PIAS Manual  2023
Program for the Integral Approach of Shipdesign
Grainmom: calculation of grain heeling moments according to the IMO Grain Code
This module enables you to calculate the actual grain heeling moments according to the requirements of IMO Grain Code, or according to the requirements of the Dutch Shipping Inspectorate.

Main menu

Grainmom main menu
Defined compartments
Name of compartments

XX, YY and ZZ are the names of the compartments, as defined in module Layout. The definition method has to comply to a number or requirements, which are listed in paragraph Definition of compartments

Define void space and longitudinal girder of this grain compartment:

Void space Half breadth Height Subcompartment
0.100 -4.500 9.000 PS part
0.500 4.500 9.000 mid part
1.000 - - SB part

The function of this input screen is to define one or more longitudinal girders per subcompartment. Only the girders at the topside of the subcompartment have to be defined. If no girders are present, this is marked by a dash (-).

  • Void space: height of the void space above the grain (acc. to Chapter VI, Section I A.a of the IMO Grain Code).
  • Half breadth: half breadth of the girder from centreline (SB positive, PS negative).
  • Height: height of the underside of the girder from baseline.
  • Subcompartment: name of the subcompartment as defined at the module from Layout.

When defining a longitudinal girder the [Girder] option can be used to toggle the presence of a longitudinal girder.

Define volume interval for calculations

The tables are calculated at the volume interval defined here.

Calculate volume & COGs of graincompartment

This option calculates the table of volumes and centres of gravity, without heeling angles (see figure underneath).

Table of hold volume and COG's according to IMO Grain code

If the compartment for the grain calculation has been defined including a curved sounding pipe (see Layout), then the output table will also contain a column with the ullage. The ullage is calculated from the top of the defined curved sounding pipe. The top of the sounding pipe will normally be the top of the coaming in case of a grain compartment.

Calculate volume & grain moments grain compartment

This option calculates the table of grain heeling moments at the prescribed heeling angle (see figure underneath). There is a special option if the calculations are submitted to the Dutch Shipping Inspectorate.

Table of heeling grain moments according to IMO Grain code

Configuration for drawing of cross-sections of grain compartment

At the next 2 options a cross-section is drawn on paper. The position of the cross-section to be drawn is defined at this option.

Print cross section graincompartment including void space

Draws the grain level including void spaces, at zero angle, see the figure below.

Graincompartment 1

Print cross section graincompartment including grainlevel

Draws the grain level with the heeling angle as prescribed by the regulations, see the example below.

Graincompartment 2

Definition of compartments

A compartment which is going to be used to compute grain heeling moments will be defined by one or more subcompartments, which have to comply to the following definition requirements:

  • The subcompartments have to be defined from portside to startboard.
  • No negative subcompartments are allowed.
  • The vertical line through a longitudinal girder has to be a boundary of a subcompartment.
Appendix 1
Appendix 1
Appendix 1