Cyana
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Cyana is a small 9-ton submarine designedby Jacques-Yves Cousteau for the French “Center national pour l'exploitation des océans” (CNEXO, now Ifremer ) thatcan carrythree passengers to a diving depth of 3000 meters. Built in 1969, the Cyana was no longer in service from 2003 and has been available to the Cité de la Mer science and leisure parknear Cherbourg-Octeville since 2004.
A new concept
With the original designation SP 3000 , the Cyana (named in 1973 by CNEXO after the Greek mythical virgin Kyane ) followed the SP 350 and SP 500 , where "SP" stood for "soucoupe plongeante" (diving saucer), which aptly Unlike the rather clumsy bathyscaphs constructed in the middle of the 20th century . Unlike a bathyscaphe, the Cyana could be hoisted onto the deck of even a rather small ship . What they had in common, however, was the principle of a spherical steel capsule hanging from a float, but the wall thickness (80 mm ) and thus the weight was reduced, and synthetic foam under a polyester outer skin provided the necessary buoyancy. This was preceded by the exclusion of the Pacific deep-sea trenches as an operational area, which should instead consist of oceans of medium depth - preferably the continental shelves and slopes. The submersible was tested in a test container, where the outer shell withstood a pressure of 380 atmospheres (corresponds to 3800 meters sea depth).
Procedure for use
Diving came to ways through carried ballast ( iron shot ), which was drained to surface. Shortly before the dive, detachable balloons kept the submarine afloat. Due to the slightly ellipsoidal shape and a trimming controlled by a mercury pump, the Cyana did not sink vertically, but on a screw curve. The maximum sink rate of 40 meters per minute required timely braking when approaching the stony seabed - the high-temperature steel from which the diving ball is made sometimes tends to break brittle . The "Aquanauts" wore asbestos suits, because packed like the capsule with measuring and control instruments, there was a risk of electrical circuits scorching.
Dramatic beginning
Had there been in the 1960s, a boom in the production of small submarines were fit mostly only excursions under water, was with the SP 3000 created a real working device whose trial impatient by the planners of the FAMOUS project , its first use, was expected. There was not much time for tests: Fortunately, the SP 3000 sank to 3400 m during a test dive in the Tyrrhenian Sea in 1971 and was not lifted until fourteen days later with the help of the Archimède - the deepest mountain operation ever undertaken.
In April 1972 there were a few training dives in the Mediterranean before the Cyana arrived on board the mother ship Le Noroît in June 1974 over the mid-Atlantic rift valley . Two meters of wave height was the limit value for the water of the submarine, and such adverse conditions were encountered. During the first attempt to lower one of several stabilizing lines, the fully occupied Cyana swung over the ship like the proverbial "loose cannon on deck". It hit so hard that further dives had to be preceded by an X-ray examination of the boat.
Late successes
1990 discovered Cyana near the Rhone estuary a Gallic ship wreck . In response to a request from a private company, she was able to locate the wreck of the freighter John Barry , sunk in 1944, off Oman in 1992 , in which silver bars were suspected.
literature
- Claude Riffaud / Xavier Le Pichon: Expedition "Famous". 3000 meters below the Atlantic , Verlag Kiepenheuer & Witsch, Cologne 1977, p. 102 f.
Web links
Footnotes
- ↑ Center national pour l'exploitation des océans - rapport annuel 1971 , Paris, p. 29 ( PDF )
- ^ Mission Bravo - Chasse au trésor: le désossage du John Barry , Internet portal "Ifremer.fr" (French)