- When sailing in severe following or quartering seas, a ship is likely to encounter various kinds of dangerous phenomena, which may lead to capsizing. Although the dynamic behavior in following and quartering seas is not yet covered in present stability standards, much progress has been made in recent years towards understanding the physics of capsize mechanisms and identifying potentially critical conditions.
- The sensitivity of a ship to dangerous phenomena will depend on the actual stability parameters, hull geometry, ship size and ship speed. This implies that the vulnerability to capsizing and its probability of occurrence in a particular sea state may differ for each ship.
- The guidance aims at giving seafarers caution on dangerous phenomena that they may encounter during navigation in following and quartering seas, and providing the basis for a decision on ship handling in order to avoid such dangerous situations. It provides advice on safe and unsafe combinations of ship speed and course relative to waves, in a simplified form of a polar diagram. The diagram does not take into account the actual stability and the dynamic characteristics of an individual ship, but provides a general unified boundary of safe and unsafe combination of the operational parameters for all types of conventional ships covered by IMO instruments.
- For the ships which are equipped with an on-board computer, the Administrations are encouraged to use a specially developed software which would take into account the main particulars, actual stability and dynamic characteristics of the individual ship in the real voyage conditions. Such software should be approved by the Administration.
Read More: STANDARDS FOR SHIP MANEUVERABILITY