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 can be coupled.
The "J_" tenders could be used with the locomotive classes as shown.

Class 15E.
Class 15F, if arranged for manual stoking.

Class 16E.
Class S1.

The second letter indicates the tender's water capacity.
The "_T" tenders had a capacity of between 5,587 and 6,000 imperial gallons (25,400 and 27,300 litres; 6,710 and 7,210 US gallons).

A number, when added after the letter code, indicates differences between similar tender types, such as function, wheelbase or coal bunker capacity.
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 can be coupled. The "J_" tenders could be used with the locomotive classes as shown.
Class 15E.
Class 15F, if arranged for manual stoking.
Class 16E.
Class S1.
The second letter indicates the tender's water capacity. The "_T" tenders had a capacity of between 5,587 and 6,000 imperial gallons (25,400 and 27,300 litres; 6,710 and 7,210 US gallons).
A number, when added after the letter code, indicates differences between similar tender types, such as function, wheelbase or coal bunker capacity.
South African type JT1 tender