| South African Class MC 2-6-6-0 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
 SAR Class MC no. 1608, c. 1912 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
The South African Railways Class MC 2-6-6-0 of 1912 was a steam locomotive.
In 1912, the South African Railways placed ten Class MC Mallet articulated compound steam locomotives with a 2-6-6-0 wheel arrangement in service in Natal. [1] [2] [3] [4]
To augment the Mallet locomotive fleet operating across the more difficult sections of the Natal mainline, the South African Railways (SAR) placed an order with the North British Locomotive Company for ten compound steam locomotives which were very similar to the Class MB. They were delivered and placed in service in May 1912, designated Class MC and numbered in the range from 1607 to 1616. [1] [2] [3] [4] [5]
In a compound locomotive, steam is expanded in phases. After being expanded in a high-pressure cylinder and having then lost pressure and given up part of its heat, it is exhausted into a larger-volume low-pressure cylinder for secondary expansion, after which it is exhausted through the smokebox. [6]
In the compound Mallet locomotive, the rear set of coupled wheels are driven by the smaller high-pressure cylinders, which are fed steam from the steam dome. Their spent steam is then fed to the larger low-pressure cylinders which drive the front set of coupled wheels. By comparison, in the more usual arrangement of simple expansion steam is expanded just once in any one cylinder before being exhausted through the smokebox. [1] [3]
Like the previous Mallets, these ten compound locomotives had Walschaerts valve gear and used saturated steam. The high-pressure cylinders of the hind engine unit were equipped with piston valves while the low-pressure cylinders of the front engine unit were equipped with slide valves. [1]
Their Type TM tenders were the same as those of the Classes 3 and 3B, with a coal capacity of 8 long tons 5 hundredweight (8.4 tonnes) and a water capacity of 4,000 imperial gallons (18,200 litres). The locomotives differed little from the previous Mallets in size, power and performance and may for all intents and purposes also have been classified as Class MB. It would seem that, compared to the Cape Government Railways which tended to group locomotives in the same Class which were dissimilar even to the extent of having different wheel arrangements, the early SAR at times took locomotive classification to the other extreme. [1] [3]
Unlike the Class MB on which the sandboxes were placed on top of the boiler in accordance with American practice, the sandboxes of the Class MC were arranged on a different system, the advantages of which were questionable. The sandboxes for the hind engine unit were secured to the running board just to the rear of the high-pressure cylinders, while those for the front engine unit were placed on the upper sides of the boiler just to the rear of the smokebox. [2]
The Class MC were satisfactory locomotives but like the earlier Mallet compounds, they would have performed better if they had been superheated. Two of them, numbers 1612 and 1615, were later equipped with new boilers with superheaters and their coupled wheels were retyred to a diameter of 46 inches (1,168 millimetres). No others were modified in this manner. [1] [2] [3]
The Class MC joined the Class MA and MB fleet on the Natal mainline, working heavy coal trains between Estcourt and Highlands. In later years, some were transferred to the Cape Western System where they served into the 1930s as banking locomotives up the Hex River Railpass between De Doorns and Touws River. Others were transferred to the Witwatersrand for general service and to haul coal on the Witbank-Germiston line. They were withdrawn from service during 1933. [1] [2] [3] [7]
Under the Whyte notation for the classification of steam locomotives by wheel arrangement, 4-10-2 represents the arrangement of four leading wheels, ten powered and coupled driving wheels and two trailing wheels. In South Africa, where the wheel arrangement was first used, the type was known as a Reid Tenwheeler. In the United States of America it was known as a Southern Pacific on the Southern Pacific Railroad and as an Overland on the Union Pacific Railroad.
Under the Whyte notation for the classification of steam locomotives by wheel arrangement, 2-6-6-0 is a locomotive with one pair of unpowered leading wheels, followed by two sets of three pairs of powered driving wheels and no trailing wheels. The wheel arrangement was principally used on Mallet-type articulated locomotives. Some tank locomotive examples were also built, for which various suffixes to indicate the type of tank would be added to the wheel arrangement, for example 2-6-6-0T for an engine with side-tanks.
The South African Railways Class 10B 4-6-2 of 1910 was a steam locomotive from the pre-Union era in Transvaal.
The South African Railways Class 10 4-6-2 of 1904 was a steam locomotive from the pre-Union era in Transvaal Colony.
The South African Railways Class 3 4-8-2 of 1909 was a steam locomotive from the pre-Union era in the Colony of Natal.
The South African Railways Class KM 0-6-0+0-6-0 of 1904 was an articulated steam locomotive from the pre-Union era in Transvaal Colony.
The South African Railways Class Experimental 1 4-6-2 of 1907 was a steam locomotive from the pre-Union era in the Cape of Good Hope.
The South African Railways Class Experimental 2 2-8-0 of 1902 was a steam locomotive from the pre-Union era in the Cape of Good Hope.
The South African Railways Class Experimental 3 2-8-0 of 1903 was a steam locomotive from the pre-Union era in the Cape of Good Hope.
The South African Railways Class MA 2-6-6-0 of 1909 was a steam locomotive from the pre-Union era in the Natal Colony.
The South African Railways Class MB 2-6-6-0 of 1910 was a articulated steam locomotive from the pre-Union era in the Colony of Natal.
The South African Railways Class MC1 2-6-6-0 of 1914 was a steam locomotive.
The South African Railways Class MD 2-6-6-2 of 1910 was a steam locomotive from the pre-Union era in Transvaal.
The South African Railways Class ME 2-6-6-2 of 1912 was a steam locomotive.
The South African Railways Class MF 2-6-6-2 of 1911 was a steam locomotive from the pre-Union era in Transvaal.
The South African Railways Class MG 2-6-6-2 of 1911 was a steam locomotive from the pre-Union era in Transvaal.
The South African Railways Class MH 2-6-6-2 of 1915 was an articulated Mallet-design steam locomotive.
The South African Railways Class GA 2-6-0+0-6-2 of 1921 was an articulated steam locomotive.
The Central South African Railways Rack 4-6-4RT of 1905 was a South African steam locomotive from the pre-Union era in Transvaal Colony.
The South West African 2-8-0T of 1907 was a steam locomotive from the German South West Africa era.
| Cape gauge | |
|---|---|
