Criteria

When performing a critical KG analysis the initial requirement is to establish the specific stability criteria relevant to the vessel.

By selecting the General Particulars - Ship Data icon the resulting input dialog provides several tab files and one of which contains all the different criteria sets defined in the Calc criteria file. you can then select two sets of stability criteria, one for the intact case and one for the damage case. It should be noted that the criteria file must be in the working directory. To achieve this, you must either copy the Master criteria file that is supplied with the program and Edit it if so required, or if desired, manually bring in your own file which could be stored elsewhere.

By selecting this input master file process you have the opportunity to check or edit criteria in one of two different ways. However great care must be taken in both cases in order to ensure that criteria are not edited without first copying and renaming them or else some criteria data may be wrong!

1. You can choose a set of criteria from the following list, pre-programmed in the original installation.

   • IMO A167 Intact stability criteria.

   • IMO 749 Intact Stability Criteria non-passenger.

   • IMO 749 Intact Stability Criteria Passenger.

   • MARPOL 73/78 (Oil Tankers).

   • Load line (Oil tankers > 150m, bulk carriers >100m).

   • Passenger Ship Rules (S.I. No.1216).

   • Ro-Ro Ship Rules.

   • 1990 Passenger Ship Rules (one compartment flooding).

   • 1990 Passenger Ship Rules (two or more compartments flooding).

   • Chemical Tankers IMO A212 L>150.

   • NES 109 Intact Stability Criteria.

   • NES 109 Damaged Stability Criteria.

   • IMO A469 Intact Stability Criteria for Offshore Supply Vessels.

   • Special Purpose Ships IMO A534.

   • USSR 1987 Passenger Ships.

   • Gas Carriers.

   • Grain Criteria.

   • Norwegian Fishing Vessel.

   • Chemical Tankers IMO A212 L<150.

   • NES 109 Intact with Ice.

   • SEE-BG German Ministry of Transport.

   • Mobile Offshore Drilling Units.

   • High Speed Craft (HSC) Code intact.

   • High Speed Craft (HSC) Code damaged.

2. In addition to these pre-defined criteria it is also possible for you to create his/her own criteria sets interactively on the dialog and store them for future use. The majority of criteria which relate to the GZ curve and key hullform geometry can be defined in Calc.

   The selection of criteria types available for customizing is as follows:

   1. Minimum value of equilibrium angle.

   2. Minimum range of positive GZ.

   3. Minimum area under GZ curve in positive range.

   4. Minimum value of maximum GZ in positive range.

   5. Minimum GZ at given angle.

   6. Minimum slope (GM) at given angle.

   7. Minimum distance over waterplane for margin line (deck edges).

   8. Minimum distance over waterplane for unprotected openings.

   9. Minimum distance over waterplane for protected openings.

   10. Heeling moment: minimum (area B/area A).

   11. Heeling moment: minimum (GZc/ Max GZ).

   12. Maximum angle of heel in beam wind.

   13. Minimum area A in beam applied moment.

   14. Heeling moment: minimum (Area A/Total Area).

   15. Position of MAX - GZ.

   16. Minimum GZ value at 30 degrees (SEE-BG).

   17. Max. angle of heel for wind moment (SEE-BG 10% freeboard restriction).

   18. Minimum Area Ratio (MODU).

   19. Minimum value of maximum GZ in positive range.

   20. RS acceleration criterion K*.

   21. Minimum GZmax - heeling arm.

   22. BV1033 Min Righting Lever at Ref.Angle.

   23. Minimum S’ Value.

It is highly recommended that users do not edit a pre-programmed criteria set but instead copy the set giving it a new ID and set name, and then edit the individual criterion in the copied set.

Further information used in conjunction with the above criteria, needs to be defined through the General Particulars - Openings and Deck Edge Points dialog, as follows:

• Deck edge points which are used to identify when deck edge immersion occurs.

• Profile points which are used for wind heeling calculations.

• Unprotected openings which are those through which progressive flooding may take place, such as air pipes, hatch covers and weather-tight doors.

• Protected openings are those that are capable of being closed and made watertight such as manhole covers, flush scuttles, small tank hatches,