Please help with a community crowdfunding project..

[Fish 0]

Hey, all!

 

'Voting' is free and doesn't involve any donation or commitment.....

 

Lots of sailors and their families will send you many warm fuzzies.....

 

 

Cheers

Mark

Looks like you need reading lessons then. He's been clear. You vote for the project on another website. He wasn't ever asking you for cash.

 

If your going to jump on someone, get your facts straight.

And if your going to dish it out, you need to be able to take it too, Wheels.

[Terry B 71]

Wheels, you need to back off a bit and re-read what this guy has posted - and read the posts properly.

 

He hasn't asked for money.

 

He (politely) suggested the sharing of IP - very politely, if the other people wanted to.

 

I can't see what your problem is.

[banaari 27]

To be fair *I* only lightly skimmed the original post and assumed that "crowdfunding" meant a request for money too.

The bulk of Wheels' contribution to this forum are fair and reasonable; lay off the guy he's probably got the point already.

 

Back on track: Just how much buoyancy would be needed to prevent a large multihull capsizing, given that it would be acting on the end of a helluva long moment arm?

Because at the expense of windage aloft, you wouldn't need a terribly big float, permanently deployed and free to turn into the wind... as recently seen on the mastheads of the rental cats at Brighton.

[RushMan 31]

The float will not prevent a capsize, it is to stop the multi from turning turtle

[banaari 27]

The float will not prevent a capsize, it is to stop the multi from turning turtle

Simply following the terminology used through the thread. Even this mono-hull owner knows that a float won't do much until it's actually in the water

[Guest]

I think the new Inflatable batten technology has come a long way, this should be adapted, On his other Quirky page he has a similar drawing to my thoughts. A lot of the larger cats have foam core masts and the rigs float anyway, but they do break on impact due to the shear forces against them.

 

Im thinking of something in cloth with a reasonable volume when inflated (50 litres), attached at the caps, not at the mast head, reason for this is it will give you adequate floatation to keep the rig afloat and stop the boat turning and It is a lot more stronger structurally. Due to the size it will be a lot easier to remove being at the caps, forestay region. with a cylinder kept low in the hulls, a simple fine tube used to inflate.

 

One use, then replace buoyancy as packaging needs to be real tight to allow less windage for the inflatable buoy.

 

Ideally if it was done right you could have the boat back up and sailing for the next race, towed upright with support boat, replace inflatable pieces, then send it and try killing yourself again... Sounds fun.

[Kaihe Atamai 2]

X box accelaraometer...?? Will check it out...all ideas greatfully received.

 

And please keep the comments positive, folks, this is meant to be a "community-run-and-funded-public-project" wiyth results open to all....

 

...even so-called "legit" businesses.

 

It's about safety at sea...not profits for a few....

 

It seems to me that your project has merit and the means by which you are trying to achieve it is valid.

 

Might not need the whole Wii setup, perhaps just a MEMS gyro:

 

http://invensense.com/mems/gyro/itg3200.html

 

Also sounds like a good Raspberry Pi or Arduino project.

[Island Time 1,235]

Hmm, considering a cat (or tri) on it's side;

 

With mast horizontal, there is/would be little load on it, how much depends on the center of gravity and center of buoyancy, so design dependent. However, as the upper hull/s pass the vertical point and the boat rolls further, the load will increase rapidly. So, mast tip in, the boat is passed horizontal already, the float would need to be big enough to hold that load. Without the calcs, and a particular design specs to be certain, I'm pretty sure that a lifejacket type cartridge would be too small, except for a very small boat. However, if this can be done, then the question remains, what then?

 

Perhaps the boat, using the hulls and deck as a sail, and the rig as resistance, will turn downwind and hopefully down wave. If it does not, then a wave may well finish the capsize. This is one situation where a drogue from the masthead would be of benefit! Once orientated so the rig points to weather, it will be easier to right the vessel. This has actually been accomplished before in a cat, flooding (partially??) the lower hull to assist in the operation. The skipper did it himself, without outside assistance. I'll see if I can find a reference to that, but it's been a while....

 

Something to think about on a wet day anyway!

[Island Time 1,235]

Here is a link to it for anyone interested http://www.kelsall.com/TechnicalArticle ... Safety.pdf

[Guest]

[

 

Might not need the whole Wii setup, perhaps just a MEMS gyro:

 

http://invensense.com/mems/gyro/itg3200.html

 

Also sounds like a good Raspberry Pi or Arduino project.

 

You are onto it Revo. Perfect for Arduino, a while ago I looked at setting one up as a supplementary gyro talking NMEA to the auto pilot. The are very, very accurate and no moving parts.

[Kaihe Atamai 2]

[

 

Might not need the whole Wii setup, perhaps just a MEMS gyro:

 

http://invensense.com/mems/gyro/itg3200.html

 

Also sounds like a good Raspberry Pi or Arduino project.

 

You are onto it Revo. Perfect for Arduino, a while ago I looked at setting one up as a supplementary gyro talking NMEA to the auto pilot. The are very, very accurate and no moving parts.

 

Though they drift to leward more than a modified Ross 830 in a blow, some sort of compensation is necessary (I heard a rumor, just hope you're planning to sail with RYC...)

[buzzook 0]

sm

That's been my understanding, too, and the reason why most previous efforts (viz the CrewMaster permanently-inflated device for example) have not worked.

 

The biggest problem I think will be to figure out how to retrieve the bag once deployed and the boat flipped right side up.

 

You don't want to leave it flapping about at the top of the mast!

 

My idea as to a solution for that issue is to have it retrievable via a vaccum pump - eg: the double-acting hand-operated RIB pumps for low tech; or a battery-powered vac pump for super high, tech or larger boats.

 

I'm fairly sure that's do-able via the same hose used to inflate the bag.

 

The next problem to solve is how to secure the bag once it's deflated, which has me stumped, because unless you use some sort of electrically controlled spring - that both releases when fired and re-attaches once deflated, I'm at a bit of a loss.

 

It may be that this is unsolvable, short of climbing the mast on a bigger boat, or laying a small boat over on its beam ends to repack the bag.....

 

And I'm guessing that problem is what has stopped anyone else from pursuing this idea further.

 

I had a thought that a type of 'snuffer' - fabric but with wire reinforced opening at mast side, could attach at the top of the mast, but have a cord attached that leads down the forestay )or somewhere) and is attached at deck level with a long tail on cam cleat attached to a hinge - so that as the bag fires and the 'snuffer' is popped off the compressed bag, the deck line would 'trip' and unleash.

 

Once deflated, the snuffer leash could then be pulled taut again thus (hopefully) protecting the bag and stopping it flapping about, but leave it available for redploymen once the cartdrige or firing mechanism was re-armed, say with a couple of spare canisters carried on board.

 

Thus is ti could be used multiple times during a day sail, but could also be secured sufficiently for cruising sailors until such time as it was again safe to climb the mast and repack it [properly.

 

The only other alternatve that i can see would be to engineer it so the bag was attached to a halyard - hauled to the masthead and cleated off - then once deployed it could be lowered and repacked.

 

The biggest issue I see with this option is that an in-mast inflation tube, with canisters located at deck level, probably could not be used, and the canister would have to be integral with the bag.

 

Which may be what the Safety Systems guys were trying to do as pointed out by jono, with their airbag fired by a lifejacket mechanism.

 

Hence why I'm looking for someone with more engineering nous so we can figure out the weight of such a system, but my gut feeling is that it's already too much weight at the top pof the mast, and the canister(s) and the firing mechanism being up there as well would make it too bulky and thus interfere too much with the airstream around the top of the sail.

 

Anyone got any better / different ideas?

[rigger 47]

another option...

What about a disposable bag / balloon - something like a weather balloon only more robust.

Jettison once vessel upright and rig another one?

Have a bracket fitted at mast head that has a halyard rigged to it with downhaul, haul unit up till it locks into bracket. Downhaul and halyard rigged in such away that the downhaul can only pull the unit down when halyard is eased and as it does it releases the bag / balloon.

 

About triggering the thing????

Manual activation....

[Guest]

Sounds like air bag technology revised. Pack it in a cylinder with a bungy style retractor? You are not talking huge volumes of air per fill maybe a couple of cube/m for a 30 something foot cat at 10:1 leverage at the MH so multiple fills would be possible from a small bottle.

 

Manual activation is a great addition, nice one Rigger.

[buzzook 0]

You've still got the problem of the canister needing to be hauled up as part of the set-up, with all that bulk and extra weight up high.....

 

.....unless you had a massively long flexible airline inside the mast so that you could haul the bag down on the outside while leaving the rig attached to the airline, then pull down on the airline as the return halyard...???

 

Then the manual trigger could be at deck level.

 

This is one reason I was cooking at the cafe-style creamwhip jars, as they have a spring-loaded trigger already fitted, and the screw fitting to add CO2 canister(s).

 

I'm guessing the standard size 100mm ones for whipping cream won't be anywhere near enough for an airbag, even on a small boat, but there are larger canisters, and multiple canisters could be rigged with an adapter off the creamwhip can...so with T-junctions any multiple of canisters necessary could be added....

 

...depending on how big the airbag was for a particular sized boat.

 

Been doing some googling on fabrics, and I suspect the rubberised heavy-duty Hypalon or PVC airboat fabrics will be way too heavy, but I found where those metallic-fabric helium fairground balloons are made, and they are a type of laminated fabric - like Mylar....

 

....so maybe there is a lightweight sail fabric that could be adapted to duit the purpose, and welded rather than sewn to make it 100% airtight....

 

Thoughts?

[Guest]

at the cafe-style creamwhip jars, as they have a spring-loaded trigger already fitted, and the screw fitting to add CO2 canister(s).

 

I'm guessing the standard size 100mm ones for whipping cream won't be anywhere near enough for an airbag, even on a small boat, but there are larger canisters, and multiple canisters could be rigged with an adapter off the creamwhip can...

 

They are nitrous oxide canisters, you can get them in large bottles, aka laughing gas......, mr whippy use them and the dentist also, try boc gases??

[Guest]

Air line in the mast, plastic tubing to say a 1.5mm wall tapered alloy/carbon cylinder, bag bungyed inside, not going to weigh that much and if you are that pedantic about weight you are probably not in the market. Need a supper slippery fabric or its going to bind. Cylinder at the mast base, remote trigger + Mems Gyro chip setup or similar.

 

Have you done a patent search on the concept? that may be your biggest obstacle?

[idlerboat 116]

Hi all, I have been wondering about this ...

While waiting , looking up and hitching the crane today (we pulled three masts , on monos)

I understand the righting moment on a mono once it gets to a balance point.

But my question is....how far above water does any kind of inflation device have to get, to allow a cat to self right ?

 

I do understand that it is a factor of the beam. But is there a reasonable formular that says , and this is only an example " the mast 5 deg above reasonable horizon"?

Again I understand that enviromental factors could drasticaly change this formular, needing say a certain oreantation to wind and wave.

How difficult is it to manipulate a cat to a favourable state in crappy situations ?

 

I was thinking that it would be harder once the flotation device was deployed as opposed to when the cat is turned turtle, meaning that it would be very important to orientate before deployment....

 

Just some "food for thought"..

[Guest]

Partially sink the hull in the water, right it then pump out IB. Better than the other option.

 

Not great for the upholstery but worse things happen to upholstery at sea...

[idlerboat 116]

Ok, I understand that EE.

Can that kind of "water management" translate to a big cat , say a cruiser of 30 foot or more ? I know that we are talking about a very rare thing, cause most big cats dont turn over that easily...but just in that once in a life time ?

Fare chance you are going to flood an engine ?

Serious question ..how do you flood one hull?

Now I am a nutter as everyone now knows....but what if you could change the rig angle ?

Cats stays are by nature very simple.

If while the vessel was upside down you "canted the mast" and then activated your bouyancy you could push past the self righting moment.

HMMmmmm

now that I think about it you would have to deploy first and then cant the mast.

The vessel would stay in equalibriam (im not a speller) till the hulls went over centre. Bouyancy would then take hold.

For me the engineering side is easy (well ok a lot more bits) but not that hard.

The way I see it is that the flotation could be flat and lateral...a much easier thing.

Just a thought....