External Pressure Produced by Multi-Layers of Rope Wound about a Hoisting Drum

Abstract

The writers of this paper carried out theoretical and experimental investigations in order to ascertain precisely how the external pressure exerted on a hoisting drum by multi-layers of rope wound around it under tension increases as the number of rope layers is increased. Experiments were performed on model drums by winding ropes under constant tension and the circumferential strains produced inside the drum shells were measured. The number of layers was increased up to eight. As far as the research extended, the experimental results coincided well with the theory of the authors. The ratio between the increase in the external pressure on the hoisting drum and the number of rope layers grew the larger as the rigidity of the drum increased and the modulus of elasticity of the rope decreased. Conversely, the smaller the rigidity of the drum and the greater the modulus the smaller was the ratio. The ratios of Mr. Waters which have generally been adopted are smaller than those of the authors and are on the dangerous for the designing of hoisting drums.