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I don't see anything wrong with this setup, Billy. Obviously this death was due to diver error. I guess he forgot whether the yellow tape was air or nitrox. An innocent mistake anybody could have made. He should have had a hose wrap around the nitrox, um, or the air, that would have made everything better. Billy, I truly hope you are not implying with this post that weird, bizarre, non-standard equipment and configurations could possibly have been at fault. I mean the mere suggestion of this makes you a DIR goose-stepping nazi fanatic. It's a much better for divers to follow their own path, do their own thing. How could you possibly suggest that following a standard, proven gear configuration could do anything but stifle the creative urges of the aspiring techdiver. Take a look at this fellow, independent doubles with different mixes going to an unlabeled gas block equipped with a great big easily-moved lever. This fellow is, er, was obviously an genius of the highest order. I see that his wonderful, inspiring rig is now available for purchase. Perhaps we can all pitch in and purchase it for Black, the only person *I* know of smart enough to appreciate it's beauty of design and construction. Jim ------------------------------------------------------------------- Learn About Trimix at http://www.cisatlantic.com/trimix/ > From: <billy@bd*.co*.au*> > Date: Wed, 02 Aug 2000 20:37:41 +1000 > To: <techdiver@aquanaut.com> > Subject: Re: ABC on Diving the San Diego - STROKE ALERT > > >> on 7/31/00 2:24 AM, speez3 (Techdiver) at speez3@ea*.ne* wrote: >> >>> As for Tony Maffatone, he takes his >>> ideas, puts them on paper and makes them work. Everything he builds is from >>> his own design. This whole thread really shows ZERO intelligence from this >>> list. A proper apology is definitely in order. > > > Seems Maffatone is determined to take an outdated > and terminally stupid idea and grind it around and > around some-more. > > The old Kevorkian rig rears its ugly head again. > > rgds billyw > > > ------5. New South Wales State Coroner. Coroner's Court, 1995. File number > 94/574. ------- > > Clinical record > > A 47-year-old experienced underwater cave diver, with no significant medical > history, was diving with two tanks -- one containing compressed air, the other > a 50% mixture of oxygen and nitrogen (nitrox). Towards the end of the 47-m, > 19-min dive, he was seen floating head down, unresponsive, with his mouthpiece > out of his mouth and "his fins [flippers] moving as if he was shivering" (as > reported by another diver to the Coroner). The body was carried up to 15 m > depth and then allowed to ascend freely as the other divers decompressed. > > Cardiopulmonary resuscitation was attempted, but abandoned after 43 minutes as > there was no response. > > Autopsy findings > > Erect postmortem x-rays and autopsy of the body performed 24 hours after death > revealed large amounts of gas in the venous system of the trunk and limbs and > in both sides of the heart (Figure 1). The heart weighed 380 g and was normal, > apart from foamy blood and gas in all chambers. Analysis of gas from the right > ventricle showed O2 (20.6% by volume), and N2 (75.9%). There was bruising of > the tongue and petechiae on the lungs and heart. The brain (1740 g) showed > mild cerebral oedema and a microscopic perivascular haemorrhage in the floor > of the fourth ventricle. > > Figure 1: Postmortem erect chest x-ray, showing gas in both sides of the chest > and in the neck veins (a combination of postmortem decompression, perimortem > barotrauma and, possibly, decomposition). > > Examination of diving equipment > > Examination of the subject's diving equipment (Figure 2) revealed that he had > been breathing the 50% oxygen/nitrogen mixture for most of the dive. Each tank > had a separate first stage connected in an unusual fashion by a two-way > switch, which the diver had had made by a local engineering shop. This allowed > the diver to switch from one tank to another rapidly. This switch supplied a > single second-stage mouthpiece. The two tanks were different colours; the > circuit from the black (compressed-air) tank was marked with yellow tape, > while the circuit from the yellow (nitrox) tank was unmarked. > > Figure 2: Equipment used by the diver, showing the 50% oxygen/nitrogen gas > tank (yellow, right), compressed-air tank (black, left), yellow tape marking > the compressed-air circuit, and two-way valve which controlled the source of > the air supply (inset shows close-up of valve). > > The regulator had a small tear and a bite mark in the mouthpiece. The diver > wore a facemask and separate mouthpiece rather than a full facemask, which > covers eyes, nose and mouth. > > Discussion > > The cause of death, as determined by the Coroner, was drowning after oxygen > toxicity.(5) The "shivering" movements and the biting of the tongue and > mouthpiece suggested fitting. Using a 50% oxygen/nitrogen mixture at 47 m > depth, the diver had been exposed to a partial pressure of oxygen of 291 kPa > (2.9 atm), possibly for as long as 19 min. During diving, this gas mixture > should be used only at depths less than 14-18 m (depending on the duration of > exposure). > > Cerebral gas embolism and decompression illness were unlikely causes of death, > as the subject was unresponsive before ascent. The gas observed at autopsy > probably resulted from a combination of postmortem decompression (release of > tissue nitrogen), perimortem barotrauma and, possibly, a degree of > decomposition.(6) > > This death resulted from several compounding problems: > > 1.The diver may have turned the switch to the unmarked nitrox circuit, > thinking he was using the circuit to the compressed air in the black tank (the > yellow label marked the circuit from the black [compressed-air] tank, not the > circuit from the yellow [nitrox] tank). Alternatively, as the two-way valve > needed very little pressure to turn, it could have been accidentally switched > from a safe to an unsafe gas mix. > > 2.The diver was using a separate facemask and mouthpiece. During the seizure, > the mouthpiece fell out. A full facemask, covering both the mouth and nose, > should be worn by divers using oxygen-rich mixtures or carrying out deep > diving on compressed air, to reduce the chance of drowning should an oxygen > convulsion occur. > > This technical diving fatality and those reported in the United States in > 1992(4) were in experienced divers, who should have understood the dangers. > > source: "an article published on the Internet by The Medical Journal of > Australia <http://www.library.usyd.edu.au/MJA/>" > > -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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