Appendix – Guidelines for the Preparation of Subdivision and Damage Stability Calculations
Clasification Society 2024 - Version 9.40
Statutory Documents - IMO Publications and Documents - Resolutions - Maritime Safety Committee - Resolution MSC.281(85) – Explanatory Notes to the SOLAS Chapter II-1 Subdivision and Damage Stability Regulations – (Adopted on 4 December 2008) - Explanatory Notes to the SOLAS Chapter II-1 Subdivision and Damage Stability Regulations - Part B – Guidance on Individual SOLAS Chapter II-1 Subdivision and Damage Stability Regulations - Appendix – Guidelines for the Preparation of Subdivision and Damage Stability Calculations

Appendix – Guidelines for the Preparation of Subdivision and Damage Stability Calculations

Parent topic: Part B – Guidance on Individual SOLAS Chapter II-1 Subdivision and Damage Stability Regulations

1 General

1.1 Purpose of the Guidelines

  1.1.1 These Guidelines serve the purpose of simplifying the process of the damage stability analysis, as experience has shown that a systematic and complete presentation of the particulars results in considerable saving of time during the approval process.

  1.1.2 A damage stability analysis serves the purpose to provide proof of the damage stability standard required for the respective ship type. At present, two different calculation methods, the deterministic concept and the probabilistic concept are applied.

1.2 Scope of analysis and documentation on board

  1.2.1 The scope of subdivision and damage stability analysis is determined by the required damage stability standard and aims at providing the ships master with clear intact stability requirements. In general, this is achieved by determining KG-respective GM-limit curves, containing the admissible stability values for the draught range to be covered.

  1.2.2 Within the scope of the analysis thus defined, all potential or necessary damage conditions will be determined, taking into account the damage stability criteria, in order to obtain the required damage stability standard. Depending on the type and size of ship, this may involve a considerable amount of analyses.

  1.2.3 Referring to SOLAS chapter II-1, regulation 19, the necessity to provide the crew with the relevant information regarding the subdivision of the ship is expressed, therefore plans should be provided and permanently exhibited for the guidance of the officer in charge. These plans should clearly show for each deck and hold the boundaries of the watertight compartments, the openings therein with means of closure and position of any controls thereof, and the arrangements for the correction of any list due to flooding. In addition, Damage Control Booklets containing the aforementioned information should be available.

2 Documents for Submission

2.1 Presentation of documents

 The documentation should begin with the following details: principal dimensions, ship type, designation of intact conditions, designation of damage conditions and pertinent damaged compartments, KG-respective GM-limit curve.

2.2 General document

 For the checking of the input data, the following should be submitted:

  • .1 main dimensions;

  • .2 lines plan, plotted or numerically;

  • .3 hydrostatic data and cross curves of stability (including drawing of the buoyant hull);

  • .4 definition of sub-compartments with moulded volumes, centres of gravity and permeability;

  • .5 layout plan (watertight integrity plan) for the sub-compartments with all internal and external opening points including their connected sub-compartments, and particulars used in measuring the spaces, such as general arrangement plan and tank plan. The subdivision limits, longitudinal, transverse and vertical, should be included;

  • .6 light service condition;

  • .7 load line draught;

  • .8 coordinates of opening points with their level of tightness (e.g., weathertight, unprotected);

  • .9 watertight door location with pressure calculation;

  • .10 side contour and wind profile;

  • .11 cross and down flooding devices and the calculations thereof according to resolution MSC.245(83) with information about diameter, valves, pipe lengths and coordinates of inlet/outlet;

  • .12 pipes in damaged area when the destruction of these pipes results in progressive flooding; and

  • .13 damage extensions and definition of damage cases.

2.3 Special documents

 The following documentation of results should be submitted.

2.3.1 Documentation

  2.3.1.1 Initial data:

  • .1 subdivision length Ls;

  • .2 initial draughts and the corresponding GM-values;

  • .3 required subdivision index R; and

  • .4 attained subdivision index A with a summary table for all contributions for all damaged zones.

  2.3.1.2 Results for each damage case which contributes to the index A:

  • .1 draught, trim, heel, GM in damaged condition;

  • .2 dimension of the damage with probabilistic values p, v and r;

  • .3 righting lever curve (including GZmax and range) with factor of survivability s;

  • .4 critical weathertight and unprotected openings with their angle of immersion; and

  • .5 details of sub-compartments with amount of in-flooded water/lost buoyancy with their centres of gravity.

  2.3.1.3 In addition to the requirements in paragraph 2.3.1.2, particulars of non-contributing damages (si = 0 and pi > 0.00) should also be submitted for passenger ships and ro-ro ships fitted with long lower holds including full details of the calculated factors.

2.3.2 Special consideration

 For intermediate conditions, as stages before cross-flooding or before progressive flooding, an appropriate scope of the documentation covering the aforementioned items is needed in addition.

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