Complex sentence: The engines and tenders were built to the design of Col F.R. Collins DSO, Chief Mechanical Engineer of the SAR, and were initially placed in service in Natal and the Orange Free State, but were soon transferred to several centres around Transvaal.
Split into simpler sentences: The engines and tenders were built to the design of Col F.R. Collins DSO, Chief Mechanical Engineer of the SAR. They were initially placed in service in Natal and the Orange Free State, but were soon transferred to several centres around Transvaal.