Concept boat : some interesting ideas

[Sybarite]

http://hreko.com/concept/

The boat has two rib-like buoyancy chambers running on each side of the boat, just above the waterline. When the boat heels, these provide additional buoyancy/stiffness and the windward one contains water ballast tanks.

 

[sarabande]

hmm, some challenging thoughts there, but that RIB at the stern ??? If the boat is hit by a following sea, the RIB will be destroyed.

 

[Davegriff]

The same idea was proposed for the cross-channel ferries some years ago after some tragic accidents, but don't think it was ever taken up.

 

[sarabande]

Jack Knights had a sailing boat where the transom opened up and a dinghy, with the same profile as the cockpit, could be dragged in. That was about 1965 or so; modern materials might make it easier nowadays, e.g. a small RIB with the tubes acting as soft seats when the dinghy is on board.

 

[bbg]

Alternatively, just make the hull wider and put ballast tanks there.

 

[[70521]]

I would not like to think of the complexity of the system that in and de flated the floats; bound to go wrong at the most inopportune moment.

Would there be arguments over the colour of the balloons, much like I've seen over the colour of sails in another thread?

 

[Ex-SolentBoy]

A few nice ideas but so ugly I would want an NBC suit to wear before I went on it in case anyone saw me.

 

[ProDave]

So when you tack, you have to empty one ballast tank and fill the other?

How long is that going to take?

 

[bbg]

So when you tack, you have to empty one ballast tank and fill the other?

How long is that going to take?

Well, if it is anything like the boats that already have exactly the same system in place (albeit inside the hull) it will mean opening a valve, letting the water run down, and closing the valve. Maybe 10-20 seconds with large-bore pipes between the ballast tanks. Maybe less. Filling empty tanks can be accomplished with a retractable scoop beneath the hull.

You can ask Jean-Pierre Dick what he thinks of this idea, because he has essentially been sailing this design (without the inefficient bumps outside the hull but also without the keel) for 2000 miles. My guess is that it works well enough, but he would still prefer to have a keel bulb (in addition).

 

[Rossynant]

Having seen such ideas already tried, in small scale on lakes here. Mostly such boats did not show any 'improvement' over normal, but a lot of problems.
Whole stability concept here is based on misunderstanding of theory. Such an overly wide boat I knew was capsized by not specially strong wind on mooring - without a sail set, just wind force acting on this bottom. Mast with float on top broke the moment it hit water...
Sailed like a dog, anyway.