righting a multi gone turtle

[GordMay]

Originally Posted by roblanford

I would like to to retract the previous statement about the C&C29.
Thanks

Why is that? Have you learned something new about either of them?
Tho’ I’ve never sailed a “Piver” trimaran, I’d suppose your basic hypothesis to be generally valid (40 Ft more often “safer” than 29 Ft).

[Factor]

Towing bow over stern is a demonstrated succesful way to do it - as recently as the Bris to Gladston the other week.

[Pura Vida]

I learned to sail racing catamarans. When I moved into bigger monohulls I was concerned about them getting knocked down and so far I have not managed to make it happen. Donald Crowhurst spent a lot of effort to develop a self righting system to recover from a turtle and an automated method to ease the sheets if his tri heeled beyond a certain point. Of course we all know the rest of that story.

A couple of companies have offered self righting devices but I suspect they will all go the way of the YachtSaver. The risk vs expense equation does not seem to justify it. A device that would allow an exhausted sailor to right a boat alone at sea is going to have to be pretty simple to use. Personally, I would rather ride out a severe storm in a tank like a Westsail 32.

[Lodesman]

It seems that methods of righting an inverted cat have been around or at lesat discussed for years. I read an article about such tests in the '60s that were successful, but not commercially viable; can't find a link and the memory lacks details. There are a few articles on successful and not-so-successful rightings: Reynolds Sailing Catamarans and multihulls, boat builders and dealers of sailboats specializing in catamarans. Current boats for sale is the trailerable R33 cat and R50 cat designed by boat designers Randy Reynolds and Morrelli and Melvin. and
Speed Sailing Boats Orion that certainly prove it can be done. A while ago, a fellow was building a big aluminum cat in BC - his website (which no longer exists) described his (untested) self-righting system. IIRC, it involved flooding the forward watertight compartments, then when the boat had a bow-down attitude, he would use a counterweight (collapsible water-tanks on the end of a boom) to keep it upright as the flooded compartments are pumped-out. Seems like a plausible solution, especially if one considers Shuttleworth's opinion that sufficient positive-buoyancy be built into the topside of multis, so they float high out of the water when inverted. That would make them easier to right and failing that, more habitable.

[roblanford]

>Personally, I would rather ride out a severe storm in a tank like a Westsail 32.<

Great idea, and if you added an ama and a forward rudder it would make a slow proa. It wouldn't matter if you knew whether you were coming or going. But why would you want to be on one in the first place?

[roblanford]

on a Piver 40AA quit a bit, and a CSY33 a little bit, but never a C&C29 so I felt it was unfair including the 29 in the statement.

The Piver was a pro-built boat that sailed extremely well. I think it was one of pivers later efforts in design.

Multis and monos have at least one thing in common they are VERY stable in two orientations. The multi right side up, or up side down, and the mono on the surface, or on the bottom.

[Pura Vida]

Originally Posted by roblanford

>Personally, I would rather ride out a severe storm in a tank like a Westsail 32.<

Great idea, and if you added an ama and a forward rudder it would make a slow proa. It wouldn't matter if you knew whether you were coming or going. But why would you want to be on one in the first place?

The W32 is a fairly inexpensive boat for what you get, but as you can see I don't own one. In fact I'm sailing a boat that fits my needs in terms for size and desired performance. (I'll admit lusting after an F27, but even for a single hander the boat is too small to spend more than a week with.)

We are talking about righting a cruising multihull and the issues around that problem. My point is that it is not a problem in all but the most extreme weather. For most cruising multi's are very safe and so are mono's. I am just saying that if I am PLANNING to face weather that could turtle a Snowgoose or a Lagoon 42, I would choose a heavily build, double ended mono.

[schoonerdog]

44 cruisingcat, do you remember how the divers did it in multihull world? Did they attach the lift bags to the end of the mast as well? Seems like that would get you a good portion of the way there and then you would need a good engine on a different boat to push you the rest of the way over.

[mikereed100]

Check this out. Gives new meaning to the term "monomaran"

Self righting sailing cat "something else" - Boat Design Forums

[David_Old_Jersey]

More an interested observer than having any views one way or another.........although I have always had a soft spot ofr Tri's - but never owned any multi.

I guess on righting a cat or tri using buoyancy attached to the masts would presume that they still had the masts attached........is this usual?

Although I can see the attraction of an inverted multi over a liferaft, I still get the feeling in my gut that a well founded multi is more likely to invert than a well founded mono is to sink..........in weather where I would want to have litterally battened down the hatches. Rolling in a mono would for me rate as a very scarey event. Flipping a multi would to me be as terrifying as pitchpoling a mono

I recall back in the 1970's that some cats (Hirondelles / Iroqoius?) had large "balls" on top of the masts, with my understanding that these were meant to prevent inversion........I don't recall seeing them nowadays.......


Using all my design skills and resources (back of cornflake packet ) I would favour using both wave action, maybe a drogue AND a giant dive bag attached to one side of a tri and or the mast, with the other side flooded.......but I guess you would need the centre hull to be water / airtight..........although I guess partly flooding the centre hull may be part of the solution???

[bryanweaver]

<<<I recall back in the 1970's that some cats (Hirondelles / Iroqoius?) had large "balls" on top of the masts, with my understanding that these were meant to prevent inversion........I don't recall seeing them nowadays.......>>>


Wasn't that an Aqua-Cat's trademark? Along with an A-Pole rig?

[dennisail]

Originally Posted by mikereed100

Check this out. Gives new meaning to the term "monomaran"

Self righting sailing cat "something else" - Boat Design Forums

I posted that. Funny it didn't get any comments after I showed pics. It might be ugly, but that is the first unballasted self righting cat I have seen.

[David_Old_Jersey]

Originally Posted by dennisail

I posted that. Funny it didn't get any comments after I showed pics. It might be ugly, but that is the first unballasted self righting cat I have seen.

becuase of the large dome it will will flip back on its hulls when knocked down. He says he has been knocked down entering bars in it and it flipped back up. He went on for ages about its design features.

Self righting or not - I really would not want to go sailing with someone who seems so pleased about his self righting experiances!

It sure is ugly though!

[Lodesman]

Dennis,

OK - I'll comment. It's an interesting design, that's certain - and notwithstanding its ugliness, I generally don't judge a book by its cover and can see any boat's inner beauty. Unfortunately, the design would be impractical for a cruising cat. It looks as though it was designed to be very narrow to allow it to be trailered. With such a narrow overall beam, it lacks stability so it is inevitable that it should capsize routinely - that goes against the whole purpose of having a cat, which is to stay upright. Translate the design to a typical cat of 6m (20 ft) plus beam, and the dome would create an unacceptable amount of windage - not to mention creating a massive tipping moment by having the centre of sail effort some 12m (40 ft) from the centre of buoyancy. Not only would it have a greater tendency to capsize, it would have a greater tendency to pitchpole, too.
From an ergonomic perspective, it's certainly less roomy than a normal cat, and I would assume less roomy than a mono of similar size. If he needed a trailerable, he should have gone with a mono, or a folding cat/tri. Some people just like to be different.


Kevin

[Pblais]

Would a tank of helium to fill the bladder increase the chance of full unassisted capsize recovery?

Perhaps using the helium to inflate a balloon attached to the dinghy would serve as the better solution and thus leave the boat behind and go airborne. Using air to displace water as a mechanism would work but the balloon to encapsulate the volume without bursting might be the trick. The advantage of helium over plain air I don't see would be significant unless of course you want to go airborne.

The stress on the skin of the balloon is going to equal the amount of water displaced so this is not some wimpy balloon fabric. To attach that same force to the masthead inverted would be the next challenge. The application of such force holds all sorts of logistics especially with just a lone crew at sea. Operations performed from another platform (another boat) have all sorts of mechanical advantages.

Using the inverted hull as a rescue platform may hold more possibilities, though having a raft to leave the inverted vessel behind seems like the "more options" oriented solution. It's hard to beat redundant non-dependant options. You can stay with the boat or leave.