Introduction
2.23 Definition of the term "lightship"
1 The weight of mediums on board for the fixed fire-fighting systems
(e.g. freshwater, CO2, dry chemical powder, foam concentrate, etc.)
should be included in the lightweight and lightship condition.
Part A – Mandatory criteria
2.3 Severe wind and rolling criterion (weather criterion)
2 In applying Φf, openings which cannot be or are incapable of
being closed weathertight include ventilators (complying with regulation 19(4) of
the International Convention on Load Lines, 1966) that for operational reasons have
to remain open to supply air to the engine-room, emergency generator room or closed
ro-ro and vehicle spaces (if the same is considered buoyant in the stability
calculation or protecting openings leading below) for the effective operation of the
ship. Where it is not technically feasible to treat some closed ro-ro and vehicle
space ventilators as unprotected openings, Administrations may allow an alternative
arrangement that provides an equivalent level of safety.
Part B – Recommendations for certain types of ships and additional guidelines
3.4.2 Assumptions for calculating loading conditions
3 For tankers assigned with a tropical load line, the ship should be
assumed to be loaded in accordance with the following:
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.1 a fully loaded departure condition at the tropical load line and the
corresponding arrival loading condition are considered;
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.2 the cargo is homogeneously distributed throughout all cargo tanks; and
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.3 sea water density is 1.025 t/m3.