Inflatable Yacht?

I'm just curious about the limitations of inflatables. Has anyone ever designed a large sailing cat or tri with inflatable pontoons? How would the weight compare to an all rigid multi-hull?

 

fill the pontoons with helium.

 

The shapes possible would be limited, but I don't see why floats couldn't be engineered that complimented a specific design class. A medium/small boat would be a good size, say from 20-30 ft. A certain amount of stiffness is needed, but not too much as the material remembers how to return to its former shape.
I like the idea. Maybe a free-standing mast would allow the whole strfucture to be inflatable. I should think the one big problem with multis, collision with floating objects, might be somewhat mitigated.
As far as weight goes, that's a good question. i think maybe the inflatable would be heavier.

 

This is an engine powered cat:
http://www.antrimdesign.com/powerboats/88.htm
But no reason why it cannot be sail powered. I believe you could make the hulls lighter than a rigid version but you could not use the hulls for storage or living room.

The inflatable hulls tend to be quite forgiving of impact due to in-built shock absorbing. A light carbon fibre bridge would make for a lightweight boat.

A smaller one also:
http://www.antrimdesign.com/catamarans/waterwalker.htm

Rick W

 

The Proteus is an awesome design, I was actually looking at pictures of it yesterday. If I could only afford carbon fiber, I would seriously consider it as an option. All that room in those tubes could be exploited for storage of a lightweight fuel like hydrogen.

It seems that small-scale commercial/personal availability of a usable inflatable cloth such as hypalon beyond something in the scale of a patch-kit is extremely limited, and I was surprised at how little information I could find on home built inflatables.

 

Just an FYI: perhaps because of the lighter loading there are many hovercraft which have had inflatable parts.

Body and Hull

Side Sponsons

Fold out deck

Let me know if you want to know more, many are posted at the Hovercraft Museum website.

HM:
http://www.hovercraft-museum.org/man-index.html

Or try here:
http://www.bartiesworld.co.uk/

Ron Fishlock of Canada did a lot of work on this side topic.
http://www.howardboyle.com/canhover_history.htm
http://www.howardboyle.com/fishlockhcraft.jpg

http://www.decastris.com/hcc/builders/airidetech/airide.htm

 

I suppose it makes sense, if you have a constant supply of high pressure air while running a vehicle, why not use it to maintain the structural shape? It's certainly an interesting idea.

 

Some hovercraft designs used rubber rafts as the hull, this would be sealed and not connected to the lift fan.

Other designs I think did use the lift fans, however the folding decks and sponsons I'm thinking of were filled with an on board compressor and then sealed up.

Again the low loading might be more comparable to the tarp or netting on a catamaran or in many cases the floatation in an RIB.

 

http://letmegooglethatforyou.com/?q=inflatable sailing catamaran

or just pics - http://images.google.com/images?hl=en&q=inflatable sailing catamaran&gbv=2

 

I've seen listings for smaller inflatables of course, I was wondering more about the size potential of such craft, and often people on this forum have good knowledge of unique examples that I might not be able to find otherwise.

 

Personally, I'd be afraid the idea conceptually for anything bigger than you'd sail off a beach. Images of a cut or tear or the seams splitting 200 miles from land...

 

Here is an interesting inflatable yacht:

http://gizmodo.com/gadgets/gadgets/...ps-around-the-bay-in-dazzling-demo-230401.php

Here is a demo video:

http://www.flixxy.com/proteus-experimental-watercraft.htm

 

Looks awesome, and only sits a foot deep in the water. It looks like the pontoons are made up of multiple segments as well. I'm going to have to search for some more detailed technical info on this project.

 

There was an inflatable cat called a 'catapult' in the UK back in the 80's
Worked well but it was only about 15' long