And what do we think about this? Nice small boat, but that righting cycle looks a bit dubious in capsize conditions? Cool that somebody try to get coastal racing going on small multis! One day I'll certainly get a craft like that for fast-fast coastal cruising and daysailing with family/friends (I even want to do some fishing with it).
Question one, what kind of serious hydraulics or pulley system are installed to lift the middle hull out of the water by pulling the outer hulls together?
Question two, what is holding the mast up when doing this manoeuvre???
The boat looks cool and the re-righting concept is certainly something to think about, but in its current form, totally unfeasible.
Infact I said it was something to think about, and now that I have thought about it some more I have more to add...
The basic concept is to reduce the stability of the boat when capsized. This makes it easier to right. To reduce the stability significantly, the outer hulls need to be brought close to the centreline of the vessel. There are a couple of ways this can be achieved; by sliding them sideways (along the beams for example), by folding the beams about vertical hinges (outer hulls go fore or aft), by folding the beams about longitudinal hinges (outer hulls go up or down).
Once you've reduced the stability you have another problem to solve of applying a righting lever to get the boat upright. The easiest option is a weight of some description. The main hull may be best for this purpose.
I haven't figured out the problem of keeping the rig up without stays yet; except for having a freestanding rig, which I don't like.
THere was a demonstration of a Farrier tri doing an ama fold up while capsized to achieve self-righting. THe mast on the farrier has temporary "baby" stays that connect to the middle hull to hold the mast while the wings are folded. I guess you need to set these in place prior to self-righting. Should be tricky while inverted.
The Exploder doesn't seem to have a cantilever fold mechanism like the farrier...so it requires hydralic assistance. From the photos on the site , I can't tell how this works.
Mike.
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I didn't say it couldn't be done.
Infact I said it was something to think about, and now that I have thought about it some more I have more to add...
The basic concept is to reduce the stability of the boat when capsized. This makes it easier to right. To reduce the stability significantly, the outer hulls need to be brought close to the centreline of the vessel. There are a couple of ways this can be achieved; by sliding them sideways (along the beams for example), by folding the beams about vertical hinges (outer hulls go fore or aft), by folding the beams about longitudinal hinges (outer hulls go up or down).
Once you've reduced the stability you have another problem to solve of applying a righting lever to get the boat upright. The easiest option is a weight of some description. The main hull may be best for this purpose.
I haven't figured out the problem of keeping the rig up without stays yet; except for having a freestanding rig, which I don't like.
maybe the folded amas can be used to cradle the mast? probably would scratch up the hulls really good and put a lot of load on the mast at that resting point.
- The concept is fine. - Keeping the mast up is doable, if all stays are attached to the mainhull. - Strong and clever hardware is required in the beam-hull connection in order to keep the beams from folding up when sailing.
So far, so good. Now for the tough ones:
-Very strong hydraulics are required to fold the beams up and lift the boat out of the water to self right. -Beam restraining hardware must self release when upside down. -Activation of the hydraulics should also be authomatic. -The last two items require six relay systems, causing dependence on electricity.
Conclusion: good concept on paper. Needs a lot of R&D to come to life.
Would you hand crank or use drive motors? With sealed gel cells you wouldn't have to worry about leaks in the inverted position and they should still work. Or could you use a linear actuator (if you can get a strong enough one) to move the amas?
Well despite all those who think it`s a nice theory, they seem to have built one, photographed it for us to see it`s real, and even found a sponsor to foot the bill. I`d like to believe they`ve even tested their theory and the folding mechanism actually does work, instead of being something that "needs a lot of R&D"...
Having said that I`m sure it won`t be fun trying to right it in 7m swell and howling wind in the middle of the Atlantic in the night. But at least it allows the possibility of not having to be rescued when it all goes wrong. That is, if it works as they say it does <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />
Aha...the stays have multi-purchase systems on them for canting the rig but I bet, if long enough, that they could also be enabled to lift the amas and support the mast...although that's not what they have in the drawing and they talk about hydraulics (probably manually activated hydraulics).
Am I the only one that wonders about the word "explode" being in the boat name? <img src="http://www.catsailor.com/forums/images/graemlins/tongue.gif" alt="" />
John Williams
- The harder you practice, the luckier you get - Gary Player, pro golfer
After watching Lionel Messi play, I realize I need to sail harder.