Single vs Double Bladder Wings - Pro's and Con's ?

[Phil_C]

I have just acquired a brand new, never dived, Hollis 85 BAC Wing with double bladders for next to nothing (theres probably a reason for that )

I can see reasons why a double bladdered wing might be useful sometimes, true redundant buoyancy for example, but I can also see the arguments against - such as two inflators, greater likelihood of confusion in an emergency with trying to dump air incorrectly from the wrong bladder and so on, but what are peoples real life experience of them?

I'm currently playing around with different configurations of backplate and wing for diving manifolded twin steel 12 litre tanks and steel stages, all for cold water in a drysuit.

Anyone used this wing or have any similar experience to share? - Many thanks

Phil.

 

[tbone1004]

there's a reason they don't make them anymore, 85lbs is an insane amount of lift, so there's also that...

Real world you have two problems. They're great in theory if you're diving wet. The issue is if you're diving a wing that big wet, you aren't diving a balanced rig, or one close to being balanced so it is dangerous from the start.

You also have the issue of number of inflator hoses if you're diving dry. If you have a 5 port turret regulator on a twinset, you can have the extra inflator hose coming down from the right post and it is usually a nonissue. With something like the DS4 style regulators, you can't have the inflator hooked up all the time, so now you have to have hoses long enough to cross over, or be able to orally inflate fast enough. With a wing that big, it's a problem, it's 10+ breaths for most people to fully inflate one of those things, so you want the power inflator available, but it only works well with certain first stages.

 

[Phil_C]

Thanks tbone - guess the same reason they don't make them anymore is why I got it for next to nothing -

I've got a spare suit inflation bottle lying around and was considering rigging this to the second bladder, and then diving with it turned off, there would be no risk of accidental inflation, but it is there if you need it, just turn the bottle on and off you go.

A question though - surely the wing isn't 85b lift unless you inflate both bladders? or am I understanding this wrong. I assumed it was two bladders of 42.5 each, but then I haven't yet looked at the manual or anything. I have got a DirZone Stream 20 donut wing, which is 40 lb lift, it is what I have been using with doubles so far and the Hollis wing does not look much bigger than that. - Phil.

 

[PfcAJ]

A halcyon double bladder wing? Pic please.

 

[Phil_C]

PfcAJ - sorry - seems you have caught my fingers out ! - that should have been Hollis, not Halcyon - I'll edit my first post, well spotted

But I can post you a pic of my nice brand new HOLLIS 85, BAC Double Bladder wing !

Sorry - P

---------- Post added June 4th, 2015 at 05:24 PM ----------

Just looked it up in the Hollis manual - it is 85 lbs each, so yes an insane amount - P

• BAC D85 – Double Tank Dual Bladder System85 lbs (38.6) Lift Each – removable bungee included
  
  
  

 

[tbone1004]

That is strange they quote that because usually in a double bladder wing you can only inflate one to the limit. They are designed for redundancy, use one primarily, and use the other if the first one fails. Razor sidemount is like that, you have one bladder that is primary, then the second "bladder* though there's is a bit different design but same principle*, inflates by pushing against the other. The manual states not to inflate both at the same time, so it is a 40lb redundant wing, not 85lbs, so plan your weighting accordingly.

In that case I have no real problem with it, just don't think it is necessary. If you have a suit inflation bottle on your rig, I actually prefer to just use air if you don't really need argon, and actually use that as my wing inflation as well as drysuit, so you can put a third LPI hose on it if it will take one, or you can have drysuit/backup with the primary coming off of your backgas, your call, but I'd put all at least two of them on the inflation bottle.

 

[Phil_C]

Hadn't thought of running two off the inflation bottle - but yes, I'd only use air in it, no point for me of anything else, I don't do that sort of diving. If I do swop the double bladder wing for my DirZone wing I might try rigging DS and backup wing bladder off the inflator bottle, and primary bladder off back gas. That way it seems I keep redundancy as I would not lose the wing if I had to shut down a post on my doubles for any reason. - P

 

[nimoh]

Hadn't thought of running two off the inflation bottle - but yes, I'd only use air in it, no point for me of anything else, I don't do that sort of diving. If I do swop the double bladder wing for my DirZone wing I might try rigging DS and backup wing bladder off the inflator bottle, and primary bladder off back gas. That way it seems I keep redundancy as I would not lose the wing if I had to shut down a post on my doubles for any reason. - P

you have a wing from DIRZone that is dual bladder?

 

[PfcAJ]

Hadn't thought of running two off the inflation bottle - but yes, I'd only use air in it, no point for me of anything else, I don't do that sort of diving. If I do swop the double bladder wing for my DirZone wing I might try rigging DS and backup wing bladder off the inflator bottle, and primary bladder off back gas. That way it seems I keep redundancy as I would not lose the wing if I had to shut down a post on my doubles for any reason. - P

having two wings plugged in and on is asking for confusion should one start auto inflating.

ditch the dual bladder wings. They're baloney.

 

[Phil_C]

you have a wing from DIRZone that is dual bladder?

No - I am currently diving twins with a DIRZone wing, but have just picked up a brand new Hollis D85 BAC, which is dual bladder, and I am considering the pro's and cons of swopping it with the DIRZone one, and how I would rig it if I did. - Phil.