Abstract: A large electric dragline having a house (35) and boom (37) is provided with spaced apart in-line sheaves (34) and (36) at boom point to separate hoist ropes (31) and (32) which are led to the front and rear of bucket (30) respectively. Differential hoist rope control allows accurate and continuous adjustment of the bucket carry angle during all modes of operation. Also described is a computer control system giving continuous accurate control of carry angle by differential hoist rope operation, with manual selection of mode of operation.

Abstract: The invention provides for the design of a dragline bucket of the type where there are separate front and rear hoist ropes attached to front mounting points and rear mounting points respectively. The front and rear hoist ropes can be independently operated to vary the horizontal attitude of the bucket. The bucket design methodology seeks to equalize the loads in the front and rear hoist ropes during the major phases of the operating cycle such as digging, hoisting and dumping, and this is typically achieved by providing a bucket with comparatively shallow side walls compared with the overall length of the bucket and the positions at which the front and rear hoist ropes ultimately join onto the bucket. The bucket typically has a flat floor and relatively shallow side walls which may in some embodiments taper downwardly from the rear section to the front section.