Revision No. Revision Summary. Date. 0. Final edition. xxxxxx . on board the vessel at all times, be complete, legible and readily available for use. 1) Compliance with the stability criteria does not ensure immunity against . Ships carrying timber deck cargoes should operate, as far as possible. Ships Carrying Timber Deck Cargoes, , RECOMMENDS Governments to use the provisions of the TDC Code as a basis for .. implementation date of this Code, should meet the contents of this Code. . damage stability requirements (e.g. SOLAS regulation II-1/ or Load Lines Convention. Part 4 Special requirements applicable to ships assigned timber approval of the stability information is required. (2) a reference to a ship constructed on or after a specified date is a .. minimum range of 20° beyond the position of equilibrium with a .. as to be available for immediate use at all times.

In addition, the weight and distribution of the luggage should be determined by the Administration. Account may be taken, if necessary, of camber and sheer of deck. In this connection it is anticipated that a value higher than 4 persons per square metre will not be necessary. Permanente link Appendix 3 Memorandum to administrations on an approximate determination of ship''s stability by means of the rolling period tests 1 Recognizing the desirability of supplying to masters of small ships instructions for a simplified determination of initial stability, attention was given to the rolling period tests.

Studies on this matter have now been completed with the result that the rolling period test may be recommended as a useful means of approximately determining the initial stability of small ships when it is not practicable to give approved loading conditions or other stability information, or as a supplement to such information.

Therefore it can be expected that: If this is done, care should be taken to discard readings which depart appreciably from the majority of other observations. Forced oscillations corresponding to the sea period and differing from the natural period at which the vessel seems to move should be disregarded.

In order to obtain satisfactory results, it may be necessary to select intervals when the sea action is least violent, and it may be necessary to discard a considerable number of observations. This straight line intersects the vertical line mm in the point M. It is considered that each Administration should recommend the F-value or values to be used.

Test procedure 3 The rolling period required is the time for one complete oscillation of the vessel and to ensure the most accurate results in obtaining this value the following precautions should be observed: After allowing the roll to completely fade away, this operation should be repeated at least twice more. The area on the right side of the graph equals the area on the left side of the curve.

Both levers are multiplied by the cosine of the heeling angle in the example. Residual freeboard at midship The remaining freeboard at half length as determined from the depth and breadth in Hulldef must have a certain value at the static angle of inclination.

Distance to deck The distance from the waterline to the deckline as determined from the depth and breadth in Hulldef must have a certain value at the static angle of inclination.

- Chapter 1 General

Distance to special points The distance from the waterline to openings or margin line points as defined in Hulldef must have a certain value at the static angle of inclination. Distance to V-line points non-watertight The distance from the waterline to V-line points as defined in Hulldefsee Openings must have a certain value at the static angle of inclination, with a certain roll margin.

Roll period The roll period as calculated from selected formulae must have a certain value. See also under Whether or not to apply heeling moments. Subdivide in subcriteria A criterion of this type can be defined as a set of criteria of all listed types.

Such a set or subset of criteria can be treated, manipulated and defined as an independent set of criteria. It is even possible to create subsets within subsets. Determinative toolbar function The toolbar function [Determinative] determines whether the most or least critical criterion is normative. Defining the parameters of the stability criteria For each individual criterion, all parameters can be defined.

The type of criterion determines which value is checked, how this is done, etc.

The general structure of the menu for defining the parameters per criterion is explained by the example of the wind criterion of the Intact Stability Code: Example of definition per criterion. Description The first row contains the user-defined description, see also Manipulating individual criteria.

The description can be changed through this menu. Type The second line contains the type of basic criterion as defined in the menu of Standard stability criteria damaged stability.

Parameters Depending on the type of criterion, a number of rows containing the parameters for the concerning criterion follows. In this example there are three user-defined parameters: Setting these parameters is discussed extensively in The nature of the stability criterion parameters.

An overview of possible parameters and their meaning is given in Types of parameters.

Moments For each criterion different types of heeling moments can be accounted for wind heeling moment, turning circle moment, etcetera.

Depending on the type of moment, other settings may apply. Defining these moments and their settings is described in Defining heeling moments to be accounted for. Bollard pull At this option the trend of the heeling moment of the bollard pull, over the angles of inclination, can be specified.

No bollard pull Linear moment, so constant for all angles of inclination. Moment decreasing with the cosine of the angle of inclination.

**INTACT STABILITY CRITERIA**

IS Codeself tripping: IS Codetow tripping: Furhermore, it can also be specified which vertical lever should be used to be multiplied with the bollard force, in order to obtain the heeling moment, with options: The distance between towing hook and the point halfway between draft and the virtual keel point, which can be specified with one of the hull definition modules see Towing hook and bollard pull.

The distance between towing hook and half the draft. The distance between towing hook and the COG of the lateral area, which will be computed from the underwater contour shape of the selected wind contour, for example Settings per loading condition. The distance between towing hook and any height from base. The height is defined in Towing hook and bollard pull as a virtual keel point. This number can be set in this row. Wave influence Some criteria may be applicable to the vessel in a wave.

The way to account for a wave can be defined through a popup menu; Wave properties.

## INTACT STABILITY CRITERIA FOR ALL VESSELS

If a wave crest or wave trough is selected, the amplitude must also be specified on the same row. The GZ curve is then calculated for this criterion with the vessel in a wave with the defined amplitude and a wave length of twice the vessel length, with the crest, respectively the through at half the vessel's length. If the mean of wave crest and trough is selected, the GZ curve is calculated twice for a wave crest and a wave trough and for each angle of inclination, the average GZ value is calculated.

The criterion is then evaluated for the GZ curve constructed in the described way. The nature of the stability criterion parameters Attention It is advised to study this section thoroughly to avoid misunderstandings. Especially due to the way parameters can be defined, as described in this section, checking stability criteria has become extremely flexible in PIAS. Unfortunately, the increased freedom involves increased complexity.

Therefore, read the manual carefully in general and this section in particular Types of parameters This section describes the possible parameters that can be defined depending on the type of basic requirement. Between start angle Start angle of the range in which a parameter must reach a certain value.

### INTACT STABILITY CRITERIA FOR ALL VESSELS - MARINE GURU

And end angle Final angle of the range in which a parameter must reach a certain value. Metacentric height Inclination of the tangent of the GZ curve. At angle The angle at which a parameter must reach a certain value. Longitudinal metacentric height Metacentric height in longitudinal sense.