Inverted twins

[Hobby]

Cheers for that!I've seen that link somewhere before too,but would never have found it!
We looked at these points previously that "they" make and it's quite interesting,just let me run this by you and see what you think.
Custom length hoses.Yes,they have a point but so technically is a 'long hose' and on some regs eg Sherwoods the hose is long enough to invert as standard.Noise from a leaky hose,maybe altough a small leak from my 1st stage was easy enough to hear,I'm sure that I may hear it wherever..no guarantees though I admit!
Routing.IMHO I reckon that with inverts it can be much more streamlined,as the hose are adjacent to the body and tucked away.
If cylinder valves designed for inverted use are needed you don't require a stand/valve protector.However these can be difficult to source in rec circles so fair point.Even if a protector is fitted though to overcome this,is it really more of an entanglement hazard than valves between your shoulders?
 All the entanglements I've encountered have been around the cylinder valves(hence the benefit of inverts?)except one when I got my leg wrapped in barbed wire!I reckon an entanglenent behind your shoulders is quite inconvienient at best.
I'm not picking an argument here Lettuce I just want to discuss the pros and cons(which there are)! So many people decry inverts immediately without really knowing why,never mind having tried them.While they may not be suited to every application they're probably unbeatable in some.
I've never actually seen the points discussed that many DIR advocates hold up as it being a bad systen that's all.
Regards,Hobby.

[Dr Stevil]

I would have thought that inverts would avoid potential entanglements better than non-inverts, ie it'd be relatively easy to snag something behind your shoulders as you were entering some kind of aperture, be it cave or wreck, but snagging something in your butt region would seem to me less likely.

I'm found I'm developing a "wince reflex" whenever a certain TLA is mentioned so in the interests of neutrality I'm going to call it something different:
I really, really don't want to get back into the pros and cons of TDS (ie "That" Dive System), but I'd be interested to hear a logical argument (ie not verbatim regurgitation of something expressed by JJ & GI3) against inverts from an afficionado (I've already found at least one directive which doesn't stand up to my own experience, but best let sleeping dogs lie).
Chee-az
Steve
now, where's me flameproof coat ;) :flame:

[And]

Hi

Don't get me wrong, I do support DIR but am not an expert or anything, definitely not an afficionado and I only joined this thread because I remembered some stuff about inverted tanks and knew where to find Jack Ingles picture. I firmly believe that everyone should be able to do whatever they want to do, and that there should be more tolerance in diving, in the interest of safety and having fun which is why we all do it. (Yes idealistic I know, but I don't care. World peace would be so cool!) The thread seems to be moving towards a 'pros and cons' debate which isn't what you first asked.

However...

In the DIR fundamentals book JJ does reference Inverted tanks as an option to avoiding collisions in overhead environments, but states the disadvantages I have already mentioned. I neither support or disagree with his views as I have never tried them, or normal twins for that matter and so I am not qualified to do anything other than regurgitate his words and I have acknowledged that the info can be found in his DIR fundamentals book.

I am sorting a twinset out at the moment and it will be DIR through and through, because I have (blind?!) faith in the system knowing the types of dives and environments in which it has undoubtedly been proven. I trust JJ knows what he is talking about and I take him at his word.

Hobby has used inverts as do the RN and there should be the source of any pros and cons. There are many on the board who use twins in a DIR config and so they should be able to point out the pros and cons of that system. If everyones objective and tolerant then you might, just might, (crossed fingers) get a balanced argument to choose the one you like best.

Hope that clears some stuff up

Kindest Regards

WL

[Dr Stevil]

Chee-az WL, an un-flamelike and balanced viewpoint, even if you did say "Jehovah" ! ;)

Steve

[Mdemon]

You said "Jehova"!!!

Where's my rock...  :-)

[Hobby]

Lettuce,no,Christ no mate!I did'nt have you down as being,well,"like that".I was just glad somebody was able to put the points across in an unbiased manner to discuss.I thought that as you had a knowledge of it we could bounce it around a bit and see what we got!
I'm sure that I'm not alone in saying that,sadly,many with a good knowledge of DIR tend to show a remarked inability to discuss alternatives without getting "defensive" etc.I'm not labelling you in any way,certainly not as DIR (altough you could be,it does'nt matter)just trying to tap your knowledge!Sneaky!I really did'nt mean to give the impression I was picking an argument or having a dig,like many I am very interested in learning all I can re DIR and other aspects of diving.In this respect you're obviously much better informed than I,hence the questions.Please continue to put foward such knowledge,even if you don't agree with it,we can all ponder it then and learn!
Take care,Hobby.

[And]

Hi

Thats OK Hobby, I know you didn't mean anything, it was just in case.

I remembered I read it in an article by JJ on DIRQuest and I dug it out last night. He states the disadvantages I've already stated.

If I was to compare the pros and cons myself then I think the main 'cons' of inverted must be the hose routing. In DIR (Hogarthian)etc the same rig and routing can be used throughout all your diving. The hose routing is the same from Singles, to twins with stages, to rebreather and stages (RB80) and so on. This would mean that you could never be confused in an emergency finding a particular hose or item.

The 'long hose' deployment will be less effective as it starts from the hip, potentially leaving less room. I don't think it would be sensible with more than a five foot hose, as the routing would be difficult.

I think you have a point with the entanglement issue and this is only usually pointed at upright twins fitted with cages.

As far as difficulties donning and doffing I don't really subscribe to that as inconvenience should'nt really matter on the surface. We can still breathe ! but it is important underwater and if you can't reach your valves for whatever reason then its a waste of time having a manifolded twinset IMHO

Let the debate begin!

Kindest Regards

WL

[Kev W]

re the routing of the hoses I use OMS wings and harness I connect my regs up and run the hoses (2xreg 1xwing inflator)up between the cylinders before fitting the wing/harness this keeps them neatly out of the way and all three then come over my shoulders as with an ordinary set up.Both contents gauges (I have one for each cyl)and my drysuit hose come round my body they are close fitting and not an entanglement problem. I wouldn't dare presume my way is the be all and end all of configs but it works for me. I have a cage which doubles as protection for my valves and a stand for kitting up.
hope this helps the debate
Kev

[Mdemon]

Just got all my own gear - and found that I can hardly reach the valves, let alone turn them off!

I have no manifold at the moment, just testing with indies.

Am I a total freak, or does anyone else have trouble with this?

The reason I am posting here, is that it looks like inverted is the only option for me...  Standby for questions on "how do you make your own valve guard"!!!

[Jay]

Reaching valves is a bit like losing your virginity.

1. No one owns up to the fact they haven't done it yet
2. Everyone else HAS done it (according to them)
3. Everyone else has a thousand and one opinions on how it SHOULD be done
4. We all know someone who'll NEVER do it
5. When we finally DO do it, we are so pleased we tell EVERYONE we meet!