When things go bang.

[Freeflow]

I was helping a chap do his DM map at Guildy a few years ago, and after a couple of twinset dives we dropped in for 10 min to check out some stuff on the 8m platforms. I had 80 bar in my twin 12's, plenty for a pootle like that.

Right up to the point where there was a very loud bang, followed by the sound of a lot of gas escaping. The done thing on twins is to shut them down when something goes wrong. Ths time though it's not the classic freeflowing reg, so which side do I shut down?

My buddy is 5-6m away and taking notes, so he hasn't seen the bubbles, but when I hit him full on he wakes up and shuts off my left tank.

On the surface we see that the BC inflator hose has split, dumping a lot of gas quickly. We were in for about 5-8 min when this happened,and the shut down probably took all of 15 seconds [including the swim over] and I had 12 bar left.

Now, you may think that I was diving on a knackered hose. It was 18 months old and had split on the second thread inside the ferrule, where you can't see the damage without taking the hose end apart. I am still diving an 8 year old hose of the same make [AP Valves] with no problems-yet.

The most important thing in diving is to not get too fixated on the way you are taught to problem solve. 'Officially' I should have done the shut down myself. I may have felt the bubbles from the left post when I reached back, but I may not have done, so I would have been doing the full shut down. My buddy could instantly see the problem and sort me out, and probably saved me some gas.

[Harlequin]

Someone told me about one of these going in a pool and said it was like a thunderflash going off.

Frightening

[Philelmer]

Makes you worry about diving on singles though. I'd never even considered a pony before i started reading these forums, i just sort of borrow some gear from a dive shop and get on with it, but imagine if that happened 30m down while your buddy was busy waiting for a nemo to come out and have its picture taken (for the 18th time that minute) - pretty frightening...

Definitely getting some form of redundancy when I do get myself some kit though.....

[Freeflow]

Originally Posted by Philelmer

...imagine if that happened 30m down while your buddy was busy waiting for a nemo to come out and have its picture taken (for the 18th time that minute) - pretty frightening...

It's normally me with the camera!

[marine boy]

its even worse if its a hose on your pony
get a twin set

[BobK]

That reminds me I must check the age of all my reg hoses

I have had two hoses, go bang in my diving career.

The first was, as a trainee, just kitting up with my nice shiny straight
out of the box Scubapro Mk4 reg (it was 1987).

I fitted it to a cylinder for the very first time, and turned on the air.
BANG !!!!!!! The hp hose split just on edge of the ferrule at the 1st stage.
As a trainee, it was an embarrasing moment, I thought I had done something wrong.

More recently (2005), I had just completed a 60m dive on OC with 2 stage cylinders for deco. Got back on the boat, and stowed everything, and heard
something go 'plop' rather than 'bang'. On inspection the reg on my 32% nitrox stage cylinder had failed on the hp hose just on the edge of the ferrule next to the first stage.

This one was my fault, when I checked the age of the hose

Ooh this is quite scary. Think I may go over to twins!! That'll please Hubby

Corinne

[MATTBIN]

I looked at my spg hoses the other day, they were instantly replaced.

Just a quick point (or two) if the hose went with such a bang why didnt the buddy hear it? And shutting the Isolator would have saved half the gas straight away. The last comment is of course very easy to make sitting here in my nice warm office.

Glad you got over to the buddy and got it sorted.

Matt

[pies]

Have just gone over to an H valve on the fifteen for those sites on shore where twin twelves are just toooo heavy.

Binning the very non-standard ali pony (no-one locally will touch it as it has American markings). Redundancy is the only way forward and the only way to always dive with redundancy on a single cylinder is an H valve...unless one has an alternative???

Pies

[tom]

An H valve does not give you true redundancy. A single failure (cylinder neck O ring) will lose you all your gas. However, that's very rare - probably about as likely as a manifold going on a twinset.

Can you shut down the H valve quickly enough? I find it a lot more difficult than a twinset. When I dive with my single rig (H valve on a 15) I tend to take a pony as well.