The Class HF Modified Fairlie locomotive was designed and built by Henschel and Son to the specifications of Colonel F.R. Collins DSO, Chief Mechanical Engineer of the South African Railways (SAR).
While Henschel of Kassel in Germany had built several locomotive types for German South West Africa prior to the First World War, most of which had come onto the SAR roster in 1922, the Class HF was the first locomotive class to be built by them for the SAR [REF].