Galvanic Corrosion on Rudders
Cruise Ship, length 290 meter, 113,323 Gross Tonnage
3 months out of dry dock, galvanic corrosion caused heavy cavitation/ erosion damage on PORT and STBD side rudders.
Section loss up to 100% was repaired by build-up welding with Class A underwater welding techniques. One of the rudders was filled with water.
SGS together with cruise line and Class developed a repair plan involving the qualification of underwater wet welded groove weld procedures to AWS D3.6 Class A requirements.
Over a time period of three months SGS crew sailed with the vessel, during port stops divers were deployed to restore the wasted material.
Repair was considered permanent and was performed without interrupting the itinerary of the vessel