Hi Glen,
what about an enclosed bag with pressure relief
valves on the bottom?
As you'll know the last 33 ft the bag will double
in size & lifting ability,
so if you put it on the surface you'll get the
maximum out of the air you
put in it. You could modify a tractor tire; that
would have the potential to
expand if necessary & with a base on it,
it would be an inflatable boat
waiting for you if
you needed to escape.
Just brain storming here.
The Aussies might dump their coach, he's a
Kiwi.
Alan
----- Original Message -----
Sent: Tuesday, August 31, 2010 8:35
PM
Subject: Re: [PSUBS-MAILIST] Safety
Hook
Hi Alan
In experience as a commercial diver using '
unmaned 'standard lift bags, when they hit the surface they do so
like a rocket loose there form and sometimes the item you where lifting comes
hurtling back in your direction.This is the reason for a controlled ascend and
not letting the bag exit the water until its been established that self rescue
is not possible .With no weight it could
allso be blown over by the wind and loose form iniatialy when it reaches
the surface,but with the right construction and say a 5kg lead ball (like the
ones they use on down riggers)attached to the bottom, bright orange with a
couple of reflective flashes and instructions attached to it .Once let to the
surface it would be seen for miles.
Glen
----- Original Message -----
Sent: Monday, August 30, 2010 10:40
PM
Subject: Re: [PSUBS-MAILIST] Safety
Hook
Hi Glen,
You could just let the lift bag spool until it
stopped & then wind it
back down. Put in just enough air to have it
fully inflated by the time
it reached the surface. A colorful 1 ton lift
bag would certainly stand
out more than a small buoy & possibly take
up a similar space when
deflated.It was noted that your lift bag idea
was ratified by Phil.
Regards Alan
----- Original Message -----
Sent: Tuesday, August 31, 2010 2:09
AM
Subject: Re: [PSUBS-MAILIST] Safety
Hook
If a hand operated winch spool
filled with Spectra, marked for different depths and
controllable feed by pilot ,attached to the end is lift bag ,not much air
would be needed to fill bag as the pilot could place the lift bag closer
to surface, once free from bottom pilot could winch himself to surface by
hand.If he is unable to free himself from bottom he can release the bag
all the way to surface to act as marker
stress Buoy ect
Glen
----- Original Message -----
Sent: Monday, August 30, 2010 11:47
AM
Subject: Re: [PSUBS-MAILIST] Safety
Hook
To offset the catenary, HBOI did a series of tests running
upstream slightly. This did not straighten the curve, but rather moved
it to a more vertical position at the sub and tensioned the whole length
so that the rescue device had a better chance to get down. It worked.
Phil's suggestion of carrying enough Spectra to provide both a
marker and a lift line is certainly worth our attention. That stuff
(Spectra) is fearsome strong, and would do away with almost all of this
extra hardware. The big buoy or lift bag would provide a further lift
ability and if necessary could be released to the surface. Wrap the
Spectra around a cat head and haul away.
Vance
-----Original
Message----- From: glen brown <gbrown091@gmail.com> To:
personal_submersibles@psubs.org Sent: Mon, Aug 30, 2010 3:58
am Subject: Re: [PSUBS-MAILIST] Safety Hook
Frank
Dont forget to take in consideration the bow effect(in deeper
water) that any current will have on the
rescue cable . The hook will have to be very heavy
otherwise it will be useless in stronger current.
Glen
----- Original Message -----
Sent: Monday, August 30, 2010
12:05 AM
Subject: Re: [PSUBS-MAILIST]
Safety Hook
Hi Frank, Looks good.
You could spring load your device by putting a rubber O ring in a
grove round
the outside of the prongs, if it were necessary.
The lifting eye would be vertical when the emergency line was
tightened
providing the line from the drum was above the lifting eye.
I googled round a bit trying to find something "off the shelf"
that would work but no
success so far. It's a big world, there's bound to be something
out there.
Alan
----- Original Message -----
Sent: Monday, August 30, 2010
2:33 AM
Subject: Re: [PSUBS-MAILIST]
Safety Hook
Here's a little sketch on an idea I had for a simple hook to
follow the buoy line down. It's much like Phil's idea, but I'm using
the lifting eyes I have welded to my sub. With a "three prong"
approach, ONE of those damn things ought to grab.
It would operate like a fish hook where the support crew would
keep "jigging" the hook up and down until it grabbed.
Any comments ?
Frank D.
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