Monohull that becomes a muilthull

[mitch123]

I am studying Boat design and I'm currently researching boat stability.
Ive been researching Monohull sailing yachts and the different systems into giving increased stability. While sailing and at anchor.

Im looking at Monohull super yachts around the 30-40 meter mark.

What systems that are able to give the stability of a multi hull but still remain a Monohull.

Also is there a system that uses pontoons or outriggers to achieve this??

Any input will be appreciated.

[sabahcat]

Originally Posted by mitch123

.

Also is there a system that uses pontoons or outriggers to achieve this??

And this vessel would then be called.................

[rwatson]

You need a "flopper-stopper".

Or a heavy floating body firmly attached to the end of the boom by rope, and the boom swung at right angles to the hull.

http://www.myboatsgear.com/mbg/product.asp?prodID=1628

then there are gyroscopes
http://www.seakeeper.com/

[mitch123]

Originally Posted by sabahcat

And this vessel would then be called.................

A multi hull...yes, however if that boat could then after a days sailing retract the outriggers to give a much smaller beam? either closer to the main center hull or into the hull completely, resulting in a singular hull?

Are there any boats that incorporate such a system?

[rwatson]

Originally Posted by mitch123

A multi hull...yes, however if that boat could then after a days sailing retract the outriggers to give a much smaller beam? either closer to the main center hull or into the hull completely, resulting in a singular hull?

Are there any boats that incorporate such a system?

Farrier Trimaran for eg

[rwatson]

Another variation of a monohull stability system - enlarged handrails ?


http://www.canoekayak.com/touring-ka...south-america/

[cthippo]

Originally Posted by rwatson

Or a heavy floating body firmly attached to the end of the boom by rope, and the boom swung at right angles to the hull.

I thought that was called a "wife"

[rwatson]

Originally Posted by cthippo

I thought that was called a "wife"

is that why there is no "Mrs cthippo" ?

You have to be more careful with your friends.

[cthippo]

Originally Posted by rwatson

is that why there is no "Mrs cthippo" ?

There is no Mrs Cthippo because any woman smart enough for me to be attracted to is smart enough to run away very fast

[u4ea32]

Um. Its 30 or 40 meters LOA!

You won't have any stability problems at sea or anchor. Unless you are a total *****. Skinny, fat, deep, shallow, as long as the CG is reasonable to function as a sailboat, your length (and displacement) have you totally covered.

Now if you were talking about 30 or 40 feet, then maybe you want flopper stoppers over the side at anchor. And maybe you would pay a little more attention to vertical center of gravity, at least if the displacement is light (DL ratio under, say, 150).

But on a 30 or 40 meter sailboat, even if really REALLY poorly designed (like a cement schooner with brick decks), you won't have a problem. You wont be able to cause a problem unless you really, really try hard, AND you are a *****.

[FAST FRED]

WE were working on an Atkin 39ft that was slimmed down to fit into a shipping container. World cruising , with no ocean passages!

The simplest concept we could come up with was built pole mounts to hold the dink a couple of ft off the vessels side.
Cruising in a rolly anchorage would still require 2 anchors so the boat could be pivoted to point into the waves , but she should not period roll.

FF

[rasorinc]

I had a picture of a boat that had floats on each side that lifted up vertically over the top so that the boat could be trailered. Cannot find the pic now. It did not show the locking system when down but the arms were made of round pipe. It was a sail boat.

[rwatson]

Originally Posted by rasorinc

I had a picture of a boat that had floats on each side that lifted up vertically over the top so that the boat could be trailered. Cannot find the pic now. It did not show the locking system when down but the arms were made of round pipe. It was a sail boat.

Was it an 18ft sailing skiff like this one ?

[Fanie]

A skiff ?