Safe use of hoisting drums wound with multiple layers of wire, hybrid, fibre and/or large diameter ropes
Continuously rising requirements in marine and offshore technology on lifting
capacity, depth and equipment reliability have led in turn to increasing demands on wire ropes and fibre ropes. The use of wire ropes with compacted strands and of nominal diameters even above 100 mm is just one of the results of these
requirements. The use of modern fibre structures is to be recommended in order to meet more important requirements as regards reduced weight per length, corrosion resistance, environmental protections, ergonomics and personal safety.
The requirements arising from these fundamentally different rope characteristics and their impact on lifting equipment when using multi-layer winding are so far unknown. Experience shows that unrealistic load assumptions are presently being made about dimensioning and thus also safeguarding of existing winding equipment in the event of damage. The safe application of above-mentioned types of rope in combination with existing rope-drum-systems demands knowledge of longitudinal and transverse rope-stiffness on the drum load and also of the change in rope characteristics during the course of operation. Initial research at Institute of Mechanical Engineering showed significant differences regarding these variables and remarkable aspects regarding the consequential loading-scenario and spooling behaviour of hoisting drums and their impact on existing calculation and dimensioning bases and thus their safe application. This paper shall give a summary review on current research activities on designing and dimensioning winch drums as well as on impact aspects concerning the stability of existing winch drums for multi-layer winding with wire, hybrid and fibre ropes. Further it gives an outlook on further required steps for an adaption of existing dimensioning methods.
Author: A. Lohrengel, K. Stahr and M. Wächter