CRANE VESSEL STABILIZED BY A WATER BALLAST TANK ARRANGED ABOVE OUTBOARD WATER LEVEL

摘要

A stabilizing system for a crane vessel of the twin hull semi-submersible type having a working platform supported above sea level by columns on submersible hulls. Water ballast compartments above sea level on the corner columns are discharged selectively in order to stabilize the vessel during handling of heavy outboard loads by cranes. The water is discharged through controlled valves of special construction. This control is regulated in dependence of measured values of the moment of force applied on the vessel by the crane load, and effects the operation with the help of a computer. Lower water ballast compartments in the columns have an additional "passive" function and the water can be discharged therefrom by pressurized air or by pumping it into the upper ballast compartments.