Section 1 Background

1.1.1 In the transition to the July 2016 Rules, an amendment was made to the Rules and Regulations for the Classification of Special Service CraftPt 3, Ch 2, 6.6 Double and single bottom structure 6.6.1. The Rule change proposal to the consolidated version of the July 2015 Rules was as follows:

The change resulted in a number of repeated queries from industry, not so much relating to the introduced requirement, but rather related to the application of International Convention for the Safety of Life at Sea 1974 as amended (hereinafter SOLAS), where the Flag State does not have any explicit requirements. Clarification was also requested as to what is considered recommended practice in the absence of any requirements from the Flag State and when SOLAS is not applicable.

1.1.2 It is noted that the Rule change is located in Pt 3, Ch 2 Craft Design of the Rules and Regulations for the Classification of Special Service Craft and is therefore applicable to all SSC vessels, including yachts. However, it was the yacht industry that raised the first queries due to the difficulty associated with fitting a traditional double bottom within fine formed vessels with complex fairing.

1.1.3 This Guidance Note has been produced to clarify the intent of the Rule change, to provide guidance on the applicability of SOLAS to double bottoms in Special Service Craft, and to provide a guide to recommended practice in the absence of any governing requirements.

1.1.4 This guidance is applicable to ships the keels of which are laid, or which are at a similar stage of construction, on or after 1 January 2009.

1.2.1 The requirement for double bottoms is chiefly a survivability aspect and is therefore covered by the relevant statutory instruments for vessels. As such, the current relevant requirements for SOLAS compliant vessels are contained in SOLAS Ch. II-1 Reg. 9.

1.2.2 Also note that SOLAS is a continually evolving set of regulations, and that the next major update to the regulations relating to double bottom arrangements and construction is due to come into force in 2020.

1.2.3 In addition to the above, it should be noted that SOLAS Ch. II-1 Reg. 9, cannot be read in isolation, as some of the preceding requirements must also be considered. Of particular interest are:

SOLAS, Ch. II-1, Reg. 4.1 which states that:

‘The damage stability requirements in parts B-1 through B-4 shall apply to cargo ships of 80 m in length (L) and upwards and to all passenger ships regardless of length…’; and

SOLAS Ch. I Reg.1 and Ch. I Reg. 3, which state that the SOLAS regulations are only applicable to ships engaged on international voyages and are not applicable to:

1. Ships of war and troopships;
2. Cargo ships of less than 500 gross tonnage;
3. Ships not propelled by mechanical means;
4. Wooden ships of primitive build;
5. Pleasure yachts not engaged in trade; and
6. Fishing vessels.

Further, SOLAS Ch. I Reg. 2 gives the SOLAS definitions for passenger and cargo ships:

• ‘A passenger ship is a ship which carries more than twelve passengers.’; and
• ‘A cargo ship is any ship which is not a passenger ship.’

1.2.4 Additionally, Flag States may have differing individual interpretations, additional requirements and or relaxations (alternatives) to SOLAS which take precedence for vessels under their administration.

1.2.5 It is also noted that some Flag State codes for double bottom extents requirements rely on classification requirements; in such a circumstance it could be considered that the combination of such codes with the LR Rules would lead to circular references (the Classification Rules directing the user to Flag State requirements and the Flag State requirements directing the user back to the Classification Rules). However, in such cases common sense should prevail, and the latter part of the LR Rule would be applicable, i.e. ‘arrangements in accordance with SOLAS will be acceptable.’