Why does DIR reject quick disconnects?

[Wijbrandus]

Don't know what it's worth, but in my Open Water class, we had two broken quick-disconnects in a group of about 30. They were all on the rental gear, and failed during the weekend, not beforehand. The instructors had brought along extra bcds 'just in case'.

It was one of the factors that got me looking up and out of the mainstream.

I'll go back to my silent observation now, since this whole conversation has already surpassed my experience so far. Just thought I'd share that little tidbit.

 

[pipedope]

Just QD.

Like I said, plenty of reasons to not use QDs for most people but some (very few) people can benefit from a QD.
Of course, those people will not be DIR.

 

[Dan Gibson]

I disagree with your first line. It's too sweeping of a statement.

If it is done wrong intentionally by the person who purchased a system from someone else who manufactured it, it is not a system failure. By your statement, suicide would be a system failure. It's not.

If there's a human involved, yup.



There's the system, then there are subsystems, one of which are procedures, which includes human perception and performance.

The entire field of Human Engineering deals with how to make accomodations in the "hardware" subsystem to compensate for shortcomings on the "human" subsystem.

Probably 99% of our diving deaths are due to human error, not hardware failures. As such, its a bit insane to get all worked up over a single component such as a QD as the most evil thing in the diving world. If you want to be a safe and effective rec diver, concentrate on the big stuff and don't sweat the small stuff...back in the day before they called themselves DIR, this was referred to as "Chasing Unseen Demons". IMO, this wisdom seems to have gotten forgotten over the past 3-4 years.

Gotta run,

-hh

PS: I edited an addition onto the ballistics bit above...you might have missed noticing it.

 

[shiro85]

You have yet to make a point *for* them...

He mentioned the handicapped diver example.

The bottom line is that there's not a reason why you'd want to have any sort of unecessary device on your life support system -

Such as having a removable STA?

That's the point you're missing: if the philosophy is that all possible failure points should always be eliminated, then why has this one been allowed to stay?

you're trying to make some sort of larger, political statement about "rock-throwers."

f there's a good reason why its okay for this one to stay as an exception to the "get rid of it" rule, then there's no hypocrisy*and no politics.

So what's the good reason why its an exeption to the rule?

I don't think having a weight belt buckle (I don't think that anyone else was considering this when they said "QD" either) on a shoulder strap would be very DIR either.

Man, you're missing it SeaJay...he meant having a weightbelt buckle on your weightbelt so that you can Quickly Disconnect to ditch your weights. Its been a standard for a zillion years and DIR uses it too.

Its an example of where a QD is not eliminated because being able to ditch your weights is the good reason. If there can be one exception, there can be others.

 

[jonnythan]

Why do people expend so much effort to attack any detail of DIR they can? Why do they go through such lengths to find one little thing they feel is hypocrticial? Come on, a plastic QD gets in the way, they can break fairly easily, and are just a general PITA. Good lord. It's not a religion, I promise. This is silly beyond belief.

 

[hijumpr]

I'm with you Jonny. QD's are not DIR for the reasons Seajay has pointed out. If you want to dive them, no problem! If you want to dive by the DIR methodology, then QDs are not used to help reduce the failure points. Simple as that.

 

[jonnythan]

So what's the good reason why its an exeption to the rule?

I assume you're talking about the bolts.. I have a hard time reading through the rest of your post.

The bolts are there whether you're diving doubles or singles. So are the wingnuts. If you use them properly, there's no even remotely reasonable chance that they'll break or come undone. A plastic buckle is another matter entirely. It's a reasonable risk that a plastic buckle will break when carrying 100 pounds of doubles, plus stages, etc. Plastic buckles are not intended to carry any significant weight. I work in an outdoor store, and it's a daily occurance to have someone come in with a broken plastic buckle from a backpack that was carrying 25 pounds.

It's no exception to any rule. The intent of the system is to make things as reliable, simple, and streamlined as possible. Using an STA when diving singles makes sense. Tossing in plastic buckles on the part of the webbing that receives the most stress to solve a problem that doesn't even exist does not make sense.

If you're honestly that worried, buy a Pioneer and don't use an STA, or use one of those nifty backplates with the shaped channel that doesn't need an STA.

If you're not that worried, dive whatever you're using now. Either way, trying to equate plastic buckles on shoulder straps to steel bolts on doubles or singles is really pretty idiotic, IMO. Oh yeah, and either way, give it up. You're obviously not concerned with DIR to any extent other than to attack it any way you can. If you don't think DIR is a better way to dive, then don't dive that way and leave it the *(!&@ alone.

 

[SeaJay]

He mentioned the handicapped diver example.

...And if that works best for the handicapped diver, then fine.

This thread isn't about handicapped divers, and it isn't about "what's best" or "what's worst." It's about why DIR rejects quick disconnects... And the reasons why are above.

If you don't agree, then fine. Feel free to disagree all you like, and feel free to cite "special needs" examples all you like.

That's the point you're missing: if the philosophy is that all possible failure points should always be eliminated, then why has this one been allowed to stay?

Believe me, I'm not the one missing the point here.

Jonnythan's done a nice job of replying to your concerns, but let me just say this: I have dived many dives with QDs, and I have dived many dives without QDs. The people I learned from have done many more dives than I have - both with QDs and without. Based on the culmination of all of those dives, we all agree that QDs don't belong on our rigs. Those dives are shallow dives, deep dives, dives in doubles, dives in singles, dives wet and dry, and dives both tropical and cold. Those are boat dives, wreck dives, cave dives... Those are just about any sort of dive you could imagine in any condition you can imagine.

If you don't agree with the philosophy, then feel free - but you're not going to change our feeling on it.

The bottom line is that we feel that the failure rate of a plastic QD is significant enough to warrant leaving it off the rig. We also found that the more we dove, the less we used a plastic QD - we found other, more reliable ways of doffing gear. So... Not only did we find plastic QDs to be a failure point, but we also found them to be wholly pointless. So... We got rid of them.

If you want to dive with them, then feel free. But please understand that we're not willing to allow one more plastic QD to ruin a dive - we're not interested in spending the time, money, effort, and such to make a really great dive, only to have it thwarted by our buddy's plastic QD.

Thus, when a DIR diver sees a plastic QD on your rig, don't be surprised if he doesn't buddy with you.

It's nothing personal. If you want to dive with plastic QDs, then feel free.

If this philosophy offends you, please consider the sources from which this knowledge comes... That would be many thousands of hours of diving by many different divers in all sorts of conditions. If they feel that plastic QDs are a reason to not buddy with you, then what we say here just *might* be true.

Man, you're missing it SeaJay...he meant having a weightbelt buckle on your weightbelt so that you can Quickly Disconnect to ditch your weights. Its been a standard for a zillion years and DIR uses it too.

Yes, I'm fully aware. Thank you for pointing that out.

My point - which apparently *you* missed - was that the term "QD" is generally thought of as the 1" or 2" plastic variety... And in fact that's what was intended when the thread was started. After all, DIR does not reject weight belt buckles.

For -hh to suddenly include weight belt buckles as a form of QD because they function similarly, was suspicious at best, and little more than an ink cloud in the debate.

Its an example of where a QD is not eliminated because being able to ditch your weights is the good reason. If there can be one exception, there can be others.

There's no exception there - a weight belt buckle is not a QD, although they function similarly.

Can you not see the difference between a weight belt buckle on the waist and a plastic QD on a shoulder harness?

 

[svs3]

FWIW, according to the DIR III video GI3 recommends using the stainless steel ScubaPro buckles for weight belts - the same kind used on the the harness waist belt.

As a little aside, I broke a fairly stout looking fastex d-ring last night tightening a velcro strap while attaching a light to my bike helmet.

Personally, I don't really see the need for any additonal and unnessecary potential failure points in ANY life support gear regardless of the activity.

Sam

 

[mstevens]

In the one DIR video I've seen, George Irvine simply picked up a rig and flipped it up over his head. It just fell onto him.

This was the method taught in my NAUI basic open water course in 1980. Of course then the backplate was molded plastic and there was no wing, just a horsecollar that went on next. We (including my 104lb wife) had to be able to do that both on land and underwater to get our basic certifications. Still works just fine.