Bill Sewell's Arctic Lung Rebreather....
Bill Sewell built this rebreather, and even has a video to go with it. The rest of the contents of this page are the contents of numerous e-mails from Bill. This rebreather got the name "Arctic Lung" because most of its test dives were in 34 degree water.
Bill said that he pretty much designed this in isolation from the rest of the world, and before he found the rebreather list. I asked what "isolation" meant. He replied:
Isolation as in: I talked with no one. information data base was 2 Aqua Corps magazines, any small article in any dive mag about rebreathers AND the 1955 DIVEMASTER home study book from E.R. Cross on rebreathers. I did from time to time look on the web but never really found anything of any help. My main area of ignorance was electronics...turns out it was far more simple than I had imagined. Armed with this all encompassing quote " Its very easy to build a bad rebreather" from a magazine article I went ahead and started building.
Perhaps the two things that set this breather apart from most is the 02 management and that it was fabricated from thermoplastic with a heat gun and hot air welder. Air is injected manually and 02 is added by a normal 2nd stage regulator, this has worked well for me do to the very closely matched counter lung volume to my own lung volume. Every few breaths you can hear the regulator squirt in a little 02. It now has three sensors that read from three LCD displays on a soon to be finished wrist mount. The air valve will be harness mounted keeping everything that I need in a fixed spot. With the use of "off the shelf" plumbing parts and a little handy work this has turned out to be a very clean looking machine and it can be stripped down for cleaning in four minutes.
|This is the mouthpiece, machined from solid aluminum and lined with a plastic sleeve between the check valves ( from a North respirator ). Two stainless screws hold the end fitting to the main body and its sealed with one O-ring.|
|This shows the dry suit exhaust valve removed from the main body, a spacer was installed in the valve to boost the amount of pressure that it will hold back. This mouthpiece does not have shut off capability.|
|The tee fitting is made from 1" pvc with npt threads for the lung and modified trap adapters to couple it to the scrubber, the green coded line is the quick disconnect fitting for the 02 regulator feed.|
|This is the hand made latex counter lung with a draw tube inside. The threaded fitting is a cpvc to pvc adapter that comes stock with an O-ring seal for mating to the "tee" fitting.|
|Polertech thermal cover for the counter lungs.|
|The scrubber, its both radial and axial flow ( really ) with a filler port on the bottom and a 2" trap adapter is used for the sensor port.|
|This little plug in the bottom of the scrubber is spring loaded to absorb any space left from settling of the scrubber. The fill port is sealed with a silicone gasket.|
|This is me getting ready for another test run, I'm checking my really cool meter that does not exist yet.|
|Just came back from a short trip to the bottom, and yes that's ice in the water!|
|Nice view of the 'breather, one of my thermal sleeves is riding up the hose that its supposed to cover. SPG hoses have not been trimmed to fit yet..lots of little details to refine but overall this machine has worked really great for me.|
The video that some of these stills were taken from is available here (ArcticLung.avi, 7 MB)
Copyright © Northwood Designs, Inc. All rights
Revised: January 30, 2002.
All trademarks or product names mentioned herein are the property of their respective owners.