[PSUBS-MAILIST] I am actually a fan of potential coffins

[maxxx1@comcast.net]

Hello Ian,
Thanks for your thoughts,I believe when you are in ambient wet/dry subs you are  basicly scuba diving with a housing around you to propell you.Since you are governed by scuba dive tables with maximum bottom time,you as a ambient submariner have all the associated problems of breathing pressurized gasses as a scuba diver has.Things do happen quicker in an ambient sub,however you HAVE
the option of evacuating and ascending to the surface if problems with the sub arise.In an ambient sub you probably won't exceed the recreational dive depth of approx 130 feet and if you do go that deep you probably won't stay more than a few minutes.As I recall bottom time isn't really time on the bottom, it includes decending and ascending.So most of your time in an ambient sub will probably be farting around in 20,30 mabee 80 feet, of course you can go deeper but that limits your time under especially after all the preparation to get you sub to the dive site and back.I personally don't mess around with ambient subs.I was a scuba diver before I became involved in 1atm subs of which I am a fan actually despite my ominous coffin letter.Its just that I have seen many home built subs that people go down in and I am completly astounded sometimes that some people would put themselves at such risk going down in such contraptions.I believe the reason I like 1atm subs vs ambient subs is because I can stay down all day at say 800 feet, and thats important because of all the trouble hauling to and from the dive site and dive preparation time.It becomes a 4 am to 10pm adventure.
Seasons Greetings
Robert Rogala
maxxx1@comcast.net
> 
> Hi Robert,
> 
> you bring up some very good points about 1atm subs.  But I think you'll
> find that you can get into much as trouble with a 'seat of the pants' wet
> or dry ambient sub as you can with a 1atm.  In my eyes ambient pressure
> subs will always be frought with more risk than the 1atm - do you have a
> decompression chamber?
> 
> You're happily exploring in your wet/dry ambient sub at 100feet, suddenly
> your sub get's caught on fish nets/line/dredger cables/whatever,  the
> exit from the vehicle is resticted by the lines, before you can start on
> freeing youself the cables/ropes/lines go tight and you are being hauled
> to the surface faster than your decompresion chart says you should.  This
> happened to a friend of mine who was out diving (no submarines needed) -
> the Navy would not allow him access to a decompression chambler (they had
> the only decompression chamber for 100s miles and where later successfully
> sued for not allowing him access), now his leg's don't work any more, and
> he get's to be luck he's a live.
> 
> As I see it, the biggest issue with wet/dry ambient designs is once something
> has gone wrong you've only got a short rescue time - with a 1atm design,
> your rescue time can be as long as you design it to be...  Time will never
> be on your side - but you can buy a little (days?) extra with a 1 atm design
> (better remember to being enough cat litter for 3 days as well).
> 
> As far as psubs being coffins, whether it's a 1atm or ambient doesn't matter
> too much if you've planning everything out properly.  The idea of
> a 'seat of the pants' design does strike me as having more coffin potental
> than any well thought out design.
> 
> Wouldn't you have a prelaunch checklist for ambient subs as well?
> (It would like of suck to get to the bottom and realize nobody
> filled the air flasks....)
> 
> Thanks,
>   Ian.
> 
> On Tue, 23 Dec 2003 23:23:03 +0000
> maxxx1@comcast.net wrote:
> 
> > Hello All,
> > In my opinion,designing and building wet subs or ambient dry subs from the 
> seat 
> > of the pants could be a very rewarding accomplishment.However,building a 1atm 
> > dry sub is another matter,especially one which decends in excess of 150 
> feet.Now 
> > your dealing with life support in your self contained environment even if its 
> > just a bounce dive.Are the O2 and CO2 levels monitered correctly?
> > Do you have and use a Dragger tube periodically to confirm the gas meters are 
> > working correctly?.If only one person is in the sub and he blacks out because 
> of 
> > incorrect gas ratios,then what? Should we carry enough O2 and Soda Zorb to 
> allow 
> > for a possible rescue from above in case we are hung up on something 
> protruding 
> > from the wreck we are observing and we can't release ourself, mabee if we 
> could 
> > see what we were caught on we know what direction or angle to move the sub to 
> > release ourselves.Could the rope on the wreck be wound around our propeller,no 
> > way, because we remembered to totally encase the prop and shaft in a wire 
> > housing.Do we have enough reserve buoyancy to lift the object we are caught 
> on? 
> > Can we evacuate the sub after equalizing the pressure from 150 feet? 300 
> > feet?,600 feet? Do we need 2 pony bottles to take with us during out ascent to 
> > the surface,one air,one a tri-mix with a lable DEEP? What is the record depth 
> > anyone ever sucessfully evacuated from a sub?
> > If you go really deep say for example over 600 feet,you may as well be on the 
> > moon, will you have enough life support for a rescue allowing time for a 
> > submersible to be flown in,mabee they can spot our bouy which floated to the 
> > surface and is attached to the sub because we decided to build one on our sub.
> > Did we decide to spend the $600+ for the underwater phone so we can keep in 
> > contact with someone on shore.Did we remember to dress with static resistant 
> > clothing in a potentially O2 enriched environment,and are the lead acid 
> battery 
> > gasses kept out of the potentially O2 enriched environment cabin? Did we try  
> to 
> > eliminate all gear outside the sub which can snag things and hang us up.How 
> many 
> > volts is that switch we are touching while our knees are immersed in water?.
> > Did we remember to build an emergency drop weight because we didn't take 
> enough 
> > scuba air with us to make up for the extra 70lbs we brought aboard,will the 
> drop 
> > weight work when it is burried in mud? over one cubic foot at say 1000 feet 
> > depth is how much at  sea level? Did we incorporate any trim weights rather 
> than 
> > soft ballast tanks? What will happen when the acrylic window hits a submerged 
> > log while we are decending?
> > In other words did we remember everything?Do we have prelaunch checklists?
> > I hope nobody out there is performing manned test dives,in anything but very 
> > shallow water.Do we have a system for sending the sub down unmanned in excess 
> of 
> > our maximum dive depth for our test dives? I know we can't think of every 
> > eventuality, but lets do our homework and find out whats what before we put a 
> > man inside his potential coffin ie: a 1atm dry sub.
> > Take Great Care All! 
> > Robert Rogala
> > maxxx1@comcast.net