Halcyon RB80 info.

caveseeker7

Just adding a few thoughts:

to 1) The Brownie/Halcyon PVR-BASC has been out of production for years.
(if important, 'decoweenie' here at Rebreather World dove one during his Storm and Stress period)

to 3,6,7) The most likely reason you don't see them 'around' is the GUE/DIR doctrine and the rather high price. The former simply requires that you take a bunch of GUE courses to even qualify for the Rebreather class and that you only use a rebreather when you need it. Need as in running out of tanks to do the duration. The RB80 is simply a gas extension tool, and few people need that much gas, especially when they are DIR in the first place.

There are only two instructors to cover the world, and one of them runs Halcyon, GUE and Extreme Exposure, so I'm sure classes aren't held very often.

Nevertheless the RB80 is in production, training is held fairly regurlary and a small number of people buy and use them.

4) The unit is RMV keyed, the gas addition is tied to you breathing rate. A set amount of gas (around 1/10 is dumped on each breath), the dumped gas is replenished. Hence the pO2 at depth remains more stable than on cmf SCRs.

From what I understand pO2 monitors are used during training to show students the deviation range in different parts of the water columm, but using one is not part of the MO (or DIR ).

5) He actually has two side by side.

7) Since the concept is valid one, and GUE/DIR isn't for everyone, there have been several manufacturers producing RMV keyed SCRs that are more of less inspired by the Halcyon. IIRC two of them are working with training agencies to have classes and certifications for their customers, something that has unfortunately been lacking in the past. There are some differences in details and materials, so you'll have to do your research and see how they can affect operation and/or safety.

Look through the SCR gallery/library/threads and search for EDO-04, AH-1, Tourrill and you should find some additional info.

__________________
Cheers
Stefan



"Political Correctness is a doctrine, fostered by a delusional, illogical minority,
and rabidly promoted by an unscrupulous mainstream media,
which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.!"

decoweenie

1) Are there units (RB80) readily available? They seem to have 3 different models (the old one...the size of a car, non comp. and comp.)

I dived the PVR-BASC since 1998. Some pictures are HERE.

I also modified the EDO-04 (Rebreather-80 clone) into a CCR. Some pictures are HERE.

Depth-compensation on the original unit was done by varying the amount of discharge (thus injection) depending on depth. The deeper the less discharge. It is a simple tube using water pressure to compress a spring and pull a cable at the same time. The cable is tied to the small inner dicharge bellow, so the more pull on the cable the smaller the bellow.

A couple of the "Halcyon-2" units were built (Tom Mount had some) with no depth-compensators. Slightly small but still very big, completely useless as they were intended to sell to the shallow Nitrox divers.

2) What possible advantage do they have over CCR's ?

It is believed by Halcyon that on long dives (9-hour dive that the WKPP lead divers used to do), the sensors might be rendered inoperable due to the moisture built up within the loop. Thus they wouldn't be safe to use for O2 injection.

In addition, the unit was built for mission-specific to explore the Wakulla deep cave which has been stock-piled with bail-out gas for most of way, so it wouldn't be as critical on gas advantage.

3) They seem to task specific, is this the reason they aren't around?

Yes.

For the average diver, it is a lot cumbersome and unwielding to do the same type. I can't convince the person who bought my EDO-04 to use it as a CCR, so I cringed every time we go diving together...

4) How do you KNOW what your breathing (without electronics)?

On the Rebreather-80, Reinhard had done some theoretical calculations to determine the loop fiO2 at different depths based in the physical dimensions of the unit, the rate of discharge and injection, etc.

In addition, a single sensor was mounted on the head on the test unit to verify the calculations.

But basically, it is trust -- similar to diving a Dolphin with no sensor.

5) Has anyone on the board ever had one?

Michael Walbrenner has one and used to explore deep caves in Europe. He is the most visible on this forum, but I am sure there are a few Rebreather-80 lurkers here.

Based on my experience, the 2 groups usually don't play well together in the past so the Rebreather-80 divers stay rather quiet outside of DIR forums.

6) I have never seen one on any dive anywhere , that seems odd.

Cost might be the main issue.

IMHO, it is well overpriced. It is probably done so to keep it from getting to be too popular and get into the "wrong" hands.

Plus, it is very much a "requirement" that you are a "DIR diver" now to own one due to the prerequisite for the training course.

7) Replies from the company seem to imply that training is rarely given which is discouraging.

See 6)

__________________
"...after a while you get bored offering advice to a bull that like to keep butting the fence with its head rather than walking through the open gate..."

- Rebreather World PM

AD_ward9

I was excommunicated by Halycon for having the daring audacity to try and buy one of their wings and put it on someone else's harness.

We may winge about DIR, but let us face it, it is just a really good marketing ploy: make a company that flogs dive kit, get a religion built up around it (DIR to its folllowers, DIRe to the rest), and you can sell stuff for years that is really out of date and would never survive in the open market. Hats off to GUE and Halycon for pulling it off. Does make diving look like scientology though.

Cheers
Alex

jont

Gentleman Thanks for your insight

The DIR programs: do you think that this is a good way to go when trying to develop better skills even for experienced divers??

The reason why I ask is a follows:

Northeast Wreck divers seem to have a reputation for being Gorilla Divers that lack finesse. I for one can confirm that, I can't tell you the number of divers that are totally unaware of there surroundings and lack or ignore basic skills.

That being said almost everyone thats has been EXTENSIVELY trained in a cave ( I have )environment are much more competent AND capable.

When it comes to such a dangerous sport constantly learning and improving your skills increases your odds of coming home.


Thanks again people,

J

Freef

Training won't stop that. You need the attitude that diving is bloody dangrous hammered into you from day 1. It is the poor quality of some instructors and the actions of those who should know better that sets a poor standard of diving for larger groups.

When I used to teach for a couple of shops in Northamptonshire I was embaressed in a number of occasions by other instructors whou couldn't be bothered to do the job properly, and this attitude gets passed on.

__________________
David.

Currently owner of two differently sized ankles.

CCR900

Would it not be fair to say the RB80 isn't that much different from any other passive SCR? The European versions of the same design such as the French Joker V and other models from Switzerland and Germany are not so much different. I seem to think some of the French models came before the RB80.

As has been said before, given their design (namely the method of rich gas enrichment following fractioned gas expulsion) they seem to be great in caves but if you were to have a vertical ascent they can be bl**dy lethal (expanding gas in loop retards the ADV hence no rich gas). I have even heard that divers are taught to go OC on ascents.

There are so many other good SCR/CCRs out there to get fixated on one that only GOD can dive.

Fil

decoweenie

Well, thank you very much for the compliment, Fil!

__________________
"...after a while you get bored offering advice to a bull that like to keep butting the fence with its head rather than walking through the open gate..."

- Rebreather World PM

caveseeker7

The original PVR-BASC can be traced back to the french DC-55 SCR.

The RB80 is Reinhard Buchaly's design (db8us' dive partner in explorations),
Halcyon just builds them commercially.

__________________
Cheers
Stefan



"Political Correctness is a doctrine, fostered by a delusional, illogical minority,
and rabidly promoted by an unscrupulous mainstream media,
which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.!"

caver95

I saw 3 today, at ginnie. thoses things are huge.

caveseeker7

Corrected the person being quated.

Of course they are, the DIR chaps hate looking like girlie men.

__________________
Cheers
Stefan



"Political Correctness is a doctrine, fostered by a delusional, illogical minority,
and rabidly promoted by an unscrupulous mainstream media,
which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.!"