Coniston Water per hour () in "Blue Bird K4". Between 1956 and 1959 Sir Malcolm's son Donald Campbell set four successive records on the lake in "Bluebird K7", a hydroplane. In 1966 Donald Campbell decided that he needed to exceed 300 miles per hour (483 km/h) in order to retain the record. On 4 January 1967, he achieved a top speed of over 320 miles per hour () in "Bluebird K7" on the return leg of a record-breaking attempt. He then lost control of "Bluebird", which somersaulted and crashed, sinking rapidly. Campbell was killed instantly on impact when decapitated by the K7's
P&H Mining DC electric motor drive system. Pawling & Harnischfeger began designing and making their own electric motors and controls starting in 1893 when they acquired assets of the Gibb Electric Company that were not needed when Gibb was purchased by Westinghouse Electric Manufacturing Company. P&H shovels and draglines were originally available with prime-mover options including a Waukesha gasoline engine, a Buda diesel engine, or a P&H electric motor. By the 1930s, diesel engines and P&H electric motors became the dominant prime mover options on P&H digging machines. By the end of the 1960s, virtually all P&H excavating machines would be equipped