Förfarande för drift av arbetsfartyg och arbetsfartyg avsett för gång i öppet vatten och is

摘要

A service vessel that is designed for navigating both in the open sea and in ice conditions is provided with a demountable propeller nozzle. For an ice-free navigation period the propeller nozzle is mounted around the propulsion propeller of the vessel, whereas for a navigation period in ice conditions the propeller nozzle is removed. The power absorption of the propulsion propeller is maintained constant during nozzle and nozzle-free operation.