Report from Fatality at Devil’s Ear

Drmike · 20th May 2008, 04:24

Quote: (Originally Posted by Jerry)

Here's a scenario for the Monday Morning quarterbacks;

its not about being a monday morning quarterback . Its about trying to understand what could have happened better so as to hopefuly make sure nobody else ever comes back to a flooded staged Rebreather. I would have thought that makes the discussion worthwhile. I dont see anyone saying 'this is what happened' - just debating the physics. What people are debating here is if physics would allow a normally functioning opv to leak and flood a static Rebreather regardless of orientation- the answer to that question (according to the physics presented so far ) is no. Having established that, the discussion may encourage people to be more vigilant over opv cleaning and checking...which in turn may save a life.

Quote:

a rig passes the predive checks (pos/neg tests); it is found on the deceased nearly 24 hrs later, scubber down; onboard oxygen to solenoid empty; CLs full of gas and floating upward placing the OPV at the highest point; the OPV is witnessed venting; the DSV is closed; where did the water filling the scrubber come from???

from the diver knocking open the dsv when trying to put his unit back on in zero viz cave. That could explain the flood, the water on cells, the continuous o2 injection, the fact that 24hrs later the lungs were still +ve and floating.

If as you say 24hrs later lungs were full of gas, floating high and +ve then you are suggesting the leak was bad enough to flood a unit bad enough so a diver cant use it after just 1hr, yet 23hrs later the lungs are still +ve and floating up?? That doesnt make sense to me.

I think the whole diagnosis is quite wrong.

Based on the full venting and floating lungs witnessed 24hrs later Id suggest its far more likely that the diver flooded the unit by mistake opening the dsv and that fits exactly with the way the unit was found 24hrs later.

Bottom line is if it flooded in 1 hr due to a leaking OPV why wasnt the unit completely flooded after 24hrs and why was the opv still seen venting after 24hrs with the lungs still +ve and floating up ?

+ve pressure in cls means they simply cant flood no matter what orientation.

I suggest its far more likely the dsv was knocked open by accident causing the flood.

Drmike · 20th May 2008, 04:33

Quote: (Originally Posted by Jerry)

. If he did try the loop and then managed to RECLOSE the DSV in the midst of probable near panic, it would stand to reason that he very probably had it closed while away from it.

Its instinctive/muscle memory to close the dsv when coming off the loop for whatever reason. He could easily have knocked open the dsv when taking the unit off or putting it back on. Ive done this myself when trying to get into boris. I now have a piece of bungee that loops over the opening handle to the mouthbite to keep it closed (use this on my bob too) The inspo or turning type of dsv are less prone to this but the meg, mk15 and especially the boris dsv is easily knocked open. (boris is very easy to knock open with its long handle and easy operation)

***Beanie*** · 20th May 2008, 08:45

Quote: (Originally Posted by Drmike)

its not about being a monday morning quarterback . Its about trying to understand what could have happened better so as to hopefuly make sure nobody else ever comes back to a flooded staged Rebreather. I would have thought that makes the discussion worthwhile. I dont see anyone saying 'this is what happened' - just debating the physics. What people are debating here is if physics would allow a normally functioning opv to leak and flood a static Rebreather regardless of orientation- the answer to that question (according to the physics presented so far ) is no. Having established that, the discussion may encourage people to be more vigilant over opv cleaning and checking...which in turn may save a life.

from the diver knocking open the dsv when trying to put his unit back on in zero viz cave. That could explain the flood, the water on cells, the continuous o2 injection, the fact that 24hrs later the lungs were still +ve and floating.

If as you say 24hrs later lungs were full of gas, floating high and +ve then you are suggesting the leak was bad enough to flood a unit bad enough so a diver cant use it after just 1hr, yet 23hrs later the lungs are still +ve and floating up?? That doesnt make sense to me.

I think the whole diagnosis is quite wrong.

Based on the full venting and floating lungs witnessed 24hrs later Id suggest its far more likely that the diver flooded the unit by mistake opening the dsv and that fits exactly with the way the unit was found 24hrs later.

Bottom line is if it flooded in 1 hr due to a leaking OPV why wasnt the unit completely flooded after 24hrs and why was the opv still seen venting after 24hrs with the lungs still +ve and floating up ?

+ve pressure in cls means they simply cant flood no matter what orientation.

I suggest its far more likely the dsv was knocked open by accident causing the flood.

Those are my thoughts problem with this is that noone knows what happened down there so its all guessing.

jaap · 20th May 2008, 09:28

Quote: (Originally Posted by Drmike)

its not about being a monday morning quarterback . Its about trying to understand what could have happened better so as to hopefuly make sure nobody else ever comes back to a flooded staged Rebreather. I would have thought that makes the discussion worthwhile. I dont see anyone saying 'this is what happened' - just debating the physics. What people are debating here is if physics would allow a normally functioning opv to leak and flood a static Rebreather regardless of orientation- the answer to that question (according to the physics presented so far ) is no. Having established that, the discussion may encourage people to be more vigilant over opv cleaning and checking...which in turn may save a life.

from the diver knocking open the dsv when trying to put his unit back on in zero viz cave. That could explain the flood, the water on cells, the continuous o2 injection, the fact that 24hrs later the lungs were still +ve and floating.

If as you say 24hrs later lungs were full of gas, floating high and +ve then you are suggesting the leak was bad enough to flood a unit bad enough so a diver cant use it after just 1hr, yet 23hrs later the lungs are still +ve and floating up?? That doesnt make sense to me.

I think the whole diagnosis is quite wrong.

Based on the full venting and floating lungs witnessed 24hrs later Id suggest its far more likely that the diver flooded the unit by mistake opening the dsv and that fits exactly with the way the unit was found 24hrs later.

Bottom line is if it flooded in 1 hr due to a leaking OPV why wasnt the unit completely flooded after 24hrs and why was the opv still seen venting after 24hrs with the lungs still +ve and floating up ?

+ve pressure in cls means they simply cant flood no matter what orientation.

I suggest its far more likely the dsv was knocked open by accident causing the flood.

Had to look up: Monday morning quarterback. Then I checked: Derogative. Since that word some how sprung to my mind. Though about posting some reply but it sort of made me loose interest in this thread.

Anyway, good analysis. I agree with your alternative view of what could have happened.

Jerry · 20th May 2008, 12:10

Believe what you wish. The rig was inspected by several very experienced Meg divers; I stood back to listen and learn as I don't dive a Meg. The people that recovered and inspected the unit wish to remain anonymous but I will go so far as to say Leon trusts their abilities.

I find it amazing that you can diagnose the problem from the other side of the world without ever seeing the unit.

Jerry

Drmike · 20th May 2008, 12:32

Quote: (Originally Posted by Jerry)

Believe what you wish. The rig was inspected by several very experienced Meg divers; I stood back to listen and learn as I don't dive a Meg. The people that recovered and inspected the unit wish to remain anonymous but I will go so far as to say Leon trusts their abilities.

Its not about believing what I wish or having any bias. Its about thinking for oneself. Im sure whoever examined the unit is well qualified, thats not under debate. Im just asking if its physically possible? Ive done dozens of tests since reading this thread on CL and opv and I simply cant get any water in no matter what the orientation or no matter how bad the seal IF theres positive pressure in the CL (venting) I dont see why having an open mind and asking questions is a problem.

All I have done is ask questions and put up what I think is a logical argument backed up with my understanding of the physics involved, about why I am doubtful it could have happened this way. I took quite some time to write up my reasoning-I would have hoped, and think it more useful to have had some counter argument or highlight flaw in my logic-alas all I got was 'believe what you want'

Quote:

I find it amazing that you can diagnose the problem from the other side of the world without ever seeing the unit.

Jerry

Why are you so defensive? nobodyis attacking anyone. Where I am doesnt change the laws of nature. I havent stated as a fact this or that happened I dont know what happened-but based on my testing and understanding of physics what you have described is not possible. You can choose to argue my logic or you can choose to take offense at my having the ordacity to think for myself and ask questions - looks like you have made your choice, and Im sorry for that.

Im not trying to upset anyone or critisise anyone, theres no call for you to be defensive or take any of my questions personally - Im just debating if what your saying happened is actually physically possible - whats wrong with that?

Jerry · 20th May 2008, 14:37

Defensive No. Sick to death of people that were not at the site, haven't seen the rig, and don't have all the facts telling us we are wrong; yes.

I spoke with Lamar about why reports weren't published anymore because I also was curious. Besides pending lawsuits; it is this very thing. You post a report for peoples edification and then every expert in the world comes out to tell you how you are wrong.

In every report there are many details that are left out even though they may have contributed to the problem because the public just doesn't need to know. You disagree, so what. You are arguing a point that doesn't matter. Mark made so many little errors whether or not he left the DSV open is immaterial; besides that we will never know.

You say you tested your valve and you have your equations. I have worked in the field as a geologist enough to know that mathmatical calculations and real world values are quite frequently divergent. Did you test Mark's OP? Did you test the same type OP valve as Mark's? If not your testing is meaningless.

Jerry

Drmike · 20th May 2008, 15:56

Quote: (Originally Posted by Jerry)

Defensive No. Sick to death of people that were not at the site, haven't seen the rig, and don't have all the facts telling us we are wrong; yes.

again not being at the site and not seeing the rig doesnt change physics. Is it reasonable to just ignore what sounds unlikely/impossible from a physics perspective just because one wasnt there? again I just put up my logic - if my logicis wrong then please show me as I and others do stage rbs and dive Bobs - so we do have a vested interest.

Quote:

I spoke with Lamar about why reports weren't published anymore because I also was curious. Besides pending lawsuits; it is this very thing. You post a report for peoples edification and then every expert in the world comes out to tell you how you are wrong.

I never said I was an expert, nor did I state anyone was wrong,nor am I critising anyone - there is no need for your anger. I do have a bit of an understanding of physics especially fluid dynamics, and I took the time to put up my logic - if its wrong then I welcome the correction. I did this as a debate, not as an attack. Debate should be to try to gain better insight through open discussion
But thats not happening is it - just show of needless anger

Quote:

In every report there are many details that are left out even though they may have contributed to the problem because the public just doesn't need to know.

sure but Im not looking at anything other than the physics of a venting opv the other mistakes dont change that which is why my knowledge of them is irelevant

Quote:

You disagree, so what. You are arguing a point that doesn't matter.

Im sorry but it does matter.

It matters to people who stage or will stage rbs. It matters if the mechanism for flooding are incorrectly stated as we need to learn as much as we can from deaths. It matters for people who are looking at their protocals for staging rbs in light of this death. Should they turn off gas, off electronics, does orientation matter, should opvs be trusted/removed if staging is often done or to be done in very silty caves where opv is likely to get cruded up, should the opv have a filter fitted to help keep crud out ? Should they (as I do) use a bungee or other method to secure dsv so its harder to accidentally knock it open when getting in or out of rig?

Quote:

Mark made so many little errors whether or not he left the DSV open is immaterial; besides that we will never know.

Its not immaterial. Deaths and accident analays serves only one purpose and that is to help make sure it doesnt happen again - to learn what ever there is to learn. Ergo we should ensure we attribute as correcty as we can given what little we know, the cause. Frankly its a waste not to -its a legacy people we lose leave us

Quote:

You say you tested your valve and you have your equations. I have worked in the field as a geologist enough to know that mathmatical calculations and real world values are quite frequently divergent. Did you test Mark's OP? Did you test the same type OP valve as Mark's? If not your testing is meaningless.

Jerry

Jerry the design of the opv makes no difference - its simple physics, field work or my equations will never change physics. Ill try to explain it as simply as I can:

Physics dictates that volumes cant transfer from low pressure to high pressure regions and can in fact only move the other way - from high to low pressure regions. This is how pressures balance.

In other words so long as CL pressure is above ambient water pressure water can not enter the CL.

So its not possible that water can enter through the opv as 'it belches out O2' (as was suggested as the likely reason in the report) Its simply physically impossible

The design of the opv will have no influence on the above basic law of physics nor will orientation of the unit/opv nor will condition of opv.

Physics dictates that the only way water can transfer into the CL is if the CL pressure is same or lower than water pressure.

If you disagree with the above I would be interested to hear your logic.

Earlier I believed that the opv may have been cruded up and once it had vented all the o2 it could have kept leaking out the gas until CL was same pressure as water - at that point it would start to flood. I assumed that was likely what happened until you later stated that 24hrs later the cls were full (of gas) and floating up and still venting gas....that suggests the CL pressure is higher than water - so again water could not enter. Are you sure the lungs were 'full' of gas and not just at ambient pressure?

Its not a case of quarterbacking or trying to be an expert. Its a genuine interest in undestanding what ever can be understood from accidents. Of course I wasnt there and its hard to be sure of anything.....but when something that is physically impossible is suggested - it would be wrong not to ask no?

anyway this is going nowhere so ill sign off on this discussion and you can go away missunderstanding my motivation and intent.

**UWSojourner** · 20th May 2008, 16:16

Quote: (Originally Posted by Jerry)

Defensive No. Sick to death of people that were not at the site, haven't seen the rig, and don't have all the facts telling us we are wrong; yes.

I spoke with Lamar about why reports weren't published anymore because I also was curious. Besides pending lawsuits; it is this very thing. You post a report for peoples edification and then every expert in the world comes out to tell you how you are wrong.

In every report there are many details that are left out even though they may have contributed to the problem because the public just doesn't need to know. You disagree, so what. You are arguing a point that doesn't matter. Mark made so many little errors whether or not he left the DSV open is immaterial; besides that we will never know.

You say you tested your valve and you have your equations. I have worked in the field as a geologist enough to know that mathmatical calculations and real world values are quite frequently divergent. Did you test Mark's OP? Did you test the same type OP valve as Mark's? If not your testing is meaningless.

Jerry

Hi Jerry,

Just some observations. The report itself doesn't claim to have the only possible scenario for the sequence of events leading to this death.

The report used language (appropriately) to communicate this uncertainty. "We aren't sure of the sequence of events", "There are some questions that can't be answered". The writers of the report can't be told they are wrong if they never claimed to have been definitively right. My reading of the report was that they offered one scenario of "... a few [that] are consistent with the evidence we evaluated."

In the end I'm sure most everyone agrees that "this was not a rebreather fatality but one of very bad choices." For every alternate theory proposed here and elsewhere on how the flood might have occurred (that still basically fits the data presented by your group), an appropriate response might be "could be". For alternate theories that don't line-up with the data, you could just point to the evidence.

I appreciate the groups efforts to communicate as much as possible and offer a reasonable scenario for what might have transpired. It is inevitable that others, who are also very knowledgable, might try to expand on the other few scenarios that are consistent with the evidence.

Cheers.

Drmike · 20th May 2008, 16:37

Jerry quick question if you dont mind from the Devil incarnate; when the unit was inspected after recovery was there crud in the opv and was it able to seal?

20th May 2008, 04:24	#41 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,328	Re: Report from Fatality at Devil’s Ear Quote: (Originally Posted by Jerry) Here's a scenario for the Monday Morning quarterbacks; its not about being a monday morning quarterback . Its about trying to understand what could have happened better so as to hopefuly make sure nobody else ever comes back to a flooded staged Rebreather. I would have thought that makes the discussion worthwhile. I dont see anyone saying 'this is what happened' - just debating the physics. What people are debating here is if physics would allow a normally functioning opv to leak and flood a static Rebreather regardless of orientation- the answer to that question (according to the physics presented so far ) is no. Having established that, the discussion may encourage people to be more vigilant over opv cleaning and checking...which in turn may save a life. Quote: a rig passes the predive checks (pos/neg tests); it is found on the deceased nearly 24 hrs later, scubber down; onboard oxygen to solenoid empty; CLs full of gas and floating upward placing the OPV at the highest point; the OPV is witnessed venting; the DSV is closed; where did the water filling the scrubber come from??? from the diver knocking open the dsv when trying to put his unit back on in zero viz cave. That could explain the flood, the water on cells, the continuous o2 injection, the fact that 24hrs later the lungs were still +ve and floating. If as you say 24hrs later lungs were full of gas, floating high and +ve then you are suggesting the leak was bad enough to flood a unit bad enough so a diver cant use it after just 1hr, yet 23hrs later the lungs are still +ve and floating up?? That doesnt make sense to me. I think the whole diagnosis is quite wrong. Based on the full venting and floating lungs witnessed 24hrs later Id suggest its far more likely that the diver flooded the unit by mistake opening the dsv and that fits exactly with the way the unit was found 24hrs later. Bottom line is if it flooded in 1 hr due to a leaking OPV why wasnt the unit completely flooded after 24hrs and why was the opv still seen venting after 24hrs with the lungs still +ve and floating up ? +ve pressure in cls means they simply cant flood no matter what orientation. I suggest its far more likely the dsv was knocked open by accident causing the flood. __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment Last edited by Drmike : 20th May 2008 at 04:28.
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20th May 2008, 04:33	#42 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,328	Re: Report from Fatality at Devil’s Ear Quote: (Originally Posted by Jerry) . If he did try the loop and then managed to RECLOSE the DSV in the midst of probable near panic, it would stand to reason that he very probably had it closed while away from it. Its instinctive/muscle memory to close the dsv when coming off the loop for whatever reason. He could easily have knocked open the dsv when taking the unit off or putting it back on. Ive done this myself when trying to get into boris. I now have a piece of bungee that loops over the opening handle to the mouthbite to keep it closed (use this on my bob too) The inspo or turning type of dsv are less prone to this but the meg, mk15 and especially the boris dsv is easily knocked open. (boris is very easy to knock open with its long handle and easy operation) __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment
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20th May 2008, 08:45	#43 (permalink)
*Beanie* Gallery Administrator Current Rebreather/s: Inspiration Classic Other Rebreather/s: Inspiration Vision Join Date: Jan 2005 Location: In da house! yeah baby! Posts: 3,186	Re: Report from Fatality at Devil’s Ear Quote: (Originally Posted by Drmike) its not about being a monday morning quarterback . Its about trying to understand what could have happened better so as to hopefuly make sure nobody else ever comes back to a flooded staged Rebreather. I would have thought that makes the discussion worthwhile. I dont see anyone saying 'this is what happened' - just debating the physics. What people are debating here is if physics would allow a normally functioning opv to leak and flood a static Rebreather regardless of orientation- the answer to that question (according to the physics presented so far ) is no. Having established that, the discussion may encourage people to be more vigilant over opv cleaning and checking...which in turn may save a life. from the diver knocking open the dsv when trying to put his unit back on in zero viz cave. That could explain the flood, the water on cells, the continuous o2 injection, the fact that 24hrs later the lungs were still +ve and floating. If as you say 24hrs later lungs were full of gas, floating high and +ve then you are suggesting the leak was bad enough to flood a unit bad enough so a diver cant use it after just 1hr, yet 23hrs later the lungs are still +ve and floating up?? That doesnt make sense to me. I think the whole diagnosis is quite wrong. Based on the full venting and floating lungs witnessed 24hrs later Id suggest its far more likely that the diver flooded the unit by mistake opening the dsv and that fits exactly with the way the unit was found 24hrs later. Bottom line is if it flooded in 1 hr due to a leaking OPV why wasnt the unit completely flooded after 24hrs and why was the opv still seen venting after 24hrs with the lungs still +ve and floating up ? +ve pressure in cls means they simply cant flood no matter what orientation. I suggest its far more likely the dsv was knocked open by accident causing the flood. Those are my thoughts problem with this is that noone knows what happened down there so its all guessing. __________________ Beanie Gallery Admin & Library Assistant. www.outlawdivers.org.uk www.beandiving.co.uk www.beanengineering.co.uk
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20th May 2008, 09:28	#44 (permalink)
jaap Normal people worry me Current Rebreather/s: Classic Kiss Other CCR RB80 / Clone Ray Other SCR Home Build Other Rebreather/s: Other CCR RB80 / Clone Ray Other SCR Home Build Join Date: Jun 2005 Location: Stockholm Sweden Posts: 455	Re: Report from Fatality at Devil’s Ear Quote: (Originally Posted by Drmike) its not about being a monday morning quarterback . Its about trying to understand what could have happened better so as to hopefuly make sure nobody else ever comes back to a flooded staged Rebreather. I would have thought that makes the discussion worthwhile. I dont see anyone saying 'this is what happened' - just debating the physics. What people are debating here is if physics would allow a normally functioning opv to leak and flood a static Rebreather regardless of orientation- the answer to that question (according to the physics presented so far ) is no. Having established that, the discussion may encourage people to be more vigilant over opv cleaning and checking...which in turn may save a life. from the diver knocking open the dsv when trying to put his unit back on in zero viz cave. That could explain the flood, the water on cells, the continuous o2 injection, the fact that 24hrs later the lungs were still +ve and floating. If as you say 24hrs later lungs were full of gas, floating high and +ve then you are suggesting the leak was bad enough to flood a unit bad enough so a diver cant use it after just 1hr, yet 23hrs later the lungs are still +ve and floating up?? That doesnt make sense to me. I think the whole diagnosis is quite wrong. Based on the full venting and floating lungs witnessed 24hrs later Id suggest its far more likely that the diver flooded the unit by mistake opening the dsv and that fits exactly with the way the unit was found 24hrs later. Bottom line is if it flooded in 1 hr due to a leaking OPV why wasnt the unit completely flooded after 24hrs and why was the opv still seen venting after 24hrs with the lungs still +ve and floating up ? +ve pressure in cls means they simply cant flood no matter what orientation. I suggest its far more likely the dsv was knocked open by accident causing the flood. Had to look up: Monday morning quarterback. Then I checked: Derogative. Since that word some how sprung to my mind. Though about posting some reply but it sort of made me loose interest in this thread. Anyway, good analysis. I agree with your alternative view of what could have happened. __________________ My initials: JAAP Last edited by jaap : 20th May 2008 at 09:35.
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20th May 2008, 12:10	#45 (permalink)
Jerry New Member Current Rebreather/s: Optima Other Rebreather/s: Join Date: Jul 2005 Location: USA Posts: 23	Re: Report from Fatality at Devil’s Ear Believe what you wish. The rig was inspected by several very experienced Meg divers; I stood back to listen and learn as I don't dive a Meg. The people that recovered and inspected the unit wish to remain anonymous but I will go so far as to say Leon trusts their abilities. I find it amazing that you can diagnose the problem from the other side of the world without ever seeing the unit. Jerry
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20th May 2008, 12:32	#46 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,328	Re: Report from Fatality at Devil’s Ear Quote: (Originally Posted by Jerry) Believe what you wish. The rig was inspected by several very experienced Meg divers; I stood back to listen and learn as I don't dive a Meg. The people that recovered and inspected the unit wish to remain anonymous but I will go so far as to say Leon trusts their abilities. Its not about believing what I wish or having any bias. Its about thinking for oneself. Im sure whoever examined the unit is well qualified, thats not under debate. Im just asking if its physically possible? Ive done dozens of tests since reading this thread on CL and opv and I simply cant get any water in no matter what the orientation or no matter how bad the seal IF theres positive pressure in the CL (venting) I dont see why having an open mind and asking questions is a problem. All I have done is ask questions and put up what I think is a logical argument backed up with my understanding of the physics involved, about why I am doubtful it could have happened this way. I took quite some time to write up my reasoning-I would have hoped, and think it more useful to have had some counter argument or highlight flaw in my logic-alas all I got was 'believe what you want' Quote: I find it amazing that you can diagnose the problem from the other side of the world without ever seeing the unit. Jerry Why are you so defensive? nobodyis attacking anyone. Where I am doesnt change the laws of nature. I havent stated as a fact this or that happened I dont know what happened-but based on my testing and understanding of physics what you have described is not possible. You can choose to argue my logic or you can choose to take offense at my having the ordacity to think for myself and ask questions - looks like you have made your choice, and Im sorry for that. Im not trying to upset anyone or critisise anyone, theres no call for you to be defensive or take any of my questions personally - Im just debating if what your saying happened is actually physically possible - whats wrong with that? __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment Last edited by Drmike : 20th May 2008 at 12:42.
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20th May 2008, 14:37	#47 (permalink)
Jerry New Member Current Rebreather/s: Optima Other Rebreather/s: Join Date: Jul 2005 Location: USA Posts: 23	Re: Report from Fatality at Devil’s Ear Defensive No. Sick to death of people that were not at the site, haven't seen the rig, and don't have all the facts telling us we are wrong; yes. I spoke with Lamar about why reports weren't published anymore because I also was curious. Besides pending lawsuits; it is this very thing. You post a report for peoples edification and then every expert in the world comes out to tell you how you are wrong. In every report there are many details that are left out even though they may have contributed to the problem because the public just doesn't need to know. You disagree, so what. You are arguing a point that doesn't matter. Mark made so many little errors whether or not he left the DSV open is immaterial; besides that we will never know. You say you tested your valve and you have your equations. I have worked in the field as a geologist enough to know that mathmatical calculations and real world values are quite frequently divergent. Did you test Mark's OP? Did you test the same type OP valve as Mark's? If not your testing is meaningless. Jerry
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20th May 2008, 15:56	#48 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,328	Re: Report from Fatality at Devil’s Ear Quote: (Originally Posted by Jerry) Defensive No. Sick to death of people that were not at the site, haven't seen the rig, and don't have all the facts telling us we are wrong; yes. again not being at the site and not seeing the rig doesnt change physics. Is it reasonable to just ignore what sounds unlikely/impossible from a physics perspective just because one wasnt there? again I just put up my logic - if my logicis wrong then please show me as I and others do stage rbs and dive Bobs - so we do have a vested interest. Quote: I spoke with Lamar about why reports weren't published anymore because I also was curious. Besides pending lawsuits; it is this very thing. You post a report for peoples edification and then every expert in the world comes out to tell you how you are wrong. I never said I was an expert, nor did I state anyone was wrong,nor am I critising anyone - there is no need for your anger. I do have a bit of an understanding of physics especially fluid dynamics, and I took the time to put up my logic - if its wrong then I welcome the correction. I did this as a debate, not as an attack. Debate should be to try to gain better insight through open discussion But thats not happening is it - just show of needless anger Quote: In every report there are many details that are left out even though they may have contributed to the problem because the public just doesn't need to know. sure but Im not looking at anything other than the physics of a venting opv the other mistakes dont change that which is why my knowledge of them is irelevant Quote: You disagree, so what. You are arguing a point that doesn't matter. Im sorry but it does matter. It matters to people who stage or will stage rbs. It matters if the mechanism for flooding are incorrectly stated as we need to learn as much as we can from deaths. It matters for people who are looking at their protocals for staging rbs in light of this death. Should they turn off gas, off electronics, does orientation matter, should opvs be trusted/removed if staging is often done or to be done in very silty caves where opv is likely to get cruded up, should the opv have a filter fitted to help keep crud out ? Should they (as I do) use a bungee or other method to secure dsv so its harder to accidentally knock it open when getting in or out of rig? Quote: Mark made so many little errors whether or not he left the DSV open is immaterial; besides that we will never know. Its not immaterial. Deaths and accident analays serves only one purpose and that is to help make sure it doesnt happen again - to learn what ever there is to learn. Ergo we should ensure we attribute as correcty as we can given what little we know, the cause. Frankly its a waste not to -its a legacy people we lose leave us Quote: You say you tested your valve and you have your equations. I have worked in the field as a geologist enough to know that mathmatical calculations and real world values are quite frequently divergent. Did you test Mark's OP? Did you test the same type OP valve as Mark's? If not your testing is meaningless. Jerry Jerry the design of the opv makes no difference - its simple physics, field work or my equations will never change physics. Ill try to explain it as simply as I can: Physics dictates that volumes cant transfer from low pressure to high pressure regions and can in fact only move the other way - from high to low pressure regions. This is how pressures balance. In other words so long as CL pressure is above ambient water pressure water can not enter the CL. So its not possible that water can enter through the opv as 'it belches out O2' (as was suggested as the likely reason in the report) Its simply physically impossible The design of the opv will have no influence on the above basic law of physics nor will orientation of the unit/opv nor will condition of opv. Physics dictates that the only way water can transfer into the CL is if the CL pressure is same or lower than water pressure. If you disagree with the above I would be interested to hear your logic. Earlier I believed that the opv may have been cruded up and once it had vented all the o2 it could have kept leaking out the gas until CL was same pressure as water - at that point it would start to flood. I assumed that was likely what happened until you later stated that 24hrs later the cls were full (of gas) and floating up and still venting gas....that suggests the CL pressure is higher than water - so again water could not enter. Are you sure the lungs were 'full' of gas and not just at ambient pressure? Its not a case of quarterbacking or trying to be an expert. Its a genuine interest in undestanding what ever can be understood from accidents. Of course I wasnt there and its hard to be sure of anything.....but when something that is physically impossible is suggested - it would be wrong not to ask no? anyway this is going nowhere so ill sign off on this discussion and you can go away missunderstanding my motivation and intent. __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment Last edited by Drmike : 20th May 2008 at 16:18.
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20th May 2008, 16:16	#49 (permalink)
UWSojourner Pacific Northwest Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Feb 2005 Location: Portland Oregon Posts: 556	Re: Report from Fatality at Devil’s Ear Quote: (Originally Posted by Jerry) Defensive No. Sick to death of people that were not at the site, haven't seen the rig, and don't have all the facts telling us we are wrong; yes. I spoke with Lamar about why reports weren't published anymore because I also was curious. Besides pending lawsuits; it is this very thing. You post a report for peoples edification and then every expert in the world comes out to tell you how you are wrong. In every report there are many details that are left out even though they may have contributed to the problem because the public just doesn't need to know. You disagree, so what. You are arguing a point that doesn't matter. Mark made so many little errors whether or not he left the DSV open is immaterial; besides that we will never know. You say you tested your valve and you have your equations. I have worked in the field as a geologist enough to know that mathmatical calculations and real world values are quite frequently divergent. Did you test Mark's OP? Did you test the same type OP valve as Mark's? If not your testing is meaningless. Jerry Hi Jerry, Just some observations. The report itself doesn't claim to have the only possible scenario for the sequence of events leading to this death. The report used language (appropriately) to communicate this uncertainty. "We aren't sure of the sequence of events", "There are some questions that can't be answered". The writers of the report can't be told they are wrong if they never claimed to have been definitively right. My reading of the report was that they offered one scenario of "... a few [that] are consistent with the evidence we evaluated." In the end I'm sure most everyone agrees that "this was not a rebreather fatality but one of very bad choices." For every alternate theory proposed here and elsewhere on how the flood might have occurred (that still basically fits the data presented by your group), an appropriate response might be "could be". For alternate theories that don't line-up with the data, you could just point to the evidence. I appreciate the groups efforts to communicate as much as possible and offer a reasonable scenario for what might have transpired. It is inevitable that others, who are also very knowledgable, might try to expand on the other few scenarios that are consistent with the evidence. Cheers.
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20th May 2008, 16:37	#50 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,328	Re: Report from Fatality at Devil’s Ear Jerry quick question if you dont mind from the Devil incarnate; when the unit was inspected after recovery was there crud in the opv and was it able to seal? __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment
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