LOAD LINES CONVENTION
Spring 2023
Annex B/Annex I/Regulation 27: Watertight Openings
An amendment to the Load Lines Convention provides new considerations for the placement of watertight openings regarding the final damaged water line, which is critical to determine satisfactory equilibrium after flooding.
This amendment specifies additional types of openings fitted with watertight closures that may be excluded from the requirement of being located above the final water line after flooding:
• Quick acting or single action type hinged watertight access doors with open/closed indication locally and at the navigation bridge and that are normally closed at sea
• Hinged watertight doors permanently closed at sea
This change was also made to correlate with related amendments made to the SOLAS Convention and several other IMO standards.
Effective Date: 1 January 2024
Sources: MSC.491(104)
Annex B/Annex I/Regulation 37: Unified Interpretation Superstructure Deduction
An IMO unified interpretation was adopted to ensure an accurate freeboard assignment and to clarify circumstances in which a superstructure deduction may or may not be applied to the ship when assigning a freeboard to type B ships.
Ships assigned a type B or reduced type B freeboard, cannot have a superstructure deduction applied if the effective length of a forecastle is less than 0.07 L.
If the ship has no forecastle or the effective length of the forecastle is less than 0.07 L, no superstructure deduction is to be applied, even if other superstructures are present.
In case the ship has a full superstructure, one that extends from AP to FP, per Regulation
3(10)(h) of Annex B of the 1988 Load Lines Protocol, the deduction for a superstructure may be applied.
Effective Date: 22 May 2022
Sources: MSC.1/Circular.1535/Revision.2
