South African Class K 4-6-4T

South African Class K 4-6-4T

300px Class K no. 352, c. 1920

Type and origin Power type Steam Designer North British Locomotive Company Builder North British Locomotive Company Serial number 20854-20860 Model Class K Build date 1914 Total produced 7

Specifications Configuration 4-6-4T (Baltic) Driver axle 2nd coupled axle Gauge 3 ft 6 in (1,067 mm) Cape gauge Leading dia Coupled dia 48 in (1,219 mm) Trailing dia Wheelbase  • Leading 5 ft (1,524 mm)  • Coupled 12 ft 3 in (3,734 mm)  • Trailing 5 ft (1,524 mm) Wheel spacing (Assymetrical) 1-2: 5 ft 3 in (1,600 mm) 2-3: 7 ft (2,134 mm) Length:  • Over couplers Height 12 ft 6 in (3,810 mm) Frame type Plate Axle load  • Leading  • Trailing Adhesive weight Loco weight Fuel type Coal Fuel capacity 4 LT (4.1 t) Water cap Boiler:  • Pitch 7 ft 3 in (2,210 mm)  • Diameter  • Tube plates 12 ft (3,658 mm)  • Small tubes 85:  • large tubes 21:  • Firebox type Round-top Boiler pressure 160 psi (1,103 kPa) Safety valve Pop Firegrate area 18.4 sq ft (1.71 m2) Heating surface 962 sq ft (89.4 m2)  • Tubes 844 sq ft (78.4 m2)  • Firebox 118 sq ft (11.0 m2) Superheater:  • Heating area 257 sq ft (23.9 m2) Cylinders Two Cylinder size 17 in (432 mm) bore 24 in (610 mm) stroke Valve gear Walschaerts Valve type Piston Couplers Bell link-and-pin

Performance figures Tractive effort 17,340 lbf (77.1 kN) @ 75%

Career Operators South African Railways Class Class K Number in class 7 Numbers 347-353 Nicknames Manila Delivered 1917 First run 1917 Withdrawn 1938

The South African Railways Class K 4-6-4T of 1917 was a steam locomotive.

In 1917, the South African Railways placed seven Class K tank steam locomotives with a 4-6-4T Baltic type wheel arrangement in service. They had been built for the Philippines, but could not be delivered due to wartime disruption.

Manufacturer

Seven 4-6-4T side-tank steam locomotives were built for the Manila Railway Company in the Philippine Islands by the North British Locomotive Company (NBL) in 1914. Because of difficulties experienced in delivering them to the Philippines during the First World War as well as a critical wartime shortage of locomotives on the South African Railways (SAR), the NBL eventually offered the seven locomotives for sale to the SAR. They were purchased and delivered in 1917, designated Class K and numbered in the range from 347 to 353.

Characteristics

The locomotives had inclined cylinders, arranged outside the plate frames. The piston valves were actuated by Walschaerts valve gear, while the reversing gear was controlled by a combination of hand and steam mechanism. The locomotives were superheated and their smokeboxes were equipped with Stone's Patent louvre spark arrestors. Their coupled wheel axleboxes were provided with mechanical force-feed lubrication. They were the first locomotives in South Africa to be equipped with exhaust steam injectors, which were of the Davies and Metcalfe pattern.

The only modifications required to these locomotives for them to be put to work on the SAR, were to the buffing and drawgear. As built, they had 12 inches (305 millimetres) "bull's eyes" acetylene gas headlamps, supplied from a generator affixed to the running board on the right hand side adjoining the smokebox. The same medium was used for the cab lighting, but these lights were removed and SAR headlamps were installed.

The original works photographs showed a hand-operated bell on top of the boiler, but there is no record that the bells were still on the engines when they reached South Africa.

Service

The locomotives proved to be extremely useful. They were placed in service on the Reef's suburban services, shedded at Braamfontein and working between Randfontein and Springs. They were well suited for suburban service, since they were free-steaming, had rapid acceleration and were capable of relatively high speeds, even though they lacked power and speed compared with the Class 16. They remained in this service until the last of them were withdrawn and scrapped in 1938.

Illustration

• SAR Class K (4-6-4T).jpg

  A Class K on the up suburban between Maraisburg and Florida, c. 1930