General Considerations

A grain hold, plus any 'tween decks, is just one compartment in Calc. Any decks must be modelled by deck surfaces, either defined by facets, or imported from a CMP file. The decks must extend over the whole length and width of the compartment.

A grain compartment must be modelled to include the hatch up to the top of the coaming, but exclude the hatch itself. For filled hold calculations, sections through the compartment, are required. These will be generated when setting up the calibration data, however, generating a closed curve from facet data, is not without problems, and from GDS portion data, is practically impossible. For this reason, Calc provides a facility for exporting and importing section data as Britfair files, which can be edited in Digit, or a simple text editor. This procedure will be further described below. Calc will generate 7 sections through the compartment:

• At the aft and forward ends of the compartment,

• At the aft and forward ends of the hatch,

• A further 3 sections midway between others.

When Calc requires a section it will take the nearest one, thus often only 3 sections will be necessary: midway between the hatch ends, and midway between the hatch and the ends of the compartment.