Minimising Rebreather Deaths / Fatalities

CeeBee · 3rd January 2007, 08:20

Thank you, Stuart

Christine x

**Steve** · 3rd January 2007, 08:25

Quote: (Originally Posted by PCDiver)

Hi Stuart,

great article.

My comments:
Bailout via open loop as prefered method.
I doubt that open loop breathing, which has higher WOB than a BOV or normal regulator, can be used in case of a CO2 hit. In case of a CO2 hit you will initially overbreath even the best regulator. Any extra WOB is not wanted and will increase the problem. For me a BOV is the preferred solution.

Good point. Sadly most units don't ship with a BOV. It should be the first purchace after getting a CCR though IMO.

**RichClark** · 3rd January 2007, 08:55

Great article Stuart, KISS everytime!

Cheers

Rich

***ScubaDadMiami*** · 3rd January 2007, 15:49

Quote: (Originally Posted by PCDiver)

eCCR as a parachute only (flying it manually)
Flying an eCCR manualy has a higher task load than mCCR. Manualy operating the eCCR certainly needs to be practiced as a skill in case something happens to the solenoid, but as SOP?

I fly manually most of the time. You bump up the PPO2 to 1.1, wait for it to go back to 1.0 (or even .9), hit the manual O2 add back up to 1.1. Very easy to do and makes sure you are regularly checking status. As the "back up," you either create a custom set point (such as .9) or just go with something on the unit like .7.

You can go with a wider spread if you will be busy for part of the time. This will not involve as many manual adds. However, part of the reason I purposely keep the spread within a narrower range is to make sure that I am cross checking frequently.

It's really not a big deal once you get used to doing it.

**jepuskar** · 3rd January 2007, 15:58

Miami,

How are often are you adding O2 at depth using your method?

Thanks,

Jason

***schford*** · 3rd January 2007, 16:14

Quote: (Originally Posted by PCDiver)

Hi Stuart,

great article.

My comments:
Bailout via open loop as prefered method.
I doubt that open loop breathing, which has higher WOB than a BOV or normal regulator, can be used in case of a CO2 hit. In case of a CO2 hit you will initially overbreath even the best regulator. Any extra WOB is not wanted and will increase the problem. For me a BOV is the preferred solution.

That was an example from my scenarios - as I do not have a BOV then Open Loop for me is the method I would use to hopefully get my respiration under control before going for my bailout reg with a CO2 hit and being forced into taking a mouthful of water. Those scenarios are specific to me and my unit and I know that individuals will vary.

Quote: (Originally Posted by PCDiver)

eCCR as a parachute only (flying it manually)
Flying an eCCR manualy has a higher task load than mCCR. Manualy operating the eCCR certainly needs to be practiced as a skill in case something happens to the solenoid, but as SOP?

You don't have the continous flow that you get with a mCCR. Therefore, there wil bel more deviations from the setpoint, since more manual interventions are required. So, if you are diving without integrated deco computer, how valid will your deco profile be?

I bought rebreathers for deep filming. In my case, manual operation is almost impossible. I have only two hands and both of those are on my camera. But even without camera, I run my Vision on automatic (except during long deco stops). It allows me to enjoy my dive more.

Peter

Electronics go wrong - in my research I did not find a single fatality where someone was flying the unit manually. I do realeaise it is an individual choice though.

I do find though that it does not increase my task loading and becomes very instinctive and I have never had more than a minute or twos deviation between my plumbed in deco and my offboard deco. If you are worried though set your electronics to maintain 1.2 and your off board deco to calculate on 1.2 and if you fly at 1.3 you gain a slight deco advantage.

Quote: (Originally Posted by AD_ward9)

Your article is excellent! Especially, highlighting do not head for the surface if you have a problem. Bail out first.

This is such a good synopsis, I must ask, do you have any objection to companies incorporating it verbatim in their manuals? E.g. declaring it as being under GNU type copyright release.

Alex

Not at all Alex - thanks for your feedback.

bgpartri · 3rd January 2007, 16:30

Excellent Stuart.

There are areas that one could quibble with, but if everyone followed those rules, deaths would plummet.

Bruce

Jim · 3rd January 2007, 16:37

I must confess moving from Inspo to Meg the thought of running manually was my area of concern .....

It was surprisingly easy and I now wouldn't do anything else - I usually hold setpoint at 1.3 with the unit firing at 1.2 as back up - works very well and the solenoid is a very good alarm if you are not use to it every couple of minutes - and of course it is very reliable if you have your hands full !

I have the option of using the Meg's electronics to maintain setpoint but do like the lekkies backing me up rather than the other way round. Complacency or distraction was my biggest concern on my Inspo at the potential wrong time, I can confess to not looking at those hand sets as often as I should have on occasions. Could've been fatal given the wrong circumstances?!

Having said that, on the Meg (APECS II) I do need to change that setpoint on the way down to back me up & it is always part of my buddy check before swimming away from the shot .... I wouldn't want to forget - just in case!!

Pros and cons to both I suppose?

Cheers.

bgpartri · 3rd January 2007, 16:49

Quote: (Originally Posted by Jim)

I must confess moving from Inspo to Meg the thought of running manually was my area of concern .....

.....

Pros and cons to both I suppose?

Cheers.

My solution is probably going to be to put an orifice on my Meg. After diving the KISS and realizing how easy it is to maintain setpoint with an orifice, I think I'll add one.

It will go on just before the solenoid so that the solenoid would still kick in if a great white bites my camera. Of course the pre-dive needs to test both systems.

The disadvantage is the MOD with the blocked IP, but I never go deeper than 300 any more anyway.

Bruce

Crazyduck · 3rd January 2007, 17:03

Bruce,
Excellent idea….
It was crossed my mind that this could be the best of both worlds.
Plus, hypothetically it would slow the battery drain for firing the solenoid in the first place.

Would you keep the solenoid on the same 1st stage as the orifice or just use a slide shut off for potential solenoid runaways/failures?

300ft is a long way down- I am not too worried about that.
Great Whites- not to worry about in the Gulf of Mexico- just large tiger sharks.

Regards, Andrew

3rd January 2007, 08:20	#11 (permalink)
CeeBee Found pills and ate them. Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Sep 2006 Location: Liverpool Posts: 1,019	Re: Minimising Rebreather Deaths / Fatalities Thank you, Stuart Christine x __________________ "In Ceebs We Trust. All others pay cash." Denz 1973-2007 King of the One-Liners www.justgiving.com/markginsberg1
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3rd January 2007, 08:25	#12 (permalink)
Steve Ladies bring a plate Current Rebreather/s: Megalodon Home Build Other Rebreather/s: Not Bought Yet Inspiration Classic Sport Kiss Classic Kiss MK 15.X Home Build Join Date: Feb 2005 Location: Perth - Australia Posts: 1,119	Re: Minimising Rebreather Deaths / Fatalities Quote: (Originally Posted by PCDiver) Hi Stuart, great article. My comments: Bailout via open loop as prefered method. I doubt that open loop breathing, which has higher WOB than a BOV or normal regulator, can be used in case of a CO2 hit. In case of a CO2 hit you will initially overbreath even the best regulator. Any extra WOB is not wanted and will increase the problem. For me a BOV is the preferred solution. Good point. Sadly most units don't ship with a BOV. It should be the first purchace after getting a CCR though IMO. __________________ WARNING: I contain occasional coarse language, extreme sexual references, nudity, and adult themes, which may offend some people - Usually churchy types.
(Online)

3rd January 2007, 08:55	#13 (permalink)
RichClark Classic KISS No. 226 Current Rebreather/s: Classic Kiss Other Rebreather/s: Join Date: Mar 2005 Location: Hove, UK Posts: 779	Re: Minimising Rebreather Deaths / Fatalities Great article Stuart, KISS everytime! Cheers Rich __________________ The more I learn about women, the more I want to go diving... just don't tell my wife I said that To taste something a little different, try http://www.thechillikitchen.co.uk
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3rd January 2007, 15:49	#14 (permalink)
*ScubaDadMiami* Moderator Current Rebreather/s: Optima Other Rebreather/s: Join Date: Sep 2005 Location: Florida, USA Posts: 2,141	Re: Minimising Rebreather Deaths / Fatalities Quote: (Originally Posted by PCDiver) eCCR as a parachute only (flying it manually) Flying an eCCR manualy has a higher task load than mCCR. Manualy operating the eCCR certainly needs to be practiced as a skill in case something happens to the solenoid, but as SOP? I fly manually most of the time. You bump up the PPO2 to 1.1, wait for it to go back to 1.0 (or even .9), hit the manual O2 add back up to 1.1. Very easy to do and makes sure you are regularly checking status. As the "back up," you either create a custom set point (such as .9) or just go with something on the unit like .7. You can go with a wider spread if you will be busy for part of the time. This will not involve as many manual adds. However, part of the reason I purposely keep the spread within a narrower range is to make sure that I am cross checking frequently. It's really not a big deal once you get used to doing it. __________________ Howard Packer IANTD CCR Instructor Miami Beach, Florida CCRDiveTraining.com
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3rd January 2007, 15:58	#15 (permalink)
jepuskar NA Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Aug 2005 Location: Chicago, IL Posts: 397	Re: Minimising Rebreather Deaths / Fatalities Miami, How are often are you adding O2 at depth using your method? Thanks, Jason
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3rd January 2007, 16:14	#16 (permalink)
*schford* Despotic Overlord Current Rebreather/s: Megalodon Sport Kiss Other Rebreather/s: Join Date: Jan 2005 Location: London, UK Posts: 3,687	Re: Minimising Rebreather Deaths / Fatalities Quote: (Originally Posted by PCDiver) Hi Stuart, great article. My comments: Bailout via open loop as prefered method. I doubt that open loop breathing, which has higher WOB than a BOV or normal regulator, can be used in case of a CO2 hit. In case of a CO2 hit you will initially overbreath even the best regulator. Any extra WOB is not wanted and will increase the problem. For me a BOV is the preferred solution. That was an example from my scenarios - as I do not have a BOV then Open Loop for me is the method I would use to hopefully get my respiration under control before going for my bailout reg with a CO2 hit and being forced into taking a mouthful of water. Those scenarios are specific to me and my unit and I know that individuals will vary. Quote: (Originally Posted by PCDiver) eCCR as a parachute only (flying it manually) Flying an eCCR manualy has a higher task load than mCCR. Manualy operating the eCCR certainly needs to be practiced as a skill in case something happens to the solenoid, but as SOP? You don't have the continous flow that you get with a mCCR. Therefore, there wil bel more deviations from the setpoint, since more manual interventions are required. So, if you are diving without integrated deco computer, how valid will your deco profile be? I bought rebreathers for deep filming. In my case, manual operation is almost impossible. I have only two hands and both of those are on my camera. But even without camera, I run my Vision on automatic (except during long deco stops). It allows me to enjoy my dive more. Peter Electronics go wrong - in my research I did not find a single fatality where someone was flying the unit manually. I do realeaise it is an individual choice though. I do find though that it does not increase my task loading and becomes very instinctive and I have never had more than a minute or twos deviation between my plumbed in deco and my offboard deco. If you are worried though set your electronics to maintain 1.2 and your off board deco to calculate on 1.2 and if you fly at 1.3 you gain a slight deco advantage. Quote: (Originally Posted by AD_ward9) Your article is excellent! Especially, highlighting do not head for the surface if you have a problem. Bail out first. This is such a good synopsis, I must ask, do you have any objection to companies incorporating it verbatim in their manuals? E.g. declaring it as being under GNU type copyright release. Alex Not at all Alex - thanks for your feedback. __________________ Bailout and Kit Management account for Murphy's Law The only bad question is one you did not ask and later wish you had. Use of Rebreather World is subject to the Rebreather World Terms & Conditions of Use
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3rd January 2007, 16:30	#17 (permalink)
bgpartri Rebreather Zealot Current Rebreather/s: Megalodon Other Rebreather/s: Inspiration Classic Sport Kiss Classic Kiss Titan Join Date: Apr 2005 Location: Vancouver, Canada Posts: 414	Re: Minimising Rebreather Deaths / Fatalities Excellent Stuart. There are areas that one could quibble with, but if everyone followed those rules, deaths would plummet. Bruce __________________ http://www.shearwaterresearch.com Good judgment comes from experience. Experience comes from bad judgment.
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3rd January 2007, 16:37	#18 (permalink)
Jim Lovable Cockhead ! Current Rebreather/s: Megalodon Other Rebreather/s: Inspiration Classic Join Date: Jun 2005 Location: Purley, UK Posts: 145	Re: Minimising Rebreather Deaths / Fatalities I must confess moving from Inspo to Meg the thought of running manually was my area of concern ..... It was surprisingly easy and I now wouldn't do anything else - I usually hold setpoint at 1.3 with the unit firing at 1.2 as back up - works very well and the solenoid is a very good alarm if you are not use to it every couple of minutes - and of course it is very reliable if you have your hands full ! I have the option of using the Meg's electronics to maintain setpoint but do like the lekkies backing me up rather than the other way round. Complacency or distraction was my biggest concern on my Inspo at the potential wrong time, I can confess to not looking at those hand sets as often as I should have on occasions. Could've been fatal given the wrong circumstances?! Having said that, on the Meg (APECS II) I do need to change that setpoint on the way down to back me up & it is always part of my buddy check before swimming away from the shot .... I wouldn't want to forget - just in case!! Pros and cons to both I suppose? Cheers. __________________ Jim Spence
(Online)

3rd January 2007, 16:49	#19 (permalink)
bgpartri Rebreather Zealot Current Rebreather/s: Megalodon Other Rebreather/s: Inspiration Classic Sport Kiss Classic Kiss Titan Join Date: Apr 2005 Location: Vancouver, Canada Posts: 414	Re: Minimising Rebreather Deaths / Fatalities Quote: (Originally Posted by Jim) I must confess moving from Inspo to Meg the thought of running manually was my area of concern ..... ..... Pros and cons to both I suppose? Cheers. My solution is probably going to be to put an orifice on my Meg. After diving the KISS and realizing how easy it is to maintain setpoint with an orifice, I think I'll add one. It will go on just before the solenoid so that the solenoid would still kick in if a great white bites my camera. Of course the pre-dive needs to test both systems. The disadvantage is the MOD with the blocked IP, but I never go deeper than 300 any more anyway. Bruce __________________ http://www.shearwaterresearch.com Good judgment comes from experience. Experience comes from bad judgment.
(Offline)

3rd January 2007, 17:03	#20 (permalink)
Crazyduck Underwater Mechanic Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Mar 2005 Location: TEXAS, Dallas/ Ft.Worth Posts: 712	Re: Minimising Rebreather Deaths / Fatalities Bruce, Excellent idea…. It was crossed my mind that this could be the best of both worlds. Plus, hypothetically it would slow the battery drain for firing the solenoid in the first place. Would you keep the solenoid on the same 1st stage as the orifice or just use a slide shut off for potential solenoid runaways/failures? 300ft is a long way down- I am not too worried about that. Great Whites- not to worry about in the Gulf of Mexico- just large tiger sharks. Regards, Andrew __________________ Howdy Senor- What’s Happening! Rob Davie April 2005- Presently in a state of transition from Open Circuit to Closed Circuit. "You will not be punished for your anger; you will be punished by it." - Buddha.
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