CCR Trimix Simplified by Mel Clark question

Mikel-Deko · 20th December 2007, 09:19

Hi,
I've just finnished to read the book. I wanted to read it again because with two kids jumping arround it is not the best way to undestand thinks, but...

Maybe is my fealing but i don't think that the best solution for some problems in CCR trimix is going to OC as Mel sais in the book.

I think that for air dives, i mean maximum of 40 mtrs, it could be a goog solution, but for Trimix dives, i don't think so.

I think that a good SCR tecnique with a good gas compromise is the best solution for most of the incidents with CCR Trimix.

Obviously i'm not a expecialist in CCR Trimix but i've made a few deep dives and i've been thinking a lot about it.

I remember a good thread with Dave Sutton about "Hot Diluyent" that make me think about it.

Please, any commentary will be welcome.

Best

Mikel

Happy hollidays !!!

***jradomski*** · 20th December 2007, 09:30

Quote: (Originally Posted by Mikel-Deko)

Hi,
I've just finnished to read the book. I wanted to read it again because with two kids jumping arround it is not the best way to undestand thinks, but...

Maybe is my fealing but i don't think that the best solution for some problems in CCR trimix is going to OC as Mel sais in the book.

I think that for air dives, i mean maximum of 40 mtrs, it could be a goog solution, but for Trimix dives, i don't think so.

I think that a good SCR tecnique with a good gas compromise is the best solution for most of the incidents with CCR Trimix.

Obviously i'm not a expecialist in CCR Trimix but i've made a few deep dives and i've been thinking a lot about it.

I remember a good thread with Dave Sutton about "Hot Diluyent" that make me think about it.

Please, any commentary will be welcome.

Best

Mikel

Happy hollidays !!!

Every instructor/agency has their own opinion..

From ANDI's perspective on depths that require Trimix, OC in general is the LAST option that you should choose.. I haven't read Mel's book so I can't comment on specifics, but other than a total loop failure, a good and fast loop flush, followed by SCR mode should be the first choice IMHO.

To this date I HAVE NEVER run into a situation where I would bail to OC first, and the deeper I go the farther OC choice becomes an option..

jhaaja · 20th December 2007, 09:50

Scrubber breakthrough would also need quick switch to OC. In general it is safest to go OC if you find yourself in difficulties. Then just try to figure out what is wrong and if youi find the reason, fix it and finish the dive on CC.

JH

***jradomski*** · 20th December 2007, 09:56

Quote: (Originally Posted by jhaaja)

Scrubber breakthrough would also need quick switch to OC. In general it is safest to go OC if you find yourself in difficulties. Then just try to figure out what is wrong and if youi find the reason, fix it and finish the dive on CC.

JH

Proper flushing will give good gas as fast or faster as OC would, and probably be more effective since you would have to hold you breath to switch to OC (increasing your co2 load) or have the increased WOB trying to breathe through a BOV.. (the attached second will always breath worse than the primary gas path)

BTW I HAVE had co2 issues deep and staying ON the loop gave me alot more options.. FLushing works fine when done correctly...

Mikel-Deko · 20th December 2007, 10:03

Quote: (Originally Posted by jradomski)

Every instructor/agency has their own opinion..

From ANDI's perspective on depths that require Trimix, OC in general is the LAST option that you should choose.. I haven't read Mel's book so I can't comment on specifics, but other than a total loop failure, a good and fast loop flush, followed by SCR mode should be the first choice IMHO.

To this date I HAVE NEVER run into a situation where I would bail to OC first, and the deeper I go the farther OC choice becomes an option..

Yes, it is what i was teach and it is what i think.
It is not so easy to close the dsv, take your bailout and breathe instead make a good loop flush and see what is wrong.

Best
Mikel

jhaaja · 20th December 2007, 10:03

Quote: (Originally Posted by jradomski)

Proper flushing will give good gas as fast or faster as OC would, and probably be more effective since you would have to hold you breath to switch to OC (increasing your co2 load) or have the increased WOB trying to breathe through a BOV.. (the attached second will always breath worse than the primary gas path)

BTW I HAVE had co2 issues deep and staying ON the loop gave me alot more options.. FLushing works fine when done correctly...

But after flushing you need to go OC anyway, or use open loop. Open loop is quite hard work at least on YBOD. The ADV is quite tight to suck. Good points anyway.

JH

Mikel-Deko · 20th December 2007, 10:04

Quote: (Originally Posted by jhaaja)

Scrubber breakthrough would also need quick switch to OC. In general it is safest to go OC if you find yourself in difficulties. Then just try to figure out what is wrong and if youi find the reason, fix it and finish the dive on CC.

JH

I don't think so. It is not so easy when you have a problem.

Even a good loop flush gives you time to think ...

Best

Mikel

Mikel-Deko · 20th December 2007, 10:09

Quote: (Originally Posted by jhaaja)

But after flushing you need to go OC anyway, or use open loop. Open loop is quite hard work at least on YBOD. The ADV is quite tight to suck. Good points anyway.

JH

I only see two scenarios when you need to go OC.
Hipercapnia and something broken in the loop.
If the hipercapnia is because the scrubber is over even then you can try SCR but it not sure you can stay in the loop.

If you breathe is going out the loop because something is broken (loop, cannister, dsv, etc) then you need to go OC.

In any other circunstances, you can stay in the loop.

Best
Mikel

jhaaja · 20th December 2007, 10:17

Quote: (Originally Posted by Mikel-Deko)

I only see two scenarios when you need to go OC.
Hipercapnia and something broken in the loop.
If the hipercapnia is because the scrubber is over even then you can try SCR but it not sure you can stay in the loop.

If you breathe is going out the loop because something is broken (loop, cannister, dsv, etc) then you need to go OC.

In any other circunstances, you can stay in the loop.

Best
Mikel

If the scrubber is not working you can not use scr. Your CO2 levels will start to rise and you end up in difficulties. For scr you need a working scrubber.

In most cases it is usually the safest solution to go oc for a few breaths and asses the situation before going back on the loop.

JH

***jradomski*** · 20th December 2007, 10:36

Quote: (Originally Posted by jhaaja)

But after flushing you need to go OC anyway, or use open loop. Open loop is quite hard work at least on YBOD. The ADV is quite tight to suck. Good points anyway.

JH

if the scrubber is not TOTALLY failed.. you should be able to get 2-3 breaths on each flush of fresh gas, just doing this for a few minutes while deep can save a significant amount of gas and give you much more leeway later on in the dive.. Even with "breakthough" there should be some co2 absorbing capacity for a while..

Breakthough just means it exceeded a specific level.. when you get near the end of scrubber life you still have some usable chemical, but its not enough to CONTINUALLY breath the same gas..

20th December 2007, 09:19	#1 (permalink)
Mikel-Deko RBW Member Current Rebreather/s: Inspiration Classic Other CCR Other Rebreather/s: Other CCR Join Date: Jul 2005 Location: Basque Country -Sp- Posts: 476	CCR Trimix Simplified by Mel Clark question Hi, I've just finnished to read the book. I wanted to read it again because with two kids jumping arround it is not the best way to undestand thinks, but... Maybe is my fealing but i don't think that the best solution for some problems in CCR trimix is going to OC as Mel sais in the book. I think that for air dives, i mean maximum of 40 mtrs, it could be a goog solution, but for Trimix dives, i don't think so. I think that a good SCR tecnique with a good gas compromise is the best solution for most of the incidents with CCR Trimix. Obviously i'm not a expecialist in CCR Trimix but i've made a few deep dives and i've been thinking a lot about it. I remember a good thread with Dave Sutton about "Hot Diluyent" that make me think about it. Please, any commentary will be welcome. Best Mikel Happy hollidays !!! __________________ Mikel-Deko Basque Country www.olatu.net "DIR is the nanny state for divers who cannot think on their own" Ron Micjan
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20th December 2007, 09:30	#2 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Join Date: Mar 2005 Location: "Da" Bronx Posts: 3,113	Re: CCR Trimix Simplified by Mel Clark question Quote: (Originally Posted by Mikel-Deko) Hi, I've just finnished to read the book. I wanted to read it again because with two kids jumping arround it is not the best way to undestand thinks, but... Maybe is my fealing but i don't think that the best solution for some problems in CCR trimix is going to OC as Mel sais in the book. I think that for air dives, i mean maximum of 40 mtrs, it could be a goog solution, but for Trimix dives, i don't think so. I think that a good SCR tecnique with a good gas compromise is the best solution for most of the incidents with CCR Trimix. Obviously i'm not a expecialist in CCR Trimix but i've made a few deep dives and i've been thinking a lot about it. I remember a good thread with Dave Sutton about "Hot Diluyent" that make me think about it. Please, any commentary will be welcome. Best Mikel Happy hollidays !!! Every instructor/agency has their own opinion.. From ANDI's perspective on depths that require Trimix, OC in general is the LAST option that you should choose.. I haven't read Mel's book so I can't comment on specifics, but other than a total loop failure, a good and fast loop flush, followed by SCR mode should be the first choice IMHO. To this date I HAVE NEVER run into a situation where I would bail to OC first, and the deeper I go the farther OC choice becomes an option.. __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.
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20th December 2007, 09:50	#3 (permalink)
jhaaja Custom Title Allowed! Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Mar 2005 Location: Finland Posts: 885	Re: CCR Trimix Simplified by Mel Clark question Scrubber breakthrough would also need quick switch to OC. In general it is safest to go OC if you find yourself in difficulties. Then just try to figure out what is wrong and if youi find the reason, fix it and finish the dive on CC. JH
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20th December 2007, 09:56	#4 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Join Date: Mar 2005 Location: "Da" Bronx Posts: 3,113	Re: CCR Trimix Simplified by Mel Clark question Quote: (Originally Posted by jhaaja) Scrubber breakthrough would also need quick switch to OC. In general it is safest to go OC if you find yourself in difficulties. Then just try to figure out what is wrong and if youi find the reason, fix it and finish the dive on CC. JH Proper flushing will give good gas as fast or faster as OC would, and probably be more effective since you would have to hold you breath to switch to OC (increasing your co2 load) or have the increased WOB trying to breathe through a BOV.. (the attached second will always breath worse than the primary gas path) BTW I HAVE had co2 issues deep and staying ON the loop gave me alot more options.. FLushing works fine when done correctly... __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.
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20th December 2007, 10:03	#5 (permalink)
Mikel-Deko RBW Member Current Rebreather/s: Inspiration Classic Other CCR Other Rebreather/s: Other CCR Join Date: Jul 2005 Location: Basque Country -Sp- Posts: 476	Re: CCR Trimix Simplified by Mel Clark question Quote: (Originally Posted by jradomski) Every instructor/agency has their own opinion.. From ANDI's perspective on depths that require Trimix, OC in general is the LAST option that you should choose.. I haven't read Mel's book so I can't comment on specifics, but other than a total loop failure, a good and fast loop flush, followed by SCR mode should be the first choice IMHO. To this date I HAVE NEVER run into a situation where I would bail to OC first, and the deeper I go the farther OC choice becomes an option.. Yes, it is what i was teach and it is what i think. It is not so easy to close the dsv, take your bailout and breathe instead make a good loop flush and see what is wrong. Best Mikel __________________ Mikel-Deko Basque Country www.olatu.net "DIR is the nanny state for divers who cannot think on their own" Ron Micjan
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20th December 2007, 10:03	#6 (permalink)
jhaaja Custom Title Allowed! Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Mar 2005 Location: Finland Posts: 885	Re: CCR Trimix Simplified by Mel Clark question Quote: (Originally Posted by jradomski) Proper flushing will give good gas as fast or faster as OC would, and probably be more effective since you would have to hold you breath to switch to OC (increasing your co2 load) or have the increased WOB trying to breathe through a BOV.. (the attached second will always breath worse than the primary gas path) BTW I HAVE had co2 issues deep and staying ON the loop gave me alot more options.. FLushing works fine when done correctly... But after flushing you need to go OC anyway, or use open loop. Open loop is quite hard work at least on YBOD. The ADV is quite tight to suck. Good points anyway. JH
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20th December 2007, 10:04	#7 (permalink)
Mikel-Deko RBW Member Current Rebreather/s: Inspiration Classic Other CCR Other Rebreather/s: Other CCR Join Date: Jul 2005 Location: Basque Country -Sp- Posts: 476	Re: CCR Trimix Simplified by Mel Clark question Quote: (Originally Posted by jhaaja) Scrubber breakthrough would also need quick switch to OC. In general it is safest to go OC if you find yourself in difficulties. Then just try to figure out what is wrong and if youi find the reason, fix it and finish the dive on CC. JH I don't think so. It is not so easy when you have a problem. Even a good loop flush gives you time to think ... Best Mikel __________________ Mikel-Deko Basque Country www.olatu.net "DIR is the nanny state for divers who cannot think on their own" Ron Micjan
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20th December 2007, 10:09	#8 (permalink)
Mikel-Deko RBW Member Current Rebreather/s: Inspiration Classic Other CCR Other Rebreather/s: Other CCR Join Date: Jul 2005 Location: Basque Country -Sp- Posts: 476	Re: CCR Trimix Simplified by Mel Clark question Quote: (Originally Posted by jhaaja) But after flushing you need to go OC anyway, or use open loop. Open loop is quite hard work at least on YBOD. The ADV is quite tight to suck. Good points anyway. JH I only see two scenarios when you need to go OC. Hipercapnia and something broken in the loop. If the hipercapnia is because the scrubber is over even then you can try SCR but it not sure you can stay in the loop. If you breathe is going out the loop because something is broken (loop, cannister, dsv, etc) then you need to go OC. In any other circunstances, you can stay in the loop. Best Mikel __________________ Mikel-Deko Basque Country www.olatu.net "DIR is the nanny state for divers who cannot think on their own" Ron Micjan
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20th December 2007, 10:17	#9 (permalink)
jhaaja Custom Title Allowed! Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Mar 2005 Location: Finland Posts: 885	Re: CCR Trimix Simplified by Mel Clark question Quote: (Originally Posted by Mikel-Deko) I only see two scenarios when you need to go OC. Hipercapnia and something broken in the loop. If the hipercapnia is because the scrubber is over even then you can try SCR but it not sure you can stay in the loop. If you breathe is going out the loop because something is broken (loop, cannister, dsv, etc) then you need to go OC. In any other circunstances, you can stay in the loop. Best Mikel If the scrubber is not working you can not use scr. Your CO2 levels will start to rise and you end up in difficulties. For scr you need a working scrubber. In most cases it is usually the safest solution to go oc for a few breaths and asses the situation before going back on the loop. JH
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20th December 2007, 10:36	#10 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Join Date: Mar 2005 Location: "Da" Bronx Posts: 3,113	Re: CCR Trimix Simplified by Mel Clark question Quote: (Originally Posted by jhaaja) But after flushing you need to go OC anyway, or use open loop. Open loop is quite hard work at least on YBOD. The ADV is quite tight to suck. Good points anyway. JH if the scrubber is not TOTALLY failed.. you should be able to get 2-3 breaths on each flush of fresh gas, just doing this for a few minutes while deep can save a significant amount of gas and give you much more leeway later on in the dive.. Even with "breakthough" there should be some co2 absorbing capacity for a while.. Breakthough just means it exceeded a specific level.. when you get near the end of scrubber life you still have some usable chemical, but its not enough to CONTINUALLY breath the same gas.. __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated. Last edited by jradomski : 20th December 2007 at 10:38.
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