Investigate increasing margin line distance to bulkhead deck for new Ro-Ro designs

The Court recommends that detailed investigations and model tests should be carried out with a view to increasing the required distance from the margin line to the bulkhead deck in new design Ro-Ro passenger ferries to perhaps 1 m. The model tests should be ballasted to give the waterline at the margin over a range of 'damage' positions fore and aft and with the relevant openings in the superstructure representing statutory damage. Tests should be run in irregular sea conditions for significant wave heights. The present definition of the margin line (76 mm below the bulkhead deck) derives from conventional passenger ships and has no inherent relevance to ships with no subdivision above the bulkhead deck. It should not apply to them.