Floodable Length

The Floodable Length module has been revised in this version of Calc to include criterion of service calculations, and the determination of permeabilities for and aft of, and in way of the engine room. The output has been changed accordingly. This means that the module now does complete floodable length calculations in accordance with the regulations.

In order to perform floodable length calculations, you can select the Form Calculations - Floodable Length icon and ensure that all input data is complete and current. The floodable length curve is produced by ensuring for each calculated damaged draft, that the waterline touches a point on the margin line but without making any other point on the margin line go below the waterline. From the subdivision design draft and corresponding trim specified on the Input dialog, the program begins by calculating the subdivision displacement and LCB from the geometry model. Either the moulded or the extreme draft can be used. For each permeability specified, the end points on the floodable length curve are computed first and then the lowest point on the margin line is used to compute the floodable length for zero trim. Finally, the intermediate points are computed and then the results are produced in both graphical and tabular format.

The tabular output is produced in terms of lost buoyancy, LCB of floodable length, floodable length itself, and centre of floodable length, together with the corresponding mean draft and trim.

Superimposed on the floodable length curve in the graphical output, is a plot representing the distribution of watertight transverse bulkheads. The objective, naturally, is for this plot to lie within the floodable length curve, thus demonstrating adequate lengthwise sub-division. The bulkheads must be defined by you in the Input dialog prior to the analysis.

Before running the analysis, the margin line must also be defined. The margin line is assumed to be established by the deck edge points as defined in the Input dialog.