The cableway masts were made by Messrs John M. Henderson and Co of Aberdeen, but subsequent structural problems necessitated alterations undertaken by Perry Engineering Co, South Australia who supplied a new load carriage, fall - rope carriers and a traversing drum. The masts were located 4 metres upstream of the core wall centre line, and the masts were 'buffed' so that the cable was aligned over the centre of the wall. The masts were constructed of latticed steel, 40 m high, and carried on a ball and socket to permit luffing while handling large form - units. According to Kelso, however, they were never put to this use. The cable traversed the corewall at 300 m per minute with a hoisting speed of 100 m per minute, driven by a 150 horsepower motor.