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| Daste, S. |
| The "CRABE" method is a crack detection technique based on the use of low electromagnetic frequencies. This (patented) method relies on a global injection of current within the structure under inspection. The presence of a crack shall cause a disruption in the current flow, and consequently of the magnetic field off the surface in the vicinity of a defect. It is this magnetic signature which is detected by the magnetic sensor used with "CRABE". The major advantage of this process, developed by TRAVOCEAN and the LETI Division of CEA with the help of IFREMER, appears clearly: No preliminary cleaning of the welds to be inspected is required, since no contact is necessary. Similarly, it shall be possible to inspect the whole of structures to a total cost all... |
| Tipo: Text |
Palavras-chave: Offshore structures; Fouling; Underwater exploration; Steel structures; Sensors; Cracks; Detection; Unmanned vehicles; Marine technology. |
| Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/1990/acte-1161.pdf |
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| Mollard, J; Sauzade, Didier. |
| Developed in France by IFREMER and COMEX, SAGA is the first prototype of a new generation of industrial submarines capable of carrying out underwater operations using divers or robots at close proximity to the work site without surface assistance. SAGA (28 meters long, 550 tons submerged displacement, 6 crew members) has a hyperbaric compartment for 4 to 6 divers. Several important innovations, in particular with regards to energy, give SAGA an exceptional autonomy, essential for performing deep underwater operations. The submarine was launched in October 1987 and has just completed to three-year qualification programme. Since May 1990 SAGA holds the world record of the deepest (-317 m) diver lock-out operation from a submarine. This paper presents the new... |
| Tipo: Text |
Palavras-chave: Working underwater; Underwater exploration; Marine technology; Underwater vehicles. |
| Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/1990/acte-1166.pdf |
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