[2][4] Type MP1 tenders originally entered South African Railways (SAR) service in 1912, as tenders to Class 12 Mountain type locomotives.

[2][3][4] At some stage, probably after the Class MC1 were withdrawn from service in 1939, the intermediate draw and buffing gear of Type MP1 tender no.

[4] The Type XP1 tender had a water capacity of 4,250 imperial gallons (19,300 litres), a coal capacity of 10 long tons (10.2 tonnes) and a maximum axle load of 13 long tons 15 hundredweight (13,970 kilograms).

The first letter of the tender type indicates the classes of engines to which it could be coupled.

[4] A number, when added after the letter code, indicates differences between similar tender types, such as function, wheelbase or coal bunker capacity.

[4] Prior to the modification of its intermediate draw and buffing gear to convert it to the Type XP1, the tender had already been modified.