KB from lines plan

Hi,

Just a quick question.
What is the simplest way to calculate the KB from a lines plan, shall i first calculate say the sectional area of say 15 sections and then ???

Thanks for your help.

Ivan

 

I don't know of any real shortcuts... It's pretty much the same as finding the centre of gravity of a homogenous solid... something that should be described in most basic math, physics, or engineering texts (solids). If you've got it in cad you can often get the areas of regions from the package, and if on paper a planimeter is a common tool... either that or graph paper... From there you've gotta calculate the moments of areas from a reference pt and then divide that by the total area to get the location of the CoB from the reference point. Usually has to be done in all three dimensions, but most boats have symmetry so TCB is often zero...

Good luck with it...

Cheers,

Dave

 

You can use Morrish's formula (approximation):

KB = 1/3*(2,5*Tc-V/WPA)

Tc = Draft of canoe body
WPA = Water plane area
V = Dispacement volume

Not sure if this is the original, anyway it gives reasonable numbes.

 

Do the standard 11 or 21 station layout, compute sectional areas and use simpsons rule.