It has been sometimes reported that cracks occured at the connection between a lower stool of transverse bulkhead and tank top plate in way of ballast hold of large bulk carriers. As a repair wark, scallops at the connection were covered by collar plates to relax the stress concentration there. In this paper, studying the mechanism of the crack initiation through the fatigue strength analysis, the method of the repair work is prooved to be effective and the guideline to prevent this crack from occuring is introduced.
