bwerb once bubbled...
-hh...you understand engineering...what's so difficult and "a potential weakness" in the modularity of a system which uses two stainless steel wingnuts as the parts you have to undo and redo to switch wings...ie. the modular part? I just don't see the operation of two wingnuts as "mucking around" and "an opportunity to make mistakes."
The wing nuts are a wear item, as well as an opportunity for an assembly mistake to be made (a failure in the making). From a Hogarthian philisophical approach, if something can be eliminated as a potential failure point, it should be.
Pragmatically, the sole purpose of the BP/Wings' modularity is to save the diver money (by not having 2 BC's), which is not the same as striving to eliminate potential failure points. As such, its basic design violates fundimental Hogarthian principles.
And as we know, Hogarthian was the root of DIR, and GUE.
(BTW, if you didn't hear, a Trademark on DIR has been applied for...but not by GUE!).
Since when diving doubles you tend to remove the wing from the tanks for drying, filling etc...just where does the difficulty lie? Since the operation takes like two minutes tops, I don't see how this is a great vacuum of free time.
Errors can be made in even easy procedures, and opportunities for errors is "any and all" measurement. This means that disassembly for maintenance or drying counts. So too also does removing the tanks to fill them.
For every opportunity, we can either accept it, or look to eliminate them. There will never be zero of them, but in the case of a modular BP/Wing/STA assembly, we've generally chosen to accept more error opportunities than what can exist from known alternatives.
Why? Well, since we inevitably see dollar signs in conversations like this, its safe to say that divers are willing to accept the risk to save money. We simply need to recognize that this individual choice doesn't change what is or isn't an Objective Risk.
EDIT: Also note that the amount of time it takes to do something is not a direct factor when it comes to the metric of "Opportunity for Mistake". It is an indirect factor in that tasks that take longer are generally more complex, and each step typically is an error opportunity.
Also...since a BP/wing can be had for a fraction the cost of most "tech" or "top of the line" BC's and can be used for either singles or doubles with simply a wing switch (around $350), why would you want to buy two complete set-ups?
The reason why is because doing so can eliminate error/failure points.
Consider flipping the question: is it worth $150 to you to eliminate a a "dive ending" failure point?
Is it worth an extra $100 if it improves the equipment's repair interval by 75%? By 100%?
(BTW, please look at these questions as generalized examples of the underlying principle, and not specifics).
IMO, it is all too easy to allow the cost of doing something the right way to adversely influence our risk acceptances.
And IMO, it is often quite ironic to see loud claims about the "EVILS" of Quick Disconnects as potential failure points when the same people unthinkingly accept STA wing nuts.
This is the same bunk some LDS's use to badmouth Bp/wings. Oh yeah...once you buy a BP...you'll never have to buy another one...
Since the average diver only dives for ~5 years, that's the benchmark for how long a product is expected to reliably last, and from which LDS claims are going to be based.
My last BC lasted for over a decade...which is functionally two full "average diver lifetimes"...before I replaced it. I consider that to be good enough lifecycle performance.
...and wings are relatively cheap
Considering that $300-350 for a replacement wing is 50%-66% of the prices of those allegedly horribly overpriced BC's, I'd not exactly agree that a wing is a "relatively cheap" consumable replacement item. Perhaps its because I've never seen these fabled $1000 BC's...can you please cite some examples?
YMMV, but I'd just rather just spend another $100-$150 and get a completely new rig, as likely the better overall value. Particularly since when you get "Nickled and Dimed" on little widgets (a set of spare SS wingnuts anyone?), it often ends up costing you more in the long run.
-hh
