 In 1912, these locomotives were renumbered in the range from 1619 to 1627 and designated Class MF on the South African Railways (SAR).Five more of the type had been delivered from ALCO in November 1911, but these were numbered directly onto the SAR roster in the range from 1629 to 1633, marking the introduction of the SAR renumbering scheme under the Union programme.These locomotives were delivered with smaller Type XM4 tenders which had the same coal capacity as the Type XS tenders of the first nine engines, but a smaller water capacity of .