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Registros recuperados: 31 | |
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Bivaud, J. |
At present, offshore placers are generally exploited by means of traditional dredging equipment. This technique, called the "vertical method," consists of working the seabed directly from the surface support vessel through a rigid upflow pipe equipped, when necessary, with a sediment preloosening system. In contrast with the vertical method, this approach is based on the principle of working along the seabed with transfer of spoil up to the surface after extraction. We therefore call this the "horizontal method." Although it varies according to sites, in most cases this method comprises the design of a vehicle, self-propelled to some degree, which moves along the seafloor, carries and operates the appropriate mining tools and includes a system to transfer... |
Tipo: Text |
Palavras-chave: Offshore operations; Marine technology; Unmanned vehicles; Mining vessels; Placers; Deep sea mining. |
Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/1990/acte-1168.pdf |
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Freitas, A. |
Service submarines have been developed for support duties in offshore operations in deep waters. Three submarine concepts have been designed for water depths ranging from 400 to 1500 m. The operation philosophy is to use an autonomous manned submarine as a carrier for components, tools and work modules and as a base for IMR operations on subsea installations. The design principles are similar to that of the Space Shuttle incorporating a payload bay, energy supply and a closed environment for the crew and operators. The operation profile of an offshore submarine demands capabilities above those of naval submarines: deep diving, long endurance underwater, dynamic positioning. New technology had to be developed: air-independent energy system, regenerative... |
Tipo: Text |
Palavras-chave: Dynamic positioning; Marine technology; Diving; Offshore equipment; Offshore operations; Underwater inspection. |
Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/1990/acte-1165.pdf |
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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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Monsaingeon, L. |
The search for a panoramic, real-time, high frequency sonar has been a major goal for operating ranges where optical systems have established limitations. HYPSON 400 meets such requirements and provides a simultaneous and continuous beam-forming, no-scanning, wide opening system, using a hybrid beam-forming technique allowed by new component technologies. Up to seven images per second can be formed at a range of 100 meters, and more at shorter distances, as allowed by the speed of sound, thus providing the highest possible rate of information renewal required by operations at sea. |
Tipo: Text |
Palavras-chave: Instruments; Sonar imagery; Marine technology. |
Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/1990/acte-1156.pdf |
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Guillerm, G. |
MORS ENVIRONNEMENT has developed for the University of Hawaii a new system, SI 4X1-3, for study of movement of tectonic plate. In a single unit are gathered an acoustic rangemeter, a data acquisition unit (for 8 external sensors), a long range telemetry, and a power pack for 6 to 10 years life. The surface unit is a standard 16 frequencies RM 201 "OCEANO INSTRUMENTS" rangemeter. The programmation, the data transmission control, and the exploitation of the measures are done with a compatible IBM/AT. This system includes the know-how of SUBER and OCEANO INSTRUMENTS, and finds today a very large application field: Control and command of instrumented closing pigs; Seawater quality control without buoys and transmission up to 8 km; Corrosion control on platform... |
Tipo: Text |
Palavras-chave: Acoustic equipment; Marine technology; Plate tectonics. |
Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/1990/acte-1169.pdf |
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Iwai, Y; Nakanishi, T; Takahashi, K. |
After the four years of development of the modern maximum depth submersible, JAMSTEC has successfully completed the training dives of "SHINKAI 6500", a new manned submersible whose maximum operating depth is 6,500 meters, from June to October in this year. "SHINKAI 6500" was constructed by Kobe Shipyard and Machinary Works of Mitsubishi Heavy Industries Ltd. (MHI) and marked 6,465m and 6,527m dives in the Japan Trench during the sea trials with the support "YOKOSUKA" (built by Kawasaki Heavy Industries Ltd.) in August 1989. This paper presents the results of the sea trials, training dives and the features of "SHINKAI 6500" with her supporting technologies. |
Tipo: Text |
Palavras-chave: Japan; Deep water; Underwater cameras; Biology; Manned vehicles; Marine technology. |
Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/1990/acte-1136.pdf |
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Michel, J; Duranton, R. |
Autonomous Underwater Vehicles, also called "free-swimming vehicles" are self propelled bodies, equipped with their own energy package and with no solid communication link with the surface. At the beginning of the 90s, a renewed interest from the Underwater Intervention Community for autonomous vehicles and quite a number of new projects were announced or started. The present paper aims at presenting an updated State of the Art on the development of autonomous vehicles. It addresses the following points: A brief historical review presents some existing systems and uses. The French experience, in particular, allows to position the potential, and complementary contribution of autonomous vehicles, in a range of various operational systems. A short review of... |
Tipo: Text |
Palavras-chave: Design; Research; Research programmes; Historical account; Marine technology; Free swimming vehicles. |
Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/1990/acte-1135.pdf |
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Dransfeld, Steffen; Larnicol, Gilles; Le Traon, Pierre-yves. |
Having already shown its potential of deriving the vector fields representing the ocean-surface advection from sequential 1.1-km-resolution local area coverage (LAC) Advanced Very High Resolution Radiometer (AVHRR) images, the maximum cross-correlation (MCC) technique here is applied to four 4.4-km-resolution global area coverage (GAC) AVHRR images. The resulting three vector fields are compared to the vector fields obtained from the LAC imagery corresponding to the same satellite passages. To quantify the reduction in accuracy inevitable when applying the method to the lower resolution imagery, the LAC vector fields were assumed to be error free. The deviation of the GAC vectors from the LAC vectors is expressed as percentage errors of the signal variance... |
Tipo: Text |
Palavras-chave: Remote sensing; Marine technology; Infrared imaging; Image motion. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2319.pdf |
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Greger, B. |
A conceptually new, modularly designed exploration system for the deep sea (600 m) has been constructed and tested. In its base unit, different soil sampling tools can be integrated. These are, for the time being, a drill core barrel with 0 48 mm iD and a length of 500 mm for rocky basements as a box corer for softer soils as well as an orange peel grab. Towed along via a coaxial cable from a research vessel, the system is TV-guided and can be actively positioned by means of 2 thrusters in order to be lowered precisely and horizontally levelled on the seafloor. The total system is operated by the help of an onboard computer and may be controlled by sensor displays and operation messages. Microprocessors control the underwater unit which is partially... |
Tipo: Text |
Palavras-chave: Marine technology; Mineral exploration; Towed vehicles; Research vessels; Geology; Ocean floor. |
Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/1990/acte-1158.pdf |
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Duncan, N. |
Pressures of economics are driving the ROV industry to develop NDT equipment which will allow the ROV to detect, and assess, the presence of fatigue induced surface breaking defects in nodal welds and their associated heat affected zones. Two main techniques of NDT are currently being developed by Comex to provide ROV services to meet client needs. One is an MPI system and the other an Eddy Current system. Both are derivatives of equipment currently being used successfully by divers in the North Sea. The two systems are complementary to each other rather than in competition and offer a high degree of defect evaluation. This paper will discuss the requirements placed on the tool deployment system by the task, the worksite, the ROV characteristics and the... |
Tipo: Text |
Palavras-chave: Nondestructive testing; Manipulators; Marine technology; Unmanned vehicles. |
Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/1990/acte-1160.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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Avedik, Felix. |
Detecting and localizing nuclear blasts was an essential stimulus of the actions undertaken in the 1960's to emplace seismological observatories on the seafloor. The plate-tectonic theory, in which the oceanic areas play a major role, greatly accelerated the evolution of modern oceanology. The contribution of Ifremer's department of Marine Geosciences, in helping to advance this area of research, has been significant since 1972. The need for refraction studies to explore the deep structure of the margins and ocean-continent transition zones led us to design a deep-sea Ocean Bottom Seismograph (OBS) MK I in 1975, rated to 6,000 metres depth. This system introduced, for the first time, the concept of "isolated seismic sensors". This principle was adopted... |
Tipo: Text |
Palavras-chave: Geology; Seismometers; Digital records; Seismology; Surveys; Marine technology; Seismic data. |
Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/1990/acte-1140.pdf |
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Priour, Daniel. |
The quick evolution of fish farming in Europe, and its development towards the open sea needs suitable farming tools. These tools must withstand the difficult sea states, but they must be easy to use, well adapted to the fish farming and not too much expensive. This book helps the design of such tools. It defines the solicitations of the sea on all the structures, and presents rules and methods to control these solicitations. Here, a structure is composed of a rearing support, a mooring system and equipments. This book describes these components, class them and gives lists of providers. The rearing support can be a cage, a group of cages or a boat. The support can float or to be submersible. The mooring system can be made up ropes, chains, anchors,... |
Tipo: Text |
Palavras-chave: Aquaculture equipment; Mooring systems; Anchoring; Aquaculture techniques; Structures; Sea water; Life support systems; Aquatic environment; Cage culture; Marine technology; Rearing; Fish culture. |
Ano: 1995 |
URL: http://archimer.ifremer.fr/doc/1995/rapport-1667.pdf |
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Registros recuperados: 31 | |
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