General HydroStatics
Ship Stability Software
Command of the Week
(New or interesting aspects of GHS that you may not know about)

(Requires GHS FL module)

The classic Floodable Lengths calculation is a quick and easy way to get guidance about spacing between bulkheads without needing compartments in the model. The curves show the maximum hypothetical distances between transverse bulkheads such that flooding keeps the margin line above water. Minimum GM can be added to that criterion simply by specifying it on the FL command line.

The "teepees" shown under the curves (preferably under and not much crossing the curves) derive from bulkhead locations which you provide on the FL command line. In this case the teepees are for single-compartment flooding; multiple-compartment flooding can be represented as well. Yes, there is tabular output too.

When damage stability is studied in detail, other GHS commands are used and a complete geometry model is required including compartments and tanks subject to flooding. The model is experimentally flooded and stability is evaluated via criteria applying to the righting-arm curve. Many things may be considered such as loss of loads, cross flooding, and probabilities of flooding and damage. Don't forget intermediate stages of flooding, did someone say? FL does that (when it looks at GM), and it always did even before intermediate stages were commonly required.

While newer methods may overshadow the importance of Floodable Lengths, none of them can boast a graph as pretty as the one you get from FL. We recommend that every stability report include the FL plot if for no other reason than that.

Questions, comments, or requests?
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