Bailout Breather - do you NEED independant tanks....

Padowan · 15th March 2005, 21:29

OK so if you're designing a bailout rebreather, how high up on the list of thing to make totally independant do you put the tanks? Essential, quite high, optional??

It's all hyothetical at the moment, but I'm thinking that a sidemounted Rebreather, with the cannister and lungs on one side, and 2x 1L Ally bottles (flat bottoms so clamped end to end to make like a single cylinder sized thing) side slung on the other would make a nice balanced config....

***Beanie*** · 15th March 2005, 21:48

Quote: (Originally Posted by Padowan)

OK so if you're designing a bailout rebreather, how high up on the list of thing to make totally independant do you put the tanks? Essential, quite high, optional??

It's all hyothetical at the moment, but I'm thinking that a sidemounted Rebreather, with the cannister and lungs on one side, and 2x 1L Ally bottles (flat bottoms so clamped end to end to make like a single cylinder sized thing) side slung on the other would make a nice balanced config....

well what you could do it have small 1-1.5l cylinders on your main unit to cover gas failure sticky solenoids etc and use them or your main cyls to run a bailout

chances are you main cyls would be fine if you have to come off loop and if not you'd have reserve ones aswell

Mdemon · 16th March 2005, 08:04

Assuming that redundant O2 is desireable for the main Rebreather anyway, you are only looking at providing enough dil of the right mix to start your escape. One idea would be to connect to the main dil via ADV so the loop volume will be correct as will be the mix. You can bail at any time knowing you have enough dil even if you have a bad day and loose dil cylinder AND main loop at the same time.

That said, you'd loose the benefit of being able to pass it off to another diver unless you keep the redundant O2 tin on the bailout Rebreather. Having two small tins would seem to be the most robust all round solution...

Duncan Price · 16th March 2005, 09:27

[quote=Padowan]OK so if you're designing a bailout rebreather, how high up on the list of thing to make totally independant do you put the tanks? Essential, quite high, optional??

[/QUOTE]

I take my cue from John Volanthen who was diving his YBOD and S/M Rebreather at Vosbster last Friday. He had completely seperate drive gases for both but also the facility to cross contect between back mounted and sidemounted gas configs. The diluent for the S/M RB was a 10 l of something with a Y valve on it thus providing additional OC diluent in the event of having to go OC for a while.

If you are going to go to the trouble of a bail out Rebreather then you might want to consider what additional bailout you can figure in for minimal extra effort.

***schford*** · 24th April 2005, 20:22

You know if i was carrying a bailout Rebreather I think I would like it to be able to operate stand alone if it had to.

I could hand it off then if I had to as I sure as hell would not be carrying an OC reg to pass to someone.

Stuart

Pierre Farrugia · 24th April 2005, 20:59

But don't you still need some kind of OC bail out in case of Co2 or a flooded loop?, Or is it that simple to start using your bailout breather? I don't think (keep in mind my limited experience) that you can switch to bailout as fast as on OC?

onetime · 25th April 2005, 13:15

Quote: (Originally Posted by Pierre Farrugia)

But don't you still need some kind of OC bail out in case of Co2 or a flooded loop?, Or is it that simple to start using your bailout breather? I don't think (keep in mind my limited experience) that you can switch to bailout as fast as on OC?

As I've been working through the details of a bailout Rebreather, it's become more and more clear to me that you're talking about more than just having something strapped to you for bailout. With OC bailout (or in OC diving in general) you should be occassionally going to your backup to verify it's funtioning. That's even more true on a BOB as keeping the sorb warmed up, so to speak, will only make the transition easier and using it for some length of time will give you the opportunity to fine tune changes in buoyancy that may occur as you transition from one RB to the other. Just my .02 as I ponder the procedure changes required as bail out breathers are worked into the mix.

lizardland · 26th April 2005, 11:38

I'd thought about this too. I'd built a sidemount rebreather as a bailout for my backmount. But then I thought about the psychological aspects of bailing out to another CC. Personally, if I was that stuck I'd want to go straight to what I know works... in my case that's OC and then decide what to do. I don't know that I would want to go from one temperamental machine to another. Has the ADV been firing? Has it stayed dry? Is the right gas in it? Is it ready to breathe? For me that has been influencing my thinking on bail out, I still want some OC. It's simple, it works and requires minimal thought. For me, that has shaped my thinking on double/bail out Rebreather systems.

The guys who make the EDO-04 dive double units which they swap between every 15min, ensuring everything is always ready to use.

OTOH, I like my sidemount Rebreather so much that I've been using it as a primary system. Small twinset of backgas (7's), rebreather clips on like a stage, small O2 stage (or pony mount, still undecided which I prefer). Bags of bail out. If it all goes tits up, undoing two clips and swapping a hose gives me a standard Hog rigged twinset, a system which I know and is intuitive and doesn't consume massive brainpower. Adding a 2nd RB (and maybe reducing the twinset to 5's) wouldn't be a stretch. That said, I'm a homebuilder so my trust in my CC kit may not match everyone else's.

Duncan Price · 26th April 2005, 14:36

Quote: (Originally Posted by lizardland)

OTOH, I like my sidemount Rebreather so much that I've been using it as a primary system. Small twinset of backgas (7's), rebreather clips on like a stage, small O2 stage (or pony mount, still undecided which I prefer). Bags of bail out. If it all goes tits up, undoing two clips and swapping a hose gives me a standard Hog rigged twinset, a system which I know and is intuitive and doesn't consume massive brainpower. Adding a 2nd RB (and maybe reducing the twinset to 5's) wouldn't be a stretch. That said, I'm a homebuilder so my trust in my CC kit may not match everyone else's.

Exactly the rig I used for my dive that upset the NDC. Inverted independent 5's backmount. D5 on the left sidemount, O2 on the right sidemount. Worked a dream - OK so I was driving the Rebreather with a 4l of 10/50 also slide slung not my back gas but the principle is the same. I could go OC on any one of my drive gases as well. After "that dive" I dumped the CCR and went for a splash just on my OC backmounts.

Drmike · 27th April 2005, 03:59

Quote: (Originally Posted by onetime)

you should be occassionally going to your backup to verify it's funtioning. That's even more true on a BOB as keeping the sorb warmed up,

I thought that this (pre-breathing to kick start scrubber) has been shown to be a urban myth? I recall reading somewhere that going straight to a cold scrubber will not be a problem.

Excuse me if Im talking nonsense - but Im sure I read that somewhere......anyone?

15th March 2005, 21:29	#1 (permalink)
Padowan Proper Boffin Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Feb 2005 Location: Kent, UK. Posts: 518	Bailout Breather - do you NEED independant tanks.... OK so if you're designing a bailout rebreather, how high up on the list of thing to make totally independant do you put the tanks? Essential, quite high, optional?? It's all hyothetical at the moment, but I'm thinking that a sidemounted Rebreather, with the cannister and lungs on one side, and 2x 1L Ally bottles (flat bottoms so clamped end to end to make like a single cylinder sized thing) side slung on the other would make a nice balanced config.... __________________ Padowan The future's bright, the future's Yellow .....for now padowan.net - Latest Video: Scapa Flow Rebreather Diving
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15th March 2005, 21:48	#2 (permalink)
*Beanie* give a man an inch....... Current Rebreather/s: Inspiration Classic Other Rebreather/s: Inspiration Vision Join Date: Jan 2005 Location: In da house! yeah baby! Posts: 3,174	Quote: (Originally Posted by Padowan) OK so if you're designing a bailout rebreather, how high up on the list of thing to make totally independant do you put the tanks? Essential, quite high, optional?? It's all hyothetical at the moment, but I'm thinking that a sidemounted Rebreather, with the cannister and lungs on one side, and 2x 1L Ally bottles (flat bottoms so clamped end to end to make like a single cylinder sized thing) side slung on the other would make a nice balanced config.... well what you could do it have small 1-1.5l cylinders on your main unit to cover gas failure sticky solenoids etc and use them or your main cyls to run a bailout chances are you main cyls would be fine if you have to come off loop and if not you'd have reserve ones aswell __________________ Beanie Gallery Admin & Library Assistant. www.outlawdivers.org.uk www.beandiving.co.uk www.beanengineering.co.uk
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16th March 2005, 08:04	#3 (permalink)
Mdemon SiegeEngine II Current Rebreather/s: Inspiration Classic Home Build Other Rebreather/s: Inspiration Classic Home Build Join Date: Feb 2007 Location: SWUK Posts: 1,927	Assuming that redundant O2 is desireable for the main Rebreather anyway, you are only looking at providing enough dil of the right mix to start your escape. One idea would be to connect to the main dil via ADV so the loop volume will be correct as will be the mix. You can bail at any time knowing you have enough dil even if you have a bad day and loose dil cylinder AND main loop at the same time. That said, you'd loose the benefit of being able to pass it off to another diver unless you keep the redundant O2 tin on the bailout Rebreather. Having two small tins would seem to be the most robust all round solution... __________________ www.southwestmafia.com "small minds talk about people, Average Minds Talk About Events, GREAT MINDS TALK ABOUT IDEAS!" The WRONG Attitude will get you killed. "Once the agenda-monkeys and perfect-worlders have moved on, perhaps we can do some diving?"
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16th March 2005, 09:27	#4 (permalink)
Duncan Price Sump Monster Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Feb 2005 Location: Wells, Somerset, UK Posts: 335	[quote=Padowan]OK so if you're designing a bailout rebreather, how high up on the list of thing to make totally independant do you put the tanks? Essential, quite high, optional?? [/QUOTE] I take my cue from John Volanthen who was diving his YBOD and S/M Rebreather at Vosbster last Friday. He had completely seperate drive gases for both but also the facility to cross contect between back mounted and sidemounted gas configs. The diluent for the S/M RB was a 10 l of something with a Y valve on it thus providing additional OC diluent in the event of having to go OC for a while. If you are going to go to the trouble of a bail out Rebreather then you might want to consider what additional bailout you can figure in for minimal extra effort.
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24th April 2005, 20:22	#5 (permalink)
*schford* Despotic Overlord Current Rebreather/s: Megalodon Sport Kiss Other Rebreather/s: Join Date: Jan 2005 Location: London, UK Posts: 3,562	You know if i was carrying a bailout Rebreather I think I would like it to be able to operate stand alone if it had to. I could hand it off then if I had to as I sure as hell would not be carrying an OC reg to pass to someone. Stuart
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24th April 2005, 20:59	#6 (permalink)
Pierre Farrugia Custom Title Allowed! Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Feb 2005 Location: Malta Posts: 636	But don't you still need some kind of OC bail out in case of Co2 or a flooded loop?, Or is it that simple to start using your bailout breather? I don't think (keep in mind my limited experience) that you can switch to bailout as fast as on OC? __________________ Pierre Farrugia My wife told me " If you don't quit diving I'm going to leave you" My reply " God, I'll miss you" www.atlam.org www.divemed.com
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25th April 2005, 13:15	#7 (permalink)
onetime Classic KISSer #138 Current Rebreather/s: Classic Kiss Other Rebreather/s: Join Date: Mar 2005 Location: US, NJ Posts: 673	Quote: (Originally Posted by Pierre Farrugia) But don't you still need some kind of OC bail out in case of Co2 or a flooded loop?, Or is it that simple to start using your bailout breather? I don't think (keep in mind my limited experience) that you can switch to bailout as fast as on OC? As I've been working through the details of a bailout Rebreather, it's become more and more clear to me that you're talking about more than just having something strapped to you for bailout. With OC bailout (or in OC diving in general) you should be occassionally going to your backup to verify it's funtioning. That's even more true on a BOB as keeping the sorb warmed up, so to speak, will only make the transition easier and using it for some length of time will give you the opportunity to fine tune changes in buoyancy that may occur as you transition from one RB to the other. Just my .02 as I ponder the procedure changes required as bail out breathers are worked into the mix.
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26th April 2005, 11:38	#8 (permalink)
lizardland Yak Current Rebreather/s: MK 15.X Home Build Other Rebreather/s: Classic Kiss Home Build Join Date: Mar 2005 Location: North... Posts: 1,301	I'd thought about this too. I'd built a sidemount rebreather as a bailout for my backmount. But then I thought about the psychological aspects of bailing out to another CC. Personally, if I was that stuck I'd want to go straight to what I know works... in my case that's OC and then decide what to do. I don't know that I would want to go from one temperamental machine to another. Has the ADV been firing? Has it stayed dry? Is the right gas in it? Is it ready to breathe? For me that has been influencing my thinking on bail out, I still want some OC. It's simple, it works and requires minimal thought. For me, that has shaped my thinking on double/bail out Rebreather systems. The guys who make the EDO-04 dive double units which they swap between every 15min, ensuring everything is always ready to use. OTOH, I like my sidemount Rebreather so much that I've been using it as a primary system. Small twinset of backgas (7's), rebreather clips on like a stage, small O2 stage (or pony mount, still undecided which I prefer). Bags of bail out. If it all goes tits up, undoing two clips and swapping a hose gives me a standard Hog rigged twinset, a system which I know and is intuitive and doesn't consume massive brainpower. Adding a 2nd RB (and maybe reducing the twinset to 5's) wouldn't be a stretch. That said, I'm a homebuilder so my trust in my CC kit may not match everyone else's.
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26th April 2005, 14:36	#9 (permalink)
Duncan Price Sump Monster Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Feb 2005 Location: Wells, Somerset, UK Posts: 335	Quote: (Originally Posted by lizardland) OTOH, I like my sidemount Rebreather so much that I've been using it as a primary system. Small twinset of backgas (7's), rebreather clips on like a stage, small O2 stage (or pony mount, still undecided which I prefer). Bags of bail out. If it all goes tits up, undoing two clips and swapping a hose gives me a standard Hog rigged twinset, a system which I know and is intuitive and doesn't consume massive brainpower. Adding a 2nd RB (and maybe reducing the twinset to 5's) wouldn't be a stretch. That said, I'm a homebuilder so my trust in my CC kit may not match everyone else's. Exactly the rig I used for my dive that upset the NDC. Inverted independent 5's backmount. D5 on the left sidemount, O2 on the right sidemount. Worked a dream - OK so I was driving the Rebreather with a 4l of 10/50 also slide slung not my back gas but the principle is the same. I could go OC on any one of my drive gases as well. After "that dive" I dumped the CCR and went for a splash just on my OC backmounts.
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27th April 2005, 03:59	#10 (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: 3,323	Quote: (Originally Posted by onetime) you should be occassionally going to your backup to verify it's funtioning. That's even more true on a BOB as keeping the sorb warmed up, I thought that this (pre-breathing to kick start scrubber) has been shown to be a urban myth? I recall reading somewhere that going straight to a cold scrubber will not be a problem. Excuse me if Im talking nonsense - but Im sure I read that somewhere......anyone?
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