ES306353A1 - A shipboard travelling derrick crane - Google Patents

Abstract

Two pairs of ship's derricks 16, Fig. 1, are mounted on a gantry 5 which runs on longitudinal rails 9 on the deck on either side of hatches 12. The Sampson posts 13 and beams 14, 15 support the derricks. The gantry is driven by pinions which engage teeth on the sides of rails 9 and are driven by shafts 35, 37 from an electric or hydraulic motor. Alternatively the wheels may be individually driven, Fig. 8, by a motor 44 and a splined shaft 45 which engages a wheel axle 40. These drive motors may be synchronized. Rail clamps 46, Fig. 9, prevent overturning of the gantry under load and are interlocked with the drive motors and the hoisting winches. The jaws 49 are raised into engagement with the rail 9 by a solenoid 48 or an hydraulic ram. Power is supplied to the gantry via a cable which is wound on to a motor-driven reel 57, Fig. 1. The derricks may be used individually or in pairs as in Fig. 1, in which case they are connected by a cable 21. In either case the derricks are controlled from a console 32. Fig. 6 shows each derrick handling an electro-hydraulic grab 64. Power is supplied to the grabs through cables 67 wound on reels 69. Fig. 7 shows a pair of derricks operating one grab 70 to which current is supplied through a cable 73. Two or more gantries may be provided on a single vessel.