200639 Contact with wharf

08 Feb 2009 MARS

 


A ship, lying starboard side to a river wharf, was unberthing at night with the assistance of her bow thruster and a tug's towline on the vessel's port quarter. After all lines were let go, the ship attempted to clear the berth by putting both the bow thruster and rudder full / hard to port. Soon, with the ship's bow canting about 80° away from the wharf, it was realised the swing to port was bringing the stern rapidly towards the wharf. At this time it was also realised that the tug was pushing on the port quarter, instead of pulling. With the starboard quarter closing rapidly with the wharf, the bow thruster was set full to starboard and the controllable pitch propeller was set to dead slow ahead, then half ahead with rudder hard-a-starboard. Despite these manoeuvres, the starboard quarter struck the wharf with considerable impact.

Thereafter, the vessel cleared the wharf and anchored in stream for investigations and hull damage survey, which found structural damage above the water line. After completion of repairs to class satisfaction, the ship proceeded on her intended voyage.

Root cause/contributory factors
  • Lack of completion, or misunderstanding, of master-pilot information exchange regarding planned unberthing manoeuvre, or deviation therefrom;
  • Bridge team's failure to notice rapid swing to port and implement corrective action in good time;
  • Lack of continuous reporting on tug's actions and clearing distances from aft mooring team;
  • Inability of master to monitor pilot-tug communications as these were in the local language;
  • Tug pushing the stern before the vessel had cleared the wharf, as a result of miscommunication or a misjudgement on the part of the pilot;
  • Possible effect of unberthing while stemming a strong current, with initial hard-a-port rudder and bow thruster full to port, which would have pushed the bow off rapidly, thus bringing the stern rapidly towards the wharf;
  • Tentative engine movements (dead slow ahead, half ahead) when a 'full ahead' order with rudder midships would almost certainly have enabled the stern to clear the wharf. (The report does not mention any obstruction ahead.)

Other valuable lessons

  • The passage plan and critical manoeuvres must be carefully discussed with the pilot beforehand. Simple sketches on a handy scrap pad may overcome language difficulties.
  • The art of short, effective and continuous communication of vital information between the bridge team and mooring teams must be practised to perfection.

Editor's note: The report mentions that accurate reconstruction of the events would need the downloading of voyage data recorder (VDR) as the entries in the 'bell book' were found to be very scanty. While this is understandable, given the rapidity of evolutions during such manoeuvres it may well be worthwhile for masters to invest in a digital voice recorder and record bridge orders. It is doubtful if the VDR microphones would be able to capture all voice communications between the invariably 'roving' pilot and master during navigation under pilotage and especially during berthing/unberthing. These devices have become very affordable and efficient.
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