Gantry

An overhead gantry crane at Ashio Copper Mine runs the length of one of the processing halls, the structural steel beam carrying a trolley along its lower flange and a lift hook hanging from the trolley. The beam is supported at each end by upright columns bolted into the floor and braced into the building's structural framing. The crane control hangs from a cable beside the column, the pendant box about waist height for an operator standing on the floor. The hook is currently parked at the centre of the beam. The whole assembly is painted in a pale industrial green, weathered to a darker tone at the joints and the trolley wheels.

Overhead gantries are essential plant in any heavy industrial works. At Ashio they lifted ball-mill components, motor housings, and assemblies that were too heavy for hand handling, moving them along the length of the building for maintenance or replacement. The crane in this photograph carried the mill's working parts across the operational decades of the plant under Furukawa modernisation from 1877 to the Excavation Department's 1973 closure. It has not lifted since. The cable on the hook is the cable from the last job. The trolley is parked where the last operator left it.