Loss of rig anchor wire from vessel Karm Fork

What happened?

There was an unplanned retraction of the Karm Fork on an Anchor Handling vessel, leading to an anchor tow wire and chain to be dropped.  The incident occurred during a rig move.  The Anchor Handling vessel was following the rig with the anchor line secured in the Karm Fork on deck with 300m of wire and 150m of chain between the rig and vessel.  During the transit to the new location, the vessel accidentally retracted its Karm fork, allowing the wire and chain between the vessel and rig to slip over the vessel stern roller into the sea.  Water depth at the time was 370m.  No subsea assets were in the vicinity, no personnel were in the line of fire.

What went wrong?

Our member noted that the preliminary investigation revealed that the causes were lack of communication, failure to follow company procedures and failure to follow the Masters’ instructions:

• The Chief Engineer raised the port side Karm Fork with no command from the Master – the company procedure states “All instructions for operation of the anchor handling plant will be disseminated directly from the Master“;
• Ignoring the Masters’ request and lack of attention — even after the Masters’ second command to lower the port side Karm Fork, the Chief Engineer delayed the task implementation and then in a rush accidentally pushed the emergency release buttons of the wrong Karm Fork.

What actions were taken?  What lessons were learnt?

• Revision of operations manual and task risk assessment;
• Relocation of CCTV camera to cover deck area;
• Reiteration of need for strict compliance to manual requirements and specifically, the need to follow the requirement that such commands or actions should come from the Master only.

Members may wish to refer to:

• Inadvertent opening of circuit breakers
• High potential near miss – unsecured sheave
• Anchor drag near-miss incident