Ersatz Multihull?

[y6e29x7]

Hello,

I've been thinking about building an ersatz multihull in the 30 to 40 foot range; but on the cheap. I'm willing to use unconventional materials and construction methods, such as pontoons, pvc and ping-pong balls, or even strapping a couple of monohulls together. This will be a strictly no-frills afair. I'm also considering the salvage route. Has anyone done something similar?

Any ideas appreciated.

[Sos]

I would suggest that the salvage route will be safer!

[atoll]

ferro cement hulls and telegraph poles for mast and cross beams.......
talk to simon for ideas on propulsion.........

https://www.youtube.com/watch?v=2Dx7lHKH5I0

[Teleman]

The professionals who will have to come and rescue you will not be amused.....

[Sojourner]

Originally Posted by Teleman

The professionals who will have to come and rescue you will not be amused.....

Right?? I get a little puckered up sometimes in my proper little ship. I couldn't imagine how many valiums i'd need to take anything like that cat in the video out farther than i could wade back....

[GordMay]

Greetings and welcome aboard the CF, y6e.

Yes.
“Hot Rod” did just that ➥ http://www.cruisersforum.com/forums/...-108559-3.html

[NCGunDude]

I second the salvage route, why re-invent the wheel?

[owly]

There are some Utubes on a J 24 converted to a trimaran using Hobie hulls for amas. There are of course structural issues that have to be taken into account when joining two or more hulls. It absolutely can be done, and can be done safely if one has the engineering knowhow, and is willing to spend the time and money, and chooses appropriate hulls. People have been doing it for thousands of years. The polynesian double canoes were nothing more than two large canoes joined together with tree trunks. James Wharram's designs which are highly successful are based on these. That said, even multihulls built by professionals have come apart at sea. Read about the 1968 Golden Globe Race (the first solo round the world race). A voyage for madmen. Two of the trimarans in that race suffered structural breakup to at least some extent. The famous designer Arthur Piver was lost at sea, and it is suspected that the boat he was sailing, which was a poorly built borrowed boat, may have broken up at sea.

Another thing to consider is performance. Catamaran hulls, and trimaran hulls are narrow beam for their length. You have to drive the resulting boat through the water..... What are you going to do for a mast / masts, and rig. You also have to consider leeway prevention. You will be removing the ballasted keel, or ballast. You don't want a keel hanging down to trip and flip the boat, so you will want a centerboard (s), or daggerboards, or a low aspect ratio keel. If you do a catamaran, you will probably want to go with a biplane rig, or you will have to design a mast beam capable of taking a lot of down pressure, but with two large hulls, a single rig may not be sufficient without making it huge, and that increases capsize potential.

The real question is what is gained by doing this? Is the object to save money? If so, forget it. There are a host of problems, and it's up to YOU to work through every one of them. By the time you're finished, that Searunner 37 that needs work will look like a screaming bargain, or that old Prout, etc....


H.W.