Pro-active intervention prevented high potential dropped objects

What happened?

During inspection of the vessel crane, it was noted that a steel spacer plate had become partially detached due to corrosion forming behind the plate. The plate had been installed by the manufacturer during the crane installation but had not been removed as intended. On touching the spacer, it detached completely but was prevented from falling.

What went wrong? What were the causes?

The spacer plate had been present since original vessel/crane build. It weighed 1.5kg and had the potential to fall 40 meters to deck. The only means of attachment for the steel plate to the structure was by tack welding. This was an accepted form of attachment by the manufacturer for temporary use, but not for permanent equipment.

What lessons were learned?

• Be vigilant during dropped object reviews for items with similar method of attachment i.e. tack welded;
• Ensure that any identified items are securely attached;
• Report any incidents of non-continuous welding and obtain guidance on corrective actions;
• If required, adjust maintenance actions to monitor for corrosion.

Members may wish to refer to the following incident:

• Crane boom dropped object [an object fell from a crane as a direct result of a failed tack weld]