Dropped Object - Chemical Tank PRV

Cause & Consequence

• Moving, flying or falling object

Incident Location

Drilling unit

Incident Activity

Modification of plant/structures

Incident Info Source

Marine Safety Forum

Specific Incident Equipment

Chemical Tank PRV

Lessons Identified

Initial and further investigation revealed that the valve must have been subject to unauthorised removal and replacement, during which it had been cross-threaded thereby weakening the connection sufficiently to allow it to loosen and fall.

The valve is only meant to be removed during periodic inspection by a qualified inspector.

The investigation also revealed that it was difficult if not impossible for the quayside gantry to have spotted the fault.

Incident Recommendations

The Supplier is adding an extra visual check to their procedure and is investigating ways to either isolate the valves or physically mark them as only to be removed by qualified inspectors.