The following pictures and information were contributed Walter Stark, the designer of the Electrolung. He is a rebreather list member.
Excerpt from Rebreather list posting "Electrolung design VI.
Final (Reflections and speculations)"
Jul 21 1998
Development of the Electrolung came about through the chance meeting of John Kanwisher and I aboard Ed Link's diving research vessel in the Bahamas in early 1968. Ed was trying out his new diver lock-out submarine Deep Diver and had invited along several researchers with relevant interests. I was there to do some deep biological collecting and John was there to do heart rate/respiration measurements on divers using some new acoustical telemetry equipment he had developed.
Lock-out dives from Deep Diver were done using hose fed OC Kirby Morgan helmets. Gas for this purpose and to pressurize the lock-out chamber was supplied from a large high pressure sphere carried by the sub. The large amount of gas required for a single dive severely limited the number of dives which could be made and involved substantial cost and logistic considerations. The need for more efficient utilization of gas was clearly apparent.
It turned out that John and I had both been considering the feasibility of a mixed gas CCRB using electronic sensors to control PPO2. We both knew in general terms what was needed but John wasn't a diver or a machinist and I didn't know that much about electronics. However, I had been diving for 15 years and had built a wide range of underwater equipment and John, in addition to being a physiologist, had invented the first polariographic oxygen sensor and held a dual appointment at Woods Hole Oceanographic Institute and MIT where he lectured on electronic instrument design.
When we returned to our homes John started putting together the sensors and control circuit and I started getting together the hardware and machining all of the necessary bits. Six weeks later we both had our respective parts together. John sent me the board and sensors, I installed them and it worked. The overall configuration and design was basically as described but there were, of course numerous details to clean up. The electronics for example were wire connected on a breadboard and the solenoid valve I had hand made and actuated with a solenoid scavenged from a battery operated coo-coo clock.
Although the prototype was put together quite quickly it was far from a "first thing which comes to mind" effort. Quite a few years experience and thought had led up to it so that when actual construction was began we both knew pretty clearly what needed to be done and how to do it. Later at Beckman I had the opportunity of working with a whole group of specialists on improving the same device. The outcome was some tidying up of details but no fundamental improvement. The biggest problem was to prevent the creation of problems which didn't previously exist but could be introduced through changes made by specialists who were unaware of consequences outside of the narrow area of their expertise. The experience gave me a real appreciation of both the power and the limitations of specialist expertise and the importance of systems analysis in coordinating and integrating the input of specialists.
Although development of the Electrolung was interesting, even exciting, in itself it was just an interesting incident in a bigger, far more interesting and significant picture. Like most historical events, I suppose, what was happening didn't appear to the participants at the time so remarkable as it later does in the broader perspective of hindsight. The larger perspective on what is taking place right now tends to be somewhat obscured by the ordinary events of living. Except for rare instances whatever we are doing, however interesting and exciting it may be, tends to still feel like life, not like history in the making.
Click on any image to get a full size image with the associated description.
|The two diver images were shot in the Bahamas in 1970 and scanned on 22 July 1998 with the worst of the fungus touched up. The remainder were taken on 22 July 1998 with a Sony VX 1000 Digital Video camera using photo mode. The Electrolung pictured was a Beckman model which I carried on my boat as a spare for 20 years. It hasn't been used since 1971. I dug it out of the garage and blasted the dust off with a high pressure water jet to take the pictures. Sorry if it is a bit untidy but 20 years aboard ship and 10 more in a garage in the wet tropics does that to things.|
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Revised: September 07, 2005.