Securing the tank

[rocketry]

Hey guys, I have a question that is ALWAYS on my mind when I dive, and when I see pictures/watch others dive. This question pertains to a BC/jacket style setup, and probably not a BP/wing setup (though I do not know).

Has anyone ever experienced a tank slip through the strap on their BC? I see many divers that position their tanks DANGEROUSLY low, and, while I know the tank is secured, it seems like less than one-inch until the bottleneck begins. What is the procedure if the tank slips through? While I know steel tanks are normally neutrally buoyant, this could be a VERY large problem for someone doing a giant stride with a full AL80, a slipped tank could rip the regulator out of their mouth, and pull their BC/SPG (both conviently attached to their BC, attached to THEM) down with the tank, and thus drag the diver down until they could get out of their outfit - with no air supply, mind you. Am I over-exadgerating the outcome? would it not be as violent as my nightmares entail?

its just a phobia of mine. Some divers position their tanks SO low! there are many other ways to adjust trim, so i dont think that is an acceptable excuse.

thanks, guys.,

 

[Mike Newman]

Rocketry - two quick observations. If the tank strap(s) are correctly used there should be no question of the tank slipping. But - it does happen - usually if the diver hasn't wet the strap(s) before mounting them. The tank then slips downwards in the pack - stopping when the LPI hose is extended to full stretch. The diver may not always be aware, but their buddy should be - and it is they who will usually effect a re-attachment.

Second small point - all full tanks are negative in the water - steel remain negative even when close to empty - but buoyancy shouldn't affect the likelihood of tank slip.

Tighten and close your straps each time carefully and forget about the tank position - it has minimal effect..

Enjoy your diving...

 

[rocketry]

If the tank strap(s) are correctly used there should be no question of the tank slipping.

I agree in full. Just seeing if my phobias could, or have, happened.

Second small point - all full tanks are negative in the water - steel remain negative even when close to empty - but buoyancy shouldn't affect the likelihood of tank slip.

But, upon (boat) or deep water entry, i would assume that the negativity would pull the tank down in a bad strap-setup.

Tighten and close your straps each time and forget about the tank position - it has minimal effect..

You make a good point, just forget about it! Wetting the straps, though, I have never done that. I can see the logic, however. I have also never seen it done---but i will do it in the future.

Enjoy your diving...

as always, and you as well

 

[Mike Newman]

Whoever trained you failed you - or perhaps, more charitably, you just missed the point about webbing straps. They have a dangerous tendency to stretch out slightly when wet. This is especially so with newer straps...

A more common cause of tank slip is divers failing to keep tension on their tank band(s) after they have taken up the slack, but before applying the cam band and closing the buckle...

 

[in_cavediver]

Hey guys, I have a question that is ALWAYS on my mind when I dive, and when I see pictures/watch others dive. This question pertains to a BC/jacket style setup, and probably not a BP/wing setup (though I do not know).

Has anyone ever experienced a tank slip through the strap on their BC? I see many divers that position their tanks DANGEROUSLY low, and, while I know the tank is secured, it seems like less than one-inch until the bottleneck begins. What is the procedure if the tank slips through? While I know steel tanks are normally neutrally buoyant, this could be a VERY large problem for someone doing a giant stride with a full AL80, a slipped tank could rip the regulator out of their mouth, and pull their BC/SPG (both conviently attached to their BC, attached to THEM) down with the tank, and thus drag the diver down until they could get out of their outfit - with no air supply, mind you. Am I over-exadgerating the outcome? would it not be as violent as my nightmares entail?

its just a phobia of mine. Some divers position their tanks SO low! there are many other ways to adjust trim, so i dont think that is an acceptable excuse.

thanks, guys.,

I have seen numerous diver with tanks that have fallen out, Both in the water and on land walking to the water. The most fun I have had was convincing a diver that thier (major) problem underwater was the tank had slipped out and was only attached by the hoses. (I was able to get that fixed underwater even). In that case, the tank fell out after being submerged.

The cases on land are usually caught before the tank actually falls. (but the times that the tank did fall, about half of those the yoke o-ring popped). I would guess the same thing is likely with a giant stride.

Now you ask, how do I ensure my tank doesn't fall, its simple, I bolt them on! (doubles)
When I dive singles, I tend to properly torque the cam strap. When they were new, I always wet them. Now, I have gotten lazy (and I rarely dive singles) and still no problems after the bands were broken in so long as I made sure it was tight.

 

[rocketry]

Whoever trained you failed you - or perhaps, more charitably, you just missed the point about webbing straps.

Lets not make large generalizations, Now! In the spirit of progressiveism and education, now I know something new!

 

[in_cavediver]

Tighten and close your straps each time carefully and forget about the tank position - it has minimal effect..

I would beg to differ. The tank is a large mass on your back. The postition of said negative mass WILL affect your trim. If you don't believe me, next time your out or in the pool, play with the tank position is a true motionless hover. If you want even more fun, try a steel tank or two. Then see why divers choose different tanks based of CG and size.

Sorry, just found this active thread as well that really makes my point:
http://www.scubaboard.com/showthread.php?t=125060

 

[nadwidny]

Hey guys, I have a question that is ALWAYS on my mind when I dive, and when I see pictures/watch others dive. This question pertains to a BC/jacket style setup, and probably not a BP/wing setup (though I do not know).

Has anyone ever experienced a tank slip through the strap on their BC? I see many divers that position their tanks DANGEROUSLY low, and, while I know the tank is secured, it seems like less than one-inch until the bottleneck begins. What is the procedure if the tank slips through? While I know steel tanks are normally neutrally buoyant, this could be a VERY large problem for someone doing a giant stride with a full AL80, a slipped tank could rip the regulator out of their mouth, and pull their BC/SPG (both conviently attached to their BC, attached to THEM) down with the tank, and thus drag the diver down until they could get out of their outfit - with no air supply, mind you. Am I over-exadgerating the outcome? would it not be as violent as my nightmares entail?

I've seen a lot of tanks fall out and even have had it happen to me a few times. It really ain't no biggy. Most don't even know it happened, especially new people.

Best cure I've found to make sure this doesn't happen is dive doubles. Best thing to definitely not do is car wax your tanks. A buddy of mine did this and the results were hilarious. He couldn't go 2 minutes without the tank falling out.

 

[rockjock3]

I have never had this happen. I do practice taking my whole rig off underwater (BP/W) ever now and then. I unwrap my hoses and then remove my whole rig, then I reverse the process. I always practice this with a buddy present. This would be an option if it happened to you.

As for fixing the problem for somebody else. I have often caught somebody's tank when it slipped out underwater and you just have to wrangle it a little to put it back in the strap and tighten it up.

 

[spectrum]

I'll add that for peace of mind that if the tank breaks free it is the buoyancy + or - that in play, not he weight. So it may be 5 pounds pulling on the LPI hose, not 35.

Whn my wife an I are securing our tanks we listen got a ping or a stiff thud when the buckle cams over. If it just rolls over it's not loaded well.

I've done some underwater resets for buddies and it's not a big deal. We have not had one break free however.

Pete