A report describing a new build vessel with poor handling characteristics when in the loaded condition.
What the Reporter told us:
Description of Event: A pilot reported that when berthing a specific vessel, a considerable amount of port helm was required to stop a tendency of the vessel to go to starboard. The vessel was in the loaded condition and the speed varied between six and nine knots. The weather and water depth were considered not to be a contributing factor.
The vessel is a new generation bulk carrier with a very rounded bluff bow and is the third vessel of this hull form where I have encountered this tendency. The first couple of times, I thought perhaps it was the weather, but now I believe it is a quirk of the design. When the vessel is in a light condition, there has been no issue.
CHIRP wrote to the designers of this particular class in order to seek any clarification of the reported manoeuvring issues but received no response. Similarly, a letter was sent to the Quality Assurance department of the vessel’s ISM Managers – likewise, no response was received.
The Maritime Advisory Board discussed this report in depth. Some members had historical first-hand experience of other new build vessels where poor handing was attributable to the design of the rudder. Regarding one such class in particular, a change of rudder design was required and the installation of a “high lift” rudder rectified the problem.
In general, sea trials for new building vessels are conducted in the ballast condition only, with the laden condition being extrapolated from the results.
It was pointed out that the lessons are similar to those of the rudder angle indicator report above. If the handling of the vessel does not feel right, then report this to your managers for further investigation. Poor manoeuvring characteristics, if unrecognised, present a danger to safe navigation and the potential for grounding or collision in restricted waters.
In addition, CHIRP will be writing to the relevant Classification Society, primarily as an awareness raising exercise, but also to try to determine whether this is a known common problem. Any feedback will be promulgated in a future issue of Maritime FEEDBACK.
In order to widen the debate, CHIRP would like to hear from anyone else who has experienced similar problems.