On 15 Jan 2005 08:49:10 -0800, "Narasimham"
wrote:

Am mechanical engineer with a composites background presently residing
in south India. After recent Tsunami disaster, toying with the idea to
help make hand /sail/outboard moter powered fiberglass fishing boats of
standard 30 feet length. Raw materials .. chopped strand mat,
fiberglass cloth, polyester resin and rigid PU foam are commercially
available locally, as is semi-skilled labour who could make boats to
pre designed drawings.

Can someone help to guide in the following ?
Shapes: Are drawings available on net? or on payment? What hull shape
is better? U? Flatbottom?

Do Lloyds or other certifying agencies based in Europe/US have a
branch or mechanism to test and certify marine craft after fabrication
and testing when involved right from beginning stages in India?

If existing wooden hull shapes are duplicated but replaced by solid
fiberglass laminate or polyurethene foam (closed cell to keep out
water) sandwich, would it serve the purpose with stability resisting
wave forces with adequate margin before capsizing?

If the density of the new hull materials duplicates the wood, the
capsize behavior won't change. If the new hull is thicker or thinner
but weighs the same overall the behavior still won't change enough to
notice.

For a physics picture of stability:

1) Is metacentric height a parameter to assess stability?

Yes, it is one factor.

2) Draft. On what factors is load-depth of immersion relations
established?

The volume of the immersed part of the hull displaces the weight of
the vessel in water. That is what displacement means.

HTH



Rodney Myrvaagnes NYC J36 Gjo/a


Capsizing under chute, and having the chute rise and fill without tangling, all while Mark and Sally are still behind you