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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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| Rougier, R. |
| Installation and tie-in using tig automatic hyperbaric welding of 3 expansion loops to the Gullfaks "C" gravity base platform at 220 meters in the Norwegian sector of the North Sea. Operation performed from a dynamically positioned diving support vessel using divers and construction ROV during the summer 1989. Facing the technological challenge created by the deep diving aspects, the technical difficulties of doing welding operation at this depth, and the tight commercial constraints, a review of the tasks was conducted to optimize and reduce the offshore time, leading to innovations in the procedures selected to perform the work: Use of a working ROV, assisted by an observation vehicle, to carry out subsea tasks traditionally reserved for construction... |
| Tipo: Text |
Palavras-chave: Diving; Offshore structures; Robots; Divers; Welding underwater; Offshore engineering; Unmanned vehicles; Marine technology; Offshore. |
| Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/1990/acte-1162.pdf |
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