Need to work on your ladies grip then. Its easy to stop gas flow by folding a hose.
You look and find the loop hypoxic....
Need to work on your ladies grip then. Its easy to stop gas flow by folding a hose.
Mr fish
Active Member
Yes your right , but I didn't want to stop all the flow and pop the hose some place behind me and end up with nothing to breath ,
Next time I'll put a kink in it , lol
To be fair gobbers, this was a major failing. Having discovered his backup system wasnt compromised, he should've restored it to full operation before continuing. Thats the problem with that thread, its focusing WAY too much on the technology and not enough on the procedures.
If you need a one size fits all solution, its the good old bailout. As I said before, it wouldnt be my first choice in the scenario being described.
Mr fish
Active Member
E
Procedure
Yes he only put the problem off he never fixed it , then added to his problems , put,s himself under some stress and that was that ,
Im with the procedure thing , and that's what gets my hump up in this thread
Foolking low ppo2 , like it just jumps out of no where ,
If I follow my procedure the only place I'm ever going to see a low sp is at bottom over time
6m I'm full of O2 , on the way down my dill is good and getting better as I hit bottom
So I'm now at risk if I dont keep a eye on the numbers , all good bottom time over ,
I'm heading up sp 1.3 im topping over that with the green button to 1.4 ish in looking often at the depth time stops and in all that info is my ppo2 , so it s hard to miss a problem . Back to 6m job done back on O2 safe known gas
Not hard is it ,
Unless you have a kink in your hose
Or your trained to pump in a shit gas like air in your breather as you swim to the shot , Fooking madness
Procedure
Yes he only put the problem off he never fixed it , then added to his problems , put,s himself under some stress and that was that ,
Im with the procedure thing , and that's what gets my hump up in this thread
Foolking low ppo2 , like it just jumps out of no where ,
If I follow my procedure the only place I'm ever going to see a low sp is at bottom over time
6m I'm full of O2 , on the way down my dill is good and getting better as I hit bottom
So I'm now at risk if I dont keep a eye on the numbers , all good bottom time over ,
I'm heading up sp 1.3 im topping over that with the green button to 1.4 ish in looking often at the depth time stops and in all that info is my ppo2 , so it s hard to miss a problem . Back to 6m job done back on O2 safe known gas
Not hard is it ,
Unless you have a kink in your hose
Or your trained to pump in a shit gas like air in your breather as you swim to the shot , Fooking madness
Last edited:
DSix36
Well-Known Member
If you have po2 that is seriously low (as in life threatening) and you should be unconscious already, like say maybe .12, why f**k around with trying to get a BO reg shoved in your head to breathe when a simple dil button will be the fastest? I have not yet heard any argument against this training procedure that has any merit.
Mr. Fish has some good measures to use if trying to mitigate the issue and time is not the utmost concern. I still think the training agencies have a lot more time and energy invested in developing the proper (and safest) course of action in this scenario. But then again, why did it EVER get that low in the first place, might be a more relevant concern.
Mr. Fish has some good measures to use if trying to mitigate the issue and time is not the utmost concern. I still think the training agencies have a lot more time and energy invested in developing the proper (and safest) course of action in this scenario. But then again, why did it EVER get that low in the first place, might be a more relevant concern.
No dil button? (classic kiss - hey..... if people want a protocol thats unit agnostic....)
don said:
Yup, this in spades. However, a good friend of mine did a dive that I refused to do..... he entered a cave when the water surface was absolutely boiling from outflow. about 5 mins later he got spat out in a mess, with a PO2 about 0.1 Hes a good diver, shit happens, i think even he'd admit now that it was caused by a poor initial choice. The "incident pit" is often a series of small mistakes that add up under stress to bite your arse. You may note the correct spelling of arse here......
Last edited:
And if you pass out while your on the button, what then? Keep breathing the bad gas? If the loop is compromized, and it is at .12, you get off it and onto breathable gas. You can ventilate bad gas from your lungs much faster breathing from a reg then breathing from the Diluent button and venting through your nose.
This is why I feel a BOV is essential equipment as its one motion to get on breathsble gas for you AND your buddy.
Cam
Last edited:
DSix36
Well-Known Member
I am not trying to argue either for or against a BOV. That is a topic for its own thread. My posts are directed at the units that I was trained on and my training on them. Non of them had BOV's as standard equipment.
To answer our question as it pertains to my previous posts. If you pass out while on the button, then your arse is going to drown and it was going to happen even if you tired to bailout to an OC source. The dil flush has been proven to be faster and thus the best option. In a hypoxic event such as we are discussing, it would only take the initial breathe to raise your lung content of O2. Now what is getting to your brain and if it will be in time is another story, but it would not be any faster with OC, in fact it would be a bit longer.
I realize that in most instances my thinking about this is really splitting hairs, but the difference in a nano second could very well make the difference in blacking out and thus drowning, or living to tell the tale.
GLOC
real name: Gareth Lock!
Here are the papers I have. There is also a MSc thesis by Elizabeth Humm in the Cranfield library from 2010
http://www.hse.gov.uk/research/rrpdf/rr436.pdf - Formal risk identification in professional SCUBA (FRIPS)
- This report describes how fault tree analysis and failure modes and effects criticality analysis (FMECA) can be carried out on activities and hardware typical of a professional SCUBA diving activity. The methodologies are described and conclusions drawn from each technique. Examples are given of how the techniques can be used to assess diver risk in a quantitative way to aid assessing equipment configurations.
https://www.shearwater.com/wp-content/uploads/2012/08/Underwater_Technology_Paper.pdf - The use of fault tree analysis to visualise the importance of human factors for safe diving with closed-circuit rebreathers (CCR)
- Closed-circuit rebreathers (CCR) have been used for many years in military diving but have only recently been adopted by technical leisure divers, media and scientific divers. Rebreather divers appreciate the value of training, pre-dive checks and equipment maintenance but it is often difficult to visualise just how important these factors are and how they inter-relate for a rebreather. In this paper, the well-known tech- nique of fault tree analysis (FTA) is used to identify risk in a rebreather. Due to space constraints, only the branch of the tree for unconsciousness as a result of hyperoxia is considered in detail but, in common with the whole tree, end events are shown to be human- factor related. The importance of training to the emer- gency situation, the use of formal pre-dive checklists and the value of good design to prevent accident escalation are discussed further.
http://www.hse.gov.uk/research/rrhtm/rr871.htm - RR871 - Assessment of manual operations and emergency procedures for closed circuit rebreathers
- Closed Circuit Re-breather (CCR) diving has become increasingly popular as more sophisticated units enable diving for longer and at greater depths. CCR diving is much more complex than traditional open circuit diving in many ways and there is an increased potential for problems and diver errors to emerge. However, formal research examining CCR safety has been rare. To address this, the UK Health and Safety Executive commissioned the Department of Systems Engineering and Human Factors at Cranfield University to conduct a scoping study into the human factors issues relevant to CCR diving apparatus. The scoping study was designed to explore five principal subject areas: accident / incident analysis, unit assembly / disassembly, normal / non-normal diving operations, training needs analysis, interface and display. This scoping study has approached this with a series of studies each addressing separate issues that are relevant to the principal subject areas. These studies can be seen as potentially stand alone, each with its own objectives, method and results. These studies comprise; Accident / Incident Analysis; Human Error Potential Analysis: Assembly and Disassembly; Human Error Potential Analysis of Diving Operations; Training Needs Analysis; Interface and Display Recommendations and Human Error Potential in Non-Normal Operations.
http://www.dhmjournal.com/files/Fock-Rebreather_deaths.pdf - Analysis of recreational closed-circuit rebreather deaths 1998--2010
-There is a probability failure tree for failure modes of both OC and CCR within this paper.
Regards
Let's work the other way. The risk with a hypoxic loop is that you may pass out but what kills you is drowning. Paul Hayes gave a great talk on this at Oztek. He said do you all agree that at some stage on a ccr you have a high risk of breathing an inappropriate gas? (including hypoxic) So you all agree there is also a reasonable risk of this inappropriate gas resulting in unconsciousness. And this results in a high chance of spitting the loop OR oc regulator and drowning. To give yourself the highest chance of survival you need to keep your breathing apparatus in your mouth. This means using a FFM or gag strap. Both of which have saved divers.
In line with this in a Hypoxic loop situation where there is a chance of me loosing consciousness, I am going for a dil flush as even if I pass out I still have a good chance of either my buddy rescuing me or waking back up and rescuing myself as I have a gag strap protecting my airway. If you are on an open circuit reg or Bov without gag strap and you spit it........the chances are very slim. Remember, its drowning that'll kill you. Not a hypoxic gas. In short, always use a Gag strap and dil flush is my response.
Sent from my HTC Desire using Tapatalk 2
In line with this in a Hypoxic loop situation where there is a chance of me loosing consciousness, I am going for a dil flush as even if I pass out I still have a good chance of either my buddy rescuing me or waking back up and rescuing myself as I have a gag strap protecting my airway. If you are on an open circuit reg or Bov without gag strap and you spit it........the chances are very slim. Remember, its drowning that'll kill you. Not a hypoxic gas. In short, always use a Gag strap and dil flush is my response.
Sent from my HTC Desire using Tapatalk 2
Remco
Member
http://www.golemgear.com/docs/Bailout.pdf
This is for me a good story of what you can do.
It surpises me that we have a lot of experianced CCR divers and even more ideas how to slove a problem.
That means we are al differant trained , ore ignore what we have learned.
This is for me a good story of what you can do.
It surpises me that we have a lot of experianced CCR divers and even more ideas how to slove a problem.
That means we are al differant trained , ore ignore what we have learned.
Mark Chase
ATB=AlwaysTalkingBollocks
The ADV on a KISS was behind my head on the top of the scrubber I had about as much chance of reaching it as I did of flying to the moon
leaning left or right made sod all diferance.
On my JJ I can get to my ADV but its not "to hand"
Droping my left sholder to get dill to inject does absolutly nothing on my unit as I have a harder ADV spring fitted after complaining I strugled to find minimum loop on tyhe protatype JJ i dived.
If you have a hypoxic loop you need to get above 0.16 ASAP and the easiest way to do this is inject pure 02 at depth into the loop or bailout.
IMHO with the exception of the Inspo (and other simila units) where the dill inject is so easy to get at and FAST you can purge the loop very quickly but in hind sight I am thinking even on an inspo its probably better to inject 02 first?
High PP02 wont kill you in the 20 seconds it takes to calm down and sort out your loop.
ATB
Mark
Mark Chase
ATB=AlwaysTalkingBollocks
A lot of people sugesting bailout as a first option?
With a BOV this makes sense but without a BOV bailouts are risky as the posabuility of flooding the loop accidentaly or cocking up the OC bit you havent done for the last 5 years is IMHO about as significant as the risks of injecting pure 02.
50/50 call IMHO not so black and white without a BOV.
ATB
Mark
With a BOV this makes sense but without a BOV bailouts are risky as the posabuility of flooding the loop accidentaly or cocking up the OC bit you havent done for the last 5 years is IMHO about as significant as the risks of injecting pure 02.
50/50 call IMHO not so black and white without a BOV.
ATB
Mark
matt
Well-Known Member
Could the casual bystander argue that the complexity of the setup, specifically the addition of the bailout, is to blame here? It was a confusion during the burst hose, it was out of service when needed. Perhaps the complexity of the setup and procedures around it are not at optimal as this thread suggests? Perhaps a stay-on-loop procedure would have worked better?
Matt.
matt
Well-Known Member
I lost the will to like will to live with the crazy rotation issue. Page 24 totally illegible for me, I assume this includes the tree for "5 - Toxic Gas", where the boxes are blank?
So Dead Diver -> Drowning -> Toxic Gas -> <something>
Maybe the <something> is useful, is there a working copy of this or id my PDF reader toxing, lol?
Matt.
Megangel1
Member
Just what are the things that could cause a .18 READING?
I can think of just two.
CCR software/hardware failures including o2 cell failures
or
Lack of user monitoring/intervention at an earlier stage
Anything else not fitting into one of the two above?
Most cases seem to me to come back to a lack of user awareness of their loop. The level of o2 should have been noticed way before this point!
The semantics of what remedy is best/quickest is secondary and probably personal/unit specific in many cases.
Get back to the golden rule of CCR
ALWAYS KNOW YOUR PPO2
Best cure is prevention.
I can think of just two.
CCR software/hardware failures including o2 cell failures
or
Lack of user monitoring/intervention at an earlier stage
Anything else not fitting into one of the two above?
Most cases seem to me to come back to a lack of user awareness of their loop. The level of o2 should have been noticed way before this point!
The semantics of what remedy is best/quickest is secondary and probably personal/unit specific in many cases.
Get back to the golden rule of CCR
ALWAYS KNOW YOUR PPO2
Best cure is prevention.
Megangel1
Member
Doesn't everyone regularly practice reaching for their bailout reg and actually swapping to bailout? Even for a couple of breaths? I can't remember ever doing a full bailout from depth other than on courses but do regularly practice swapping to bailout and back.
