Floodable Lengths Analysis

Floodable lengths are one factor that determines the load line.  This is a measure of reserve buoyancy in the vessel.  Other fac

A floodable lengths analysis happens at the beginning of a concept design.  It is part of the stability analysis for the vessel.  You use the floodable lengths analysis to determine the beginnings of vessel compartmentation.  The vessel is carefully divided to consider damage stability.  The intent is that any compartment can be punctured and flooded without the vessel sinking.  This is different from a damage stability analysis.  A floodable lengths analysis is a quick process and only checks that the vessel remains floating.  A damage stability analysis a long involved process and ensures the vessel remains floating upright when damaged.  Eventually, a damage stability analysis is required.  But this should be done later it the design, after you have decided on several other design parameters.

A floodable lengths analysis is sometimes also used to determine the vessel load line.  Floodable lengths are one factor that determines the load line.  This is a measure of reserve buoyancy in the vessel.  Other factors include structural strength.

Deliverables

The output from this task is typically a report.  The report normally includes several other types of stability analyses as well.  The report is not always submitted to regulatory bodies.  It may be internal use only.

In some cases, the floodable lengths analysis is used as part of a larger analysis to determine the vessel loadline.  These do need to be submitted for regulatory review.  Expect additional engineer support to address any comments from the regulatory society.

Budget

An experienced naval architect will require 1 – 2 weeks to complete the analysis, depending on available information.  The engineer will use hydrostatic software to analyse the vessel for a variety of loading conditions.  This also may require developing a hydrostatic model.  Model development may require an additional 1 – 2 weeks.

Schedule

The schedule should be somewhere between 1 – 4 weeks.  The report writeup is a contributing factor.

Required Information

The following documents will be especially helpful.

1. General Arrangement
2. Stability Booklet
3. Lines Drawing
4. Any 3D models of the vessel
5. Tank plan
6. Tank capacity table
7. Typical operating region