Line of fire: deck tugger wire failure

A tugger wire connected to a tow wire and chain sling, unexpectedly came under tension, the chain sling failed, and the rigging recoiled. 

The incident occurred when a technical fault in the plough made it necessary to recover it to deck. The deck foreman requested the tugger wire operator to provide adequate tugger wire slack, which was then provided.  The intention was to haul the tugger wire up the deck with the main winch. 

This intention was not clearly communicated to, nor was it understood by, the tugger winch operator or the deck crew. The tension on the chain sling rapidly increased, it failed, and the released rigging recoiled and narrowly missed the personnel in line of fire. The chain sling contacted a deck plate which dissipated much of the energy.

• There was no opportunity taken to have a time-out to discuss the change in task plans when moving from the launch of the plough to its recovery.
  
  
• There were inconsistencies between shifts, and inadequate documentation, between marine crew and project personnel, of who exactly was responsible for deck operations.
  
  
• The change in the “standard” practice of manually pulling the tugger wire up the deck was not communicated to all parties involved, and the consequence of the change was neither evaluated nor understood.
  
  
• There was a failure to follow the risk assessment which required a “Clear Deck Policy” when using tuggers and spooling with personnel positioned in a safe zone.