Mailing List Archive

Mailing List: techdiver

Banner Advert

Message Display

Subject: Re: Upside down tank mounting - What's your opinion.
Date: Fri, 12 Mar 1999 13:53:46 -0500
From: Jim Cobb <cobber@ci*.co*>
To: "Craig Waldman" <craig.waldman@er*.co*>,
     "Tech Diver"
Upside down tanks are yet another attempt to slay invisible dragons. 
There is simply no issue of reaching valves or banging them if you have 
rigged your gear correctly and know how to dive.

And anybody who has spend any time at all on a diveboat does not have to 
think about this for very long to see the problems that would be created 
by this setup. There was a thread not too long ago on this foolishness, 
check the archives

 As far as that Royal Navy air management system is concerned, the RN 
does all kinds of stupid, time-honered ridiculous bullshit. One day a SPG 
will wind it's way through their procurement system and actually make it 
to a diver and they will change.

   Jim

Sender: Craig Waldman  Date: 3/12/99 11:57 AM

>Hello Everyone,
>
>I have been reading this list for a few months now.  This is my first
>posting to this list. (please be gentle)
>
>First a little about myself,  I still consider my self a baby diver. I have
>been diving for 11 years.  My most recent certification is as a Commercial
>HSE Surface Supplied (Top Up) diver (Part 1 equivalent)  I got back from Ft.
>Bovisand, Plymouth England only four months ago.  I do not consider myself a
>Tech Diver yet, but I am learning. My personal focus is on wreck diving and
>not cave diving.
>
>I have been very interested in the DIR methodology.  Its practitioners seem
>devoted, if not fanatical, about safety, and the furtherance of diving
>technique.
>
>With that said, I would like to open for discussion a possible alteration to
>the standard DIR method.  I DO NOT currently dive with this rigging method,
>but am considering it. I would like your input and suggestions.
>
>
>
>While in England I was introduced to the idea of mounting your tanks so that
>the valves were mounted on the bottom. (near your butt).  At first I
>dismissed this as being silly.  But after a proper introduction to the
>reasoning behind it, I think it has some possible advantages.
>
>One of my own concerns with this arrangement is that with the tanks being
>upside down, any particulate matter in the tanks would head straight for the
>valves.  (this shouldn't be a problem with properly inspected, and
>maintained tanks, but still...)
>
>The first possible advantage is that the valves are much easier to reach.
>If you can scratch your butt you can turn a valve.  This comes in especially
>handy for doubles with an isolation manifold.
>
>A second possible advantage.  When using round bottom (now top) tanks, you
>are even more streamlined, and have greater clearance around your head.
>It's easier to look up or forward with NO obstructions behind your head.
>
>A third possible advantage. Your manifold is less likely to get banged
>during a "Push" though an overhead environment.
>
>
>And here is a big one for the Remove all excess potential failure points
>fans:
>
>The Royal navy divers do not use a pressure gauge. That's one less hose.
>They employ an interesting method of gas management.
>
>1- They start with two full tanks Isolated.
>One on, one off
>
>2- They breath the first tank to empty,
>then open the second tank
>The tanks then equalize so each tank is now at %50 capacity.
>They then shut off the second tank, isolating it.
>
>3- They breath the first tank to empty again,
>They then open the second tank
>The tanks then equalize so each tank is now at %25 capacity.
>This is the reserve point, so begin ascent procedures.
>
>I'm not sure I would want to dive without an SPG, but in this configuration
>the hose length could at least be dramatically reduced.
>
>
>
>-- Finally my questions.
>
>First, what is your opinion on this upside down idea?
>
>Second, how do you see this would effect the long hose, and other hose
>routings?
>
>- Craig Waldman
>    New Jersey
>--
>Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'.
>Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
>


 -------------------------------------------------------------------
 Learn About Trimix at http://www.cisatlantic.com/trimix/trimix.html


--
Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'.
Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.

Navigate by Author: [Previous] [Next] [Author Search Index]
Navigate by Subject: [Previous] [Next] [Subject Search Index]

[Send Reply] [Send Message with New Topic]

[Search Selection] [Mailing List Home] [Home]