[PSUBS-MAILIST] onboard gear
MerlinSub@t-online.de via Personal_Submersibles
personal_submersibles at psubs.org
Thu Apr 25 03:42:22 EDT 2019
We figure out that the best escape equipment will be a Steinke hood (hard
to get now)
or a traditional scuba west with a small on board air bottle.
Both give you the high lift capacity you need to make an fast rise.
For bigger subs and cold waters light diving suits will help muxh.
Second it will help you a lot if you allready a diver or had make a
course.
We make some years ago some exercieces with a semi finish Psub scuttled in
a pool .
First go out were really bad feelings and schock about the water rush in
and the cold and so.Have these in mind: panic.
But after 3-4 times and with the knowledge it was fun to do the escape
exercice.
With training and the right gear I see no problem to get out of a sub even
from much greater dephts.
The releasing signal bouy should have a stopper on the reel. Otherwise a
300 m rope bouy will drived far away with a sub sunken in 30 m .
And make the life of the rescue diver much harder. The rope shall resitance
the force a human can pull on it - say 150 Kg at least.
Somebody on the surface can come to the conclusion to lift the baot on
these rope- better make a mark on the Bouy "Sunken submarine - dont pull on
the rope!"
vbr Carsten
-----Original-Nachricht-----
Betreff: Re: [PSUBS-MAILIST] onboard gear
Datum: 2019-04-25T00:07:11+0200
Von: "Alan via Personal_Submersibles" <personal_submersibles at psubs.org>
An: "Personal Submersibles General Discussion"
<personal_submersibles at psubs.org>
Perhaps a Psub plan for escape from down to 100ft, as you could do this
100 times out of 100 if you knew what you were doing.
Also even though most subs are capable of diving deeper there is more
probability that entanglements like ropes & nets are going to be
encountered
In shallower depths.
BTW the pressure in the sub is going to increase incrementally quicker as
it
floods & you need to keep equalising your ears like mad toward the end or
you'll burst your ear drums, & aside from that pain, will have freezing
water
going in to your inner ear. That would increase your chances of failure.
Alan
On 24/04/2019, at 4:12 PM, Stephen Fordyce via Personal_Submersibles <
personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org> >
wrote:
Hi all,
This is an interesting discussion I've been meaning to weigh in on - as
an experienced tech/deep/cave diver rather than a sub person.
My feel is that unless the escapee is an experienced diver (and even
then), the chances of a successful escape from below 50m/150ft depth
are so low as to be almost negligible. And I'd suggest having a plan
for such is (almost) an entirely false sense of security - and energy
should be diverted elsewhere to reduce risk.
A few of the scarier things like narcosis and the bends have had a lot
of airtime, but basic stuff like keeping a diving mask clear (and one
that's probably fogging up), panic-breathing a soggy SCUBA reg and
dealing with the thermal shock of sudden immersion are likely to cause
death by drowning much earlier. Don't underestimate the thermal shock
and how useless it makes you with no exposure suit. Breathing a
regulator without a mask is a skill in itself. You're probably already
suffering from fatigue, stress, high CO2 and/or low O2 from waiting for
rescue and getting to such a desperate point. All of these cause
significant mental impairment before you even start on the escape.
Forget about planning to hold stops on the way up, switch gases or do
decompression. Even if you're lucky enough to still be conscious and
thinking in the latter stages of the rapid ascent, personal buoyancy
control is unlikely to be possible.
So if you're going to attempt to escape, I suggest the best chance for
survival is to plan on a very simple setup (per person), buoyancy for a
rapid/undignified ascent, and needing urgent medical attention and
oxygen on the surface. Maybe carry a cylinder of trimix on board to
give yourself a better chance of being able to think, but it's a big
weight/cost premium if it's enough to be useful. Use a divers (with
closed bottom) "lift bag" and a loop around at the armpits as a quick
and easy way to get a person shooting upwards. CO2 inflatable life
jacket to keep unconscious head above water on surface. (Inflate at
depth while conscious - won't fill much, but will expand on way up)
Might be better put towards things like extra life support duration.
Consider doing regular practise drills that are as realistic as
possible.
Highly skilled divers mess up basic skills in stressful situations and
die with sad regularity. Don't imagine your (and passengers) chances of
winging it at depth will be anything other than tiny. 30m/90ft and
shallower they are a bit better.
I hate to be negative, but perhaps for deep PSUB diving, the inability
to escape is just one of those residual risks that can be accepted for
a recreational activity.
Cheers,
Steve Fordyce
Melbourne, Australia
On Wed, 24 Apr 2019 10:57 hank pronk via Personal_Submersibles <
personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> > wrote:
I think all submarines should have an escape pod or jettisoning
occupant sphere. I admit I made a mistake with my escape pod by
making it only for one. An easy fix that I will likely tackle, and
that is to stretch the pod making it big enough for two. E3000 has a
jettisoning occupant sphere.
Hank
On Tuesday, April 23, 2019, 5:39:01 PM MDT, TOM WHENT via
Personal_Submersibles <personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> > wrote:
A compact bail out rebreather might be the most surviveable solution
however it would require a significant commitment in training,
maintenance as well as the cost of the equipment itself. I personally
have not been following the development of bailout rebreathers,
although i'm aware that some are working on this. My dive group
relies on planning for open circuit bailout in the event of
rebreather failure.
If money is no object, I am partial to the ISC Megalodon classic CCR.
In terms of robustness and deep water capability, you will find none
better.
It will get you home and flies itself. It is an electronic CCR which
maintains PPO2 for the user. This is the unit I dive myself and feel
very confident in.
KISS classics, which are a simple and reliable mechanical CCR
apparatus, often come up on the used market in affordable price
ranges.
Both would require significant equipment specific training but would
get you out of a 400 ft jam with only two small cylinders and gas to
spare. CCR duration is driven by metabolic rate and is the same
irrespective of operational depth. Even the lowest end units will
give you an hour plus.
On ascent, rebreathers do require the diver to be monitoring the
oxygen level display in the breathing loop and very likely adding
oxygen manually - particularly in the mCCR type on a fast ascent.
The other benefit of this setup is that an air cell for buoyancy can
be integrated easily in one compact package.
It sounds like a lot of effort for the non diver, but it is a
functional answer to the risks of a sub disabled in deep water.
What is a life worth?
How much risk can one accept for a hobby?
Food for thought anyhow.
Get Outlook for Android <https://aka.ms/ghei36>
On Tue, Apr 23, 2019 at 7:34 PM -0400, "Alan via
Personal_Submersibles" <personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> > wrote:
As an alternative to possible death or even worse, the loss of your
submarine,
I am in early stages of designing a buoy release mechanism that is
used
for surfacing safely but has an emergency beacon that can be
activated
with an electro magnet.
Thoughts are to use 150 lb braid with a tensioning mechanism & have
an
automatic boat latch mechanism that can slide down the braid but is
fixed
to the buoy with instructions, "tie a long rope to the ring & let
down untill
latch attaches to submarine. Pull up"
The automatic latch is a device that Phil described & provided a
drawing for,
but there may be a cheap & suitable automatic boat latch ( used on
release
& retrieve on boat launching) on the market. I am still searching &
if anyone
knows of one that may be suitable I would be interested.
Alan
On 24/04/2019, at 10:51 AM, Sean T. Stevenson via
Personal_Submersibles <personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> > wrote:
There is a significant difference between submarine escape and a
planned SCUBA dive with regard to both the dive profile and the
equipment that you can reasonably carry. An escape is more akin
to what is known as a buoyant emergency ascent in recreational
diving, where you need to get to the surface yesterday and all
other considerations are secondary. In this specific case,
trying to keep to a slow ascent rate would significantly increase
the incurred decompression obligation that you must necessarily
then blow off as you ascend through the shallows, introducing an
even greater risk. You also have the hypothermia issue to deal
with if you are not equipped with exposure protection
specifically intended for submersion at depth. Being cold reduces
decompression effectiveness. In order to keep to a target ascent
rate or perform decompression stops, you would need diving
instrumentation (depth gauge and timer), would need the skills
and experience to perform gas switches and hold stops, and would
need significantly more bulky equipment to have enough gas to
perform a proper decompression (slow ascent, gas switches, etc.).
When I dive to these depths on SCUBA, I wear twin cylinders (>100
cu. ft. each) on my back with the bottom gas (10/70 or whatever
for the planned depth and time), plus three or four off-board
cylinders (80s) carrying the decompression gases (typically
21/35, 35/25, EAN50 and oxygen), plus a small bottle of argon for
drysuit inflation. Obviously, as an escapee you are not so
equipped. Far better to lockout as quickly as possible and
rapidly ascend (with buoyant assist) to get clear of those depths
where you are ongassing the most, and if at all possible, to slow
the ascent as you approach the surface, and then have your
surface support or emergency responders administer oxygen as
transport is arranged to recompression. To be clear, an
emergency escape from a disabled submarine at these depths is not
even remotely a good idea - it is simply a marginally better idea
than dying on the bottom.
To illustrate, if you were to attempt a continuous ascent from
300 fsw, the average depth is 150 fsw, which is about 5.5
atmospheres absolute. If you assume a surface air consumption
rate of 1 cu. ft. / minute (high, but typical of a diver who is
stressed or working hard, which is inevitable in a submarine
escape scenario), that corresponds to 5.5 cu. ft. / min at the
average depth of the ascent. At a 30 ft/min ascent rate, that's
10 minutes, or 55 cu. ft. of gas consumed just for the continuous
ascent with no decompression stops, without consideration for the
gas consumed while blowing down and locking out. You can judge
for yourself the practicality of carrying an 80 on a PSub sized
vessel just for emergency escape purposes.
Sean
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Tuesday, April 23, 2019 12:32 PM, David Colombo via
Personal_Submersibles <personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> > wrote:
Hi Guys, This topic is fascinating and scary at the same
time. Accent rates form the old Navy logs had 60ft / minute
max with a recommended max accent rate of 30 ft/ min. At
300ft escape depth, what volume of mixed gases would you need
for a 10 minute accent assuming you choose not to swim
60ft/min.
Best Regards,
David Colombo
804 College Ave
Santa Rosa, CA. 95404
(707) 536-1424
www.SeaQuestor.com <http://www.SeaQuestor.com>
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As an alternative to possible death or even worse, the loss of your
submarine,
I am in early stages of designing a buoy release mechanism that is
used
for surfacing safely but has an emergency beacon that can be
activated
with an electro magnet.
Thoughts are to use 150 lb braid with a tensioning mechanism & have
an
automatic boat latch mechanism that can slide down the braid but is
fixed
to the buoy with instructions, "tie a long rope to the ring & let
down untill
latch attaches to submarine. Pull up"
The automatic latch is a device that Phil described & provided a
drawing for,
but there may be a cheap & suitable automatic boat latch ( used on
release
& retrieve on boat launching) on the market. I am still searching &
if anyone
knows of one that may be suitable I would be interested.
Alan
On 24/04/2019, at 10:51 AM, Sean T. Stevenson via
Personal_Submersibles <personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> > wrote:
There is a significant difference between submarine escape and a
planned SCUBA dive with regard to both the dive profile and the
equipment that you can reasonably carry. An escape is more akin
to what is known as a buoyant emergency ascent in recreational
diving, where you need to get to the surface yesterday and all
other considerations are secondary. In this specific case,
trying to keep to a slow ascent rate would significantly increase
the incurred decompression obligation that you must necessarily
then blow off as you ascend through the shallows, introducing an
even greater risk. You also have the hypothermia issue to deal
with if you are not equipped with exposure protection
specifically intended for submersion at depth. Being cold reduces
decompression effectiveness. In order to keep to a target ascent
rate or perform decompression stops, you would need diving
instrumentation (depth gauge and timer), would need the skills
and experience to perform gas switches and hold stops, and would
need significantly more bulky equipment to have enough gas to
perform a proper decompression (slow ascent, gas switches, etc.).
When I dive to these depths on SCUBA, I wear twin cylinders (>100
cu. ft. each) on my back with the bottom gas (10/70 or whatever
for the planned depth and time), plus three or four off-board
cylinders (80s) carrying the decompression gases (typically
21/35, 35/25, EAN50 and oxygen), plus a small bottle of argon for
drysuit inflation. Obviously, as an escapee you are not so
equipped. Far better to lockout as quickly as possible and
rapidly ascend (with buoyant assist) to get clear of those depths
where you are ongassing the most, and if at all possible, to slow
the ascent as you approach the surface, and then have your
surface support or emergency responders administer oxygen as
transport is arranged to recompression. To be clear, an
emergency escape from a disabled submarine at these depths is not
even remotely a good idea - it is simply a marginally better idea
than dying on the bottom.
To illustrate, if you were to attempt a continuous ascent from
300 fsw, the average depth is 150 fsw, which is about 5.5
atmospheres absolute. If you assume a surface air consumption
rate of 1 cu. ft. / minute (high, but typical of a diver who is
stressed or working hard, which is inevitable in a submarine
escape scenario), that corresponds to 5.5 cu. ft. / min at the
average depth of the ascent. At a 30 ft/min ascent rate, that's
10 minutes, or 55 cu. ft. of gas consumed just for the continuous
ascent with no decompression stops, without consideration for the
gas consumed while blowing down and locking out. You can judge
for yourself the practicality of carrying an 80 on a PSub sized
vessel just for emergency escape purposes.
Sean
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Tuesday, April 23, 2019 12:32 PM, David Colombo via
Personal_Submersibles <personal_submersibles at psubs.org
<mailto:personal_submersibles at psubs.org> > wrote:
Hi Guys, This topic is fascinating and scary at the same
time. Accent rates form the old Navy logs had 60ft / minute
max with a recommended max accent rate of 30 ft/ min. At
300ft escape depth, what volume of mixed gases would you need
for a 10 minute accent assuming you choose not to swim
60ft/min.
Best Regards,
David Colombo
804 College Ave
Santa Rosa, CA. 95404
(707) 536-1424
www.SeaQuestor.com <http://www.SeaQuestor.com>
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