The Structural Repair of a North Sea Platform Using Underwater Wet Welding Techniques

Underwater wet welding repair techniques using ferritic electrodes have, until recently, been limited to low strength steel with carbon equivalents below 0.4% because the fast quench that occurs after welding produces hard head affected zones susceptible to hydrogen cracking. This paper describes the first documented structural wet weld repair of the North Sea offshore platform constructed with steel that had a carbon equivalent greater than 0.40%. It describes the events that lead to the failure and documents the repair using underwater wet welding techniques.