The eighteen members of the 1600 class diesel electric locomotive were designed and constructed by the English Electric Co. at their Rocklea Brisbane, works. Two contracts were let of which the first was for twelve with a follow on contract for another six. The first batch were delivered between December 1962 and June 1963, with the others arriving between October 1963 and January 1964. A lengthy delay occurred before delivery owing to the first four being over the design weight. This resulted in numbers 1604 and 1605 being the first to enter service. All others were delivered after the weight problem had been overcome. The unit at Swanbank is 1616 (construction number A079 of December 1963). It was condemned by the Queensland Railways during April 1991 and was purchased by QPSR in August 1991. Designed for branch line use these units are a hood-type with a full width cab across one end. They are fitted with dual driving stations to permit operation in either direction without the requirement to turn the locomotive.