ad_ward9 slamming everyone elses gear

mstroeck · 21st November 2006, 17:27

Quote: (Originally Posted by PhilSiswick)

Alex has put himself into a difficult position, trying to play the role of Cassandra about the kit that we are diving and at the same time being a manufacturer aiming to be in direct competition with the incumbents. That devalues his message and opens him up to the criticisms in this post. To be really effective in either, he's going to have to decide to be one or the other.

I disagree completely. Any other manufacturer is free to come here and offer counter-arguments. That they are curiously absent from these debates is their problem, not Alex's.

CharlieT · 21st November 2006, 18:00

Have I misunderstood things here? Does Alex Deas manufacture a unit already or a major component of one?

Unless he does he's not a CCR manufacturer just a diver who posts like the rest of us albeit perhaps one with a greater knowledge of electronics than most.

I don't think we can realistically expect Leon, Kevin and or Martin Parker to participate in our informal discussions on Rebreather World. Martin does post on the Inspiration Users site.

These guys are running companies of various sizes with responsibility for these businesses and wages to pay. I post on Rebreather World for the fun of it, to make contact with other CCR users and to learn what I can.

If the manufacturers start to participate in Rebreather World postings then which do they respond to? All of them, some of them, mine, yours? Unless their responses were substantially caveated could they then be used against them in some later legal action?

If they are substantially caveated then their replies would be virtually worthless and they might as well be left to get on with the running of their businesses.

As far as AP is concerned (the maker of my Vision), I want them to answer the phone promptly when I ring to order something or for help (they do this), to stay in business (they have been in business for many years), to continue to develop their CCR units (the Vision is proof of this), and to service and repair my unit (they are very capable of doing this).

These are my priorities not their diverting resources into participating in discussions on Rebreather World.

Charlie

Barrie Law · 21st November 2006, 18:28

Quote: (Originally Posted by CharlieT)

Have I misunderstood things here? Does Alex Deas manufacture a unit already or a major component of one?

Unless he does he's not a CCR manufacturer just a diver who posts like the rest of us albeit perhaps one with a greater knowledge of electronics than most.

I don't think we can realistically expect Leon, Kevin and or Martin Parker to participate in our informal discussions on Rebreather World. Martin does post on the Inspiration Users site.

These guys are running companies of various sizes with responsibility for these businesses and wages to pay. I post on Rebreather World for the fun of it, to make contact with other CCR users and to learn what I can.

If the manufacturers start to participate in Rebreather World postings then which do they respond to? All of them, some of them, mine, yours? Unless their responses were substantially caveated could they then be used against them in some later legal action?

If they are substantially caveated then their replies would be virtually worthless and they might as well be left to get on with the running of their businesses.

As far as AP is concerned (the maker of my Vision), I want them to answer the phone promptly when I ring to order something or for help (they do this), to stay in business (they have been in business for many years), to continue to develop their CCR units (the Vision is proof of this), and to service and repair my unit (they are very capable of doing this).

These are my priorities not their diverting resources into participating in discussions on Rebreather World.

Charlie

Hi Charlie,

Good points well made and possible getting near the hub of this debate.

Alex Deas may not be as visible on Rebreather World if and when his plans develop and an affordable manufactured unit hits the streets.

I still think Alex deserves the right to his opinion, as do the rest of us but I refuse to be drawn into this constant your either 'with us' or 'against us' mentality that seems to pervade some of these more technical threads.

Starting a reply with "I'm with ??? on this one" suggests a total inability by some to accept there are often two sides to a discussion and that both can be valid or at least be worth some consideration.

It is positive for Rebreather World to have someone like Alex around and his posts I read with interest but I also suspect he takes at least a size 11 shoe.

Regards

Faceless · 21st November 2006, 19:07

Quote: (Originally Posted by Andy M)

Well, I read it, and it says that the sensors have exactly the same performance.

Your point is?

Andy

Glad talking with a reasonable and curious man in this topic.
I'm serious.
Document describing tests performed by Navy isn't complete of course ( i dont'know why, maybe due to NDA issues), for example I didn't found any references/investigations on extreme cases, forex when we have total flood of the loop, how sensors readings are drifting over time, drop and shock tests, CO2 contamination.But at least Navies ARE claiming that AI sensors are comparable to Teledyne in terms of linearity and responce time, so they anyway are worth consideration.
I've not seen anyone from oxygen sensors producers performing all the tests, described in Alex's plan, so his efforts providing results for testing sensors under extreme conditions are first I've heard so far.

My point is: let's calm down and wait for Alex's report, and AFTER that make any assumption, moreover Alex has explicitly stated publishing timeframe for it.

Sorry for my bad English, guys.

RonMicjan · 22nd November 2006, 04:45

my .02 on the various points folks are making...

Alex really is building things, right now prototypes, but the stuff I have seen is impressive, no idea what market this is aiming for, but impressive none the less. He has some serious manufacturing history and some serious partners, I dont doubt his abilities to bring out a new unit or two. Obviously the jury is still out on time frame, pricing, and market. I, for one, think that some of his points are quite valid and some solutions (O2 injection lead, for example) are quite innovative. The goal of 1 billion hours mean time to failure would be what the industry needs. Question: is that total time on multiple units, or total time on a single unit? Enquiring minds want to know. We all can sound like we are bashing at times (I am as guilty as any), but how do you point out a deficiency, without sounding like you are either: bashing, or have an agenda? difficult, I know. "Hey M8, your Lada there is blowing blue smoke, the tie rod looks like it a bit loose, is that brake fluid dripping onto the manifold about to catch fire? but hey, nice paint job!! Want to take my sister to the dance?" right then! off you go!

I dont think so. If you can show a deficiency in any CCR that we all can recognize and understand the problem, goodonya, please show us. But it better not be "mines better than yours cause my flow goes Xwise and xxxx said you will die if you flow the other way" cause Im going to feed that right back at ya, with spicy hot peppers on it. Confusious say, "man should not point out what cannot be done, to man already doing it." So, instead of telling Alex he is full of anything, lets ask honest, intelligent, questions and get him to prove to us where his thoughts are coming from.

next thought...

Most manufacturers have a person or two on Rebreather World, posting "the company viewpoint", either like a lightning rod, or a white house press secretary, depending on the Post.

Jurgensen has Joe Radomski, Jetsam has Phi Le, Prism has Stefan, ISC has myself, not sure who does this for APV, cause i typically dont read from the inspio posts, but you get the idea. I know that Kim Smith reads Rebreather World, so do Leon and Steve, KJ occasionally posts here to clear some things up, so its not a complete vacuum from the manufacturers viewpoint, they are paying attention, silly for them not to. Jumping into the middle of a slag fest is probably the wrong way to approach the situation, however.

So we (the lightening rods) tend to answer questions, draw the criticism and keep the "bosses" up to date on what folks are speculating on.

I too am curious about the test data on sensors, but speculation on the subject isnt healthy, the first few times I read Alex going after teledyne I was a bit put out, but, hey, I dont have the facility to do these kind of tests myself, so I can only go on my own limited experience. I have run through maybe 20 or so sensors in my CCR experience, all of them have failed except the ones Im using now (go figure) anywhere from 6 months to over 3 years from one oxygauge sensor that just wouldnt die. I finally replaced it when I sold the oxygauge (liability conscious feller that I am), but Im pretty happy with my limited results, most every sensor went at least a year, no one said CCR diving was going to be cheap...sigh, another $200 in the kitty. Sure, better sensors, Im all for it, lets see the test data, meanwhile, go but a butt load of sensors and test them yourself, but dont just say "mine is better" without having data to back it up.

Ok, on with the show!

Genesis · 22nd November 2006, 05:10

My problem with a "1 billion hours MTBF!" claim is the same problem that I have with any claim like that.

Specifically, you can only calculcate a probability of failure on risks you are aware of. Formal design is thought of to be able to catch the issues that can bite you, but does it really catch all of them? I argue that no, it does not and cannot.

Why? His name is Murphy, and he's a baztard. I've had just enough experience with him to know that when its time for something like that to happen it will be in the most mysterious format.

As just one example, Juergenson's "threat matrix" has had many people cheering at one time or another. But - nobody thought about the handset rebooting due to contact problems with the SS cap and Aluminum, and the (bad) reaction from trying to fire a solenoid with insufficient V+ rail power. Should it have been thought of and dealt with before the units went out? Well you can say "sure", and that's the easy way - to slag off on him for this "screwup".

But in reality, what happened there? A failure that was not anticipated by the design process bit you.

Its like the guys who claim "ISO" certification. That's not even a bit funny, because all ISO certification says is that you do the same thing every time, within some level of formal deviation. That's nice - but if you screw it up once, all ISO means is that you'll screw it up every single time in the same way! So did you really buy anything with ISO cert? Well, consistency, yes. But safety? Not by virtue of the ISO cert!

Why does all this matter? Because perusing the accident info that we do have (and which is terribly incomplete and can be inaccurate) what we keep coming back to is that the number 1 preventable cause of death on a CCR is complacency.

You go in the water with your O2 turned off, and die.
You go in the water with a KNOWN bad cell, tox, and die.
You go in the water with ALL THREE cells just replaced, without a checkout in shallow water, after you saw what looked like a current limiting failure on ALL THREE previous cells on your last dive, tox, and die.
You go in the water, the batteries bounce, YOU FAIL TO NOTICE THAT THE UNIT IS WAITING FOR YOU TO ACCEPT THE STARTUP, it is not monitoring PO2 and doing its thing, and you die.
You go in WITHOUT ANY SCRUBBER MEDIA, and die.
You go in the water WITH THE POWER OFF, and die.

and on and on and on.

Now Alex goes after most of these as design faults. Ok, but does fixing them really solve the problem? No. Indeed, fixing all those "faults" may actually make the unit more dangerous.

Why? Because if you are forced to treat the unit as The Homicidal Spawn of Satan, then complacency becomes "not an option" - you know if you don't pay atteniton you're going to die, because it is what you expect if you're not watching! My evidence for this is the KISS - you MUST monitor the PO2 readings with the big brain, or you die for sure. Has this kept people from dying? It certainly appears so - no cold bodies (thus far!)

But if you are sold a unit with a "1 billion hour MTBCF", well, you won't live 1 billion hours in any event, right? Indeed, your life expectancy is about 750,000 hours (birth to age 85 1/2, plus or minus a few.) To put that number in perspective the "uber Gods" of Rebreather diving have what - single-digit thousands of hours underwater? Let's call it 10,000 hours if you dive your butt off in you career. Given THAT level of activity the unit can only kill 1 in 100,000 users at that activity level!

That's such a remote risk of death that you'd be foolish (if you believed the number) to NOT believe that the unit will "keep the loop safe at all times." Indeed, its SUCH a low risk of failure that you're probably more likely to suffer a bailout tank explosion than a critical unit failure, which is the best argument I've ever seen for flying alpine!

Now - is that decision wise? Hmmmm.... is Alex willing to go on record, in their formal documentation, and state that the unit is SO reliable that no bailout is needed?

My personal view is that you'll live longer in all your diving if you believe that your equipment (whether OC or CCR) is The Homicidal Spawn of Satan, and plan your diving accordingly.

Bruce P appears to share my philosophy on this - I read through the manual for his GF CCR computer recently, and saw in big bold print a statement ot the effect that "this computer has bugs. All software has bugs. By definition we don't know what they are, or we would have fixed them. It is not a question of whether it will fail, it is a question of WHEN it will fail."

While this may be considered either "unnecessary" (e.g. "we can control for that risk") or simply pessimistic, the fact remains that if you treat your gear in this fashion you've lost nothing if you're wrong and it never does break.

The difference is that IF it breaks, you're far more likely to stay alive with this approach.

silent running · 22nd November 2006, 07:50

Ron, Genesis and many others have said good things above.

And as I have said before, Alex is entirely right that we should expect more from our life support gear and he is a leader in this respect, no matter how abraisive he may seem. If he's right-I think he's much more right than wrong-he couldn't help but appear abraisive in this community, considering the small numbers of us and the difficulty of bringing a viable CCR to market and the subsequent expense of purchasing one. After all, none of us would even be talking about this stuff if it weren't for the fact that we have all bought and dive units that have flaws, some which may even be fatal. Was there any other way? Considering the narrow profit margins, how many manufacturers would have been willing to test, invest and wait for a faultless design before bringing it to market? Would you rather have a flawed unit and be vigilant, or have none at all and not even have the liberty to dive CCR and have this discussion?

My doubts about Alex's claim of '00000's hrs btw failures and the complacency that would likely come with it, and the idea that one can actually anticipate all failure modes, including stoopid human tricks, are significant. I can't help but wonder if the most imediate and practical solution is making ECCRs more simple, not more complicated. And focus instead on the most problematic parts of the system-O2 sensors, lack of CO2 sensor-instead of trying to design a unit that has taken care of all failure modes, big and small.

But I'm still very impressed by Alex's sharp focus and the effort he's made to raise the bar. -Andy

***caveseeker7*** · 22nd November 2006, 09:09

Quote: (Originally Posted by RonMicjan)

my .02 on the various points folks are making...
Most manufacturers have a person or two on Rebreather World, posting "the company viewpoint", either like a lightning rod, or a white house press secretary, depending on the Post.

Jurgensen has Joe Radomski, Jetsam has Phi Le, Prism has Stefan, ISC has myself, not sure who does this for APV, cause i typically dont read from the inspio posts, but you get the idea. I know that Kim Smith reads Rebreather World, so do Leon and Steve, KJ occasionally posts here to clear some things up, so its not a complete vacuum from the manufacturers viewpoint, they are paying attention, silly for them not to.

Not quite, but close.

For most part I respond because I happen to know both the PRISM and SMI pretty well. And they're friends. Same with Divematics, or OTS.

Shas lurks frequently and does read posts to Pete. On occasion she replies, after running 'politically fairly correct' and 'diplomatic' filters sometimes Pete's comments.

Tracy Robinette tries to have a look when he can find the time.

Martin Parker has also made quite a few posts here on the board.

Jordan is the company connection to Dive Rite.

So all in all Rebreather World has most of the manufacturers reading and, though not all that often, responding. Which I think is great.

Quote:

Jumping into the middle of a slag fest is probably the wrong way to approach the situation, however.

So we (the lightening rods) tend to answer questions, draw the criticism and keep the "bosses" up to date on what folks are speculating on.

Remembering some of the nasty verbal slug fests in the past, on the nw or tech diver lists before the boards, I can understand that no one wants to repeat that. Including Stuart and the rest of us mods and admins. The same is likely true for the manufacturers. The ones I know have grown tired and leery of those battles, and with the much broader audience the boards have, they'd be exponentially worse.

jkaterenchuk · 22nd November 2006, 11:58

Take a look at the number of views this thread has.....more than the threads dealing with cell testing.....its kind of sad that a title (containing a direct personal attack on an individual) like the one used in this case generates so much interest.

John Langley · 22nd November 2006, 12:08

Quote: (Originally Posted by jkaterenchuk)

Take a look at the number of views this thread has.....more than the threads dealing with cell testing.....its kind of sad that a title (containing a direct personal attack on an individual) like the one used in this case generates so much interest.

Of course it does , you would'nt be human if you did'nt take a look.

But having said that it has turned into a sound dicussion.

J.L.

21st November 2006, 17:27	#41 (permalink)
mstroeck New Member Current Rebreather/s: Dolphin Other Rebreather/s: Dolphin Join Date: Nov 2005 Location: Vienna, Austria Posts: 32	Re: ad_ward9 slamming everyone elses gear Quote: (Originally Posted by PhilSiswick) Alex has put himself into a difficult position, trying to play the role of Cassandra about the kit that we are diving and at the same time being a manufacturer aiming to be in direct competition with the incumbents. That devalues his message and opens him up to the criticisms in this post. To be really effective in either, he's going to have to decide to be one or the other. I disagree completely. Any other manufacturer is free to come here and offer counter-arguments. That they are curiously absent from these debates is their problem, not Alex's. __________________ Michael Ströck
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21st November 2006, 18:00	#42 (permalink)
CharlieT Custom Title Allowed! Current Rebreather/s: Inspiration Vision Other Rebreather/s: Join Date: Nov 2005 Location: London Posts: 449	Re: ad_ward9 slamming everyone elses gear Have I misunderstood things here? Does Alex Deas manufacture a unit already or a major component of one? Unless he does he's not a CCR manufacturer just a diver who posts like the rest of us albeit perhaps one with a greater knowledge of electronics than most. I don't think we can realistically expect Leon, Kevin and or Martin Parker to participate in our informal discussions on Rebreather World. Martin does post on the Inspiration Users site. These guys are running companies of various sizes with responsibility for these businesses and wages to pay. I post on Rebreather World for the fun of it, to make contact with other CCR users and to learn what I can. If the manufacturers start to participate in Rebreather World postings then which do they respond to? All of them, some of them, mine, yours? Unless their responses were substantially caveated could they then be used against them in some later legal action? If they are substantially caveated then their replies would be virtually worthless and they might as well be left to get on with the running of their businesses. As far as AP is concerned (the maker of my Vision), I want them to answer the phone promptly when I ring to order something or for help (they do this), to stay in business (they have been in business for many years), to continue to develop their CCR units (the Vision is proof of this), and to service and repair my unit (they are very capable of doing this). These are my priorities not their diverting resources into participating in discussions on Rebreather World. Charlie
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21st November 2006, 18:28	#43 (permalink)
Barrie Law RebreatherWorld Sponsor Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Jun 2005 Location: Ireland Posts: 459	Re: ad_ward9 slamming everyone elses gear Quote: (Originally Posted by CharlieT) Have I misunderstood things here? Does Alex Deas manufacture a unit already or a major component of one? Unless he does he's not a CCR manufacturer just a diver who posts like the rest of us albeit perhaps one with a greater knowledge of electronics than most. I don't think we can realistically expect Leon, Kevin and or Martin Parker to participate in our informal discussions on Rebreather World. Martin does post on the Inspiration Users site. These guys are running companies of various sizes with responsibility for these businesses and wages to pay. I post on Rebreather World for the fun of it, to make contact with other CCR users and to learn what I can. If the manufacturers start to participate in Rebreather World postings then which do they respond to? All of them, some of them, mine, yours? Unless their responses were substantially caveated could they then be used against them in some later legal action? If they are substantially caveated then their replies would be virtually worthless and they might as well be left to get on with the running of their businesses. As far as AP is concerned (the maker of my Vision), I want them to answer the phone promptly when I ring to order something or for help (they do this), to stay in business (they have been in business for many years), to continue to develop their CCR units (the Vision is proof of this), and to service and repair my unit (they are very capable of doing this). These are my priorities not their diverting resources into participating in discussions on Rebreather World. Charlie Hi Charlie, Good points well made and possible getting near the hub of this debate. Alex Deas may not be as visible on Rebreather World if and when his plans develop and an affordable manufactured unit hits the streets. I still think Alex deserves the right to his opinion, as do the rest of us but I refuse to be drawn into this constant your either 'with us' or 'against us' mentality that seems to pervade some of these more technical threads. Starting a reply with "I'm with ??? on this one" suggests a total inability by some to accept there are often two sides to a discussion and that both can be valid or at least be worth some consideration. It is positive for Rebreather World to have someone like Alex around and his posts I read with interest but I also suspect he takes at least a size 11 shoe. Regards __________________ Barrie Law Rebreather World Store Supplying the Rebreather World Tel:US +19548403892 Fax:US+19543333792 Tel:EU+442071930496 Fax:EU+442077606344 Mobile+353876880628 Skype:barrielaw Email: barrie@rebreatherworldstore.com
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21st November 2006, 19:07	#44 (permalink)
Faceless alone lurking in wrecks Current Rebreather/s: Other CCR Other Rebreather/s: Not Bought Yet Other CCR Join Date: May 2006 Location: France, Montpellier Posts: 112	Re: ad_ward9 slamming everyone elses gear Quote: (Originally Posted by Andy M) Well, I read it, and it says that the sensors have exactly the same performance. Your point is? Andy Glad talking with a reasonable and curious man in this topic. I'm serious. Document describing tests performed by Navy isn't complete of course ( i dont'know why, maybe due to NDA issues), for example I didn't found any references/investigations on extreme cases, forex when we have total flood of the loop, how sensors readings are drifting over time, drop and shock tests, CO2 contamination.But at least Navies ARE claiming that AI sensors are comparable to Teledyne in terms of linearity and responce time, so they anyway are worth consideration. I've not seen anyone from oxygen sensors producers performing all the tests, described in Alex's plan, so his efforts providing results for testing sensors under extreme conditions are first I've heard so far. My point is: let's calm down and wait for Alex's report, and AFTER that make any assumption, moreover Alex has explicitly stated publishing timeframe for it. Sorry for my bad English, guys. __________________ Peoples risk perception is almost always focused on the most dramatic rather than the most probable. (c) Gordon Smith Last edited by Faceless : 21st November 2006 at 19:17.
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22nd November 2006, 04:45	#45 (permalink)
RonMicjan Cap Ron scourge of the NW Current Rebreather/s: Megalodon Dolphin Home Build Other Rebreather/s: Sport Kiss Classic Kiss Dolphin Home Build Join Date: Feb 2005 Location: Cape Disapointment, The Graveyard of the Pacific Posts: 1,100	Re: ad_ward9 slamming everyone elses gear my .02 on the various points folks are making... Alex really is building things, right now prototypes, but the stuff I have seen is impressive, no idea what market this is aiming for, but impressive none the less. He has some serious manufacturing history and some serious partners, I dont doubt his abilities to bring out a new unit or two. Obviously the jury is still out on time frame, pricing, and market. I, for one, think that some of his points are quite valid and some solutions (O2 injection lead, for example) are quite innovative. The goal of 1 billion hours mean time to failure would be what the industry needs. Question: is that total time on multiple units, or total time on a single unit? Enquiring minds want to know. We all can sound like we are bashing at times (I am as guilty as any), but how do you point out a deficiency, without sounding like you are either: bashing, or have an agenda? difficult, I know. "Hey M8, your Lada there is blowing blue smoke, the tie rod looks like it a bit loose, is that brake fluid dripping onto the manifold about to catch fire? but hey, nice paint job!! Want to take my sister to the dance?" right then! off you go! I dont think so. If you can show a deficiency in any CCR that we all can recognize and understand the problem, goodonya, please show us. But it better not be "mines better than yours cause my flow goes Xwise and xxxx said you will die if you flow the other way" cause Im going to feed that right back at ya, with spicy hot peppers on it. Confusious say, "man should not point out what cannot be done, to man already doing it." So, instead of telling Alex he is full of anything, lets ask honest, intelligent, questions and get him to prove to us where his thoughts are coming from. next thought... Most manufacturers have a person or two on Rebreather World, posting "the company viewpoint", either like a lightning rod, or a white house press secretary, depending on the Post. Jurgensen has Joe Radomski, Jetsam has Phi Le, Prism has Stefan, ISC has myself, not sure who does this for APV, cause i typically dont read from the inspio posts, but you get the idea. I know that Kim Smith reads Rebreather World, so do Leon and Steve, KJ occasionally posts here to clear some things up, so its not a complete vacuum from the manufacturers viewpoint, they are paying attention, silly for them not to. Jumping into the middle of a slag fest is probably the wrong way to approach the situation, however. So we (the lightening rods) tend to answer questions, draw the criticism and keep the "bosses" up to date on what folks are speculating on. I too am curious about the test data on sensors, but speculation on the subject isnt healthy, the first few times I read Alex going after teledyne I was a bit put out, but, hey, I dont have the facility to do these kind of tests myself, so I can only go on my own limited experience. I have run through maybe 20 or so sensors in my CCR experience, all of them have failed except the ones Im using now (go figure) anywhere from 6 months to over 3 years from one oxygauge sensor that just wouldnt die. I finally replaced it when I sold the oxygauge (liability conscious feller that I am), but Im pretty happy with my limited results, most every sensor went at least a year, no one said CCR diving was going to be cheap...sigh, another $200 in the kitty. Sure, better sensors, Im all for it, lets see the test data, meanwhile, go but a butt load of sensors and test them yourself, but dont just say "mine is better" without having data to back it up. Ok, on with the show! __________________ Marine rescue, towing and salvage. Interfering with natural selection since 1983. www.tmishop.com Diving bits etc. www.seatowpdx.com The Summer Job
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22nd November 2006, 05:10	#46 (permalink)
Genesis Bubbless Box of Death Current Rebreather/s: Home Build Other Rebreather/s: Home Build Join Date: Oct 2005 Location: Sunny Florida Posts: 1,397	Re: ad_ward9 slamming everyone elses gear My problem with a "1 billion hours MTBF!" claim is the same problem that I have with any claim like that. Specifically, you can only calculcate a probability of failure on risks you are aware of. Formal design is thought of to be able to catch the issues that can bite you, but does it really catch all of them? I argue that no, it does not and cannot. Why? His name is Murphy, and he's a baztard. I've had just enough experience with him to know that when its time for something like that to happen it will be in the most mysterious format. As just one example, Juergenson's "threat matrix" has had many people cheering at one time or another. But - nobody thought about the handset rebooting due to contact problems with the SS cap and Aluminum, and the (bad) reaction from trying to fire a solenoid with insufficient V+ rail power. Should it have been thought of and dealt with before the units went out? Well you can say "sure", and that's the easy way - to slag off on him for this "screwup". But in reality, what happened there? A failure that was not anticipated by the design process bit you. Its like the guys who claim "ISO" certification. That's not even a bit funny, because all ISO certification says is that you do the same thing every time, within some level of formal deviation. That's nice - but if you screw it up once, all ISO means is that you'll screw it up every single time in the same way! So did you really buy anything with ISO cert? Well, consistency, yes. But safety? Not by virtue of the ISO cert! Why does all this matter? Because perusing the accident info that we do have (and which is terribly incomplete and can be inaccurate) what we keep coming back to is that the number 1 preventable cause of death on a CCR is complacency. You go in the water with your O2 turned off, and die. You go in the water with a KNOWN bad cell, tox, and die. You go in the water with ALL THREE cells just replaced, without a checkout in shallow water, after you saw what looked like a current limiting failure on ALL THREE previous cells on your last dive, tox, and die. You go in the water, the batteries bounce, YOU FAIL TO NOTICE THAT THE UNIT IS WAITING FOR YOU TO ACCEPT THE STARTUP, it is not monitoring PO2 and doing its thing, and you die. You go in WITHOUT ANY SCRUBBER MEDIA, and die. You go in the water WITH THE POWER OFF, and die. and on and on and on. Now Alex goes after most of these as design faults. Ok, but does fixing them really solve the problem? No. Indeed, fixing all those "faults" may actually make the unit more dangerous. Why? Because if you are forced to treat the unit as The Homicidal Spawn of Satan, then complacency becomes "not an option" - you know if you don't pay atteniton you're going to die, because it is what you expect if you're not watching! My evidence for this is the KISS - you MUST monitor the PO2 readings with the big brain, or you die for sure. Has this kept people from dying? It certainly appears so - no cold bodies (thus far!) But if you are sold a unit with a "1 billion hour MTBCF", well, you won't live 1 billion hours in any event, right? Indeed, your life expectancy is about 750,000 hours (birth to age 85 1/2, plus or minus a few.) To put that number in perspective the "uber Gods" of Rebreather diving have what - single-digit thousands of hours underwater? Let's call it 10,000 hours if you dive your butt off in you career. Given THAT level of activity the unit can only kill 1 in 100,000 users at that activity level! That's such a remote risk of death that you'd be foolish (if you believed the number) to NOT believe that the unit will "keep the loop safe at all times." Indeed, its SUCH a low risk of failure that you're probably more likely to suffer a bailout tank explosion than a critical unit failure, which is the best argument I've ever seen for flying alpine! Now - is that decision wise? Hmmmm.... is Alex willing to go on record, in their formal documentation, and state that the unit is SO reliable that no bailout is needed? My personal view is that you'll live longer in all your diving if you believe that your equipment (whether OC or CCR) is The Homicidal Spawn of Satan, and plan your diving accordingly. Bruce P appears to share my philosophy on this - I read through the manual for his GF CCR computer recently, and saw in big bold print a statement ot the effect that "this computer has bugs. All software has bugs. By definition we don't know what they are, or we would have fixed them. It is not a question of whether it will fail, it is a question of WHEN it will fail." While this may be considered either "unnecessary" (e.g. "we can control for that risk") or simply pessimistic, the fact remains that if you treat your gear in this fashion you've lost nothing if you're wrong and it never does break. The difference is that IF it breaks, you're far more likely to stay alive with this approach. __________________ "A venturesome minority will always be eager to get off on their own, and no obstacles should be placed in their path; let them take risks for Godsake, let them get lost, sunburnt, stranded, drowned, eaten by bears, buried alive under avalanches - that is the right and privilege of any free American." http://www.denninger.net http://www.diversunion.org/liability.htm - Fix the Diving Cert racket Last edited by Genesis : 22nd November 2006 at 05:14.
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22nd November 2006, 07:50	#47 (permalink)
silent running Mature mouth breather Current Rebreather/s: Prism Topaz Other Rebreather/s: Join Date: Jun 2005 Location: U.S.A. Brooklyn, New York Posts: 1,832	Re: ad_ward9 slamming everyone elses gear Ron, Genesis and many others have said good things above. And as I have said before, Alex is entirely right that we should expect more from our life support gear and he is a leader in this respect, no matter how abraisive he may seem. If he's right-I think he's much more right than wrong-he couldn't help but appear abraisive in this community, considering the small numbers of us and the difficulty of bringing a viable CCR to market and the subsequent expense of purchasing one. After all, none of us would even be talking about this stuff if it weren't for the fact that we have all bought and dive units that have flaws, some which may even be fatal. Was there any other way? Considering the narrow profit margins, how many manufacturers would have been willing to test, invest and wait for a faultless design before bringing it to market? Would you rather have a flawed unit and be vigilant, or have none at all and not even have the liberty to dive CCR and have this discussion? My doubts about Alex's claim of '00000's hrs btw failures and the complacency that would likely come with it, and the idea that one can actually anticipate all failure modes, including stoopid human tricks, are significant. I can't help but wonder if the most imediate and practical solution is making ECCRs more simple, not more complicated. And focus instead on the most problematic parts of the system-O2 sensors, lack of CO2 sensor-instead of trying to design a unit that has taken care of all failure modes, big and small. But I'm still very impressed by Alex's sharp focus and the effort he's made to raise the bar. -Andy
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22nd November 2006, 09:09	#48 (permalink)
*caveseeker7* Who loves ya, baby Current Rebreather/s: Sport Kiss Other Rebreather/s: Prism Topaz Join Date: Jan 2005 Location: Too far from Neverland Posts: 5,456	Re: ad_ward9 slamming everyone elses gear Quote: (Originally Posted by RonMicjan) my .02 on the various points folks are making... Most manufacturers have a person or two on Rebreather World, posting "the company viewpoint", either like a lightning rod, or a white house press secretary, depending on the Post. Jurgensen has Joe Radomski, Jetsam has Phi Le, Prism has Stefan, ISC has myself, not sure who does this for APV, cause i typically dont read from the inspio posts, but you get the idea. I know that Kim Smith reads Rebreather World, so do Leon and Steve, KJ occasionally posts here to clear some things up, so its not a complete vacuum from the manufacturers viewpoint, they are paying attention, silly for them not to. Not quite, but close. For most part I respond because I happen to know both the PRISM and SMI pretty well. And they're friends. Same with Divematics, or OTS. Shas lurks frequently and does read posts to Pete. On occasion she replies, after running 'politically fairly correct' and 'diplomatic' filters sometimes Pete's comments. Tracy Robinette tries to have a look when he can find the time. Martin Parker has also made quite a few posts here on the board. Jordan is the company connection to Dive Rite. So all in all Rebreather World has most of the manufacturers reading and, though not all that often, responding. Which I think is great. Quote: Jumping into the middle of a slag fest is probably the wrong way to approach the situation, however. So we (the lightening rods) tend to answer questions, draw the criticism and keep the "bosses" up to date on what folks are speculating on. Remembering some of the nasty verbal slug fests in the past, on the nw or tech diver lists before the boards, I can understand that no one wants to repeat that. Including Stuart and the rest of us mods and admins. The same is likely true for the manufacturers. The ones I know have grown tired and leery of those battles, and with the much broader audience the boards have, they'd be exponentially worse. __________________ Cheers Stefan "Political Correctness is a doctrine, fostered by a delusional, illogical minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.!"
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22nd November 2006, 11:58	#49 (permalink)
jkaterenchuk . Current Rebreather/s: Inspiration Classic Megalodon Classic Kiss Other Rebreather/s: Join Date: May 2006 Location: Lititz, PA Posts: 827	Re: ad_ward9 slamming everyone elses gear Take a look at the number of views this thread has.....more than the threads dealing with cell testing.....its kind of sad that a title (containing a direct personal attack on an individual) like the one used in this case generates so much interest.
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22nd November 2006, 12:08	#50 (permalink)
John Langley New Member Current Rebreather/s: Inspiration Vision Other Rebreather/s: Not Bought Yet Classic Kiss Join Date: Apr 2005 Location: in an appartment on the 99th floor of my block Posts: 103	Re: ad_ward9 slamming everyone elses gear Quote: (Originally Posted by jkaterenchuk) Take a look at the number of views this thread has.....more than the threads dealing with cell testing.....its kind of sad that a title (containing a direct personal attack on an individual) like the one used in this case generates so much interest. Of course it does , you would'nt be human if you did'nt take a look. But having said that it has turned into a sound dicussion. J.L.
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