In addition to being a highly competitive racing car, the Cooper Bob-tail was to form the basis for Cooper's first true attempt to enter the World Championship in their own right. Jack Brabham had gained a strong reputation as a racer in his native Australia driving a lightly modified Cooper Bristol which he branded the "RedeX Special". On moving to the UK he picked up where he had left off, driving a Cooper-Alta in domestic British series. Brabham's visits to the Cooper works to collect spares led to collaboration with the Cooper outfit, and subsequently wholesale integration with the Cooper works team. Eventually, he persuaded the Coopers to allow him to create a Formula One version of the T39 chassis around a 2-litre Bristol engine. Brabham, working almost alone on the car, completed the Formula One special the day before its first race: the 1955 British Grand Prix at Aintree Circuit. Although the car's engine failed on this first outing, subsequent development proved that the rear-engined Cooper was competitive with the Formula One machinery of the day, ultimately winning the 1955 Australian Grand Prix, and paved the way for the Cooper works to develop a proper slipper-bodied challenger.