[1][2] During the 1930s, several of the Type MP1 tenders were rebuilt by the SAR by mounting a completely new upper structure with a larger water tank on the existing underframe.

The modification was done to drawings approved by Chief Mechanical Engineer (CME) A.G. Watson in 1929 in respect of Type MP1 tenders of the Classes 12, 12A, 12B, 14, 14A, 14B, 15, 15A, 16, 16A, 16B and 16C.

These rebuilt tenders had a more modern appearance, with flush sides all the way to the top of the self-trimming coal bunker.

[1][2][4] The program to rebuild several older tender types with new upper structures was begun by Col F.R.

Collins DSO, who approved several of the detailed drawings for the work during his term in office as CME of the SAR from 1922 to 1929.