Cranes and rails on Prince's Wharf

Group of four Stothert and Pitt high-speed electric cranes, 1951.

PLAN: the cranes stand on Prince’s Wharf, on the Floating Harbour. Numbered 29 to 32, they are mounted on rails running east-west between the quayside and the M-Shed. DESCRIPTION: each crane consists of the carriage or truck, upon which is the motor room and driver’s cab, the jib and its counterweight, and the luffing derrick.

The carriages have four legs made up of rivetted iron panels and lattices. Each pair of legs is attached to a base of horizontal paired I-beams, with an enclosed motor and driving wheels on either side, powering the lateral movement of the cranes along the rails. Crane 32, to the west, was designed to carry much heavier loads, and its latticework carriage is broader at the top. The cabs are clad in vertical timber weatherboarding with full-height glazing to the front, in multi-light metal frames, with windows to either side enabling clear views for the driver. The jib is a tapering square-section truss of 65 feet (20m), with the hook assembly, including a Liverpool hook, on one end, and the balancing counterweight, consisting of concrete slabs in iron housing, at the other. The luffing derrick – part of the Toplis Level Luffing system – stands on the top of the cab.

The interior of the cab has four sets of controls – for lateral movement along the tracks, slewing, luffing and hoisting – along with space for the driver, at the glazed front. The motor room is enclosed to the rear, and has three motors driving the slewing, luffing and hoisting mechanisms. The motor room also contains resistance banks and cabinets with electro-mechanical switch gear.

SUBSIDIARY FEATURES: the cranes stand on rails embedded in the dockside. There are various cast iron fixtures related to the original power supplies to each crane.