Section 4 Stability due to ice accretion

401. Stability calculations and criteria

1. The effect of icing is to be considered in the stability calculations and is to comply with the IMO Code on Intact Stability Resolution MSC.267(85), as amended - Chapter 6 - Icing considerations. The ice accretion values are to be taken as an additional mass per unit area, as given in Table 4.9.

Table 4.9 Ice accretion values

2. Where surfaces are inclined or shaped, e.g. spherical covers or deck-houses, the most onerous con- dition from the projected horizontal or vertical area is to be taken in conjunction with the asso- ciated ice accretion value given in Table 4.9. All areas above the design waterline are to be in- cluded, e.g. side shell, deck-house sides and projected areas of deck cargo.

3. The stability criteria as given in the IMO Code on Intact Stability Resolution A.749(18) - Chapter 3.1 General intact stability criteria, are to be complied with, see 101. and 102.

4. Stability calculations are to include the effects of ice accretion on the loading conditions specified in the IMO Code on intact stability. In addition, stability calculations are to be provided for the most onerous conditions and, at least, the following conditions:

(1) Establish specific winterization conditions of loading and ballasting corresponding to the limits of compliance with the criteria, taking into account ice accretion as follows:

(a) Design draught condition.

(b) Minimum design ballast condition.

(c) Seagoing conditions, including both departure and arrival conditions:

• homogeneous loading conditions

• alternate and part load conditions, where applicable

• normal ballast condition

• heavy ballast condition

• any specified non-uniform distribution of loading

• for oil and chemical tankers, conditions with high density cargo

• mid-voyage conditions relating to tank cleaning or other operations where these differ

significantly from the ballast conditions and

• conditions covering ballast water exchange procedures

(2) Establish ice accretion compliant conditions and limits for specified harbour/sheltered water con-

ditions as follows:

(a) conditions representing typical loading and unloading operations;

(b) docking afloat condition; and

(c) propeller inspection afloat condition.