The
End of Stability
Work,
work, work! No time for blogging until now.
Let's
look at a really round bottom boat first.
So
first we'll join the chines which leaves us with a trapezoid, and
finding the centre of that is described here (centre already marked).
If we join the centre of that line with the centre of the curve we
essentially have two almost triangles and finding the centre of those is
described here.
Once
we have the centre of each almost triangle
We
can join those centres with a line.
Where
that line crosses the line join the center of the curve and the chine
line is the centre of the area as both almost triangles are the same
size.
We
then join the two centres of area and do the math set out here and
that gives us the centre of buoyancy
Again
if you overlay this hull with the other two the centres of buoyancy
are almost the same.
Well
what about a boat with no parallel sides. That's even easier than our
square boat.
You
can divide the underwater area into two triangles and we already know
how to find the centers there so I won't go into detail. What is most
amazing is that an overlay of this dory type hull onto the other
three puts the CB in almost the same place as all the others.
The
only thing that is the same about the four hulls is their waterline
at the beam. The dory shape is very much smaller displacement
although the other three are about the same. I'm going to investigate
this further and will comment on it at some later date.
Next time aesthetics or does it look good?
