularly when viewed from the front.

One hundred Class S2 locomotives were subsequently built by Krupp and delivered between 1952 and 1953, numbered in the range from 3701 to 3800. Even with the smaller Krupp-designed boiler, the locomotive’s eventual working order weight of 104 long tons (106 tonnes) was still 4 long tons (4.1 tonnes) more than the desired maximum.

Characteristics

The locomotives had Walschaerts valve gear and were superheated. Their cast steel frames were a single casting with separately attached cylinders. Like the Class 24 and the last batch of the Class 19D, the Class S2 had Type MY1 tank wagon type tenders, similar in appearance to the American Vanderbilt type tenders with cylindrical water tanks. The tenders ran on three-axle Buckeye bogies to reduce the axle load and became commonly known as Torpedo tenders. As was done with the tenders of the Class S and Class S1, the top sides of the coal bunker were scalloped out to improve the crew’s rearward vision.

Service

Most of the Class S2 locomotives were placed in shunting service in the Durban, Cape Town and Port Elizabeth harbours, where they replaced a variety of aged 4-6-0, 4-8-0 and 4-8-2T locomotives. About twenty were also allocated to yards on the Witwatersrand and in the Eastern Transvaal, where they were employed in light general shunting.

File:Class S2 3706 (0-8-0) IDL.JPG

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One Class S2 locomotive, stationed at Capital Park in Pretoria, was painted in blue livery to be used for the shunting of Blue Train stock, until it was eventually replaced by a Class 19D locomotive that was also painted blue. During 1981 four Class S2 locomotives were hired to Mozambique for dock shunting in Maputo.

All but one were withdrawn from service in 1982. The last Class S2 in service was the shed pilot at Waterval Boven, which remained in service until 1985. In Cape Town and Durban they were replaced by Class 36-000 and Class 36-200 light general purpose diesel-electric locomotives, but in Port Elizabeth their initial replacements were older steam locomotives of larger capacity.

Commemoration

A 10c postage stamp depicting a Class S2 locomotive was one of a set of four commemorative postage stamps that were issued by the South African Post Office on 27 April 1983, to commemorate the steam locomotives of South Africa that were rapidly being withdrawn from service at the time. The artwork and stamp design was by the noted stamp designer and artist Hein Botha.

The particular locomotive depicted was number 3781. The outline of a traditional SAR locomotive number plate was used as a commemorative cancellation for De Aar on the date of issue.

Illustration

The main picture and the following photographs illustrate different views of the Class S2 locomotive and its Torpedo-type tender.

• Class S2 3728 (0-8-0) a.jpg

  No. 3728 in Table Bay Harbour yard, Cape Town, August 1973

• Class S2 no. 3706 b.JPG

  No. 3706 at Millsite shortly before being moved to George, c. 1990

• Class S2 3744 (0-8-0).jpg

  No. 3744 in Table Bay Harbour yard, Cape Town, August 1973