Lessons form Marine Accident Reports
The UK MAIB issued last yearSafety Digest including lessons learnt from maritime accidents. One case draws the attention on the importance of effective communication between crew onboard. Assumptions on on scanty information should be avoided, because they may lead to faulty conclusions and result in inevitably accidents.
A platform supply vessel lost control during aharbour manoeuvre, resulting in heavy contactwith another vessel moored alongside. After the vessel left her berth, her master,who was positioned at the aft-looking bridgeconsole, handed control to the chief officerstationed at the forward-looking bridge consoleto take the vessel through the harbour. Thechief officer was newly appointed and this wasto be his first time in control of the ship.Although he had handled an azimuth thrusterpropelled ship before, it had been on a semi-automated system.
The preferred system adoptedby the bridge team on this vessel, however, wasfor full manual control of the thrusters. Thechief officer did not inform the master that hehad little experience in this mode of operationas he did not believe that it would be substantiallydifferent to what he was used to, and the masterhad not questioned the chief officer’s experiencebecause he knew he had extensive recentexperience on board similar vessels.
The vessel was very shallow draughted, withthe result that her bow tunnel thruster wasnot deeply submerged. Additionally, the tunnelthruster had no readily visible gauge to showhow much power was being delivered to it.For the harbour manoeuvre, only two of theship’s generators were on line to supply poweras it was not envisaged that much power wouldbe needed.
The chief officer set each azimuth thrusterto face 45 outwards for the ship move andproceeded to take the ship through a narrowchannel between moored craft. As he progressed,he found that the bow thruster was having littleeffect when applied. As a consequence of thishe controlled the ship’s head by applying powerto the appropriate aft azimuth thruster.Unfortunately, applying power to thrusters ontheir 45 orientation had the effect of increasingthe vessel’s forward speed as well as inducinga turning moment.
At a crucial point in the manoeuvre, the ship’sspeed increased to over 4 knots and she swungrapidly towards a moored vessel. The chief officershouted to the master, who was still at the aftstation, that the vessel was out of control. Themaster ran to the forward station and tookevasive action by turning the azimuths to faceastern and demanding full power.
Unfortunately,before the non-running generators could comeon line to give the demanded additional power,the ship collided with the moored vessel,damaging her bridge wing and windows . Fortunately there was no one on thebridge of the moored vessel at the time.
The master regained control and completed theship move without further incident.
Read more cases atUK MAIB’s Safety Digest 02/2013 (click at image below)