Hawthorne had started racing in the mid-to-late 1960s with a Ford Anglia. After moving to Europe to work as a racing mechanic at Ron Tauranac's Brabham factory. He planned to bring home a competitive race car which he could use. He then built a Brabham BT21 and had it shipped back to New Zealand. He returned to New Zealand himself and raced in the National Formula category for twin-cam, 1600 cm3 engines. He came close to a man named Allan McCall, who was impressed with Hawthorne's race talent. Hawthorne then went over to the United Kingdom again, this time to race, in Formula 3 with a limited budget. Soon after, he went over to the USA, to race in the North American Formula B/Atlantic Championship, which turned out to be very successful, becoming the vice-champion of the series in 1971. In 1972 Hawthorne won the Bogota Grand Prix, giving the Brabham BT38 its maiden victory. However he did not continue with Brabham, and decided to link up again with McCall, who was developing Formula 2, under the banner Leda Engineering. Hawthorne's first Formula 2 race was the Jochen Rindt Memorial Trophy in Thruxton, which was a round of both the British and European Formula 2 Championships. Hawthorne won a heat race, and in the final race was putting on an impressive display, until he retired on lap 38 with a fuel pickup problem.
Death
Hawthorne was killed on 14 April 1972 in the following round of the European Championship, the Jim Clark Memorial Race at Hockenheim. Bert was driving Allan McCall's TUI car. He was racing with German driver Bernd Terbeck when Hawthorne's car slowed. Terbeck could not swerve and hit Hawthorne at speed, pitching it head-on against the barriers. His car skidded along the guard-rail, pulling out security uprights. It came to rest on fire. At the track, it was known that both Terbeck and Hawthorne were missing, but the incident wasn't known till two laps later, when Niki Lauda pulled in to the pits. He then asked why nothing was apparently being done about a car on fire on the circuit. It was later confirmed that Hawthorne had been killed instantly from serious head injuries.
