Ivan's MCCR Dolphin
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It is a pleasure to read people are inspired by work of others and combine many ideas in their ideal concept. This concept itself is used by others to even improve diving systems. Last years many conversions of the Dolphin semi closed rebreathers has been seen. Ivan Calcoen from Belgium used many of the ideas of homebuilders and added his own. Another step in manual controlled closed circuit rebreathers. Here is his story. Ivan thanks for contributing!
Hello all, I would like to present my Dräger Dolphin which I have modified to MCCR Kiss style Dolphin in the winter of 2004-2005.
Before I started to modify my rebreather, I spent a lot of time searching how I should do this. There are several  Dolphin owners who showed me there various systems; i.e. with needle valve, with Gordon Smith’s Kiss Valve, with different oxygen injection positions, how PPO² monitoring should be done etc.etc.
Thanks to JW. Bech  “www.therebreathersite.nl”, I was able to figure out how others have done it. Some of them have their own website which I also looked
through several times.
However, I rebuild my rebreather using a mix of different modifications :
1)     I used the oxygen injection system similar than Kerry McKenzie
(Tubbie), which is perfectly explained on his beautiful website
2)     PPO² monitoring is done with VR3 with O² sensor, and a     
O² sensor in the inhale breathing hose ( Michel Urbani ) and read out by a display (design Paul Raeymakers) and fitted in a Mark Munroe Lexan Tube (purchased through TECME).
3)     A Halcyon wing has been fitted since the original Dräger does not have enough lift if extra bailout bottles are carried for the deeper dives
Below you can find some detailed pictures with some explanation on certain details.


This is the oxygen injection system, O² is injected through a Swagelock needle valve, manual bypass is done through a Clippard Minimatics 2 way valve (converted to 3 way by drilling an additional hole opposite to the threaded outlet port).

Just before the shut off valve , is a 1/8-1/4 brass nipple which I plugged on the inside by silver soldering a brass bar. At first I drilled a 0.35 mm hole to meet the 8l/m manual bypass feed as is used by Kerry.
Well, I found that on the deeper dives it took a while to get the PPO² to level (1.3-1.4). So, I re drilled the
Hole with a 0.6mm drill and suits me fine now. At  40m I only need 2 short bursts to bring the PPO² to level. (I could measure the bypass flow rate if required by someone)
I also fitted the Swagelock in line 15micron filter just after the O² 1st stage as well as the O² gauge.
During a dive, you don’t look at the gauge anyway, so why put it over your shoulder… another hose
Hanging around…
One thing I would like to mention… I got a bit scared reading all the different warnings regarding the depth compensation on the O² 1stage regulator. Well, I had a Poseidon Jetstream, which I like a lot, so had to look for closing off the ambient pressure above the diaphragm. Here is my solution:

I soldered a 6mm SS bolt in the end cap where normally the hex. The hole is for adjusting the intermediate pressure.
I also soldered the end cap to the diaphragm cap!
By doing so, it is easier for the annual maintenance. No sealant should be removed which is a hell of a job!
Of coarse one would say, yes but now you can’t adjust the intermediate pressure by Allen key..
Yes, but I adjusted the intermediate pressure by placing a SS washer above the spring and gave me
9.5 bar!!
Adjusting the O² flow can easily be altered through the Swagelock needle valve.
The point where I inject the O², is in the original bypass valve. I used an original orifice
and removed both the Rubin  flow restrictors. The plastic tubes I leave in place.
The original bypass was moved to where the OPV was fitted. Then the OPV  was moved to where the
Original P-connector on the back side of the inhalation lung. (Normally Plugged).
The OPV manual function had to be removed and was easily done (after opening the valve) by fitting two "of the shelf" O-rings.
So, no additional holes had to be made in either breathing  bag!!


For the PPO² monitoring I use MY VR3 with O² sensor which fits in the P-connector where normally the bypass valve is fitted.
The second sensor was fitted using a PVC HP cross : (Michel Urbani design)

This means that very easily a second (so 3 in total) O² sensor can be added in the inhale side.

I will add a 2nd sensor in this cross at a later stage.



The PVC cross was a little bit shortened as well as the standard screw fittings using a lathe.
When fitting the cable through a cable gland and in my case an elbow, a friend of me pointed out that he had had a lot of trouble with water coming in.. He advised to cut the wires (4 in my case) solder them independently together, feed them through the cable gland (making sure the soldering connections don’t touch each other, not easy… and fill the whole with epoxy resin..
If one looks at the Delta P oxygen cell holder for Dräger users, you can see they did the same !! (or they were first!!)
The second PPO² display is fitted in a Marc Munroe Lexan tube and end caps purchased from Tecme.


I fitted the VR3 and 2nd PPO² display together and that works very fine for me.  It just hangs close to my belly and is very easily spotted looking down. I like this way since I have nothing fitted to my arms and hands.
This is a very nice feature when diving wrecks on the North Sea!! (cfr my wife: my second home!)
That 2nd display has a very nice feature…
audible alarm if PPO² drops below 0.35 or is above 1.6 bar (Hmmm I like it).
I once , while struggling with a huge conger (against my will ;)) had my sensor connector pulled out off my VR3. Recently I read that another Kiss Dolphin diver Kim Meiniche had similar problems.
Therefore, I fitted a small rope on the cable tie to the little groove on the VR3 where normally the blind plug was strapped on.
Diluent addition is done through a 4 ltr-200bar cylinder, a regular 1stage regulator and using the
Original Dräger bypass. Therefore you need to remove the original spring and replace it with another
One with same length but less tension. I had some trouble finding one, but finally found one in an old
Inflator. (8 mbar opening pressure, to be tested !!)


At last I wanted to fit a wing instead of the original BC, but didn’t want to use a wrench for removing

The wing. I came up with a nice solution :





For removing the wing, I just have to pull 2 SS clips and lift the wing up. This is a very quick and nice feature for working on the RB.. for example with problems on the negative or positive pressure test !!
Below are some pictures with different views of my “second wife”







Well, that was it! I am very happy that Janwillem Bech allowed me these pages to be put or accessed on his website.
By doing this I wanted to show my appreciation to all of you who have contributed through Janwillem Bech’s website http://www.therebreathersiter.nl
Without this help I really wouldn’t have been able to modify my Dolphin.
Thanks to all of you and safe diving.
Oostende, Belgium
Special thanks to:   JanWillem Bech
                             Kerry McKenzie
                             Paul Raeymakers
                             Michel Urbani

page created on 29 June 2005

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