-hh once bubbled...
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.
C'mon.... wing nuts are a wear item and an opportunity to make a mistake?
I'd like to meet the man that could wear out a wing nut, or assemble it wrong.
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.
More likely failure points are the plastic buckles and dangling straps associated with adjustable harnesses.
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.
Very true. But lets not go overboard with the 'Safety is Paramount' argument. While we all agree that safety is important, risk managment must be sensible. Most people don't wear helmets in case they fall down, or kevlar vests in case some nut goes on a rampage, or even put seatbelts on their toilets. It could be argued that they are just cheap.... but I don't think so.
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.
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%?
Absolutely! What you are talking about is the price of an extra BP/harness. As I said before, I've seen multiple posts where people describe their gear and refer to several backplate/wing assemblies. I've also seen several where divers have gone to exclusively diving doubles and only sell their singles wing. In those cases, a completely redundant system is unnessessary.
(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.
I've never seen a broken wing nut -- I've seen broken buckles.
If you're really bent about the wing nuts, assemble your rig with Nylocks. Since you'll be one of the people only building your rig once, it shouldn't be too much problem to DIWW (do it with wrenches) and eliminate the failure point indefinitely. When it comes to building a rig for doubles, do the same thing.
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.
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.
Again, that $100-$150 could buy you another plate and harness and you could assemble just what you want.
In the long run, as long as you can competently tighten 2 bolts, the modularity is just a side benefit to having a rig that is streamlined, comfortable, and efficient.
Perhaps PADI should offer a Wing Nut specialty course??? Wadda ya think? Anyone? Anyone?
