Operational challenges: Extension of propeller welding repairs for a higher availability of ships

Enlarging the power capacity of a propulsion plant could also be performed by improving the overall efficiency of the propulsor. Many devices and measures are know, which enhance the propulsive efficiency. However, even the most optimum combination of devices would not reveal an efficiency gain in excess of 10-15% based on an optimum ship design. Consequently the installed power has to be raised. Different concepts will be described in the following. Regardless of the propulsion system in use, the availability of the ship on her targeted service depends on the reliability of the components of the main drive. The most endangered component is the propeller. Therefore a solution has been developed in order to enhance the reliability of welded propellers and to extend the scope of repairable b lade damages in order to avoid long term restrictions until a spare propeller is available.