Dead Ship Condition Stability Criterion

The dead ship condition is the stability failure mode in which a ship loses all propulsion and power, drifts beam-on to wind and waves, and must survive the combined heeling moment of a sustained wind, a wind gust and resonant rolling without capsizing. It is the failure mode most closely related to an existing mandatory rule, because the severe wind and rolling criterion of the 2008 Intact Stability Code, Resolution MSC.267(85), addresses the same scenario with a simpler deterministic method.

The Second Generation Intact Stability Criteria treat the condition probabilistically rather than through a single design gust. That change matters because the IS Code weather criterion was calibrated on a fleet of smaller and more conventional hulls than the ships now trading, and its fixed assumptions about roll amplitude and wind pressure do not scale evenly across modern beam-to-draft ratios.

The full article will cover the physical scenario and the loads involved, the relationship between the IS Code weather criterion and the newer probabilistic treatment, the Level 1 and Level 2 vulnerability criteria, the direct stability assessment route, and the ship types for which the two methods diverge most.