General Considerations

A grain hold, plus any included 'tween decks, is just one single compartment in Calc. Any decks must be modelled by deck surfaces, either defined within an XML geometry file or a Facet (.fct) file, 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 cover 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 EditBritfair, or a simple text editor. This procedure will be further described below. Calc will generate 7 sections through the compartment namely:

• At the aft and forward ends of the compartment,

• At the aft and forward ends of the hatch, and

• 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: that is midway between the hatch ends, and the other two midway between the hatch and the two ends of the compartment.