What happens if I increase the size of the boat by 30% than the intented size

[abrahamg]

Hi everyone


Can anyone tell me what happens if i increase the size of the sailboat by 30% for construction than it is intented for as stated in the design ???
( Basicly I intent to add 30% to all dimentions, including the frame thickness)

Also please tell me how make a wooden mast or to find out the radius for a given mast and to put the sail groove in a wooden mast


Any input will be greatly appriciated

Abraham

[Thunderhead19]

I believe that this is a very bad idea, because the resultant effects on stability, resistance and the resulting forces on mast steps and decks doesn't change in simple proportion. You could be horrified at the outcome unless you crunch the numbers.

[jfblouin]

When you change lenght by 30%, you change area by 69% and volume by 120% so your old boat of 30 feet and 6000 pounds displacement look 39 feet long and 13200 pounds displacement after a 30% upgrade. Like Thunderhaed16 said, all parameters while be change, you need to redesign the boat.

[abrahamg]

Thanks buddies.... I was just about to do that.. I changed the berths and the galley and the stowage and was thinking that's it, I got a bigger boat with more volume and cruising capacity.... Guess I have to start all over again....

[mackid068]

Yeah, I guess you do.

[FAST FRED]

Most times it works just fine , IF you crunch the numbers properly.

It will take loads more than a 30% increase in balast , and sail area.

You Might get away with only a 30% larger engine , as many sail boats are way overpowered to start with.

FAST FRED

[chandler]

Francis Kinney has a law of similitude. It deals with changing dimensions in designs. Maybe take a look at it in Skenes elements of yacht design. An excellent book anyway.
He worked for Sparkman and Stephens as well as Rhodes so I think he may know what he's writing about.