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<font color='#000080'>Can someone give me a step by step shutdown procedure for manifolded twins.   Anything I can use for practice drills would be much appreciated.

Daz
 

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<font color='#0000FF'>Hi

1. Signal to buddy to watch you.
2. Check backup reg with a little push of the purge button
3. Close Right post (Right hand) and then breathe it down
4. Swop to backup reg, clip off primary long hose
5. Open right post (important, this is a common error!!)
6. Close and then open isolator
7. Check primary reg with a little push of the purge button
8. Unclip Primary Reg, Close Left post and breathe it down
9. Swop to primary reg, check backup hose with a little push of the purge button
10. Signal to buddy that you're OK

Congratulate yourself on a job well done


Also at the buddy check and during the dive do a flow check

1. Right post open and can close
2. Isolator Open and can close
3. Left post open and can close
4. Stages closed and can open

Hope that Helps

WL
 

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Why exactly do you want to breathe all the air out when you've shut down a valve?
Water can enter the system if there's no air, and O-rings are most likely to blow when you pressurise the system..
 

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<font color='#0000FF'>Well...

A valve drill is a simulation. Usually you would just do a flow check during a dive and so you wouldn't normally do it.

However in a real situation such as a freeflowing right post (most common situation as this is the post doing the work) you would shut down and change regs. After you shutdown you would have no air and so it becomes natural when you have experience of breathing a shut down reg.

It also ensures that you have opened the valve properly because you check each reg after you have opened it by tapping the purge. If there was air still in the system then you would not know that it was fully operational and this could cause a major event, I did point out that a common error is to shut the right post and then go straight onto the manifold which is what I did the very first time I did a valve drill, luckily my buddy pointed it out before it became a problem.

The left post is most likely to get rolled off during a dive and so the same logic applies.

Kindest Regards

WL

PS Sorry forgot to say that a valve drill is done at a safe depth like 6 mtr just in case an oring goes like dominic suggested.
 

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<font color='#000F22'>I would say that it's a folly to clip off the primary reg.

What happens if someone needs your air? The come belting in and grab the reg to find it connected to a d-ring.

IMHO - just leave the reg around your neck whilst you breathe the secondary. Also I would not advise using the purge buttons at all.

There are three main senarios to consider.

1. Primary is free-flowing/bolloxed - action  - swap to secondary and shut down primary. Then re-open primary.
2. Secondary is freeflowing/bolloxed - action - as above in reverse.
3. Your SPG hasn't moved - check secondary - could be that manifold is closed? - open manifold - check SPG again - and bollock yourself for being a tw*t.

I agree it well worth while making sure that everything is in order - valves open etc on the 6m check. Don't dive a manifold with isolator if you can't reach it.
 

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<font color='#0000FF'>Hi

Gavin, we are talking about a valve drill, which should mean that your buddy would have his ducks in a row and won't need your air for the few seconds it is clipped off. If so you are diving with the wrong buddy!! Clipping off the long hose is good housekeeping so it is there when you want it and not dangling behind you or causing a nuisance. You would clip it off when using a stage or when you are out of the water so it makes sense to get used to clipping it off whenever it is not in use. Its part of the 'muscle memory'.

Just like tapping the purge button of the reg you are swopping to BEFORE you close the valve prevents you from closing a valve and then finding out that your left post has rolled off or that you forgot to turn it on before your dive.

There are actually 9 possible faults that can occur with a manifold aside from poor diving skills. A diagram can be seen on Howards site which is adapted from GUE's tech1 course http://www.bitz.fsnet.co.uk/bitzmanifoldfailuremodes.htm

But anyhow its up to you the way you do it, I just gave my opinion. Perhaps you can go through your better technique and we can all pick holes in that or adopt it in our diving


Kindest Regards

WL
 

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<font color='#000F22'>Hey Lettuce - It's only my opinion.

Yes, buddy should have "ducks in a row" but OOA situation can happen at any time and it might not be my buddy that comes screaming in for air it could be another member of the dive team.

Also - I would advocate not clipping off your primary when you've moved to your deco gas. You buddy could o2 tox and easy access non-deco gas could save his life.

If you're diving the long hose then it shouldn't be waving in the wind but under the right arm, round the neck and hanging in the triangle.

If you want to check that a post hasn't rolled then reach behind and feel for it. Purging is never a good idea in cold water unless you really need to. Also If the post has rolled and you tap the purge it'll flow and you'll think everything is fine - then you'll go to breathe of it and get diddly.

There are many failure possibilities - I was just outlining the most common ones.

All I would say is do whatever you're comfortable with but remember to check the back-up reg on the dive every now and then cos you don't want it failing when you need it. The easiest way to check is to breathe off it.

Again - just my views - not necessarily the right ones!
 

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<font color='#0000FF'>Hi

I don't want to hijack the thread and I hope Daz has enough info to come up with a drill he can use. Let me clarify the circumstances in which you should IMHO, do a valve drill.

In my opinion a valve drill is planned as part of a training dive, done in the first stages at a shallow depth with no deco obligation. This means you can always do an ESA (Emergency Swimming Ascent) It is not done during a dive with other objectives. That just needs a flow check and checking your backup as Gav suggested. This negates the point about needing to donate air to anyone. If there is an emergency from someone other than your buddy then surely your buddy will handle it (question: where the f**k is their buddy ?!!). If your buddy can't help because they can't see them then you will have time to react because they are approaching from behind your buddy. I really think that its an issue that is not worth planning for as it is so unlikely. We are talking about a VALVE DRILL of which the sole aim is to determine that you are able to operate your valves in an emergency. We don't try and plan for donating air when we remove and replace our mask do we ? Then why do we have to make a valve drill so complicated.

This is a response regarding clipping off the long hose.

Regarding not clipping off during deco. Assuming you are on the same gasses and are at the proper depth then Ox Tox is unlikely because you would be toxing too. However I am sure that a toxing buddy will not be asking you to donate air but effectively having a fit right in front of you! The only reponse to this is to ensure their reg stays in their mouth (because they will spit it out) if you can and get up to the surface. Even if they stop convulsing at a shallower depth it is common for them to have a second convulsion. I seriously doubt that you will be able to donate in that situation as that might introduce water into their airway.

Again it is a case of overthinking and creating problems. You always donate what you are breathing and go to backup. It is that simple. Clip off your long hose when it is not in your mouth. It is that simple. When you make diving simple it makes it more enjoyable in my opinion.

Hope that helps

WL

PS I wasn't being nasty or anything Gav, its just that you said that what I recommended was 'Folly' so I thought I'd play a little.
 

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<font color='#000F22'>Ok we agree to differ.

My view is always be ready for anything and other people's buddies do go missing so they might just come screaming into you for gas.

You say that if they're otoxing then you probably would be too. Not true - different people haven't different levels and again it might not be your buddy but someone else.

You don't plan to be able to donate whilst in mask off situation but you should be able to cope.

Anyway, having to spent the weekend having had various different OOA and mani failure drills thrust upon me I'll stick with my way and remain upclipped under the water. It was in my training to do do this and I still concur with that.

We all train for unlikely events - broken harness - complete failure of rig and emergency swim to buddy - hole in wing and drysuit - is it being over-complicated or planning for the worst case.

I agree with you that keeping it simple is the best thing one can do.

BTW I meant no offense by using the word "folly" it is very mild.

Keep well
 

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<font color='#000080'>
[b said:
Quote[/b] (wetlettuce @ April 29 2003,12:04)]Flow check

1. Right post open and can close
2. Isolator Open and can close
3. Left post open and can close
4. Stages closed and can open
3.5 Unclip SPG, check it then reclip.

 

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<font color='#000080'>Thanks all for the advice, info and tips.  

I really appreciate when conflicting views are discussed as generally it allows me to hear a more in depth view of why different people do things differently.

I will endevour to try as many different scenarios as possible and who knows maybe I will come up with my own adaption to bring to the discussion.

Thanks again all,  and thanks WL for the reply to my other query on assembly.

Cheers,
Daz
 

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<font color='#000080'>Hi,

here is a video of a valve drill from FifthD -  Valve drill

Nb. The diver fails to check his backup is working (by purging it) prior to shutting down his right post. He then forgets to purge and unclip the long hose prior to shutting down the left post. Just to be really picky, he would find it easier to reach that left post if he kept his head up. Great trim and buoyancy though  
but then he is doing it just off the bottom. Try doing it in 6m mid water with no visual reference (like a on a deco stop).

BTW... Howard (bitz) has really done the world a huge favour by producing that flowchart on the nine 1st stage/valve/manifold failures. It is exactly what Andrew G. taught us on the Tech-1 course and is not available anywhere else AFAIK (unless you do a GUE course).

Mark
 

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<font color='#000F22'>Mmmmmmmmm Just a thaught,

Dont suck down your reg after switching off the gas supply,  it will let water into the second and probably the 1st stage and this will require a service to clean the valve seats prior to using the reg again.

If you like cliping off the main reg to keep it all tidy just use a 3lb breaking strain rubber band. That way if someone grabs and pulls the reg hard it will snap and release the reg no problem leaving your expensive bolt snap still cliped to the D ring.

Personaly:

Check back up reg as a precaution

Hold breath

Shut central isolator (slob knob)

Shut left post (thats my main reg and therefore most likley problem)

Swap to back up reg.

OK holding my breath is a PADI no no. BUT in realiaty you will be holding your breath wether you like it or not if it realy goes sh#t shaped. Number one priority is isolation of the back gas, number two priority is saving as much gas in the faulty cylinder as possable and number three priority is breathing the next breath.

I can do this drill in about 9 seconds on a good day and 15 on a bad day. I can hold my breath for about 1 1/2 mins if totaly calm and prepaired and about 45 seconds in a panic. So I have about 30 seconds lee way if it becomes a bit technical all of a sudden.

perhaps not standard procedure but somthing to think about

Mark Chase
 

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I have to agree with Mark, surely the first thing you should be going for is the isolator - isn't that what everyone is taught? Even if this is only a drill, a drill should simulate how you should be dealing with the problem.
So my buddy and I practice:
1) Check backup
2) Close isolator
3) Close right, swap reg, open right
4) Close left, swap reg, open left
5) Open isolator

Just my opinion - any thoughts?
Regards.
 

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<font color='#000F22'>Why go for the isolator?

I certainly wasn't taught this. If you are not sure what the problem is then isolate. If you're pretty sure that your primary is freeflowing/o ring problem then swap and switch off right post.

Isolating will only cause you to lose precious gas and not assist.

If you're surrounded by bubbles then isolate and get buddy to see what's going on for you.
 

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<font color='#000080'>
[b said:
Quote[/b] (Robert @ May 01 2003,12:04)]surely the first thing you should be going for is the isolator - isn't that what everyone is taught? Even if this is only a drill, a drill should simulate how you should be dealing with the problem.
The way WL has described is the GUE taught (i.e. DIR) methodical 'system' approach to dealing with it. You perfrom the drills the same way every time so that when you have a real problem you don't cock it up.

The most common failures are 1st stage related and that's why we allways go for the 1st stage first. Going for the isolator just wastes time.

The size of the leak makes no difference to the approach. If you can't hear which side it's comming from, start with the right post (as you signal your buddy), then isolate if needed.

PS. Daz - the drill will be a waste of time for you if you invert your tanks (unless you have an ear on your arse).
 

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<font color='#000F22'>Surely the thing to do is note "just act" but to produce the appropriate response.

As I said - if the primary's gone haywire then shut it down.

If the reg under yer chin goes then you don't shut down the primary you shut the back-up down.

And if you haven't got a freakin scooby what's going on then isolate and make sure you keep at least half your gas. And get your buddy to evaluate.

This latter situation is less likely cos you can usually work out where the problem is by breathing.

If both sides are f*cked (compete manifold failure) then start swimming to you buddy quickly - or get to a depth where you can use your first deco gas.

You should drill to be able to turn any valve whenever you need to - not go in a didactic order based upon "routine".

A lot of the DIR stuff makes sense, a lot of Kevin Gurr's book is great but nothing beats being able to react to a situation by awareness and not habit.

Just my opinion.
 

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[b said:
Quote[/b] (Gavin Yates @ May 02 2003,16:19)]Surely the thing to do is note "just act" but to produce the appropriate response.

....nothing beats being able to react to a situation by awareness and not habit.
<font color='#0000FF'>Well said Gav, I agree. Formulae have their uses  but there's no point in going straight for the isolator if you know which reg is causing the problem, if it's your primary you'll feel the freeflow, if you don't feel the air pressure in your mouth, then it's your secondary.


As for "bubbles heard from X hand pillar"  as my rig is inverted this does't enter my equation, but even if they were upright, I seriously doubt I'd hear anything but a really big leak anyway as:
(i) I'm wearing a hood
(ii) in water sound is pretty omni-directional even at close quarters
(iii) The sound of my buddy's exhalations will be very apparent and mask sound of a small leak.

All IMVHO of course
Chee-az
Steve
 

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Another interesting thread......

It seems to me, reading throught his thread, that Wetlettuce and Mark have got this right for all the right reasons (Hmmm.....I wonder why that is?)

The only thing I would add is that the most likely failure (for "our" sort of UK diving) would be a right post free flow.  In any case you *will know* which post is causing the problem (assuming, of course, that your rig is "the right way up").  In that case the motor skill which should be developed is to shut down the offending post first. Instinctively shutting the isolator is not a good option.

Regarding drills (s-drills).  This is exactly as WL stated.  A simple "right to left" procedure.  Important to signal your buddy and get his attention before attempting any of this.

Howard's flowchart is also a very good representation of how this should be done.

This, of course is all "IMHO" (but with a heavy bias towards how I have been shown how to do this countless times)

Regards

Bob
 

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Hi,

As an oblique thought, being the stroke that I am, I have my main reg on the LHS, and a slob knob coming out low on the RHS, I have found, (with a lot of practise I admit) that I can isolate and shut down my main at the same time.

Strokes rule OK!!!!!!!!!!!!!!

As it goes, TDI teach you to isolate first, swap then close, but then the requirement is to be able to do the procedure in 40 seconds, a lot of gas disapears in 40 seconds. I can see why the people who follow DIR would recommend shutting down first.

Andrew
 
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