Powered trolley for towing ships in dry dock - runs along pair of parallel tracks and has diesel motor powered hydraulic drive

摘要

The powered trolley is for towing large ships in dry dock. The trolley (1) runs along a fixed track (2) formed by two parallel toothed racks (3,4) on three wheels (6,7,8); one of which (8) runs between the racks (5) as a guide wheel, and another (7) is driven by a hydraulic motor (9). For towing, four hydraulically driven gear wheels (12,13,14,15) engage in the racks to drive the trolley and to centralise it. Inner guide wheels (10,11) may be used. The hydraulic motors are operated from a diesel driven pump. With a 250 hp diesal engine a ship of 5000 tonnes can be towed.