shutdown drills please help

[splosh]

can anyone advise me on shutdown drills on twinsets. Ive only just got my first twinset up and running, custom divers tcw with sport harness, twin 10l 232 custom divers valve protectors. I went for my first dive yesterday at capernwray to check that all was well and in shallow water have a first bash at reaching the manifold isolator for shutdowns. On my first attempts i was no where near reaching even the valve protector so that i could lift the twinset furthur up my back to help me reach the centre valve, however after a while i tried unfastening my waist band, this is easy on this harness as it is a pinch clip, with velcro cumberbund. After doing this i could hitch the twinset up my back and reach the valve no problem, and i could do the whole process in under 10 seconds. Re fastening the cumberbund was no problem and the whole exercise was done while controling my bouyancy . So on the way home i was quite pleased with myself , until i mentioned this to another diver who has more experience than me with twinsets, and he rekons that under no circumstances should i unfasten my waist band as this could be unsafe, i dont use my wing for bouyancy control only for surface support. i just thought i would ask peoples opinions on here as to be honest i dont think i could reach the valves any other way, and i dont like slob knobs as ive seen them kink when the isolator valve is a bit stiff, any advise would be appreciated thanks

[Vic]

On my first attempts i was no where near reaching even the valve protector so that i could lift the twinset furthur up my back to help me reach the centre valve

OK - so don't lift the twinset :-)

If you stand in front of a mirror & do a shutdown, I'll put money on it that you'll see your elbow sticking out to the side. This means that all the movement you need to get your hand back to the valve is coming from your shoulder - that's the difficult way to do it.

Here's a drill: hold your hand straight out in front of you, *palm up*. Now reach straight back behind you so that your arm brushes your ear. The extension is now coming from the length of your forearm, not from your shoulder joint. This makes life much easier...

he rekons that under no circumstances should i unfasten my waist band as this could be unsafe

He might be over-emphasising the risks, but you shouldn't undo the waist band; it implies that there is a problem elsewhere.

i dont think i could reach the valves any other way

I bet you can...

Vic.

[splosh]

thanks for that vic ill give it a try, but im sure i was reaching back correctly, i will have a go tommorrow night, cheers mate

[TerryH]

any advise would be appreciated thanks

Well you said it ;)

To be honest and if new to twins, the last thing I would be doing is messing
around with shutdowns and putting my back out.

Forget drills, just spend a few dives getting use to the basic unit.

Once you become more familar you might even suss that a strap is too
tight/loose etc. Until then stop thinking to hard and have a play :D

[Nigel Hewitt]

To be honest and if new to twins, the last thing I would be doing is messing around with shutdowns and putting my back out.Darn...
I'm agreeing with Terry again.

Shut downs are a very ephemeral part of diving. You could never do it on your single so don't make a big scene about it on twins. OK. If you get a big free-flow it is nice to come home on your own gas not your buddies but when was the last time you had a big freeflow?

As Terry says, get the twins under control first. Once you are comfortable plug in Vic's suggestions. Also playing dry you rapidly discover if it is you, your suit or your harness that is the problem.

[Fiona]

Terry and Nigel certainly know more about it than I do, however I'll post anyway ;)

I have been using inverts for several years and decided to go the other way up, but I knew if I couldn't reach the valves then I would have to revert to inverts, something I don't want to do.

I have done about a dozen dives now and was frankly struggling I could reach back and feel the manifold and the 1st stages but was becoming frustrated as I couldn't find the valves. On the second dive at the weekend I found them - hurrah during the dive I found them each time with more and more confidence.

So don't worry it will come, don't give up. Although frankly I would ditch the valve protector.

Which knobs do you have ? if you don't have them I would change them for the large rubber "sherwood" type which are far easier to get hold of.

[PeteM]

Here's a drill: hold your hand straight out in front of you, *palm up*. Now reach straight back behind you so that your arm brushes your ear. The extension is now coming from the length of your forearm, not from your shoulder joint. This makes life much easier...

To add to that...

Once you have the movement correct, before going for the valves push both arms straight up (relative to your body) quickly. Imagine an over eager child keen to answer a question in class but with both arms at the same time.

This has the effect of pulling your suit and undersuit up slightly which makes the movement easier. and therefore gives an extra inch of movement. Some people do this on the descent on every dive to prepare themselves, personally I don't as I find it all settles back down after a bit of finning around and it only takes a split second anyway

[Mark Papp]

In agreement with everybody else so far. It's some sort of record.

Just one other thing; Try the advised shutdown movement when you're wearing but a T-shirt. I bet you find it very easy. Now try it in your undersuit. Is it still easy, or even possible? Now add your drysuit. Can you still reach almost as much as you could when you were just wearing the T-shirt?

This is, for many, the crunch. Most divers I've seen are unduly restricted by their suits. I used to be, but bit the bullet and bought again. I think the cut of Weezle undersuits is particularly restrictive when it comes to shutdowns - mine certainly was.

However, as Terry suggested, go diving, have fun but until you can shutdown simply and quickly, stick to NDLs.

Regards,

Mark

[Kelvin Rutt]

Hi,
I've been diving twinsets for a while now and decided (incorrectly) that I couldn't reach the isolation knob on my manifold so I fitted a slob knob.

I recently went on the BSAC ERD course where they insist on you being able to do a full shutdown. I put myself through a lot of pain trying to reach. After 2 dives, I could shut down the right valve ( + centre using slob knob) but this was using the very tips of my fingers and was a real struggle.

When talking to the instructor who told me to "hutch" the cylinders up my back to reach. I replied I can't do that because my waist band won't let me ( the penny dropped) so I slackened my waist band and could easily reach my right valve but not quite my left (was very close). But I don't undo the waist strap, I just make sure it has a bit more "play" than before (I had the twinset held solid to my back by an overly tight harness)

Anyway, on a dive a few weeks after the course, I tested the slob knob and it snapped the spindle in the manfold isolation valve (partially open). I've not got a replacement spndle and I'm working on shutdown drills as well (no more slob knob for me).

So I'll be back in the water soon, trying to reach the centre valve as well. I also found I have limited movement in my drysuit for my left arm (explains a lot) and need to invest in a new suit. But before I do that, I'm going to have a few more "play" sessions to really see if I can reach.

I'll certainly try a few of the suggestions provided.

[Sarah Gauci Carlton]

Another thing to watch out for is that your shoulder straps do not trap your drysuit and restrict your movement that way. It helps if, once your twinset is on your back, you support its weight on the side of the boat and move your arms and neck to ensure that movement is not restricted that way.

You say that you mounted the rig slightly higher the second time round - a problem I have with twin 10s is that if I mount them high enough to reach the valves, they tip me forward and dig in the middle of my back. For a small difference in out of water weight, twin long 12s are more comfortable for some people, although if you have already bought twin 10s you probably don't want to change.

The other thing you can do if you aren't sure of your ability to shut down in a hurry is keep the isolator manifold shut and dive the rig as independents, breathing each cylinder down evenly keeping to rule of thirds. If one of your regs does go into an uncontrollable free flow, then at worst, you can only lose the remaining gas in that cylinder. This buys you time to switch to the good regulator (which will be your priority), loosen waist straps and shut down the free flow. If you have been on thirds, even at your most exposed point of the dive which would be the turnaround point, you will still have two thirds of one cylinder to get you back.

Cheers,
Sarah

[Woz]

Here's my two pennorth on shutdowns:

In my 100g undersuit I can shutdown easily. Reach all the valves, twiddle them shut. In my 300g suit- no chance at all so I dive them with the isolator shut and swap regs.

You may find when kitting up that before you put your harness on, stretch upwards to pull your suit and undersuit up so it's "baggy" on the top.

Oh and put the valve guards on eBay. You don't need them and they make shutdowns slower- they really do. If your harness has a chest strap then remove this too as you don't need it. And while we are at it, unless you are scootering ditch the crotch strap. I got rid of mine and it makes life so much easier and makes not a jot of difference.

[Mark Powell]

All of the above are good suggestions. To do a shutdown you need to have everything set up correctly. Harness, waistband, undersuit, dry suit. You also need to have the right technique.

One additional bit of technique is to make sure you lean your head back rather than ducking your head. To try this stand with your back against the wall, the wall represents you backplate with the valves just above. With your head back so that its touching the wall, reach back and you can touch the wall easily. Now bend your head forward. This is what most people do naturally during a shutdown. Try and reach back now and you can only just reach the wall. This is because your head, shoulders and arms move away from the wall but the wall, like your backplate, is fixed and so you are moving away from your valves.

[splosh]

thanks everyone loads of handy tips there, mark that bit about undersuits is interesting as i have a weezle extreme, so i might try and borrow my mates exotherm and see if its any better, and i have found the same problem as sarah with been nose heavy, in my first dive i was using force fins and i kept tipping forward, i had to keep righting myself before finning again, then on the second dive i wore heavy jetfins and these seemed alot better and i was much better balanced, and thanks kelvin for your coments, its just confirmed my suspicions about slob knobs, im thinking of fastening my velcro waistband as slack as i can then fastening the actual waist belt tightly over the top, this would make the rig solid on my back for using the wing on the surface without riding up my back, and if i had to shutdown, i could just slaken the waistbelt im sure this might make a difference

[Taz]

Check out this website and look at V-Drills

www.divetekadventures.com/Images.htm

[DEEP DOWN DEVIANT]

HI THERE,
Lets hope the shutdowns go abit better than your car driving or Microlite landings.:D

[Rick]

Check out this website and look at V-Drills

www.divetekadventures.com/Images.htm

out of interest how does this help the original poster with his problems of reaching valves? At least the other posters were helpful??

[Ben Panter]

Seems pretty helpful to me Rick, it's a video demonstrating how to reach for the valves successfully...

Ben

[Rick]

i thought the guy needed help with why he couldnt reach valves rather than what a shutdown was itself

[splosh]

yeah i know what rick means, it looks very easy on there, but what lenght are the cylinders they look like ali cylinders to me, and also where they placed in an unnatural position for the video who can tell

[johnskerry]

You could lose a lot of air in 10 seconds, especially when you consider the thinking time added to this, and thing can you wrong it the worst places. I have dived on twin tens for many years, so shut offs have always concerned me. And as they are best placed to make you balanced in the water, which is not always best for shut offs. I took the view when I had my cylinders valve up to keep them isolated. However a few years ago I was persuaded by the access to all air principle, and fitted a manifold, this has lead me to go upside down. I can now isolate the cylinders easily. The centre is still a problem, so a manifold failure would be bad news. On deeper dives I also carry a upside down 5L bolted onto the side of the twins

[Smudge]

I've dived twin tens for quite a while now (that I bought from Ben actually! :D ) and I found on two different sorts of wings and either with a drysuit or with a semi dry I just can't reach the valves *reliably*. Don't know if it's 'cause I'm a shorta**e or because I lack arm movement (not likely given other pursuits) or just the way I dive. As a result I've dived them isolated up till now.
After reading hundreds of posts (really!) and talking to a great many divers I've just inverted. I'll find out on Sunday what I really think aout the rig but straight away from "dry" experiments I can comfortably and instantly reach the cylinder valves and the isolator is still WAY easier than having it behind my head. Quite similar to operating rebreather valves.....
I'll try to remember and let you know how it goes once I try it on some proper dives :)

[splosh]

thanks smudge ill await your reply

[graham nurse]

one other sugestion to help with shut downs,try exhaling first as this will reduce your chest volume and create a bit more room in the suit.

[Alwassia]

Having read most of the replies, i think that the gentlemen should attend a twin set introduction session IN THE POOL, before takeing his twinset for furhter dives.

Khaled

[Smudge]

First dives today with the set inverted.
Reaching all three valves was easy and I was doing it with a proper full hand grip on the knob not just fingertips.
I'd set up the cylinders too low in the bands so I am having to raise them to get my balance right. This will actually make it easier still to reach the valves.
An unexpected bonus is I can now move my head fully back without touching anything where with "conventional" cylinders I was bumping against the 1st stages/hoses. So I have better vision as a bonus :-)

It's only first impressions and I need to do a good few more dives to make sure I'm absolutely comfortable with all aspect of the change, but first impressions are I wish I'd tried it some time ago!