halcyon rb80

[madmole]

Plenty of folks have been into Wakula wearing other rebreathers (the Wakula II project for one). George dives what his sponsers give him and has stated so many times in the past.

Its interesting that here is a quote from GI about the Inspiration
> We are talking cave diving - you can either work the machine or the cave
> - so we use the Halcyon. If you do not pay attention to the Inspiration,
> or any electronic rb ( if they indeed are functioning properly ), you
> have accidents. The Inspiration is much simpler and better made than
> most, and that makes it better than most.

So He changes his tune

I may not like GI's mannerisms or spouting but I cannot detract from the diving he has done and his fatality record. Its his constant putting down of others that gets many down especially when he perpetuates half truths on units he is not trained to use. At least he has done 1 dive on an Inspiration, which is what prompted his above quote

Also if youre going to quote me please do so, but dont add stuff in the middle???

 

[madmole]

Bit more searching

From Georges Wife

>As everyone in the States knows we also work with Halcyon in its
>rebreather development and have since its inception

So they were paid by Halcyon during the development of the units

The RB80 is a very nice unit. Illegal to sell in Europe (shame), but like ALL scr's it has weaknesses

1) It has no PO2 monitor (essential, but can easily be retro fitted)
2) It can be outbreathed on the surfcae under stress (at least the RB80 does physicall warn you that is happening unlike the Dolphin and Azimuth)
3) You plug in the wrong gas and you die (always analyse your gasses)

It is probably the nicest SCR on the market at present and if a PO2 meter is fitted probably one of the safest. I wouldn't mind one myself apart from the fact that you cant get hold of one in Europe (legally) and that the Inspiration is available, much cheaper and much more capable. It too has its failure modes and bad points and is far from perfect. But is very usable

 

[C_C]

Don't Let Pina hear that...

http://www.pina3.net/

C_C

 

[madmole]

The place I stole the quote from definately says "his Wife", I went back and checked.

GI replied to it so it's legit, may well be wrong though. Wished my SO was as pretty

 

[roakey]

madmole once bubbled...
Plenty of folks have been into Wakula wearing other rebreathers (the Wakula II project for one).

Don't trot that out without disclosing the Wakulla II project's record! In the space of three months or so:

1 Diver bent
1 Diver toxed
1 Diver dead

Feel free to read about the accidents in their own words:

http://www.usdct.org/update.htm

Roak

 

[swimndive]

To the Brits who seem to have a bug up their collective arses regarding the Halcyon RB80, I must confess that I am not an owner or even a user. I have neither the need, nor the training to use this device, but in the process of researching rebreathers in general, I have come across much information. Madmole I do apologize for my unfamiliarity with this interface, I did not intend to place any of my comments within yours, in fact I too would have preferred that the two remain separate. I will henceforth address your points in separate text.

To nickjb, the comments that you excerpted from the BAUE transcript are not complete. If you ever had a chance to see Mr. Irvine's DIR II tape, you would understand that Mr. Irvine was no doubt refering to staged safety bottles (Bottles which are left in the cave for extended periods of time). On the tape George stated that the only regulators that stood up to that environment were the Scubapro mk20's. As you can imagine, Scubapro was pleased enough to hear this, that they agreed to make as many mk20's as needed, available at "super cheap" prices to the WKPP. Mr. Irvine has since then apparently experienced maintenance problems with these regulators once they had been removed from the cave. He now has apparently decided to store all of his Scubapros wet to minimize maintenance costs. Apeks on the other hand,it seems survive a dry storage environment without needing service. It is interesting to note, that the man you criticize for diving a sponsor's "gifted" equipment, actually pays for and uses a non-sponsor's brand. Oddly Mr. Irvine seems to have done more for the popularity of Apeks regulators than anything Apeks has ever done.

You asked the question did Mr. Irvine get a good deal on his RB 80? I would think so. His buddy Reinhard is the designer and is also the one who made it for him. Probably traded some of those magnum scooters that they ran in Doux de Coly ( http://www.tekdyk.dk/doux/UK/welcome.htm ), for a prototype which Mr. Irvine's other buddy at Halcyon used to set up production. All of this information by the way is readily available on the net, if one is even mildly curious.

I find it strange, that the criticisms leveled against the RB80, seem to come from people who seem to require a rebreather to function more as some type of optimal decompression machine. My understanding is that a rebreather is a tool, a type of gas extension device, easily capable of delivering sufficient gas to actually put a diver into a state of high pressure gas saturation. You only have to look as far as the previous Wakulla examples you mentioned to see how well this concept worked. Ask yourself why a CIS lunar diver does a shorter dive and longer decompressions than a diver using the original Halcyon rebreather.

As I said, I am not a rebreather diver, but it seems to me that anyone contemplating using one, must be planning on using it to extend bottom times based on some fixed gas supply, and perhaps extending that duration to a level to complete saturation. Not knowing how to decompress from such a dive would be akin to playing Russian Roulette. Not knowing how to decompress and relying on some "optimal" po2 to avoid or shorten decompression is like adding another bullet to the chamber. Using an array of sensors, in a humid, hyperbaric environment to not only monitor but to maintain that "optimal" po2 is would be like adding a third round. The very things that you don't like about the RB80, are actually the things that make it the right tool for the job. Don't worry about these two machines being in competition with each other. As you have stated, Halcyon does not make it easy to buy them. They cost more than an Inspiration, you have to already know how to decompress and plan your dives, and you have to take rebreather training from one of the only two very busy GUE rebreather instructors. Clearly it's not a rebreather for the masses.

Here are some links to some rebreather articles discussing the problems with sensors: http://www.silent-submersion.com/articles/index.htm#sensor
Here is a link to an article which discuss these problems as they relate to the Inspiration. http://www.nobubblediving.com/inspirationpuffer.htm
There really is quite a bit more, but I'm sure you don't want to read any of it anyway. Do your own research and make your own decisions. Dive and let dive.


Cheers

 

[madmole]

And both the articles and the nonsense spoken about the Inspiration wet cell problem relates to a type of cell available in 1998-99. The cells on the Inspiration were swapped to hydrophobic cells long ago. Again misinformation spread and taken as the truth

There is NO cell moisture problem on the Inspiration (I admit there may have been 2-3 years ago). In fact the "fix" of blowing diluent at the cells is more likely to damage them. They do have the complete tidal volume of your lungs blowing over the cell every breath, thats more than enough to distrubute any moisture and it cant collect on the ptfe face

Personally I'm not critisising the RB80, I think it is a very good unit, It is not geared up for the type of diving I do and I would incur too great a decompression penalty using it as it is a fixed mix machine. The Inspiration will always give a shorter decompression if the same max PO2 is selected and you follow the same deco model (I know GI does his own thing with deco, some of which I agree with, but I'm not brave enough to try, so thats not a fair comparison)

The reason we have a problem with the RB80 in the UK is that in Europe we have laws that require all Life supprt equipment to be evaluated to a very strict standard by registered third parties. The list of attributes is very long (and I posted it on this board somewhere else not to long ago). It includes scrubber duration under certain strict quantifiable situations, breathing resistance, bailout mechanisms, cold and heat tolerance, storage conditions and a lot of other things. This is know as the CE standard. Currently only the Dolphin and Ray, Azimuth and Inspiration hold these certificates. It is illegal to sell life support equipment and parts for it into Europe unless it is CE marked. It is also illegal to use non CE marked equipment in any proffesional diving, ie Instructing, salvage etc.

It is considered by many here that the RB80 would not pass CE testing if submitted due to several reasons
1) Work of breathing would be too great (hoses and connection too narrow)
2) Lack of redundancy on the unit and no bailout. It does let you know if you have a problem etc but does not provide anyway around the problem. ie fitted bailout as standard (could be easily remedied, but must be fitted by the manufacturer)

Most of us RB aware limeys also believe the scrubber rating to be highly optimistic based on the volume, type and layout of the scrubber (which is how this thread got started). We would like to see it rated using a standard test (ie CE) then we could compare it to the other units as this is the duration they quote.

 

[Gasman]

Hi I'm new here,
But I use SCC and CCRs every day at work.
Halcyon's can achive dramatically longer canister life because of two factors.
1. As you all know a proportion of the exhaled gas in the SCC is vented with each breath. Assuming a 4:1 exchage (as quoted on the surface) then they gain an increase in canister life from say 5 hrs to 6.25 hrs.
2. If they are using radial scrubbers there is a significant gain there as well. All our scrubbers are radial. In SCC mode (3l/m) we get about 10 hours from the canister (we monitor for break through). In CCR we get about half the time (o2 @~300ml/min)
Needless to say that this relates to anaesthised humas at sea level, but it nevertheless shows that the claimed duration is possible.

Gasman
:doctor:

 

[madmole]

Possible, but not independently and quatifiably tested and thats the whole point of this thread

There are Inspiration users who rate the Inspiration scrubber at 7 hours!!!! despite the test results indicating otherwise.

Radial scrubbers for the Inspiration and Draegers are available, but have been rejected by most as the WOB is raised above the CE limits

 

[Exorcist]

Madmole,
Would like to respond to a couple of your recent posts denigrating the RB80. My observations come from personal experience, and they are at odds with your assertions about the unit.

1. Work of Breathing. No problems here. Breathes very well on Nitrox even when one is exerting himself. Beyond 100 feet, this will be less of an issue since you will have the appropriate amount of helium in the mix.

2. Scrubber Duration. Because we're cautious, we change media at 10 hours even though 16 hours is advertised for our tepid waters.

3. Bailout. Besides the rebreather function, the RB80 incorporates the full DIR OC system. You still have the long hose for air sharing and the necklaced 2nd stage as your backup. If the rebreather goes "Tango Uniform," you have sufficient gas to get you home. If your buddy runs out, he is on OC while you can go back to rebreather. BTW, these contingencies are incorporated into your predive gas management calculations.

4. Lack of a PO2 Monitoring Device. It's a passive addition unit which means it's directly tied to your breathing rate. You can not overbreathe it like you can a mass flow unit and go hypoxic. Variances in FO2 and FiO2 are well-established and narrow to a couple of points by 80 feet. If you're diving the rebreather in recreational mode, you simply use EAN32 or 36, which will prevent you from going hypoxic even on the surface. If you are diving trimix, you don't switch to rebreather until you reach the appropriate depth (e.g. 20 or 30 feet). An O2 gauge is unnecessary.

Think that Dr. Buchaly did an incredible job when he designed this piece of equipment.