Isolate and Shutdown routines

[Davey Willo]

When practising an isolate and shutdown routine what is the exact procedure and in what order is it done?

Could someone be so kind as to give me a step by step walkthrough please.

(Edited by Dave Williamson at 1:58 pm on Sep. 26, 2002)

[andy2tanx]

ascertain which reg needs sorting then isolate asap.
shut down offending reg
re-open isolation valve
check cylinder contents and end the dive carrying out any necessary stops etc.

did I miss anything?  oh yes... change underpants after kissing the earth!

[Davey Willo]

Cheers Andy

But what I meant was, when practising skill sets, one of which will be an isolate and shutdown routine there is a set sequence to follow... I've read it before somewhere but can't quite find it and can't remember the sequence.

[simon]

Dave
When we practice the shut down for extended range or tri mix
First shut down the primary valve,suck all air out of hose, then switch to secondary reg, whilst breathing open the primary valve, shut down the secondry valve, then switch onto you primary reg and open the secondry valve again.

All done in arround 30-40 seconds )

Hope this helps

Simon

[Davey Willo]

Thanks Simon

How come the isolation knob isn't brought into that routine as I thought one of the first things that was done during a real emergency was to shut the isolation valve to make sure that at least one tank is saved, re-opening the isolation once the offending bit of kit had been shutdown?

[Driftwood]

I believe that if you can definitely tell which post the problem is on, it is faster to shut that down directly rather than isolating and shutting down.

It's a case of "if this happens....." which in reality it may not be - ie a hose blows and you suddenly are engulfed in a bubblefest, so which side do you shut down, do you isolate or do you change you choose the correct post?

Add the isolator in before the 1st post shutdown and after opening the secondary at a guess......

[Dr Stevil]

Having been fortunate enough to have done some NOAA training, thought I'd give my two-cents worth:
We were taught to shut down the isolator first then shut down the problem reg. The training was done extensively on dry land (kitted up and seated) until it became instinctive. Thee was a kind-of sergeant major style to it so that the trainees were given a bit of pressure to test them. The NOAA manual is available via retail now, anyone going to the Dive Show might want to do a WHSmith and read that bit without buying it.:bandit:
Regards
Steve

[Mark Chase]

Confused ney baffeled by replys to this question:

Somthing goes bang or fizzz and you are surrounded by bubbles:

1: Isolate manifold NOW

At least you have half the gas left and if you have a slob knob or are double jointed that took about 2 seconds

2: Identifie source of gas loss (or if serious swap to back up reg if required or bail out to stage and ascend)

This could be any thing: High Pressure hose on deco bottle, reg free flow, O ring failure etc etc.

Identifie and shut down offending item if possable before total gas loss.

3: If apropriate re open manifold to redistribute un used gas to breathing reg and start ascent  

Long and short of it is if there is a catastrophic failure in any air containier first move is isolate manifold. If the reg in your gob stops working thats a good indication that thats the problem so swap to back up reg. If that dosent work go for stage or look for buddy dammed quick.

You cant practice for the panic you will feel but at least if you shut down the mainfold in a few seconds you will more than likley have the remainder of one tank to get you to the surface so practice that.

Oh yes whilst you are doing all of the above start finning for the surface at a controled rate. Unless you have a total gass loss then the prefered DIR method is finn like bug#er

Mark Chase  

[Davey Willo]

Cheers for that Mark, as usual as funny as f*ck... but!

My question was relating to practising skill sets, not a real incident, although I feel that you are right in your statement if the sh*t should actually hit the fan one day..

You see I've read articles on routines and these have dictated that the isolation is the first move, I've watched DIR videos on Fifth dimension and they run through a primary first, then isolation, then back up... others I've spoken too say go straight to primary and then backup without practising isolation..

I thought that a standard routine was practised by all and that one could time oneself from start to finish, but it appears that different organisations use different techniques, Although like you, in a real emergency I think I'd be happiest saving at least one tank of air.

[Driftwood]

Davey,

I think you'll find it's case dependant.

Example - your spg goes fizz bang and disappears off into the blue. In this case as you know the guage is run by the primary post, all you need do is shut that, switch to backup and go....

BUT, here's the ring twitcher....

BANG! You are surrounded by a cloud of bubbles and something behind you has gone.... But what? Primary inflator hose, secondary reg hose, tank o-ring or what? If you shut A.N. Other post down how do you know (apart from the abatement in noise and bubbles) tghat you got it right? What d'you do if you got it wrong? You could now have no air supply until you switch that post back on and then isolate the other - major loss of time and gas.

Basically, if it's immediately obvious then you can save time and brownies by going for the duff post. If not, go for the failsafe and shut the mannie to at least save half your gas....

Then again, it could be a stage.......