(2)
(3)
(4)
2 For ships that fulfill either of the following (1) or (2), special consideration is to be made for wave loads used in
strength assessment:
(1)
(2) For ships deemed necessary by the Society
1.1.2.3 Special Cases in Application
For ships of unusual form or principal dimensions that do not fall under 1.1.2.2-1, or ships where it is difficult to
comply with Part C for some special reasons, the hull construction, equipment, and arrangement may be decided based
upon the general principles of Part C.
1.1.2.4 Equivalency
1 Alternative hull construction, equipment, and arrangement not meeting the requirements in Part C will be deemed
compliant with Part C, provided that the Society considers that such construction, equipment, and arrangement are
equivalent to those required in Part C. However, this does not, in principle, apply to requirements based on
international conventions or the IACS Unified Requirements.
2 Where -1 above applies, special consideration is to be made according to the following (1) through (3).
(1) Information is to be submitted to the Society to demonstrate that the structural safety of the ship is at least
equivalent to that intended by Part C.
(2) The Society is to be contacted at an early stage in the design process to determine the applicability of the Rules
and additional information required for submission.
(3) When deemed necessary by the Society, a systematic review may be performed to demonstrate the equivalency or
superiority of the ship’s structural safety to that intended by Part C.
3 Where information submitted beforehand is deemed appropriate by the Society, analysis and assessment may be
carried out using one of the following (1) through (5) appropriate for each individual ship.
(1) Direct load analysis
(a) For wave loads used in strength assessment as specified in 4.4, 4.5, 4.6, and 4.7, loads may be set using direct
load analysis for the individual ship.
(b) In application of (a) above, the analysis is to be in accordance with the requirements specified in the
“Guidelines for Direct Load Analysis and Strength Assessment” issued by the Society.
(c) The sea states to be considered are to be those in the North Atlantic (all seasons). The wave scatter diagram
specified in IACS Recommendation No. 34 (November 2001) is to be considered.
(2) Whole ship finite element analysis
(a) When a finite element model reproducing a whole ship is used in lieu of the partial structure model specified
in Chapter 8, the analysis is to be performed in accordance with the requirements specified in the
“Guidelines for Direct Load Analysis and Strength Assessment” issued by the Society.
(b) In application of (a) above, loads based on the requirement in (a) above are to be used instead of those
specified in Chapter 4.
(3) Non-linear structural analysis (buckling strength assessment)
Buckling strength assessment may be carried out using a finite element method that takes into account non-linear
responses due to materials and large deformations for structural elements to be considered in lieu of the buckling
strength assessment in accordance with Annex 8.6. In this case, the analysis model is to correctly model
geometrical imperfections and the effect of the surrounding structures. Alternatively, non-linear structural analysis
may be carried out using an analysis model that correctly represents the surrounding structures or the entire cargo
hold in addition to the structural elements to be considered, so that buckling strength assessment that directly
considers the effect of the surrounding structures may be carried out. Whichever approach is adopted, detailed
information describing the analysis method and results is to be submitted to the Society.
(4) Derivation of stress concentration factors
As an alternative to 9.3.6, geometrical stress concentration factors for the end connections of stiffeners may be
derived by finite element analysis using a very fine mesh model in accordance with 9.3.7. In such cases,
information for review of the stress concentration factor derivation method is to be submitted beforehand to the
