Winch Overload Causes Extreme Bollard Pull

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The American P&I Club, as part of it’s “Good Catch” safety series, has published learnings from an incident where bollards were pulled right out of the ground of the dock by the vessel.

What happened

A large container vessel had just begun cargo operations. Approximately two hours later, the bollard holding the bow lines was pulled out of the dock. At the time of the bollard failure, the wind was mild, and the current was minimal.

The bow of the vessel swung outboard slightly, and the stern swung into the dock. The stern of the vessel contacted the fendering system but neither the vessel nor the fenders were damaged. There were no injuries nor damage to the vessel. The repair to the bollard exceeded $37,000.

What went right?

The forward spring lines held and stopped the swing of the vessel after the bollard failure. The crew was subsequently able to resecure the bow lines to different bollards.

What went wrong?

Upon investigation, the four bow lines from the vessel had all been attached to the same bollard, the one that failed. The two forward spring lines were both attached to a different bollard. The two aft spring lines were both attached to yet another bollard. The four stern lines were paired to two different bollards astern of the vessel.

The normal practice of the crew was to place no more than two mooring lines on each bollard, but the pilot and line handlers had attached all four to the same bollard because a container crane was partially blocking access to the next bollard forward that would have otherwise been used.

Some of the bolts attaching the bollard to the dock had sheared and some of the bolts were pulled out of the mounting intact. Each of the four bow lines was on a self-tensioning mooring winch. The combined load of the four winches together exceeded the bollard’s rated load.

Recommendations

Do not overload bollards with multiple mooring lines. If the load capacities of the bollards are not known, find out, and then adjust the mooring plan accordingly so the bollards will not be overloaded;

Management of Change:

  • When deviating from a normal mooring practice such as only putting two mooring lines on a bollard, the specific risk of overloading a bollard should be evaluated based on the capacity of the bollard, the number of mooring lines that will be placed on that bollard, and the settings on the self-tensioning winches;
  • If cranes or other dockside equipment block access to bollards that would normally be used, or if bollards that would normally be used are already being used by other vessels, the options should be discussed, and the risks should be identified and assessed before proceeding.

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Source: American P&I Club