PIAS Manual
2019
Program for the Integral Approach of Shipdesign

At this stage superstructures are defined (primarily deckhouse layers) which are not included in the hull form. For example, a poop already included in the hullform (with a hull shape definition module Hulldef of Fairway) is not defined in this module, while a bridge which is not already included in the hull form is defined in this module. For each superstructure, which is assumed to be rectangular, the location of the limiting bulkheads has to be specified by the user. Is the superstructure not of a rectangular shape, the mean values have to be specified. For each superstructure is specified :
For the calculation of the Net Tonnage several specific particulars, as defined in the Tonnage Convention, have to be specified here.
For checking purposes with this option the hull and the superstructure are drawn schematically in plan view.
This option calculates and prints the tonnage calculation. For the calculation of Net Tonnage, the volume of the cargo spaces has to be determined (reg. 4 from Annex I from the Tonnage Convention). To determine those volumes, the compartments as defined in Layout are used here, so there is no double definition of cargo spaces. To enable this module to recognize the appropriate compartments as cargo spaces, those compartments have to be selected in the compartment list (as discussed in Compartment list, calculation of tank tables etc.) of Layout before tonnage calculations are performed. All compartments not being part of the cargo space are not allowed to be selected. According to the regulations, the volumes of the cargo spaces are being calculated without deduction for construction (permeability = 1).
See underneath for an example of the output of tonnage calculations.