1 The master shall be supplied with stability information satisfactory to the Administration as is necessary to enable him by rapid and simple processes to obtain accurate guidance as to the stability of the ship under varying conditions of service. A copy of the stability information shall be furnished to the Administration.
2 The information should include:
2.1 curves or tables of minimum operational metacentric height (GM) versus draught which assures compliance with the relevant intact and damage stability requirements, alternatively corresponding curves or tables of the maximum allowable vertical centre of gravity (KG) versus draught, or with the equivalents of either of these curves;
2.2 instructions concerning the operation of cross-flooding arrangements;
2.3 all other data and aids which might be necessary to maintain the required intact stability and stability after damage.
3 The stability information shall show the influence of various trims in cases where the operational trim range exceeds ± 0 . 5% of L s .
4 For ships which have to fulfil the stability requirements of part B – l, information referred to in paragraph 2 is determined from considerations related to the subdivision index, in the following manner:
Minimum required GM (or maximum permissible vertical position of centre of gravity KG) for the three draughts ds, dp and d\ are equal to the GM (or KG values) of corresponding loading cases used for the calculation of survival factor st. For intermediate draughts, values to be used shall be obtained by linear interpolation applied to the GM value only between the deepest subdivision draught and the partial subdivision draught and between the partial load line and the light service draught respectively. Intact stability criteria will also be taken into account by retaining for each draft the maximum among minimum required GM values or the minimum of maximum permissible KG values for both criteria. If the subdivision index is calculated for different trims, several required GM curves will be established in the same way.
5 When curves or tables of minimum operational metacentric height (GM) versus draught are not appropriate, the master should ensure that the operating condition does not deviate from a studied loading – condition, or verify by calculation that the stability criteria are satisfied for this loading condition.
- Refer to the Code on Intact Stability for All Types of Ships covered by IMO Instruments, adopted by the Organization by resolution A.749(18), as amended. From 1 July 2010, the International Code on Intact Stability, 2008, adopted by resolution MSC.267(85), is expected to enter into force.
- Refer also to the Guidelines for the preparation of intact stability information (MSC/Circ.456); Guidance on the intact stability of existing tankers during transfer operations (MSC/Circ.706); and the Revised Guidance to the master for avoiding dangerous situations in adverse weather and sea conditions (MSC.1/Circ.1228).
Reference: SOLAS Regulation 5-1