South African type XM tender


The South African type XM tender was a steam locomotive tender.
Ten Type XM tenders entered service in 1913, as tenders to the Class 4A Mountain type steam locomotives which were acquired by the South African Railways in that year.

Manufacturer

Type XM tenders were built by the North British Locomotive Company in 1913.
The original Class 4 Mountain type locomotive was designed as a heavy mixed traffic locomotive by H.M. Beatty, the last Chief Locomotive Superintendent of the Cape Government Railways, at the Salt River shops. Soon after the South African Railways locomotive renumbering project was implemented in 1912, an order was placed with North British for a further ten locomotives of this type. They were delivered late in 1913 and were designated Class 4A. The Type XM entered service as tenders to these engines.

Characteristics

The Type XM tender had a coal capacity of, a water capacity of and a maximum axle loading of.

Locomotive

In the SAR years, tenders were numbered for the engines they were delivered with. In most cases, an oval number plate, bearing the engine number and often also the tender type, would be attached to the rear end of the tender. Only the ten Class 4A locomotives were delivered new with Type XM tenders, numbered in the SAR number range from 1551 to 1560.

Classification letters

Since many tender types are interchangeable between different locomotive classes and types, a tender classification system was adopted by the SAR. The first letter of the tender type indicates the classes of engines to which it could be coupled. The "X_" tenders could be used with the locomotive classes as shown.
The second letter indicates the tender's water capacity. The "_M" tenders had a capacity of.
A number, when added after the letter code, usually indicates differences between similar tender types, such as function, wheelbase or coal bunker capacity.

Modification

Pictures of most of these locomotives in service show them with a modified tender with built-up sides to the coal bunker to increase the coal capacity. Early versions of the built-up coal bunker sides were in the form of a slatted open-top cage, made of rectangular steel rods. Later versions were constructed of sheet-metal.

Illustration