On April 1, 2013, at 1324 local time, the 473-foot-long tanker Harbour Feature, with 20 persons on board, allided with the Sarah Mildred Long Bridge in Portsmouth, New Hampshire, after the vessel broke free from its moorings at the New Hampshire State Port Authority, Marine Terminal Wharf. No injuries or pollution resulted from the accident. The bridge sustained $2.5million in damage; the Harbour Feature sustained $1 million in damage.
The probable cause of the breakaway of the Harbour Feature from its moorings and subsequent allision with the Sarah Mildred Long Bridge was the inadequate mooring arrangement made by the master and the pilot for the vessel’s location and the prevailing tidal conditions.
General Tips for Safe Mooring
When mooring a ship at a dock, pay close attention to the following factors:
- Tidal currents – their scheduled peak time, direction, and speed
- Weather conditions, both present and forecasted
- Amount and type of vessel traffic in the area
- Ship’s position at the berth – does the bow or stern extend past the dock?
- Anticipated changes in draft or trim of vessel while alongside dock
- Number, strength, and general condition of mooring lines/wires, winch brakes, and dockside bollards
- Interval of mooring patrols, based on the factors listed above
