GB906255A - Ship's mast having a fore-and-aft outrigger - Google Patents

Abstract

906,255. Ships' derricks. HALTEN, A. E. June 14, 1960 [June 17, 1959], No. 20888/60. Class 78 (4). A lead block 9, Fig. 1, for the topping lift 12 of a boom associated with a mast of a ship is carried by an arm 8 horizontally pivoted to a sleeve 5 which is pivotally attached by a pin 4 to the mast. As described, the arm also carries pulleys 9, 14 around which the topping lift passes, and is prevented from swinging downwardly by a stop 16 and from swinging horizontally past the fore-and-aft position in one direction by a flexible stay. Fig. 9 shows in plan two such arms 8 mounted on an athwartships beam 1 and a boom 41 supported by two topping lifts 12a, 12b, by means of which the boom may be raised and lowered and slewed through substantially 180 degrees. Alternatively one arm 8 may be mounted vertically above the boom 41 which has topping lifts to the end of the arm 8 and to the ends of the beam 1. By disconnecting one of the lifts connected to the beam 1 the boom can be slewed by altering the lengths of horizontal stays connected to the arm 8. In a second construction an arm similar to the one shown in Fig. 1 is horizontally pivoted to a triangular plate which is pivoted to an athwartships beam by a vertical pin. Two such arms 24, Fig. 10, which can swing inwardly only in a horizontal plane, are associated with booms 41 controlled by topping lifts 12a, 12b, each boom being slewable over more than 90 degrees over a hatch 42. The arm 24, Fig. 6, is substantially the same as that last described but carries a multiple pulley block 30 and a single pulley 31. Two such arms 24, Fig. 12, control a boom 41, the topping lift 12 passing from the top of the boom down to the lower end, up to a block 43 and down to a winch. Specification 858,944 is referred to.