Fairbairn Steam Crane

High-capacity, steam-powered crane, 1876/77-1878, designed by William Fairbairn and constructed by Stothert and Pitt of Bath.

PLAN: the crane stands on a semi-circular outcrop of masonry, keyed into the harbour wall (listed at Grade II).

DESCRIPTION: the crane consists of a curved jib and post formed from a continuous box-section girder, mounted with a deep well foundation. A ground-level cab encloses the machinery.

The foundation of the crane is a cylindrical well, formed by a stack of four cast iron rings, restrained by wrought iron ties rods with anchor plates embedded into the quayside. Masonry is built up around the well, forming a semi-circular outcrop from the harbour wall. At the base of the well is a cast iron plate with a bearing for the jib post. At the level of the quayside is a ground ring with 28 cast iron rollers supported on eight vertical rollers, maintaining verticality and enabling the crane to rotate, or slew.

The main structural member of the crane is a riveted wrought iron box girder forming the tapering foundation post and continuing upwards as the curved jib. At its base in the bottom of the well is a bronze bearing which carries the whole weight of the crane. At its head, the jib has two pulley wheels over which the chain runs, with three cast iron rollers bolted to the back of the jib to support the chain. Fixed ladders and handrails were added to the jib at some point between 1926 and 1929.

The cab is constructed from rivetted plates of wrought iron, with generous fenestration in multi-light, cast iron frames with decorative bosses. When built, the cab did not enclose the upper winding drum and boiler top, but by 1928 an extension had been added to improve weather protection. This upper extension was scrapped during the 1970s restoration work, but reinstated in 1989. A number of side panels and butt plates have been completely replaced, identifiable by their bolt fixings. Other panels were repaired by welding in fillets and patches. On the front of the jib just above cab, is a cast iron plate that reads ‘Stothert & Pitt. Engineers Bath. 35 Tons Crane’.

The cab encloses the machinery. Two pairs of engines enable simultaneous lifting and slewing, and there is hand gear enabling occasional lifts when not in steam. The boiler, by Marshall & Sons, was installed in 1953. The jib supports two small cylinders, slewing gear, main lifting cylinders, gear train, winding drums and brackets, and the chassis. The chassis carries the water tank, donkey engine, coal bunker, floor and cab. All castings and gear wheels carry Stothert and Pitt's initials, except the three steps into the cab which bear the name of St Pancras Ironworks, London.