Heavy Rolling of Container Ship - Heavy Rolling of Container Ship
Initial Report
Report Text:
The container ship on which I am serving had been in heavy weather for several days. We were proceeding at full speed. During the watch I called the Master as the vessel’s roll was synchronising with the waves, initially to 20 degrees. The ship then rolled to 40 degrees and the engine stopped. Subsequently the synchronisation ceased and the roll angle reduced.
The vessel suffered damage including flooding of forward compartments with damage to electrical equipment, and shifting of containers.
Lessons learned: We had received weather forecasts of the severe conditions. We should have reduced speed earlier.
CHIRP Comment:
It is fortunate that this incident did not lead to fatalities or loss of the vessel. In the absence of more comprehensive information, we are not in a position to comment on the specifics of this report. However the dangers of heavy rolling are illustrated by an accident on the container vessel CMS Chicago Express in 2008 in which the vessel rolled violently to over 40 degrees during a typhoon. The bridge team members were thrown across the wide expanse of the bridge. Tragically an AB died and the Master was severely injured.
This fatal accident was investigated by the German Federal Bureau of Maritime Casualty Investigations. Their report can be found on www.bsu-bund.de and also on www.emsa.europa.eu. It made a number of recommendations, including the following related to operating in heavy swells:
- Drifting abeam would have led to a significant portion of energy from the swell being converted into a drift motion rather than a rolling motion. Consideration must be given to the sea-room available and to the possibility that the stern will turn against the sea and then be exposed to extreme slamming pressures on the flat aft section.
- Decreasing the speed below a critical value may result in a dangerous deterioration of the dynamic roll damping. Conversely, in that regard it is also necessary to be aware of the risks to the vessel and cargo associated with excessively high speed.
CHIRP will welcome correspondence on this subject.