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46-582: This chamber was first discovered in 1985 by Jochen Hasenmayer , who named it Mörikedom (Mörike Cathedral, named after Eduard Mörike ). Hasenmayer's diving accident in the Wolfgangsee resulted in a long break in its exploration. For several years the cave has been explored by the Arbeitsgemeinschaft Blautopf (Blautopf Study Group, or Consortium), a team of cave divers from several different regional groups. This group has made progress exploring

92-752: A sinkhole north of Blaubeuren , which is believed to be connected with the Blauhöhle beyond the Apokalypse . 48°24′59″N 9°47′02″E  /  48.41639°N 9.78389°E  / 48.41639; 9.78389 Cave dive sites: Jochen Hasenmayer Jochen Hasenmayer (born 28 October 1941 in Pforzheim , Germany ) is a German speleologist and cave diver from Birkenfeld in Baden-Württemberg , whose spectacular dives have frequently made headlines. Hasenmayer began his cave diving career in 1957 at

138-742: A submersible , the Speleonaut , designed and built by Hasenmayer and his friend Konrad Gehringer , to explore the Blauhöhle. In 2001 Hasenmayer reached the Mörikedom chamber of the Blauhöhle in the Speleonaut . In 2004 he reached a point beyond the Mörikedom 1,800 metres (5,900 ft) into the mountain. In the same year he discovered two more large chambers in the Blauhöhle: the Mittelschiff (or "nave") and

184-452: A clinic during his rehabilitation from his decompression accident. They live in Birkenfeld, near Pforzheim. Trimix (breathing gas) Trimix is a breathing gas consisting of oxygen , helium and nitrogen and is used in deep commercial diving , during the deep phase of dives carried out using technical diving techniques, and in advanced recreational diving . The helium

230-550: A conventional compressor. The more complicated (and dangerous) step of adding pure oxygen at pressure required to blend trimix is absent when blending heliair. Heliair blends are similar to the standard Trimix blends made with helium and Nitrox 32, but with a deeper END at MOD. Heliair will always have less than 21% oxygen, and will be hypoxic (less than 17% oxygen) for mixes with more than 20% helium. Technical diver training and certification agencies may differentiate between levels of trimix diving qualifications, The usual distinction

276-399: A dive using residual mix — only helium and banked nitrox are needed to top up the residual gas from the last fill. The method of mixing a known nitrox mix with helium allows analysis of the fractions of each gas using only an oxygen analyser, since the ratio of the oxygen fraction in the final mix to the oxygen fraction in the initial nitrox gives the fraction of nitrox in the final mix, hence

322-407: A gap in the cave, believing he was "shaking a dead man's hand", but Hasenmayer found his way out. The passage where the incident occurred became known as "Dead Man's Handshake". Hasenmayer spent decades developing the necessary diving equipment for his explorations. Well known as a safety fanatic, Hasenmayer has introduced unique practices perceived by some cave divers as safe, but which contradict

368-562: A given pressure of helium into an empty cylinder, and then topping up the mix with 32% nitrox. The "standard" mixes evolved because of three coinciding factors — the desire to keep the equivalent narcotic depth (END) of the mix at approximately 34 metres (112 ft), the requirement to keep the partial pressure of oxygen at 1.4 ATA or below at the deepest point of the dive, and the fact that many dive shops stored standard 32% nitrox in banks, which simplifies mixing. The use of standard mixes makes it relatively easy to top up diving cylinders after

414-427: A high risk of drowning. Because of its low molecular weight, helium enters and leaves tissues by diffusion more rapidly than nitrogen as the pressure is increased or reduced (this is called on-gassing and off-gassing). Because of its lower solubility, helium does not load tissues as heavily as nitrogen, but at the same time the tissues can not support as high an amount of helium when super-saturated. In effect, helium

460-518: A lake in Austria . His short decompression resulted in the bends , causing paralysis , but his colleagues immediately placed him in a waiting decompression chamber , and initially the paralysis was reversed. However, the emergency physicians at the hospital in Graz again decompressed Hasenmayer too quickly. Since that time he has been a paraplegic . Hasenmayer did not give up diving, but since 1996 has used

506-545: A maximum partial pressure of oxygen (PO 2 —see Dalton's law ) of 1.0 to 1.6 bar and maximum equivalent narcotic depth of 30 to 50 m (100 to 160 ft). At 100 m (330 ft), "12/52" has a PO 2 of 1.3 bar and an equivalent narcotic depth of 43 m (141 ft). Although theoretically trimix can be blended with almost any combination of helium and oxygen, a number of "standard" mixes have evolved (such as 21/35, 18/45 and 15/55—see Naming conventions ). Most of these mixes originated from starting by decanting

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552-483: A mix named "trimix 10/70" or trimix 10/70/20, consisting of 10% oxygen, 70% helium, 20% nitrogen is suitable for a 100-metre (330 ft) dive. Hyperoxic trimix is sometimes referred to as Helitrox, TriOx, or HOTx (High Oxygen Trimix) with the "x" in HOTx representing the mixture's fraction of helium as a percentage. The basic term Trimix is sufficient, modified as appropriate with the terms hypoxic, normoxic and hyperoxic, and

598-517: A separate supply of a different gas to inflate drysuits . This is to avoid the risk of hypothermia caused by using helium as inflator gas. Argon , carried in a small, separate tank connected only to the inflator of the drysuit, is preferred to air, since air conducts heat 50% faster than argon. Dry suits (if used together with a buoyancy compensator) still require a minimum of inflation to avoid "squeezing", i.e. damage to skin caused by pinching by tight dry suit folds. Helium dissolves into tissues (this

644-420: A trimix to be used as a decompression gas can accelerate decompression with a lowered risk of isobaric counter diffusion complications. Retaining nitrogen in trimix can contribute to the prevention of High Pressure Nervous Syndrome , a problem that can occur when breathing heliox at depths beyond about 130 metres (430 ft). Nitrogen is also much less expensive than helium. The term trimix implies that

690-496: Is a faster gas to saturate and desaturate, which is a distinct advantage in saturation diving , but less so in bounce diving, where the increased rate of off-gassing is largely counterbalanced by the equivalently increased rate of on-gassing. Some divers suffer from compression arthralgia during deep descent, and trimix has been shown to help avoid or delay the symptoms of compression arthralgia. Helium conducts heat six times faster than air, so helium-breathing divers often carry

736-487: Is between normoxic trimix and hypoxic trimix, sometimes also called full trimix. The basic distinction is that for hypoxic trimix diving the dive cannot be started on the bottom mix, and procedures for use of a travel mix for the first part of the descent, and gas switching during the descent to avoid oxygen toxicity are added to the required skills. Longer decompression using a larger variety of mixtures may also complicate procedures. In closed circuit rebreather diving, use of

782-421: Is called on-gassing) more rapidly than nitrogen as the ambient pressure is increased. A consequence of the higher loading in some tissues is that many decompression algorithms require deeper decompression stops than a similar pressure exposure dive using air, and helium is more likely to come out of solution and cause decompression sickness following a fast ascent. In addition to physiological disadvantages,

828-438: Is included as a substitute for some of the nitrogen, to reduce the narcotic effect of the breathing gas at depth. With a mixture of three gases it is possible to create mixes suitable for different depths or purposes by adjusting the proportions of each gas. Oxygen content can be optimised for the depth to limit the risk of toxicity , and the inert component balanced between nitrogen (which is cheap but narcotic) and helium (which

874-469: Is mostly used by Technical Diving International (TDI). It is easily blended from helium and air and so has a fixed 21:79 ratio of oxygen to nitrogen with the balance consisting of a variable amount of helium. It is sometimes referred to as "poor man's trimix", because it is much easier to blend than trimix blends with variable oxygen content, since all that is required is to insert the requisite partial pressure of helium, and then top up with air from

920-453: Is not narcotic and reduces work of breathing, but is more expensive and increases heat loss ). The mixture of helium and oxygen with a 0% nitrogen content is generally known as heliox . This is frequently used as a breathing gas in deep commercial diving operations, where it is often recycled to save the expensive helium component. Analysis of two-component gases is much simpler than three-component gases. The main reason for adding helium to

966-483: Is used in the 30 to 60 m (100 to 200 ft) depth range; a hypoxic mix such as "10/50" is used for deeper diving, as a bottom gas only, and cannot safely be breathed at shallow depths where the PO 2 is less than 0.18 bar. In fully closed-circuit rebreathers that use trimix diluents, the mix in the breathing loop can be hyperoxic (meaning more oxygen than in air, as in enriched air nitrox ) in shallow water, because

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1012-611: The Arbeitsgemeinschaft . Hasenmayer continued his attempts to explore the cave system in his cave submersible , Speleonaut . Since 2002 the Arbeitsgemeinschaft Höhle und Karst Grabenstetten (Cave and Karst Consortium of Grabenstetten), as a part of their work on a neighboring cave system, the Vetterhöhle , have attempted to dig a dry entrance into the Blauhöhle. In 2006 several large caverns were discovered in

1058-526: The Vetterhöhle , and in the autumn a connection was discovered between the Vetterhöhle and the Wolkenschloss . Also in the autumn of 2006, the Arbeitsgemeinschaft Blautopf discovered a chamber at the end of the Landweg, measuring 170 m (560 ft) long by 50 m (160 ft) wide by 50 m high, which was named Apokalypse . The groups are now also working with yet another Arbeitsgemeinschaft on

1104-462: The diving cylinder and then topping up the mix with air from a diving air compressor . To ensure an accurate mix, after each helium and oxygen transfer, the mix is allowed to cool, its pressure is measured and further gas is decanted until the correct pressure is achieved. This process often takes hours and is sometimes spread over days at busy blending stations. Corrections can be made for temperature effect, but this requires accurate monitoring of

1150-565: The Äonendom . For the last several years the Blautopf cave system has been explored by the Arbeitsgemeinschaft Blautopf (Blautopf Study Group, or Consortium), a team of cave divers led by Hasenmayer. The most recent fatal accident in the Blautopf occurred in 2003, killing Bernd Aspacher, a member of Hasenmayer's team. Hasenmayer developed a controversial theory on the subject of karst formation in Southern Germany. According to this theory,

1196-521: The Blauhöhle was formed between 25 million and 100 million years ago, much earlier than is currently believed. Therefore, the Blauhöhle could not drain to the original Danube Valley , today the Blau , and must have drained much farther south. Since these caves are deep enough to contain large quantities of thermal water , this could lead to the recovery of geothermal energy which could be used to solve energy problems in Southern Germany. As an indication of

1242-795: The age of fifteen, exploring the Falkensteiner Höhle near Stuttgart . Beginning in the 1960s, Hasenmayer explored many karst springs and caves in the Swabian Jura and elsewhere in Southern Germany , including the Wimsener Höhle , the Aachtopf and the Blautopf . He became famous in 1985 due to the discovery of the Mörikedom ("Mörike Cathedral", named after the German pastor and poet Eduard Mörike ),

1288-472: The analyser should be calibrated at ambient temperature before use. The mixing tube is a very simple device, and DIY versions of the continuous blend units can be made for a relatively low cost compared to the cost of analysers and compressor. The ratio of gases in a particular mix is chosen to give a safe maximum operating depth and comfortable equivalent narcotic depth for the planned dive. Safe limits for mix of gases in trimix are generally accepted to be

1334-546: The basic rules of normal diving. Hasenmayer was a pioneer in the use of trimix breathing gas mixtures (adding helium to oxygen and nitrogen ). Hasenmayer and American cave diver Sheck Exley became friends and rivals in the 1980s, each repeatedly attempting to break the depth records of the other. In 1981 Hasenmayer used mixed gas to reach a depth of 476 feet (145 m) in the Fountain of Vaucluse in France. Hasenmayer made

1380-498: The breathing mix is to reduce the proportions of nitrogen and oxygen below those of air, to allow the gas mix to be breathed safely on deep dives. A lower proportion of nitrogen is required to reduce nitrogen narcosis and other physiological effects of the gas at depth. Helium has very little narcotic effect. A lower proportion of oxygen reduces the risk of oxygen toxicity on deep dives. The lower density of helium reduces breathing resistance at depth. Work of breathing can limit

1426-546: The cave's age, Hasenmayer claimed that underwater stalactites at the back of the cave were several million years old, but scientific investigation of a drip stone yielded an age of well under 10,000 years. Hasenmayer's theory was published in 1986, but many scientists are sceptical of his claim. Hasenmayer has been awarded the Order of Merit of the Federal Republic of Germany . Hasenmayer met his life partner Gaby Barth at

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1472-464: The cave, including making exact measurements of the way to the Mörikedom . The improvement of underwater breathing technology, especially the rebreather , has allowed for longer dives carrying less weight. The discovery of the Wolkenschloss (Castle of Clouds), another large, air-filled cavern, and the so-called Landweg (land-way), a long, open cave river behind the Mörikedom, were great successes for

1518-405: The duration and the kind of breathing system used. A maximum oxygen partial pressure of 1.4 bar for the active sectors of the dive, and 1.6 bar for decompression stops is recommended by several recreational and technical diving certification agencies for open circuit, and 1.2 bar or 1.3 bar as maximum for the active sectors of a dive on closed-circuit rebreather. Increasing the oxygen fraction in

1564-526: The fractions of the three components are easily calculated. It is demonstrably true that the END of a nitrox-helium mixture at its maximum operating depth (MOD) is equal to the MOD of the nitrox alone. Heliair is a breathing gas consisting of mixture of oxygen , nitrogen and helium and is often used during the deep phase of dives carried out using technical diving techniques. This term, first used by Sheck Exley ,

1610-405: The gas has three functional components, which are helium, nitrogen and oxygen. Since the nitrogen and all or part of the oxygen is usually provided from air, the other components of ordinary atmospheric air are generally ignored. Conventionally, the composition of a mix is specified by its oxygen percentage, helium percentage and optionally the balance percentage, nitrogen, in that order. For example,

1656-405: The necessary mix for a deep dive that requires the gas. Lowering the oxygen content of a breathing gas mixture increases the maximum operating depth and duration of the dive before which oxygen toxicity becomes a limiting factor. Most trimix divers limit their working oxygen partial pressure [PO 2 ] to 1.4 bar and may reduce the P O 2 further to 1.3 bar or 1.2 bar depending on the depth,

1702-405: The oxygen and helium flows adjusted accordingly. On the high pressure side of the compressor a regulator or bleed orifice is used to reduce pressure of a sample flow and the trimix is analyzed (preferably for both helium and oxygen) so that the fine adjustment to the intake gas flows can be made. The benefit of such a system is that the helium delivery tank pressure need not be as high as that used in

1748-405: The partial pressure method of blending and residual gas can be 'topped up' to best mix after the dive. This is important mainly because of the high cost of helium. Drawbacks may be that the high heat of compression of helium results in the compressor overheating, especially in hot weather. Temperature of the trimix entering the analyser should be kept constant for best reliability of the analysis, and

1794-419: The rebreather automatically adds oxygen to maintain a specific partial pressure of oxygen. Hyperoxic trimix is also sometimes used on open circuit scuba, to reduce decompression obligations. Gas blending of trimix generally involves mixing helium and oxygen with air to the desired proportions and pressure. Two methods are in common use: Partial pressure blending is done by decanting oxygen and helium into

1840-601: The second big air-filled chamber in the Blauhöhle , about 1,250 metres (4,100 ft) into the cave system. Some of his terminuses (farthest point reached in a cave) have not been exceeded. In the late 1970s, Hasenmayer was among the divers who searched for an underwater connection between Kingsdale Master Cave and Keld Head in the Yorkshire Dales . On 5 February 1978 Hasenmayer briefly became trapped in Keld Head. A British diver, Geoff Yeadon, shook Hasenmayer's hand through

1886-400: The temperature of the mixture inside the cylinder, which is generally not available. A second method called 'continuous blending' is done by mixing oxygen and helium into the intake air of a compressor. The oxygen and helium are fed into mixing tubes in the intake air stream using flow meters or analysis of the oxygen content after oxygen addition and before and after the helium addition, and

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1932-464: The use of breathing gas mixtures in underwater breathing apparatus, as with increasing depth a point may be reached where work of breathing exceeds the available effort from the diver. Beyond this point accumulation of carbon dioxide will eventually result in severe and debilitating hypercapnia , which, if not corrected quickly, will cause the diver to attempt to breathe faster, exacerbating the work of breathing, which will lead to loss of consciousness and

1978-541: The use of trimix also has economic and logistic disadvantages. The price of helium increased by over 51% between the years 2000 and 2011. This price increase affects open-circuit divers more than closed-circuit divers due to the larger volume of helium consumed on a typical trimix dive. Additionally, as trimix fills require more expensive analysis equipment than air and nitrox fills, there are fewer trimix filling stations. The relative scarcity of trimix filling stations may necessitate going far out of one's way in order to procure

2024-553: The usual forms for indicating constituent gas fraction, to describe any possible ratio of gases, but the National Association of Underwater Instructors (NAUI) uses the term "helitrox" for hyperoxic 26/17 Trimix, i.e. 26% oxygen, 17% helium, 57% nitrogen. Helitrox requires decompression stops similar to Nitrox-I (EAN32) and has a maximum operating depth of 44 metres (144 ft), where it has an equivalent narcotic depth of 35 metres (115 ft). This allows diving throughout

2070-442: The usual recreational range, while decreasing decompression obligation and narcotic effects compared to air. GUE and UTD also promote hyperoxic trimix for this depth range, but prefer the term "TriOx". In open-circuit scuba , two classes of trimix are commonly used: normoxic trimix—with a minimum PO 2 at the surface of 0.18 and hypoxic trimix—with a PO 2 less than 0.18 at the surface. A normoxic mix such as "19/30"

2116-464: The world's first 200 metres (660 ft) dive in the Fountain of Vaucluse on 9 September 1982, diving after dark because he had been denied a diving permit. His then-wife, Barbara, waited all night for him to surface. In 1983 Hasenmayer made a mixed-gas cave dive to 656 feet (200 m) at Vaucluse. Due to a faulty depth gauge, in 1989 Hasenmayer surfaced too quickly after a dive in the Wolfgangsee ,

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