Wearing Tanks Upside Down

[roughwater]

Ok, now that you've finished laughing, I'll explain my question.

I've noticed that firemen wear their tanks upside down (valve/reg at the bottom). I thought that this may have been some 'fireman' thing, but the other night I saw on the news some police divers with the same setup. (Scuba tanks upside down, with valve/reg behind the 'behind', instead of the head).

Can anyone tell me the benefits of this, or why they do it?

Adam.

 

[roughwater]

Forget that... I've just been told the reason.

For those interested - i was told that police with twin cylinders have them setup in a manafold configuration, but they only have one cylinder turned on. When air gets low (difficult to breathe), they turn the other cylinder on to decanter, and then turn it off again.

They can apparently do this 3 times before they surface.

The reasoning behind this is that when they're in low vis water (low enough to make it difficult, if not impossible to read gauges), they're able to know how much air they have left.

Having the valve at the bottom makes it easier to turn on and off.

 

[Txfirefighter4305]

I have never seen that, it is certainly interesting.

Firefighters cylinders are upside down for several reasons. First, while crawling on the floor of a burning building, you don't have have that valve hanging out there like a grappling hook. Also, that way the rear brim on our helmet doesn't hit the valve. Just a little FYI

 

[mike_s]

Ok, now that you've finished laughing, I'll explain my question.

I've noticed that firemen wear their tanks upside down (valve/reg at the bottom). I thought that this may have been some 'fireman' thing, but the other night I saw on the news some police divers with the same setup. (Scuba tanks upside down, with valve/reg behind the 'behind', instead of the head).

Can anyone tell me the benefits of this, or why they do it?

Adam.

use the search function. You'll see this has been discussed numerous times.


Benefits?

Tanks are flat on the bottom. Put the valve on upside down and you can't set your gear down standing up.


Also, if you got an excessive amount of moisture or any debris (dust, dirt, etc) in your tank, gravity could pull it "down" into your first stage if inverted. That's why valves all have the 'dip tube' on them, in case you swim upside down so that nothing gets into the valve except for air.


Why do firemen put them upside down? dunno.. prob doing so puts the valve less at risk from heat damage. (just an idea though).

 

[Britt]

I had seen pictures of a diver wearing tanks reversed, and correct me if I am wrong, but I believe that it is done in Europe more frequently, so I tried it about 5 years ago and it worked well except for having to reroute my hoses (I was using doubles) and the buoyancy problems.

The first try had me in a standing position when I tried to level out. A little bit of weight on top helped and I had no complaints about the configuration until I got out and tried to sit down and became really paranoid about breaking the first stages and bending the DIN valves.

Having access to the valves without reaching over my head did make it easier to turn them on and off. I wasn't as worried about something rolling my valves and shutting the left side down. It was an experience, but I went back to normal later that day just to keep other divers from harassing me and saying I was nuts.

 

[Walter]

Tanks are flat on the bottom.

Not steel.

 

[fdog]

Here's my standard post on this subject:

Sheesh. This question comes up about once a month, and this is the usual sequence:

>..."Why not?"...question.
>The beat-down begins:
>Never done it that way
>It's too difficult to close valve/isolator
>OMG what about on boats
>The hoses are longer
>More breathing resistance
>Non-standard
>You will damage the valve, you dimwit
>This is easier to tangle because the valve's on the bottom
>...and on and on...
>OP, suitably bludgoned, whimpers away.

As someone who puts on an inverted cylinder about 3 times a day at work, and uses it, I can state that there is absolutely no doubt that inverted cylinders are:

>Easier to open/close valves. I can even reach around with my left hand and close the (right-handed) valve, even with the anti-close ratchet our valves have.
>Faster to switch out cylinders. There is just no comparison. Spin, click, pull out the cylinder. Shove in a new one, click, spin on the valve. all done in about 45 seconds, no kidding. I feel handicapped changing out a regular cylinder, let alone doubles.
>More tangle-resistant. Really, you think that those 1st stage(s) and valves behind your head are cleaner than the rounded butt end of a cylinder?
>More durable. Yes, my work airpack gets dropped on it's valve once in a while. Nothing happens except a sheepish look.
>Easier to put on. Yes, I can hear the gasps from BP/W users now...this is a statement from someone with 3 (edit: now 6) plates in the house, and there is no doubt in my mind, when looked at from the totality of donning the system, BP/W comes in second best.

I'd suggest that for someone to discuss the pros and cons of inverted cylinders for diving, you should have equal experience in both configurations. All you have to do is try it in zero vis, and you'll be sold.

Back to the OP's question: I believe the biggest reason that you don't see inverted cylinders, despite their advantages, is pure inertia of "that's how we always done it".

All the best, James

And here's some entertainment:

A thread

Another thread



All the best, James

 

[mike_s]

Not steel.

correct. but most have the rubber boots to make them stand up.

Last I saw, there wasn't a big market for boots to go around upside-down valves or manifolds. (If there was, it'd sure be hard to reach those vavles with the boot on.

 

[hnladue]

Why would it matter what direction the tanks are in? In a rebreather the tanks are value down......

 

[Walter]

Why would it matter what direction the tanks are in? In a rebreather the tanks are value down......

On some they are on the side.

There were upside down rigs in use in the 50s. I don't know how common they were or how long they were around. The only issue I see is tank racks on boats are designed to handle bottles with the valve up.