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Wing failure

Discussion in 'DIR Diving' started by Mr Bean, Aug 19, 2011.

  1. Mr Bean

    Mr Bean Member

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    One of the big things that I don't agree with in DIR is the refusal to use 2 wings, or a dual bladdered wing. I can understand that if your drysuit can make you neutral or even slightly positive, even if grossley over-inflated, then that could count as redundant buoyancy. However, if you are using large twinsets and/or several stages filled with nitrogen based gas, I'm sure that a situation culd occur where a drysuit by itself will not be able to offsett the negative buoyancy of the gas in the cylinders. I know that below 30m GUE use helium which reduces the weight of the gas, but I think a long 30m dive (maybe in a cave?) with, say, twin 12s and a couple of al80 stages is quite conceivable.

    The other scenario could be diving in a wetsuit with a twinset. Obviously it is important to be correctly weighted, but even so, a full twinset alone without stages is over 6kg in negative buoyancy, and this will increase as you descend with compression of the wetsuit. If your wing were to have a complete failure, such as the inflator hose disconnecting from the wing, then I don't see how you could safely achieve neutral buoyancy and complete any decompression necessary.

    The solutions that I came up with without using a second bladder were to, a) not dive in a wetsuit with twins, and, b) if you have a wing failure immediatly hand off any stages to team members and they could lift you if necessary.

    As for "a", diving in a wetsuit is so nice compared to a drysuit, if I was somewhere nice and warm I'd want to be a wetsuit if possible, so I don't think I'd be too happy with that. For "b", this seems like a reasonable solution, making the most of your team to help you overcome a problem so you don't need extra kit, but in either of the 2 scenarios mentioned above, you have no back-up adjustable buoyancy source, and while I appreciate that you don't need to have too much redundancy, to not have a plan B that you could execute yourself regarding a buoyancy failure seems a bit dodgey to me.

    Can an extra inflator hose over your right shoulder cause that much bother? Or am I just missing other obvious solutions that negate the need for a second wing?
     
  2. Suggsy

    Suggsy Banned

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    What about bungie to wrap that little lot up with... don't forget to mention the bungie!

    If I had a punctured wing or unable to add gas to it AND my drysuit was unable to provide neutral buoyancy and support me on the surface AND my life was in danger due to drowning due to NOT diving a balanced rig as I was taught then I would jettison my gear and take up golf.

    Also be careful you don't mix up a Hogarthian rig and DIR as what you describe is more than just those who follow the one true way.

    As for diving twins in a wetsuit I've not yet done so so cannot comment, although be aware aluminium cylinders are generally used abroad and therefore offer greater buoyancy characteristics. I'll be diving drysuit in Malta next year.
     
  3. j_b

    j_b Well-Known Member

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    Tbh if was diving deep enough and long enough to be needing stages and deco gas along with my back gas I'd be wanting my dysuit anyway.
     
  4. Mr Bean

    Mr Bean Member

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    Not at all, I quite understand why bungied wings aren't allowed.

    How about your life being in danger due to staying on the bottom for too long and racking up too much deco?

    Please explain how you would balance a rig where you were carrying too much gas for your drysuit alone to support.

    Well as long as the steel cylinders aren't so heavy that they make you negative even with no gas in them then I don't see how they would be better, you've still got 6kg of gas to counteract.
     
  5. Mr Bean

    Mr Bean Member

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    Fair enough, but quite a few people wouldn't.
     
  6. Mr Bean

    Mr Bean Member

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    I believe that I read on YD once that Garf, Gloc and HP (I think anyway) were on a course and a hose fitting or something came off one of their wings and even with a fully inflated drysuit they couldn't stay neutral, so had to be held up by one person while the other took their stages, so it could happen. My point is, is the response just mentioned a normal DIR style response to the situation - i.e relying on your team members to resolve a loss of your primary buoyancy source, or is there a "better" way to deal with the situation without a second wing?
     
  7. neilh

    neilh Well-Known Member

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    They aren't in widespread use anyway are they? So it's not just the DIR community that don't use them...

    However rather than DIR "refusing" to use them the point is that you avoid over complicating your setup. In this case does adding an additional bladder, inflator, hose, etc solve sufficient problems against the potential complexity and failure points you introduce.

    From what I understand you should be able to hand off a deco cylinder and manage an ascent if your kit is suitably balanced. Yes it relies on your team to assist you, but remember that they are there to help you and losing them would have been a dive ending failure.

    Which probably has a lot to do with why, from a DIR point of view, carrying out a dive with a decompression obligation in a wetsuit would not be a good idea...

    Not sure what poor discipline has to do with having a double bladdered wing? If you're in this situation chances are you're going to run out of gas to fill either wing anyway ;)
     
  8. Mr Bean

    Mr Bean Member

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    Hardly "extra failure points" - it's not adding failure points to the system that you already have, and the only extra failure points are those which could cause the second bladder to fail, nothing else, so hardly relevent. You wouldn't even know the extra bladder was there when not being used, and an extra inflator hose when not in use is hardly going to push you over the edge in task loading.

    Either I don't undertsand what you're saying, or you're not listening! In the situatiosn that i described, how should you manage an ascent if you aren't able to attain neutral buoyancy?

    Fair enough - that's answered half of the question then :)

    I didn't mean staying on the bottom in terms of forgetting to end the dive, I meant it in the sense that you would be negatively buoyant no matter what you did, so doing a nice controlled ascent may prove problematic!
     
  9. Suggsy

    Suggsy Banned

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    I can control my ascent with an empty wing, how do I know? My IANTD instructor made me do it, followed by my TDI instructor. Just because gas is lost from my wing doesn't instantly make me, you or anyone massively negative, not if correctly weighted anyhow. I don't carry that much gas for my drysuit to support, i mean, people do actually dive that way day in, day out.
     
  10. Mr Bean

    Mr Bean Member

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    Then why are you answering this thread if the question doesn't apply to you, and you then use that as a reason for not worrying about the issue I explained? I am talking about dives where there is in fact a lot of gas for your suit to carry if needed - too much for it to support my itself, as per the example with Garf, Gloc and HP above.
     
  11. Suggsy

    Suggsy Banned

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    Because you asked those questions whilst quoting me. Since you have now moved the goal posts I will bow out. Good night. Much love.
     
  12. Mr Bean

    Mr Bean Member

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    I did say in my first post that I was talking about dives where your drysuit couldn't support the weight of the gas. Anyway, sorry if that came across as arsey, I didn't mean it like that.
     
  13. Major Clanger

    Major Clanger P-Plated Meg Diver

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    Sensei has taught you well young smugsy ;)
     
  14. Major Clanger

    Major Clanger P-Plated Meg Diver

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    When would that be? Most easily support a full twin set and two 7 litre stages. If not, there's always the dsmb and dump valve.
     
  15. johnkendall

    johnkendall Member

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    Ok, Let's look first at a Double Wing.

    2 options, Leave the 2nd inflator connected or leave it unconnected.
    If connected, and you get a run-away inflator, which one is it? You are going to need to turn off that gas source to stop the run-away, but now don't know which reg to go for. Therefore it's a bad idea.
    If unconnected, you now have to try and connect an inflator to it in the event of a primary wing failure. I think your time would be better used by signalling your team and getting assistance, rather than messing about trying to connect up a disconnected inflator.

    So, we don't use double wings.
    However this is how we deal with a single bladder wing. If you can get away with diving a very thin (3mm or less) wetsuit, then you basically have almost no buoyancy change due to depth. If it's too cold to do that, then use a drysuit.
    The incident you quote happened on the surface. Without a working wing, you will always struggle on the surface if you have a full gas load, but if you're underwater it's not so difficult as you're not trying to lift stuff above the water too. Twinset plus stages means decompression, and decompression realistically means drysuit. In a drysuit you can counteract the weight of gas from the twinset.

    HTH
    John
     
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  16. Mr Bean

    Mr Bean Member

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    Thank you very much John.
     
  17. big si

    big si Well-Known Member

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  18. GLOC

    GLOC Member

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    The incident did indeed occur on the surface with 'training' gases. I would not conduct areal dive which needed 3 nitrox gases in the stages and nitrox in the back gas and a 40lb wing, there isn't enough lift. To do a 3 stage dive I would be diving a drysuit, 18/45 (or higher He), 18/45 (or higher) in one stage, 50% in one and 100% in the other.

    You would be surprised how light He is compared to 'air' based gases and a 40lb wing will support 18/45 12s & 80 plus 50% & 100% 7s (80s at a push).

    If you have a massive failure, hand off the stages to reduce weight. If near the end of the dive, your back gas will be reduced, if near the start, not much deco.

    Many people forget that DIR principles all work together and therefore 'cherry picking' them doesn't necessarily mean it works out how it is supposed to.

    Hope that helps.

    Regards
     
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  19. Gareth Burrows

    Gareth Burrows Super Moderator
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    Gareth makes a good point. It was me in this "incident" ( and I use quotes because it was hardly a drama, more an excuse for everyone to point and laugh at me. I was carrying 3 AL80s of Nitrox as part of a training dive. We would never do this on a real dive. The weight of all that gas forced the wing into the water and obviously put huge pressure on the inflator hose where it met the wing. The hose popped off and I went south at a rate of knots, hugely overweighted. As it happens, my team were close enough to grab me and just started taking bottles off me until I could manage my own buoyancy.

    If they hadn't been able to grab me I guess I'd have found myself sitting at the bottom of 18 metres with 12 thousand litres of breathable gas trying to decide whether to breathe it down for a few hours whilst my team searched for me, getting lighter all the time, or just start clipping stuff off to an SMB before ascending on my own.

    John, Gloc and I are doing a dive in a few weeks where I believe I will jump in with twin 18s and 5 AL80s. I worked out that if it was all full of nitrox I'd need something like an ocean going crane to lift me off the bottom. However, they won't have Nitrox in most of them.

    If people want to use single or indeed double wings, then who the hell is anyone else to tell them what to do. All GUE do is have a standard configuration for GUE divers to make life easier. What anyone else does is frankly their business.
     
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  20. Mr Bean

    Mr Bean Member

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    Thanks for the replies Gareths :)

    Out of interest Garf, what are you diving with your 5 stages? I presume it's a cave?
     

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