The Isolation Manifold, lessons not learned and a small defence of the IUCRR

[tursiops]

The only time I've struggled with a valve knob was when I was watering the lawn, with the hose in my right hand; I'm right-handed. I reached behind me with my left hand to turn off the faucet. I had to visualize my hand on the knob to figure out which way to turn it.

 

[Gone for diving]

If someone held a gun to your significant others head and said turn this manifold in the correct direction the first time or I shoot them, and you believed the threat to be significant I'm guessing it's slightly better than a coinflip on average for someone to be able to do it under duress. I've watched well trained shooters and and fighters make simple mistakes when asked to perform skills they've preformed well 1000s of times the first time they are under real stress. Making those mistakes less likely to happen is part of human factors that everyone wants to talk about until it's time to change how things are actually done or it challenges what they currently do.

Let's say you have 30 seconds to solve a problem, you have 1 way that solves the problem 100% correctly in 20 seconds, and one way that solves the problem correctly 70% of the time in 5 seconds, but the other 30% of the time it takes an additional 30 seconds or is never resolved correctly, which is a pretty way of solving that problem.

As was stated earlier... when have you seen someone turn pop bottle lid the wrong way? If it does happen... you learn very fast.

 

[Degenerate]

Your instructor is definitely right and to my knowledge was appeasing you. Anyone who is, or has been technical diving should have been trained or should have experienced a shut isolation valve and know to switch to backup. Monitoring turn pressure is crucial at depth.

Tell us you know nothing about technical diving, without telling us you know nothing about technical diving.

Come to think of it, you can probably remove "technical" from the sentence above and it would still be true.

 

[rob.mwpropane]

As was stated earlier... when have you seen someone turn pop bottle lid the wrong way? If it does happen... you learn very fast.

That's exactly what I did with the kid we hired to work here.. he could not figure out how to tighten fittings. I threw him a soda bottle and had him do it a bunch of times. Without fail he got it every time but when it came to fittings he just couldn't get it. Had to let him go.

@Akimbo said it.. machinists, mechanics... I'll add plumbers, gasfitters. Tons of jobs out there that wouldn't think twice to tighten or loosen something. Do it every day for 20 years and it's just not something you think about.... it just is. Diving for 2 hours a week is not the same as turning CW / CCW 10 hours a day, 5 or 6 days a week.

Great, those of us that "know" what that's like have all reached the buddha state of turning valves. Mom would be so proud

Edit: don't read this as I'm saying I'm infallible, I'm not. I just have more practice turning valves... that's it.

 

[Capt Jim Wyatt]

I am evolving my thoughts on accident analysis. I will provide one example of how I was thinking we did not learn new stuff from accident analysis. We learn in cave class to use a maximum of 1/3 of our gas supply and then begin our exit. If someone decides to use more than 1/3 before exiting and runs of of gas before getting out there is nothing new to learn.

The same applies to isolator manifolds. Before we get into our tanks we check all 3 valves to make sure they are fully open. If an accident happens because of a closed isolator there is nothing new to learn.

I challenge anyone to show me how there was something NEW to learn from either of the above two scenarios.

My evolved thinking (thanks to discussions on here, other forums and talking with fellow cave divers) is that even though we may not learn anything NEW, we will most definitely reinforce things learned in the past.

Reinforcement of past learning and actually combining the thinking of the "Rule" and how breaking that rule actually combines to be causative of an accident.

Accident analysis can be greatly simplified when we hear that an accident happened and the reason that the accident happened is because the diver broke/ignored/forgot one of the cardinal rules.

 

[crofrog]

I am evolving my thoughts on accident analysis. I will provide one example of how I was thinking we did not learn new stuff from accident analysis. We learn in cave class to use a maximum of 1/3 of our gas supply and then begin our exit. If someone decides to use more than 1/3 before exiting and runs of of gas before getting out there is nothing new to learn.

The same applies to isolator manifolds. Before we get into our tanks we check all 3 valves to make sure they are fully open. If an accident happens because of a closed isolator there is nothing new to learn.

I challenge anyone to show me how there was something NEW to learn from either of the above two scenarios.

My evolved thinking (thanks to discussions on here, other forums and talking with fellow cave divers) is that even though we may not learn anything NEW, we will most definitely reinforce things learned in the past.

Reinforcement of past learning and actually combining the thinking of the "Rule" and how breaking that rule actually combines to be causative of an accident.

Accident analysis can be greatly simplified when we hear that an accident happened and the reason that the accident happened is because the diver broke/ignored/forgot one of the cardinal rules.

The thing we're learning is about the overall system, be it insufficient or inconsistent skill or training, the normalization of deviance, insufficient safe guards to prevent lapses and mistakes, poor risk perception, etc

 

[Gone for diving]

I have heard it said. To paraphrase..
I you need a guy to fix things underwater, find a good mechanic, welder, etc, and teach him to dive.
Don't find a diver and teach him how to be a mechanic, welder, etc, ....

How many people have a garage full with tools and really know how to use most of it...
Canadian tire and home depot would be broke otherwise

 

[PfcAJ]

I have to conclude that you are suggesting people need the stop of a valve being fully open or fully closed to help remind them which way to turn a valve.

I can’t speak for others but there are some of us that it doesn’t matter what orientation a thread is in, we are gonna turn it the right way. I cut threads and install fasteners everyday, I’ve installed screws upside down blind and backwards.

I guess what I’m saying is if CW vs CCW rotation is confusing you really ought to practice more; a half open / closed isolator is not ambiguous.

There are cases all the time of instructors and DMs on dive boats closing peoples valves and opening them up 1/4 turn.

It can and does confuse people. If you think you’re infallible….

 

[boulderjohn]

There are cases all the time of instructors and DMs on dive boats closing peoples valves and opening them up 1/4 turn.

It can and does confuse people. If you think you’re infallible….

It is especially problematic if you do as I do and use a pair of sidemount tanks for a 2-tank dive trip, meaning one of those valves is in the opposite direction as usual.

 

[lostsheep]

Spend enough time working with machinery and it becomes reflexive. Finger tips just act without any perceived thinking. Mechanics, machinists, submariners, and saturation diving crew are a few examples.

^^^this

There are cases all the time of instructors and DMs on dive boats closing peoples valves and opening them up 1/4 turn.

It can and does confuse people. If you think you’re infallible….

The existence of DMs and instructors who confuse opening and closing valves, does not in any way disprove that some of us are capable of not getting confused. DM and instructor rating is not exactly a high bar and I say they need more practice.

I make plenty of mistakes, turning threads backwards is not one of them.