[PSUBS-MAILIST] onboard gear

Tue Apr 30 17:42:12 EDT 2019

Thanks Cliff, Great instructional video. Now to find one!
Best Regards,
David Colombo

804 College Ave
Santa Rosa, CA. 95404
(707) 536-1424
www.SeaQuestor.com

On Tue, Apr 30, 2019 at 2:09 PM Cliff Redus via Personal_Submersibles <
personal_submersibles at psubs.org> wrote:

> If you have not had a chance to see this old US Navy training film on
> submarine escape, you might want enjoy this.
> https://www.youtube.com/watch?v=ffOJEJwWSbs
>
> The training is on using the Steinke Hood.  I use this appliance on my
> boat.  Even though it is getting harder to find this hoods, they surface on
> Ebay periodically.
>
> Cliff
>
> On Saturday, April 27, 2019, 9:11:53 AM CDT, MerlinSub at t-online.de via
> Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>
>
> Why you want to breath the first minute of your fly?
>
> Just ensure that the gas can get out of our lungs to not overpressure it.
>
> And by the way - if you not breath you can not get additional gas which
> can expant into your blood.
>
> And how long you can stop breathing has more to do with your brain - than
> with your lungs.
>
> I am now 54 and can stop not more than 1 minute. In my best time and with
> training it was easy over 2.
>
>
>
> But this is pure theoretical. The best equipment to surfive a submarine
> exit is - training.
>
>
>
> The lung can overexpant easy  but this will happend more or less on the
> last 10 meters to the surface.
>
> If you have the training and expierence to slow down your speed there it
> will help a lot.
>
>
>
>
>
>
>
>
>
> -----Original-Nachricht-----
>
> Betreff: Re: [PSUBS-MAILIST] onboard gear
>
> Datum: 2019-04-27T05:24:20+0200
>
> Von: "Alan via Personal_Submersibles" <personal_submersibles at psubs.org>
>
> An: "Personal Submersibles General Discussion" <
> personal_submersibles at psubs.org>
>
>
>
>
>
>
>
> Thanks Tom, a lot to think about.
> Yes breathing from the BCD could be problematic on a deep ascent as the
> gas would be expanding very little over the first few hundred feet & as you
> say you could easily consume it & reduce your flotation.
> Alan
>
> On 27/04/2019, at 2:24 PM, TOM WHENT via Personal_Submersibles <
> personal_submersibles at psubs.org> wrote:
>
> That is a whole lot of task loading for an emergency. Chances are little
> of this will be reflexive from repeated practice. Having a good non
> narcotic gas to breathe during flood/exit procedures would be beneficial in
> keeping your head. Keep in mind that helium on boards  2.7 times faster
> than nitrogen and also comes out of your tissues that much faster. Too much
> time breathing on it might cause you to be severely bent before reaching
> the surface on a fast ascent. Most helium bends occur under water and it
> will even off gas through your eyes. I've never experienced this but I have
> heard that it is painful.
>
> Breathing from a BCD seems like a bad idea to me. It would be marginally
> passable as long as you are certain that you are ascending. Accidentally
> wasting or venting your buoyancy gas would be disastrous. Many trained
> divers struggle with buoyancy control and can't manipulate inflators with
> cold hands or in panic.
>
> Coming up fast from any depth, you will need to ensure that you are
> exhaling continually, or able to breath in and out so that your airway is
> never closed. You have no pain mechanism in your body to alert you to a
> lung overpressure. If you rupture a lung you have no chance of survival
> even if you do reach the surface.
>
> I had thought about the idea of wearing a neoprene wetsuit inside the sub
> as an alternate means of buoyancy and environmental protection but after
> considering the depths you guys are escaping from, that too would have
> minimal buoyancy due to the crush on the suit from the pressure. It would
> however provide some warmth, even if marginally.
>
> Whatever solution you choose,  it will have to be simple enough to deploy
> under the worst conditions imaginable and preferably protect your airway on
> the surface if you should lose consciousness.
>
> I'm generally not an advocate of full face masks for scuba diving, but in
> this circumstance, if you had one and a means of flotation, you would stand
> a better chance of survival than using a regulator (or BCD inflator) which
> will fall out of your mouth if you lose consciousness. You generally cannot
> use the firefighter style face mask, but must use one designed for diving.
> The reason being that the latter will have a flexible nose pocket to allow
> you to pinch it for equalizing.
> The hood and escape suits look better all the time.
>
>
> Tom
>
> Get Outlook for Android <https://aka.ms/ghei36>
>
>
>
> On Fri, Apr 26, 2019 at 8:14 PM -0400, "Alan via Personal_Submersibles" <
> personal_submersibles at psubs.org> wrote:
>
>
> Carsten,
> yes you could rely on air out of your BCD but it is not regarded as a good
> practice because of disinfectants used to clean out BCDs. You would need
> to find a suitable sterilising product. But this is an emergency!
> I think maybe, as I have said, an escape plan for every 100 ft based on the
> volume of your sub, how quickly you can flood it, how quickly you can
> equalise
> your ears & what mixed gas you need to avoid getting narced, bent & O2
> Poisoning. Beyond certain depths you would need to start breathing mixed
> gas from a pony bottle or whatever as the hull equalised.
> Now you have me thinking!!! What about an external scuba tank full of mixed
> gas plumbed through to the cabin to breath from during the flooding of the
> hull,
> this would give you a lot more time to equalise your ears! Plumb this tank
> to
> act as a reserve ballast blow so it is not wasted. Leave the sub with the
> pony
> bottle full of mixed gas & inflate the horseshoe BCD with it, then breath
> from
> the BCD.
> Alan
>
>
>
> On 27/04/2019, at 9:45 AM, MerlinSub at t-online.de via
> Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>
> Alan the pony is just for the first filling the vest in the moment you
> leave the sub.
>
> During the fast as possible way to the surface the air in the vest expand
> all the
>
> time and leave via the overpressure valve.
>
>
>
> Imagine you have a vest of say 4 Liter. How much air will be in if you
> leave the sub in 100 meter deeps?
>
> Right - around 40 liters. During your way to the surface 36 liters will
> leave via the overpressure vale.
>
> Pretty much air to breath. The pony bottle is just there for the first
> filling- so you have not to fill tthe
>
> vest wih your lungs because this is exhaust gas and the process may
> exhaust you also.
>
>
>
> A filled 220 bar by  0,5 Liter pony bottle contains 110 liter expand gas.
>
> If we assume the vest has 4 Liters volume you can fill the vest up to a
> depth equal to 27 bar or 270 meter dephts.
>
> And you can breath all these 110Liter air from the vest except the last 4
> liters which you need on the surface
>
> for bouancy.
>
>
>
> In real life it is may better first to leave the sub and than open the
> valve to fill the vest.
>
> Otherwise it makes you more bulky and you have the possibility to scratch
> the vest somewere on your sub exit.
>
>
>
> If you have no expiernce with such vest you should traning it in a 2-4
> meter depth pool to get an feeling for it.
>
>
>
> On Euronaut we have all that gear on board. Scuba vest, Steinke hoods and
> dive gear including suits.
>
>
>
> On a emergency exit of a sunen military argentinna submarnne which was
> sunken in the 80ies or 90ies some crew members manage to escape from 40
> meter depth. The guys with the Steinke Hoods and no dive expierence
> survifed all.
>
> The colleges with the scuba expierence use the dive gears - help the other
> guys to get out -
>
> and died later on decompression thickness. :-(
>
>
>
>
>
>
>
>
>
> -----Original-Nachricht-----
>
> Betreff: Re: [PSUBS-MAILIST] onboard gear
>
> Datum: 2019-04-26T23:03:14+0200
>
> Von: "Alan via Personal_Submersibles" <personal_submersibles at psubs.org>
>
> An: "Personal Submersibles General Discussion" <
> personal_submersibles at psubs.org>
>
>
>
>
>
>
>
> Sean / all,
> the cold will certainly be a factor but you will be exposed to that for
> some
> time while the submarine fills with water & equalises. So the extra 15
> seconds
> grabbing an external tank won't be major.
> What I fear most is bursting my ear drums, & freezing water in the inner
> ear.
> I imagine this would be very painful, maybe like brain freeze, but I am
> only guessing.
> Some people have more problems than others equalising & once you start to
> feel pain in your ear from pressure it is more difficult to equalise.
> I think some control on the flooding speed to let you equalise your ears
> would
> be an asset. Pitty to burst your ear drums when you might be doing a simple
> escape from 100ft.
> As Emile & Carsten showed with their practice escapes; they could get out
> relatively easily, & with a bit of air ( 6 cu ft pony bottle ) you could
> get to the
> surface easy enough.
> If I were escaping from deeper I would use a pony bottle with mixed gas
> some
> time after the equivalent of 150ft & this would buy me a bit of time to
> equalise
> & save my ears, then escape & use my large mixed gas tank to go to the
> surface
> making stops if I felt able.
> There is sense in you saying Keep It Simple, but if you pre plan &
> practice, a
> more complex but safer escape is possible. Maybe work out how long it is
> going
> to take to fill your particular sub at varying depths, how quickly you
> could equalise
> for varying depths. How long your pony bottle would last you & have a
> knowledge
> of what stops would be best for the varying depths you may escape from.
> At least that would take away a lot of the fear of the unknown & reduce
> panic.
> BTW I am a diver & amateur speleologist so used to cold wet tight spaces.
> Alan
>
>
>
>
>
> On 27/04/2019, at 12:17 AM, Sean T. Stevenson via Personal_Submersibles <
> personal_submersibles at psubs.org> wrote:
>
> Alan - Don't overthink this. A buoyant emergency ascent can get you to the
> surface in less than 60 seconds if you are not purposefully attempting to
> limit your ascent rate. How long can you hold your breath (not that you
> should)? A gas source helps you avoid a hypoxic blackout, but with a hood
> of any description you shouldn't drown. You'll just end up rebreathing some
> of the hood gas. As we discussed earlier, hypothermia will be an issue, as
> will the exposure time - it is actually better to get up from depth ASAP
> than to spend time messing around at depth and then having a bunch of stuff
> slowing your ascent while deep. My point about the gas consumption was to
> illustrate how impractical it would be to carry sufficient gas to enable an
> ascent as a diver would do it.
>
> Sean
>
>
> -------- Original Message --------
> On Apr 25, 2019, 23:39, Alan via Personal_Submersibles <
> personal_submersibles at psubs.org> wrote:
>
>
>
> More thoughts on escape...
> Went in to a couple of dive shops today looking at pony bottles.
> The smallest they were selling were 19 cu ft. I did see a 13 cu ft they
> were
> filling. Both looked too big for my intended dual purpose use of a horse
> shoe
> BCD as a life jacked. A bit clutsy getting in to the sub wearing a BCD &
> large
> tank. They make a 6 cu ft pony bottle but I would have to import it & it
> would
> only get me to the surface from about 100ft.
> I had the thought of filling a 6 cu ft pony bottle with mixed gas & having
> an
> 80 cuft mixed gas tank outside the hull. It could have an octopus regulator
> ( to avoid free flow) permanently on the 80 & a quick disconnect fitting
> on it that
> a hose attaches to for use as a reserve ballast blow.
> So you breath through your pony reg while flooding & escaping, then when
> outside use the 80 cu ft tank reg while detaching the ballast hose,
> attaching
> the BCD connection and un latching the tank.
> It could be practiced in the garage with your eyes closed & done in about
> 15
> seconds. Any thoughts on this?
> Alan
>
>
> On 26/04/2019, at 1:38 PM, Alan via Personal_Submersibles <
> personal_submersibles at psubs.org> wrote:
>
>
> Thanks Carsten,
> I am thinking I may go with something similar; a horse collar BCD with a
> 13 cu ft pony bottle. (BCD below).
> It could double as a life jacket, has manual inflation &  push button
> inflation.
> I would have a regulator off the pony bottle as well.
> The BCD has an over inflation valve but if you wanted your air to last in
> an emergency
> you could breath expanding air out of the BCD through the manual inflation
> mouth piece. With a BCD as apposed to a life jacket you have the chance to
> slow your ascent & do a decompression stop.
> I am not sure what the maximum depth is that I could come up from with a
> 13 cu ft
> tank.
> I could use this for shallow dives or as a supplement for snorkelling, so
> it won't be
> sitting in a sub doing nothing.
> Alan
>
> <image1.PNG>
>
>
>
> On 25/04/2019, at 7:42 PM, MerlinSub at t-online.de via
> Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>
> 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> 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> 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> 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> 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> 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> 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
>
>
>
> _______________________________________________
> Personal_Submersibles mailing list
> Personal_Submersibles at psubs.org
> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
>
>
>
> 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> 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> 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
>
>
>
> _______________________________________________
> Personal_Submersibles mailing list
> Personal_Submersibles at psubs.org
> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
> _______________________________________________
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>
>
>
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>
>
> Carsten,
> yes you could rely on air out of your BCD but it is not regarded as a good
> practice because of disinfectants used to clean out BCDs. You would need
> to find a suitable sterilising product. But this is an emergency!
> I think maybe, as I have said, an escape plan for every 100 ft based on the
> volume of your sub, how quickly you can flood it, how quickly you can
> equalise
> your ears & what mixed gas you need to avoid getting narced, bent & O2
> Poisoning. Beyond certain depths you would need to start breathing mixed
> gas from a pony bottle or whatever as the hull equalised.
> Now you have me thinking!!! What about an external scuba tank full of mixed
> gas plumbed through to the cabin to breath from during the flooding of the
> hull,
> this would give you a lot more time to equalise your ears! Plumb this tank
> to
> act as a reserve ballast blow so it is not wasted. Leave the sub with the
> pony
> bottle full of mixed gas & inflate the horseshoe BCD with it, then breath
> from
> the BCD.
> Alan
>
>
>
> On 27/04/2019, at 9:45 AM, MerlinSub at t-online.de via
> Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>
> Alan the pony is just for the first filling the vest in the moment you
> leave the sub.
>
> During the fast as possible way to the surface the air in the vest expand
> all the
>
> time and leave via the overpressure valve.
>
>
>
> Imagine you have a vest of say 4 Liter. How much air will be in if you
> leave the sub in 100 meter deeps?
>
> Right - around 40 liters. During your way to the surface 36 liters will
> leave via the overpressure vale.
>
> Pretty much air to breath. The pony bottle is just there for the first
> filling- so you have not to fill tthe
>
> vest wih your lungs because this is exhaust gas and the process may
> exhaust you also.
>
>
>
> A filled 220 bar by  0,5 Liter pony bottle contains 110 liter expand gas.
>
> If we assume the vest has 4 Liters volume you can fill the vest up to a
> depth equal to 27 bar or 270 meter dephts.
>
> And you can breath all these 110Liter air from the vest except the last 4
> liters which you need on the surface
>
> for bouancy.
>
>
>
> In real life it is may better first to leave the sub and than open the
> valve to fill the vest.
>
> Otherwise it makes you more bulky and you have the possibility to scratch
> the vest somewere on your sub exit.
>
>
>
> If you have no expiernce with such vest you should traning it in a 2-4
> meter depth pool to get an feeling for it.
>
>
>
> On Euronaut we have all that gear on board. Scuba vest, Steinke hoods and
> dive gear including suits.
>
>
>
> On a emergency exit of a sunen military argentinna submarnne which was
> sunken in the 80ies or 90ies some crew members manage to escape from 40
> meter depth. The guys with the Steinke Hoods and no dive expierence
> survifed all.
>
> The colleges with the scuba expierence use the dive gears - help the other
> guys to get out -
>
> and died later on decompression thickness. :-(
>
>
>
>
>
>
>
>
>
> -----Original-Nachricht-----
>
> Betreff: Re: [PSUBS-MAILIST] onboard gear
>
> Datum: 2019-04-26T23:03:14+0200
>
> Von: "Alan via Personal_Submersibles" <personal_submersibles at psubs.org>
>
> An: "Personal Submersibles General Discussion" <
> personal_submersibles at psubs.org>
>
>
>
>
>
>
>
> Sean / all,
> the cold will certainly be a factor but you will be exposed to that for
> some
> time while the submarine fills with water & equalises. So the extra 15
> seconds
> grabbing an external tank won't be major.
> What I fear most is bursting my ear drums, & freezing water in the inner
> ear.
> I imagine this would be very painful, maybe like brain freeze, but I am
> only guessing.
> Some people have more problems than others equalising & once you start to
> feel pain in your ear from pressure it is more difficult to equalise.
> I think some control on the flooding speed to let you equalise your ears
> would
> be an asset. Pitty to burst your ear drums when you might be doing a simple
> escape from 100ft.
> As Emile & Carsten showed with their practice escapes; they could get out
> relatively easily, & with a bit of air ( 6 cu ft pony bottle ) you could
> get to the
> surface easy enough.
> If I were escaping from deeper I would use a pony bottle with mixed gas
> some
> time after the equivalent of 150ft & this would buy me a bit of time to
> equalise
> & save my ears, then escape & use my large mixed gas tank to go to the
> surface
> making stops if I felt able.
> There is sense in you saying Keep It Simple, but if you pre plan &
> practice, a
> more complex but safer escape is possible. Maybe work out how long it is
> going
> to take to fill your particular sub at varying depths, how quickly you
> could equalise
> for varying depths. How long your pony bottle would last you & have a
> knowledge
> of what stops would be best for the varying depths you may escape from.
> At least that would take away a lot of the fear of the unknown & reduce
> panic.
> BTW I am a diver & amateur speleologist so used to cold wet tight spaces.
> Alan
>
>
>
>
>
> On 27/04/2019, at 12:17 AM, Sean T. Stevenson via Personal_Submersibles <
> personal_submersibles at psubs.org> wrote:
>
> Alan - Don't overthink this. A buoyant emergency ascent can get you to the
> surface in less than 60 seconds if you are not purposefully attempting to
> limit your ascent rate. How long can you hold your breath (not that you
> should)? A gas source helps you avoid a hypoxic blackout, but with a hood
> of any description you shouldn't drown. You'll just end up rebreathing some
> of the hood gas. As we discussed earlier, hypothermia will be an issue, as
> will the exposure time - it is actually better to get up from depth ASAP
> than to spend time messing around at depth and then having a bunch of stuff
> slowing your ascent while deep. My point about the gas consumption was to
> illustrate how impractical it would be to carry sufficient gas to enable an
> ascent as a diver would do it.
>
> Sean
>
>
> -------- Original Message --------
> On Apr 25, 2019, 23:39, Alan via Personal_Submersibles <
> personal_submersibles at psubs.org> wrote:
>
>
>
> More thoughts on escape...
> Went in to a couple of dive shops today looking at pony bottles.
> The smallest they were selling were 19 cu ft. I did see a 13 cu ft they
> were
> filling. Both looked too big for my intended dual purpose use of a horse
> shoe
> BCD as a life jacked. A bit clutsy getting in to the sub wearing a BCD &
> large
> tank. They make a 6 cu ft pony bottle but I would have to import it & it
> would
> only get me to the surface from about 100ft.
> I had the thought of filling a 6 cu ft pony bottle with mixed gas & having
> an
> 80 cuft mixed gas tank outside the hull. It could have an octopus regulator
> ( to avoid free flow) permanently on the 80 & a quick disconnect fitting
> on it that
> a hose attaches to for use as a reserve ballast blow.
> So you breath through your pony reg while flooding & escaping, then when
> outside use the 80 cu ft tank reg while detaching the ballast hose,
> attaching
> the BCD connection and un latching the tank.
> It could be practiced in the garage with your eyes closed & done in about
> 15
> seconds. Any thoughts on this?
> Alan
>
>
> On 26/04/2019, at 1:38 PM, Alan via Personal_Submersibles <
> personal_submersibles at psubs.org> wrote:
>
>
> Thanks Carsten,
> I am thinking I may go with something similar; a horse collar BCD with a
> 13 cu ft pony bottle. (BCD below).
> It could double as a life jacket, has manual inflation &  push button
> inflation.
> I would have a regulator off the pony bottle as well.
> The BCD has an over inflation valve but if you wanted your air to last in
> an emergency
> you could breath expanding air out of the BCD through the manual inflation
> mouth piece. With a BCD as apposed to a life jacket you have the chance to
> slow your ascent & do a decompression stop.
> I am not sure what the maximum depth is that I could come up from with a
> 13 cu ft
> tank.
> I could use this for shallow dives or as a supplement for snorkelling, so
> it won't be
> sitting in a sub doing nothing.
> Alan
>
> <image1.PNG>
>
>
>
> On 25/04/2019, at 7:42 PM, MerlinSub at t-online.de via
> Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>
> 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> 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> 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> 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> 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> 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> 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
>
>
>
> _______________________________________________
> Personal_Submersibles mailing list
> Personal_Submersibles at psubs.org
> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
>
>
>
> 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> 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> 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
>
>
>
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