Larry wrote:
Keith Nuttle wrote in news:gpQul.26263
:

If you read the about the exploration trips of the 1500's to 1800's one
of the techniques to save the ship was to rig a canvas patch over the
hole. The technique was used when a ship hit the rocks or when a cannon
ball holed the ship below the water line.

The foam sounds like a good substitute for canvas, and would probable
provide a better seal. Wish I had thought of it and I hope I will never
have to use it.


Navy DC school taught how to block holes in the hull so the pumps could
keep up with the leakage. Once the hole was packed with an internal dam of
wood, mattresses and whatever else would slow the flooding, canvas was
dived over the side to let the seawater pressure force it into the hole as
a sort of flapper valve. I don't see how you could get underway and keep
the canvas in place, though.....without tearing off the canvas.

We nearly drown in DC school trying to get the damned water to stop
flooding the training compartment before we ran out of airspace to breathe.
You work very hard in such a desparate situation as flooding a sealed
compartment......even harder than I did in fire fighting school pushed into
the totally dark, smoke filled compartment trying to put out the fire with
foam and spray.

The damned chief lit the diesel fire and then just stood there talking and
talking about how we were going to put it out as the flames got bigger and
bigger and HUGE! Suddenly, he simply stood aside and said, "Don't look at
me, gentlemen.....After you...", gesturing towards the watertight hatch,
which by now was so hot it was smoking, itself. We could hardly cool the
damned door, talk nothing of putting out the fire....most enlightening....

Sitting in the cockpit, alone on midwatch, of some sailboat, I've often had
flashbacks of that training while we're 100 miles offshore with no
firefighting equipment bigger than a 5# extinguisher. That won't do
anything for a fiberglass fire other than make it mad....


Those canvas thingies are called "collision mats."

I've been thinking along these lines myself. For stuff you can get to
you can use a wax toilet ring. I think Bruce mentioned that a while
back somewhere. Then you can have a bag (or two) of cement on board to
back up the hole. Weight as much as anything I guess. I know that
Moitessier carried some kind of special cement. Mixed with clay I
think. I have at times mixed plaster with mortar and it can make a
pretty fast setting mix. (Why you ask? My fist wife, delicate flower
that she was, once kicked a hole in the bathroom wall in a fit. (No I
was not home nor do I know the cause.) But the mortar/plaster fix
"fixed" the problem. She never did it again.)

Back to the foam. I have a steel boat and the aft half of my keel is
hollow and too deep for me to reach into. I can't reach about the last
foot. The top of the keel extends up so that the sole rests on it and
the hull is welded to the keel all around. My fear was that somehow I
would hole the keel and not be able to control the leak. I had thought
of pouring foam in but don't want to loose the storage space.

I sometimes use Great Stuff, sparyed into plastic shopping bags to
stabalize things, like my holding tank. Keep it firmly in place. The
problem with that is that it takes a while to set up. To long in time
of emergency. Ideally you would have some Great Stuff that would set up
in 2 or 3 minutes. You could spray it into some kind of baggie and
then, once it is nearly hard, cram it over the opening, backed up by
something (cement or sole) and the foal would push into the opening.