Unsinkable boats realy?

That's a good concept for floatation, but perhaps more challenging to design when applied to boats. The air bag on a boat would need durability against puncture from chafing/sharpness/fire/fractures and last to perhaps a lengthy rescue. Malfunction/accidental/mistimed deployment might trap or injure occupants or occupy their shelter space.

FWIW.

PC

 

I don't think I was going that far par.
I can't see some sort of airbag setup being to hard to do. I guess you would have to make sure it was clear below. It might save a steel boat from going to the bottom.

 

Been around for years, can't remember the name though.

 

A homebuilt plane crashed into a house here about 3 hours ago after engine failure. Pilot was fried in the fire. Bet he would have liked a brs.

 

Thanks bpw

 

Apologys for stealing your idea squid, I should have read all of your post first.

 

Any bags would have to be able to tolerate external water pressure on them, inside a flooded area, which means the bags would have to be pretty significant (read heavier, more costly, more bulky, etc.). External bags have been tried, but except on some specialty craft, really just volume eating, maintenance and cost increasing, dead weight that's along for the ride, just for an eventuality, that likely will never occur. Pretty much like the signal flares we replace after they lay in their storage box for their entire life, never having been removed from their wrappers. Just expensive fireworks when their expired date is reached. I'll still have them aboard, just in case, but mostly to give me an entertaining afternoon, come their expiration date. I wonder how many pilots launch off their BRS rockets after they have to replace the $1,000 to $3,000 unit every ten years or so. I can see them in some deserted parking lot with a magic marker drawn picture of their exwife, tattooed on it's side . . .

 

If i had 1 I would tattoo the mother in law on it. A bat out of hell. There was a cirrus sr 20 on the news recently. They have a factory fitted brs. The pilot could not find a landing spot after engine failure. He said the brs saved his life and his passenger's. They really are a great thing to have.

 

A few years ago I called water police at night after seeing parachute flares at night in the vicinity of a barred inlet entrance. Police found kids on a nearby beach had let off daddy's old flares.

 

They have, it was exactly that, I think it was called Yachtsaver or something like that and I believe the Pardeys used the system on Taleisen. The problem is it was expensive so did not sell well enough to stay in business. I think it was a sound idea as most boats could find places to put them where they would do the job. Wouldn't want to be in the pilot berth when the one strapped under the deck above you went off though.

Steve.

 

Always nice to hear, Cirrus are built here in Duluth.

Steve.

 

Sure it is a design challenge and more difficult to accomplish as an add on but it is not too difficult at the design stage. While i don't think it is practical on all boats, ie, I don't think I would be trying to add floatation to an overbuilt tank like a Westsail when i built what is now my sons boat in 1985 full floatation was part of the design brief i gave myself and it was easily achieved and totally unobtrusive for the type of use the boat was designed for and has in fact had unplanned positive side effects. There has never been a time when we have wanted for the storage space we gave up, in fact that's one of the positive side effects, it prevents those areas from being filled with useless stuff that would impact the performance of the boat, the boat is warm ,dry, free of condensation and quiet. There is no down side on this boat. Your mileage may differ.
The Mac 36 cat i had was the same but the loss of storage was more of an issue but i found ways to reclaim some of that without giving up the floatation. The floatation on that boat was huge. While the naysayers always talk of never needing it but a guy by the name of Hal Andersen got to put the flotation of his Macgregor 36, Silver Heels to the test when he was involved in in a collision with a trawler (which hung around at a distance and didn't offer help) in the Atlantic while on a solo crossing from the US to Ireland. A couple of feet of the port bow was knocked off, he was able to stuff a sail in the hole and continued on encountering another gale before safely completing his passage. Im sure it was very comforting knowing he was not going to sink when he was 500 miles offshore and alone.

Steve.

 

"The problem is it was expensive so did not sell well enough to stay in business."



They do, have have done for years and still are available\

eg.

http://www.nauticexpo.com/boat-manufacturer/buoyancy-bag-16658.html


http://www.doowin-dooflex.com/Products&Solutions/Inflatable-Buoyancy-Bags.html


What you have to be careful of in big boats, is trapping someone inside, pinning them or doors in the hull, or blocking companionways from the bags pressure.

Its not like a car bag that deflates seconds later

 

These bags for kayak bows and sterns are the "inflate before setting out" type.http://www.nauticexpo.com/boat-manuf...bag-16658.html

IIRC when liferafts are stored inside a boat they have a big "DO NOT PULL CORD WHILE STILL BELOW DECKS" for obvious reasons but then again I'm thinking "Gee, actually that might be exactly what I might want to do" to save the mothership rather than be sitting in a little raft.

Yes, blocking exits during a swamping/sinking is an issue, as is cost.

I'm thinking of a prepacked stand alone system maybe in Sm,Med,Lg sizes.

Something about the size of a 1/2 gallon milk jug that would contain about a 30gal heavy duty clear plastic bag, and non-toxic, non-flammable aerosol.

It wouldn't be too puncture resistant because it wouldn't rely on any one working, you would have a dozen or more in various nooks and crannies in a typical 30' keelboat, placed where they could inflate without blocking exits. If one or 4 get punctured that is OK because you still got 80% of them working.

Might even have a few instant deflate rip-cords on the bags. Just a plastic strap welded into the plastic bag to pull and cause a tear. Maybe a radar reflecting metallic strip.

The container would have nice loops on both ends and it would be up to the user to tie them into appropriate spots inside or even top sides.

Here is a pic of roughly where they might go on typical 30' sailboat. Little bit too many forward maybe but fore berth seems to be best place and this is about making sure you aren't all alone on the high seas.

Tourist helicopters have inflatables on the skids, but I'm sure those are super-expensive. http://ynaija.com/helicopter-makes-...hudson-river-with-4-passengers-aboard-photos/

I'm thinking of a price point well below a self inflating PFD because each individual unit isn't responsible for saving your life, and you would typically have a dozen or so.

Yeah, I guess you might want to tie a cord from the unit to something stout and lower down. But I think on a typical boat such as shown structural strength wouldn't be too big a factor since the soft bag's force is well spread around the deck/hull seam.

 

Another issue with air bags is simply structural. The structure above the bags has to be strong enough to lift all of the boat below. If the hull deck joint isn't strong enough, well you can imagine the result. This has been a problem with sunken boat recoveries. The recovery team has to first assess whether or not the boat is strong enough to be lifted by the air bags.