Liferaft inflated in a cabin??

[fisherman]

The older RNLI boats had a retro fit flotation bag on the roof for self righting, one of those might be good and a better shape. Stowed flat in the cabin sole, webbing straps over and to strongpoints? The water will always come over the bag anyway, so inevitable loss of space, and possibility of injury if you were caught inside.

 

[stevebrassett]

Mythbusters brought a small cabin cruiser to the surface by using table-tennis balls. They rigged up some kind of pump to send them down. I seem to remember it took quite a lot of them!

 

[jwilson]

Or perhaps a little more than a foot. Sadler 34.

Sadlers specifically made the 26 to be not just unsinkable, but sailable when flooded, and this has been tested. A number of other Sadlers had some buoyancy, but I do not think were ever claimed to be unsinkable.

 

[vyv_cox]

Sadlers specifically made the 26 to be not just unsinkable, but sailable when flooded, and this has been tested. A number of other Sadlers had some buoyancy, but I do not think were ever claimed to be unsinkable.

Sorry, not correct. The 26, 29 and 34 were all marketed as "The unsinkable Sadlers".

From the PBO review, November 1984:
LATEST IN THE RANGE of unsinkable sailboats comes the new Sadler 34. Designed by Martin Sadler she is a craft that projects a personality. Seen from a distance, .........

See Mike Lucas' history of the range http://www.mikelucasyachting.co.uk/sadler-starlight-boats/sadler-starlight-history.php

 

[sam_uk]

A company in Australia makes bags for the purpose:

http://turtlepac.com/products/underwater-lift-bags-a-yacht-floatation.html

Towards the bottom of the page they include the buoyancy figures for various materials common on boats.

Eg fibreglass 0.33, batteries 0.92 etc etc

I have a Etap 26 when tested in flooded condition with full crew and kit they were found to float with 40cm freeboard. Not a lot but better than nothing!

 

[prv]

I have a Etap 26 when tested in flooded condition with full crew and kit they were found to float with 40cm freeboard. Not a lot but better than nothing!

More than many liferafts

Pete

 

[lw395]

Or perhaps a little more than a foot. Sadler 34.

Looks like the weight of a metal rig, a few extra fathoms of anchor chain, an extra battery and a few tools would finish that off?

I'm sure I recall one or two holed racing yachts where the crew have inflated the LR inside, but I doubt it was the only thing keeping it afloat.

 

[rob2]

I would prefer to have a tube a la RIB round the gunwhale AND a liferaft to use conventionally if that didn't work. The biggest question is what would you do if the raft doesn't make the yacht buoyant? I would guess the best chance of success is if the raft blocked off the ingress of water, rather than offering floatation.

Rob.

 

[oldbilbo]

What would be the buoyancy effect on a sinking boat of a liferaft inflated inside a cabin, assuming no puncture(s) from sharp edges, tools, gear etc? Would it possibly prevent a boat from sinking, thereby giving a degree of refuge before final abandonment.

Any thoughts?

Some thoughts....

The idea has been considered for some large racing catamarans, where 'compartmentalising' of the hulls is practicable. There is/was a high risk of damage to the hull-skin by collision at speed with floating debris - whole trees, containers, cargoes of logs - and several ocean racing skippers have had their boats' bows destroyed in such a fashion.

It will be remembered, for example, that Bullimore's 'Apricot' sailed into a whole field of floating telegraph poles then was driven ashore/broken up near Brest, and there have been many others.

A facility for inflating a tough 'bladder' in a damaged bow compartment, by means of a controllable gas bottle, would permit - it was suggested - the exclusion of several tons of seawater. It was argued that the 'free surface effect' of that weight of water surging about entirely unconstrained would increase the damage considerably and limit the likelihood of the boat surviving long enough to limp slowly into port. A large bladder inside such a damaged compartment would, it was thought, reduce the problem.

 

[saltylegs]

IIRC Harold cudmore sailing in an Admirals cup in the 80's hit something harder than the boat and ordered the liferafts inflated below decks, I think she still sank and the crew were picked up fro the water.