Ship collisions and groundings make up a considerable percentage of major maritime accidents. By using attention zones similar to those that have been used by the aviation industry for decades, critical situations can be avoided.
DNV has initiated a research programme and has been joined by the Kongsberg Group and C-Map to use the ideas this comes up with to create useable tools for ship masters. Prototypes have now been completed and are demonstrated at the ongoing NorShipping event.
Introducing attention zones is equivalent to introducing safe separation distances between actual elements, as has been proven effective in the aviation industry. In shipping and when sailing, ship masters can be warned in due time and then act to avoid critical situations.
Attention zones will be set up continuously depending on the vessel’s actual position. Information on items such as reefs, bridges, floating containers, other vessels, wind and currents will be parameters used when setting this zone.
Some of the parameters used to set up the attention zone are static, such as ship type, or semi static, such as cargo, or entirely dynamic, such as meteorological and oceanographic parameters. The attention zones will thus be a continuous but simple way of visualising risk on maritime navigational chart displays.
The size of the attention zone gives the bridge navigator or VTS an intuitive clue about the vessel’s “navigational space” based on the surrounding risk potential. Overlapping zones indicate upcoming potentially critical situations. Objects that have a larger risk potential, either due to a higher accident probability or because of more severe consequences, will therefore be assigned a larger zone size. Object movement, wind or currents can correspondingly deform a zone.
As an example, when the bulk carrier Server capsized at Fedje, Norway in mid January of this year, the captain later explained that he was surprised by both wind and waves when the ship left Fedje. A simulation of an attention zone for the same area at the time in question shows that this would have prepared the master for the conditions the ship was about to move into.