Electronic vs manual CCR

[Philippe GERIN]

You guys talk funny. Anyone have an English to American dictionary?

Even more so if you consider that I'm French.
I can hear you: Oh! that explains everything....:big:
But I see you're in NJ. You're sure it's an English to American dictionary you need??....oke:
Best
Philippe

 

[Philippe GERIN]

I see one post which states that unless you have a leaky valve you are not running manual - seemingly a criticism of my set up. Help yourself - I never claimed it was or that others should copy me. I have reasons why I like to run it like this but won't belabour it.

Hey Clare,
I take it this is about my post. No worries. This is far from a criticism. Don't take it as such. This is not in fact what I mean.
I just want to emphasize that flying an eCCR manually is different from diving a mCCR. They are 2 different animals, not 2 different ways of flying the same kind of unit. That may help the OP to re-think his querry.
Best
Philippe

 

[Clare]

I don't take it as criticism mate. Just using it as an illustration that we don't have to take offence

 

[matt]

Being antagonised because someone makes different choices from you is an unnecessary distraction.

Just saying

Agreed.

 

[Ben Field]

Rubbish.

:deadhorse

Oh dear, well it seems overnight the thread has degenerated into an argument, I thought it was a well manner dicussion... what a shame.
I was just trying to give alittle light hearted MCCR insight for a couple of people who said they'd only dived ECCR and apparently for lack of some semantic sympathy I'm talking rubbish? Nice....

I'll try to clarify because I think its interesting.
IF you had a working RB you trusted you would NEVER look at the displays Ever.
The ONLY thing that makes anyone look at displays is a lack of faith/trust (call it what you like, I call it fear because I'm not trying to dress it up as something its not that the values will not be spot on.

Its just my very humble opinion but the majority of posters on forums attempt speak from a standpoint of authority and don't like realistic emotions and usage discussed (I include myself in this because I dislike scrubber pushing debates yet I know people do it, I just think its stupid to discuss (advertise) it online)

Its total nonsense to say diving isn't fun because of this but it is the Honest truth. When you dive OC you look at your SPG because you know the remaining gas limits your dive time and because you know deep down that it can run out, same with PPO2- it effects dive time, we're trained to look, we know we should, its Rule 1 etc but deep down you look because you don't trust your unit not to kill your ar*e stone dead :big:

The only reason I bought it up (Fear that is) is because its what marks the MCCR out and is why some people believe they are inherently safe, because you are driven to look at your displays and react, something which its possible to ignore in extremis on ECCR (espeacially those without HUD).

Matt, I'm not trying to say ECCR, or MCCR is better because I don't believe that or start any kind of heated debate, all I am saying is that IMVHO rebreathers benefit when the design tugs at a basic human instinct to survive. Back when Alex was going to make a rebreather it was going to have a button you pushed to silence a periodic warning- forcing you to look at the display, MCCR's force you to look and that is good.

Fear is a useful tool, don't be afraid to admit it keep you alive and allows for good fun diving :big:


Anyway I know you'll all be :yawn: of me now, I've made my point whether you agree or not.

 

[Ben Field]

Why do it? Like the control and the fact it makes me watch more. My buddy doesn't do it.

Hi Clare, I wanted to ask (but got distracted) what made you choose this approach over a Hybrid style system?

I like the philosophy behind Parachute ECCR but can't grasp how the Full-Manual (rather than hybrid) maintenance doesn't interfer with the diving- like a failed ECCR seems to, I assume you accept a bigger PPO2 window?

 

[Philippe GERIN]

Just using it as an illustration that we don't have to take offence

Oh, I didn't. And the :drink: we'll all have when we meet in person will be on me.
Best
Philippe

 

[matt]

Matt, I'm not trying to say ECCR, or MCCR is better because I don't believe that or start any kind of heated debate, all I am saying is that IMVHO rebreathers benefit when the design tugs at a basic human instinct to survive.

I agree with the sentiment but I'm not agreeing this this fear/tugging argument, perhaps it's semantics, but as it is winding people up we can chose not to discuss.

MCCR's force you to look and that is good.

It's not good or bad, it's just different.

Fear is a useful tool, don't be afraid to admit it keep you alive and allows for good fun diving :big:

I'm not afraid to admit that it's not fear driving me to look at the display, sorry if that's not aligned with your view, but it is my view.

In the spirit of Smiley experimentation -> oke:

Matt.

 

[ccrdave]

Just for the OP as the thread is getting a little confusing

an MCCR is a rebreather that has some sort of device that allows o2 to trickle into the rebreather loop, usually at or just below you metabolic rate when bimbling along

ECCR is a computer controlled solenoid valve that adds o2 as required by the controller, once at a setpopint the diver needs to do nothing but monitor.

HCCR is a hybrid of both system usually set up to have the flow device controlling the choosen setpopint and the computer (controller and solenoid) set with a setpoint a little lower as a "catch me"

some of the posters are referring to running their ECCR manually, this is different to what we commonly know as MCCR so dont confuse the two

HTH

Dave

 

[paul t]

There are other factors in the MCCR vs ECCR debate

With MCCR you are totally in control of the unit, not just when to add o2, but when not to. There are times when you know you will be ascending to get over or past something, then descending back down etc. The controller in an ECCR is dumb, it does not know what your intentions are, so, it registers a drop in po2 and injects, so you end up with high po2 etc etc

This must make diving some cave/mine systems quite frustrating to dive

Also, there is the absolute reliability of MCCR. A friend of mine has sold his ECCR after numerous problems and missed dives.

I'm not slating ECCR units, but if i have a problem with the Kiss, it's out with the spanners and fixed, there, on the boat etc, not sent back to Canada.

This is just another factor that sets the two types of unit appart. With MCCR you really are totally in control of everything

I purchased an Ouroboros last year, and dived it all season as ECCR, i have to say, i found it very frustrating at times, then, earlier this year, the Electronics failed on a dive trip in Plymouth.

So, i ripped them out, and converted it to full MCCR. Just got po2 monitors and that's it

Such is my conviction that MCCR is for ME, But it's NOT for everyone

Cheers

 

[Dave Sutton]

I purchased an Ouroboros last year, and dived it all season as ECCR, i have to say, i found it very frustrating at times, then, earlier this year, the Electronics failed on a dive trip in Plymouth.

Well, therein lays the problem:... you purchased one of the least reliable rebreathers ever constructed by humankind. There's a reason that they are out of production. There is no personal insult intended, it's just a fact. When a 'Boris works, it's dives well. But it really stands out as the example of an overengineered and overly complex rebreather that rarely actually works.

There is a lesson to be drawn from this: Divers who dove "Crap 'Lekkies" tend not to ever want to dive eCCR's again. I'm one of "you" too... but in the end I was able to undo my aversion training and am now a happy and satisfied eCCR diver.

My view of this, based on having been around rebreathers since 1977 or so, and around them as a sport diver (IE: not in the oil field diving industry) for the last 15 years or so, is that divers who dive unreliable kit then paint other kit with the same brush. I admit the same behaviour: After diving absolute CRAP electronics provided to me by a well know supplier who was reputed to be "the best in the buisiness", which NEVER really worked fully and which NEVER inspired my confidence, I dove KISS systems for ten years with complete satisfaction. I dove a KISS. I dove any of a dozen or more IDA-71 conversions that I built. I dove a KISS modified Mark-15. I then dove a rEvo, as a mCCR. All worked perfectly and my satisfaction level was 100X more than it had been with the eCCRs that had "the worlds best electronics" installed (which were ABSOLUTE crap). ... I went to the boat and went diving, while I watched other divers struggling with their (crap) eCCR's. I saw four 'Boris's come aboard the boat with a 100% failure rate. I saw at least a half dozen Hammerheads come aboard, with a high failure rate. That on top of the OVER 100% failure rate of the first two or three generations of the HH controllers. CCR-2000's never really worked. THe old Inspirations in the early days seemed to be killing a diver a week. In contrast, KISS rebreathers ALWAYS worked. So... the lines in the sand were pretty clear. KISS rigs were good, "All Singing and Dancing' eCCR's were not. End of discussion.

And that was true. Then... but not now.


Then technology advanced and we got solidly reliable eCCR controllers. And things changed. What really opened my eyes to the beauty and reliability of a eCCR controller was the Shearwater system that became available for the rEvo. I had one retrofitted to my rig, and I never looked back. It has been bulletproof, is extremely capable while being simple to use, has enormous flexibility, and has really exceeded my expectations. I trust it "with my life". This same controller is installed on the JJ, and has been completely satisfactory there. It is being installed on the new rig that John Routley (Narked@90) has shown. Really, I think it represents a paradigm shift in the confidence that we can place in an eCCR. The second "bulletproof" controller that I dove/dive is the very simple and very reliable APEKS controller on the Meg. It does one thing: Holds PP02. It always works, is a MILSPEC system accepted for issue by both the US Navy and NOAA, and has also been absolutely reliable. Putting aside my early skepticism of the Inspiration, the recent versions of the YBOD are darned good rigs too, especially with the Vision electronics. They always seem to work as well.

So... methinks much of the debate between mCCR and eCCR is based on old news. Stay away from 'Boris's, Sentinals (sorry guys), Old Mark-15's with skitterish 'Lekkies (some have good pods, some do not), anything with a Hammerhead installed, any "non-mainstream" rigs like the Titan, etc., and your opinion of eCCR's will change.

This is why "These Days" I see the "Big Four" rebreathers being the following:

Meg
JJ
rEvo
YBOD with Vision

Buy any of them with complete confidence, and enjoy them.


Note that two out of four use the Shearwater controller. My bet is that the Shearwater controller system will soon become the dominant system in the industry. Why should a builder design and build from scratch the most critical part of a system when there is a vendor wfrom which a "worlds best" solution can be sourced by picking up the phone and ordering them as an OEM?


For the REALLY skeptical diver, both the rEvo and the Meg can be ordered as hybrid systems (somebody tell me if the JJ can be done this way?), where a CMF orifice runs in parallel with the solenoid. I dove my rEvo this way for two years, and it was a thing of beauty. Two independant life support channels, either of which can fail and still allow perfect utility of the rig... low battery consumption due to very infrequent solenoid firing, etc. Just excellent. However... when I moved from NJ where our depths allow CMF use to the Great lakes, where we routinely dive deeper than CMF limits, I needed to block the orifice and revert to "Pure" eCCR. Guess what? The system still works perfectly, zero failures, zero hassle, and low workload. Ditto the Meg.



Advice from the Greybeard: Don't use last decades infomation to inform todays purchase. Don't use the examples of the "Last of the Gen-1 CRAP" electronics to inform todays purchase. Stay away...



Dave


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[matt]

Great post, Dave. For me at least that makes perfect sense, and provides some insight.

Cheers
Matt.

 

[paul t]

Insight into what?

It's now ok to buy eccr, because mr sutton has one, just as long is it's one of his recomendations

It's not about specific units, it's about the TYPE of unit

Sent from my GT-N7000 using Tapatalk 2

 

[Paul S]

It also forces you to be more aware of your PPO2 ( a VERY good thing)

I think this is the bit that antagonises eCCR divers; it creates the false implication that they are some how stupid. Just saying.

I think you're reading something that isn't there. I read no implication of the sort you're suggesting.

All packeteer is saying is that for "correct operation" an MCCR diver MUST check ppO2. It WILL drift if they don't check it and take action.

That's not saying that any CCR diver wouldn't or shouldn't know their ppO2, but the absolute "I must check this otherwise it's going to go Pete Tong*" need isn't there on ECCR. The unit should be handling it absolutely fine in most situations. The reason you're checking it is to catch the time it doesn't do it's job.

That isn't saying that people should rely on the electronics, or that they do.

* for our international friends - Pete Tong is (was?) a DJ on a UK national radio station. Somehow his name got used as rhyming slang for things going 'wrong'. Might have been one of his jingles even. Pete Tong is Wrong.

And just because I like the smiley -> :starwars:

 

[Dave Sutton]

"It's now ok to buy eccr, because mr sutton has one, just as long is it's one of his recomendations"


Knock Knock: Politeness counts... :wave:

Deciding on what to buy and use ought to be framed with todays-world data. Framing things in a historical context is all I am trying to do.

What I wrote is based on watching the industry grow from homebuilts, to glorified homebuilts passed off as factory units, to truly professionally engineered and independantly third party tested pieces of equipment. Many of the "issues" and perceptions still dogging many as the "chattering monkey on the shoulder" are perceptions based on earlier generations of rigs, which most certainly were not mature devices when they were placed into service.

Choosing an eCCR or a mCCR (or a hybrid) is based on a divers perceptions, his personal worldview, and his mission. For some a mCCR is not really an option, for depth or workload reasons. For others it's a perfect choice.

I've been diving eCCR's on and off for nearly 35 years, and dove regularly with mCCR's, both factory and homebuilt, for nearly a decade. I have enjoyed very good success with mCCR's, limited success with "Gen 1" eCCR's, and complete satisfaction with "The Big Four", which really do represent the lions share of rigs being sold and dived today.


Bear in mind that my opinions, and that's all that they are, are based on experience with a wide range of platforms. In my dive locker right now there resides in "dive it on 4 hours notice" status a trio of Mark-15's (one each with a Colkan, Steam Machines, and Biomarine REV-G pods), a CIS Mk-5P, two Megs, a Kiss, an Inspiration Classic, a hybrid rEvo, an Apoc with a Laguna controller fitted, a KISS system modified Draeger FGT-1D, a KISS system modified Azimuth, a KISS system modified IDA-71, and another pile of 02 rigs and oddities like the DC-55, LAR-V, Draeger Lund, etc. Soon there will be an Oroboris joining the crowd. I have owned and dived rigs with controllers made by Juergenson (both Mark-15 digital pods and Hammerheads of three different generations), Biomarine (the real Biomarine), ISC, Shearwater, Steam Machines, CIS, Colkan, AP Valves, Smithers, and Laguna. I have built my own displays, built my own rigs, built KISS system rigs using both fixed orifices and needle valves, and have basically "tried everything". I see many good things in some of the rigs, some really horrid things, some things that make me scratch my head, and some that are just worthless crap. The rigs that impress me that I would buy TODAY are the ones I recited. The KISS, which I was an advocate of for years, dating back to when I was friends with Gordon, has been sort of pushed aside out of the "Industry Leaders" category by the rEvo as the leading mCCR. That's not to say that it's not a good rig. The rest of the pack... well... they represent a small fraction of deliveries and of rigs being dived.


I will say that as an Instructor, training divers on both mCCR's and eCCR's that teaching the mCCR's is far easier, and divers seem to tune into them faster. I think that in the eCCR world, it's all too easy to not "really" teach the systems fully, leading to divers operating them that really are not completely up to speed. Just an observation based on watching divers aboard the two dive boats that I run and crew on.


Dave Thompson and John Routley ought to chime in here.... both have been around long enough to have seen the industry mature, and likely have similar comments. Gents?



Best,

Dave

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[beto]

Hello,

Thanks to everybody for their ideas and opinions about this topic. It looks to me like years of not very reliable eCCR units created a culture towards mCCR/KISS modality in order to stay safe and been able to go diving more reliable, which is what we all want . Over the years it looks like some eCCR units are becoming reliable, and suitable for some diving applications, specially where the mCCR limitation are.

In my case, I'll be using the unit mainly for underwater work in caves: mapping, video and archeology. From some of the messages on this list I got the idea that the extra brain-power needed for driving mCCR or eCCR manually is fine for easy diving just looking around and enjoying the dive, but that when doing task loading activities at depth an eCCR mode is preferable. Is that something people agree on?

So for example, if I'm working at 150ft/45m using something like 21/45 as my diluent as much work is required to keep Po2 in the 1.0 to 1.2 range with a mCCR or a eCCR run manually. The diluent is pretty close to the require set point.

I think figuring how one will run a unit, is a good first step towards unit selection.

Also, just for completeness. Is there are term for CCR units that do not use a solenoid, neither an orifice valve? some people call those one mCCR which make it confusing.

Thanks again
Beto

 

[paul t]

Dave. Your not getting it! And what is knock knock supposed to mean?

Stop going on about IDA this and homebuild that. It's not about which unit was crap, but is ok now. Or not to buy anything with HH Electronics??? Or any other opinion about a unit

We're talking about the difference between the two TYPES of rebreather. Should someone buy a ECCR or a MCCR. Once that decision has been made, then we can talk which specific unit

Paul

Sent from my GT-N7000 using Tapatalk 2

 

[Dave Sutton]

And my point is that when weighing the reliability of both systems, weigh the reliability of what is likely to be purchased today, not the reliability of older units that in many cases were not trustworthy enough to really warrant complete confidence. Much bias against eCCR's is bias against the generation of rigs preceeding the current one. It's part of the decision making process.


Dave


PS: We really do need to write up a Queens v/s Colonials Dictionary of Slang and Humor. "Knock Knock" is the beginning of a joke and was soliciting a smile...



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[matt]

Insight into what?

I'll let beto answer for me, he clearly read the post too...

It looks to me like years of not very reliable eCCR units created a culture towards mCCR/KISS modality in order to stay safe and been able to go diving more reliable, which is what we all want . Over the years it looks like some eCCR units are becoming reliable, and suitable for some diving applications, specially where the mCCR limitation are.

beto's summary is a good one, I'd say. And I think I both agree and see it.

It's now ok to buy eccr, because mr sutton has one, just as long is it's one of his recommendations

As previously accused I see things that don't exist. Therefore I am now not seeing this as rude.

Cheers
Matt.

-> :flypig:

 

[Dave Sutton]

In my case, I'll be using the unit mainly for underwater work in caves: mapping, video and archeology. From some of the messages on this list I got the idea that the extra brain-power needed for driving mCCR or eCCR manually is fine for easy diving just looking around and enjoying the dive, but that when doing task loading activities at depth an eCCR mode is preferable. Is that something people agree on?

Well, if you find a Navy that uses a mCCR when their divers are going to be tasked with defusing mines, let me know... :shrug: Our Navy uses the Mark-16 and the Meg. Others use others.

Working underwater is work, and in that context a rebreather is a tool. The best tool for working is the tool that does it's job silently in the background with the least fanfare. Let it do it's job, monitor it CAREFULLY, and do YOUR job.

OLED displays, HUD's, etc., have all made monitoring easier. But in the end it's the divers BRAIN that is the most important link in the chain.


Definitions;

eCCR: Electronic control. Inspiration, most Megs, JJ, etc.

mCCR: Can be PURELY manual (none exist from any manufacturer today), a fixed orifice (KISS, rEvo), or a needle valve (Pelagian).

Hybrid: Has both systems running in parallel. Many divers set the solenoid controller to fire the solenoid at a PP02 less than what they plan to hold, and then hold the desired PP02 as if the rig were a pure mCCR. If they lose their mask, get saturated, get stupid, etc... the soleniod will fire. Typical setting would be 0.7 for the solenoid and then maintaining 1.2 or so using the mCCR system. Another way to use the same system is to let the solenoid do the job of holding PP02, knowing that if it craps out the orifice will delay the time to a low PP02 state. Examples are a rEvo or Meg that is so configured (these are optional setups on both of these platforms)

Remember also that ANY eCCR can be used as a (fully) manual CCR... that's what the 02 bypass button is there for. And in the end... PP02 stability when in REAL manual mode is over-rated. Keep it someplace between 0.2 and 1.6 and all of the rest is decompression, narcosis, and CNS limits. That's a pretty broad band when things go wrong with any of these.


All three systems can be used very successfully, and are used daily all over the world. If there were a "real" answer, there would not be all of these being used by divers who are quite willing to defend their decision as the "best" decision. In the end you make your choice and you go diving.


Dave

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