[PSUBS-MAILIST] onboard gear
Alan via Personal_Submersibles
personal_submersibles at psubs.org
Wed May 1 19:34:17 EDT 2019
Cliff,
Sorry not thinking straight.
It is easier to equalise & would need to be done less frequently the deeper
you go. For instance at 10ft you would have 5psi deflecting your ear drum
inward. But if you were at 100ft & equalised then went to 110ft, this same
5psi pressure difference would not deflect your ear drum anywhere near
the same because of the amount of compression of the air already in your
inner air. So by the time you get to 300ft you would have a lot more time to
equalise as the cabin pressurised. Be interesting to calculate this out but
should be doing other things..
Alan
> On 2/05/2019, at 10:47 AM, Alan via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>
> Hugh,
> Agreed that you don't get yourself in to that situation, & eliminate any possible
> entanglements in your design.
> I was looking at pony bottles & thinking the 13 cu ft may be a good compromise.
> Haven't done the maths on how many breaths I'd get from 500ft but I would be
> relying on an 80 cu ft mixed gas to do the filling of the BCD & get me to the point
> where I am out of the sub.
> Alan
>
>
>
>> On 2/05/2019, at 10:02 AM, Hugh Fulton via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>>
>> Alan, a small pony bottle is only any good if you are rebreathing. If you are at 30 atm depth then a small pony bottle will only last a couple of breaths possibly depending on pony volume. That is why I asked the gurus for sizing of cylinders with mixed gas usage. It comes down to how long to get out of the sub etc as to how many breaths you are going to need for sizing of the mixed gas. I didn’t realise how complicated it would get and the simplest seems to be the new Mk 10 Steinke hoods.
>> I think it is like my old flying instructor when I asked him what to do in a certain situation. He said that you make sure you don’t get into those situations by good maintenance, planned flights(dives) and sticking to the plan as well as a good preflight.
>> Hugh
>>
>>
>> From: Personal_Submersibles [mailto:personal_submersibles-bounces at psubs.org] On Behalf Of Alan via Personal_Submersibles
>> Sent: Thursday, 2 May 2019 9:18 AM
>> To: Personal Submersibles General Discussion
>> Subject: Re: [PSUBS-MAILIST] onboard gear
>>
>> Additional thoughts are that in NZ you are required by law to wear
>> a life jacket on a boat, not sure about the US. You would probably get away with
>> using a BCD as a life jacket. Maybe unbolt the tank attachment if possible,
>> or just buy a horseshoe type BCD.
>> This saves space just having a BCD rather than a steinke hood & life jacket.
>> Alan
>>
>>
>> On 2/05/2019, at 7:17 AM, Alan via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>>
>> Hi Cliff,
>> I wasn't so much pointing out the hypothermia issues but all the other
>> medical diving issues that we discussed earlier in this thread; plus the fact
>> that you are getting virtually no air to breath out of a Steinke hood in the first
>> 200 ft on a 500ft escape. And no, not using an SEIE, not enough room.
>> With regard to equalising your ears just before equalisation of the hull,
>> You will not be able to judge when your sub is about to equalise by the
>> water level. If you were scuttling your boat at 33 ft then the water level
>> would be half way up the interior of your sub (by volume), where ever
>> that might be. But as you got deeper this water level would rise before
>> you equalised. Also factored in is Phil's advise to add compressed air
>> at the end to speed up equalisation, due to the slowing of water flow
>> in to the hull. At 120ft the water level is going to be 4/5ths of the way up
>> your hull before you are equalised, at 300ft around 10/11ths of the way
>> up your hull. So we are talking gradients of inches per ATM increase, with
>> an exponential decrease In water level increase required to equalise as depth increases.
>> Most diving authorities say you should equalise your ears every 2 ft of
>> descent, so that's 16 times for your first 33ft (1atm). You can burst your
>> ear drums at 10ft. It would be a real lottery as to what time in the flooding
>> you put the Steinke hood on. ( Can you get out your hatch with it inflated?)
>> As said, you might not be able to physically put it on at 300ft due to your
>> intoxicated state.
>> I would propose using a normal BCD that all divers are familiar with & a small
>> pony bottle with mixed gas in it. You can breath through the BCDs oral
>> inflator ( like a Steinke hood) if you see air start to bubble out the over inflation valve.
>> I have been formulating my escape plan as this thread has evolved, & it's
>> been great hearing from people & throwing ideas around.
>> To date I like the idea of having an external mixed gas bottle that can be used as an
>> auxiliary ballast blow, but is plumbed in to the hull & used to fill my BCD on
>> escape & for breathing air half way through the flooding of the hull.
>> Then head to the surface breathing both from the pony bottle & BCD.
>> I would look at dumping the content of the BCD & doing a stop for as long
>> as possible at around 30ft.
>> Alan
>>
>>
>>
>> On 2/05/2019, at 1:46 AM, Cliff Redus via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>>
>> Alan, I agree that if you have the room in the hull to put on a SEIE, it is better than a Steinke hood because of the hypothermia issue. This was the primary reason US Navy replaced Steinke hood with the SEIE. However, as Jon points out, most of the psubs have cabins that are too small to put on a SEIE. I have a operating boat that can reach to 300 fsw so I am back to needing a Steinke hood to give me a better shot of surviving a bailout. As to equalization, my NOP calls for strapping the hood around the waist and having the hood in my lap prior to opening the scuttle valve. The way I gage cabin vs ambient pressure to just water the water level. I will be equalizing as water level rises. When the level reaches my chest, I top off buoyancy chamber with oral fill tube and pull hood over my head and exit the boat through the hatch. If I burst my ear drums, so be it. This is better than having my body temperature reach ambient! The Steinke hoods were standard issue to submariners from 1962 to early in 2000's . US Navy did a lot of testing with units and got a lot right with the appliance. The max depth rating in the Steinke hood literature is 450'. Is the Steinke hood perfect? No. Is it better than nothing, I think so.
>>
>> You are designing a small boat as we speak. Are you planning on using a SEIE? If so, how are you going to put it on?
>>
>> Best Regards, Cliff
>>
>> On Wednesday, May 1, 2019, 5:45:07 AM CDT, Alan via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>>
>>
>> The Steinke hood might be alright for getting out of a submarine with assistance
>> from one or two hundred feet, but would be not so good for a psubber trapped
>> below that. As the escape video says, you need to equalise by pinching your
>> nose before you put the hood on. So you would be trying to put the hood on at
>> the point that your sub is equalised. This would require accurately comparing external
>> pressure with internal pressure. If you put it on too soon you wouldn't be able
>> to equalise & may need to take it off to re-try equalising, or burst your ear drums.
>> If you put it on too late the hatch may open with a forceful entry of water & exiting of air.
>> You would be required to do this while under the influence of nitrogen narcosis
>> & I think somewhere around 350 ft you are so narked that you couldn't get out.
>> You are relying on breathing expanding air from the jacket but there would be
>> very little air expansion from say 400ft to 200ft; about 1 litre from a 14 litre capacity
>> Steinke hood. Relaxed breathing is about 6 litres a minute.
>> Quote from an article on Steinke hoods....
>> As early as 1974, one study highlighted significant biomedical shortcomings in the escape system: hypothermia, nitrogen narcosis, hypercarbia, barotrauma, and decompression sickness. These shortcomings were attributed to the method of escape and operating procedures. Furthermore, the current method of submarine escape was no longer practical, because the Steinke Hood provided no thermal protection for the escaper during the escape and while awaiting recovery. Accordingly, citing emerging technology and recent studies, by 1996 researchers at the Naval Submarine Medical Research Lab presented biomedical-based recommendations for enhancing survival of escapers by a) overhauling current submarine escape systems and procedures and b) substituting existing thermal protection suits for the Steinke Hood.
>> Alan
>>
>>
>>
>> On 1/05/2019, at 9:03 PM, MerlinSub at t-online.de via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>>
>> Really good training video. Shall safe to the Psubs server..
>>
>> I have 5 or so devices for the Euronaut. Pretty old USNavy devices form the 80ies and far over it expected lifetime.
>> But it was nessesary to renew the neck scirt. Was pretty hard. Any small diver suit maker or reair company can do these job.
>> We let them make new scirts from Neopren. 50 USD or so each. Replacement comes without a neck hole
>> from the suit repair company. We make the holes ourself according to the smallest crew member neck.
>>
>> In case you have no LP hose access you can fill the unit with the small inflatour mouse tube.
>> This is clear opposite to the instruction video - but better than to lost your life.
>>
>> No.6 unit on board has a blue mark on his bag - it is our training device o teach new crew members.
>> The other ones are sealed.
>>
>> I think you can may convert a new divers vest BCD into such a device.80% of the device is allready on a BCD.
>> Show the video to a diver suit repair company and give them the new BCD to convert is may an idear.
>> The unit with a small air pony bottle as the mmost BCD have - will be a great update- no need of a LP Hose anymore.
>> If some of your guys try so for such a conversion - give the comunity here a call
>> - may it will be cheaper if you can convet a bunch.
>>
>> vbr Carsten
>>
>>
>>
>>
>> -----Original-Nachricht-----
>> Betreff: Re: [PSUBS-MAILIST] onboard gear
>> Datum: 2019-04-30T23:09:56+0200
>> Von: "Cliff Redus via Personal_Submersibles" <personal_submersibles at psubs.org>
>> An: "Personal Submersibles General Discussion" <personal_submersibles at psubs.org>
>>
>>
>>
>>
>> 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
>>
>>
>>
>> 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
>>
>>
>>
>> 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
>> _______________________________________________
>> Personal_Submersibles mailing list
>> Personal_Submersibles at psubs.org
>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>> _______________________________________________
>> Personal_Submersibles mailing list
>> Personal_Submersibles at psubs.org
>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>> _______________________________________________
>> Personal_Submersibles mailing list
>> Personal_Submersibles at psubs.org
>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>> _______________________________________________
>> Personal_Submersibles mailing list
>> Personal_Submersibles at psubs.org
>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>>
>> _______________________________________________
>> Personal_Submersibles mailing list
>> Personal_Submersibles at psubs.org
>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>> _______________________________________________
>> Personal_Submersibles mailing list
>> Personal_Submersibles at psubs.org
>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>> _______________________________________________
>> Personal_Submersibles mailing list
>> Personal_Submersibles at psubs.org
>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>> _______________________________________________
>> Personal_Submersibles mailing list
>> Personal_Submersibles at psubs.org
>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>>
>>
>> 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
>>
>>
>>
>> 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
>>
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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> 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
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>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
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