Classic wooden boat scantling

Hello,

I have a little question about the scantling of the classic wooden boat : why, if I compare with ISO 12215 rules, the planking is too thick ... and the frame too weak ?

This is maybe a stupid question, but ...

Thank you by advance


Jacques

 

What are you comparing? Classic may mean anything. Is it a workboat or a yacht?

 

My question concern sailing yacht only.

 

There were and are many acceptable scantling rules. If it is a classic, that is fairly old, boat and is still floating, the scantlings are fine. There are many approaches and rules which sometimes contradict each other. The best is to use a single system.

 

Thank you : I know the rule of Nevin, very simple to use.

If I take a boat with a deplacement of 288 cube foot, Nevin give a planking of 1" thick, frame of 1.69" by 1.69" (so SM = 0.80) for a space of 9.49".

If I use the rule ISO, it seems to me that the planking is inferior ... and the SM of frame superior !

In fact, my question is : why the classic wooden construction cannot is treated by the modern rules of scantling, as ISO ?

Best Regards


Jacques

 

You have to remember that the Nevin scantling is for first class wood which is rarely found now, and for extremely skilled boatbuilder to use.
It is not a rule to take without knowing your wood like a professional.

Daniel