Stukalenko O. Increase of operational efficiency of a cargo-handling gear of sea-going ships

The work is dedicated to solving the urgent scientific and technical problem of developing methods for calculating the parameters of safe dual tackle belts and determining the conditions under which cargo retention after cable breakage is ensured. It has been established that the maximum calculated dynamic forces in the elastic metal structure of a ship's hoisting device when using constant drag of the leveling device and working with a load of rated load capacity reach values at which the dynamic factors of efforts in the metal structure exceed the regulated margin of its strength. The use of a stepped frictional drag force to increase the time of applying a load to a metal structure in order to reduce the maximum dynamic forces in it is proposed and the effectiveness of this proposal is investigated. For the studied design of the crane with a lifting capacity of 20 tons, this allows to reduce the design force from 488 kN, which corresponds to a dynamic coefficient of 2.44, to an acceptable 345 kN, which corresponds to a dynamic coefficient of 1.73. A methodology for calculating dynamic processes in the power circuit of a ship's hoisting device with a flexible suspension of the boom after breaking a topper or a pendant of a double tackle has been developed. As a result, it was determined that the use of a spring trap-compensator for the balancer of the double boom pulley does not provide the maximum dynamic loads in the boom pulley within the permissible limits when working with a load of rated load capacity. The permissible weight of the cargo is determined, at which the cargo or boom is retained after the failure of the pendant or topenant of the double pulley with balancer. Key words: ship lifting device; cable break; safe double pulley block; cargo retention; arrow holding; leveling friction device; spring compensator catcher.