[PSUBS-MAILIST] onboard gear
Alan via Personal_Submersibles
personal_submersibles at psubs.org
Fri Apr 26 17:01:33 EDT 2019
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
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>>>
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