Sample records for catamarans

  1. Catamaran Nets (United States)


    West Coast Netting, Inc.'s net of Hyperester twine, is made of three strands of fiber twisted together by a company-invented sophisticated twisting machine and process that maintain precisely the same tension on each strand. The resulting twine offers higher strength and improved abrasion resistance. The technology that created the Hyperester supertwine has found spinoff applications, first as an extra-efficient seine for tuna fishing, then as a capture net for law enforcement agencies. The newest one is as a deck for racing catamarans. Hyperester twine net has been used on most of the high performance racing catamarans of recent years, including the America's Cup Challenge boats. They are tough and hold up well in the continual exposure to sunlight and saltwater.

  2. CATAMARAN targeted at innovative radiopharmacy

    Energy Technology Data Exchange (ETDEWEB)

    Impens, N.; Aerts, A.


    In cancer therapy there is a great need for specific treatments: therapies that kill cancer cells selectively without affecting the healthy cells. In the CATAMARAN project (Cancer Targeting Molecules Attached to Radionuclides) SCK-CEN develops, in a preclinical trial, products that deliver the right radiation doses at the right place in the human body. With the new multidisciplinary expertise that has been built up in the project, SCK-CEN is contributing to new medical applications of radiation.

  3. CATAMARAN targeted at innovative radiopharmacy

    International Nuclear Information System (INIS)

    Impens, N.; Aerts, A.


    In cancer therapy there is a great need for specific treatments: therapies that kill cancer cells selectively without affecting the healthy cells. In the CATAMARAN project (Cancer Targeting Molecules Attached to Radionuclides) SCK-CEN develops, in a preclinical trial, products that deliver the right radiation doses at the right place in the human body. With the new multidisciplinary expertise that has been built up in the project, SCK-CEN is contributing to new medical applications of radiation.

  4. Wave resistance for high-speed catamarans

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, H.B. [Para University, CEP (Brazil); Vasconcellos, J.M. [Federal University of Rio de Janeiro (Brazil). Naval Architecture Department; Latorre, R.G. [University of New Orleans, LA (United States)


    The object of this study was to investigate the wave resistance component for high-speed catamarans. Two methods were applied: the slender-body theory proposed by Michell [Philos. Mag. 45(5) (1898) 106] and a 3D method used by Shipflow{sup TM} (FLOWTECH, Shipflow{sup TM} 2.4, User Manual, 1988) software. Results were obtained for different types of twin hulls and attention was given to the effects of catamaran hull spacing. The study also included the effect of shallow water on the wave resistance component. Special attention was given to the height of waves generated by the craft to ascertain effect on river banks. (author)

  5. Discussion of grid generation for catamaran resistance calculation (United States)

    Deng, Rui; Huang, De-Bo; Li, Jia; Cheng, Xuan-Kai; Yu, Lei


    In order to get some useful parameters for grid generation of catamaran, the CFD software FLUENT is used to investigate the main effects of grid generation on flow field calculation. The influences of some elements are investigated with a series of calculations in the present paper, and some alteratives are proposed. The proposed alteratives based on the analysis of the effects are used for a catamaran resistance calculation, comparisons of the calculated results with experimental data show good agreement. It shows that the research result of this paper is useful for the numerical calculation of catamaran.


    Directory of Open Access Journals (Sweden)

    Mardi Santoso


    Full Text Available Pada tahap awal desain, untuk mendapatkan desain kapal yang optimum perlu dilakukan analisa untuk menentukan parameter utama dari kapal. Dalam penelitian ini akan dilakukan analisa terhadap pemilihan parameter utama dari kapal ferry catamaran kelas 1000GT untuk mendapatkan desain kapal ferry yang optimal. Parameter utama kapal ditentukan dari optimasi data utama kapal yang mirip yang dijadikan acuan set based design untuk mendapatkan ukuran kapal kapal ferry catamaran yang diinginkan. Geometri bentuk lambung kapal kemudian dioptimasikan dan dianalisa hambatannya menggunakan metode perhitungan, simulasi dan uji tarik. Rencana umum kapal kemudian dikembangkan untuk mendapatkan penataan ruang dan penentuan kapasitas kapal yang otimum. Dari hasil perhitungan menunjukkan bahwa kapal ferry catamaran 1000GT memiliki gross tonnage (GT sebesar 1130GT dan nett tonnage (NT 197GT. Dan daya mesin yang digunakan adalah 4 x 810 HP, untuk kecepatan dinas 15 knots.

  7. Hydrodynamics of single-deadrise hulls and their catamaran configurations

    Directory of Open Access Journals (Sweden)

    Ghazi S. Bari


    Full Text Available Asymmetric planing hulls are often used on high-speed catamarans. In this study, a linearized potential-flow method is applied for modeling steady hydrodynamics of single asymmetric hulls and their catamaran setups. Numerical results are validated with available experimental data and empirical correlations. Parametric calculation results are presented for the lift coefficient and the center of pressure for variable hull geometry, spacings, and speed regimes. The lift coefficient is found to increase at smaller hull spacings and decrease at higher Froude numbers and higher deadrise angles.

  8. Wave drag coefficient of a model `Busemann biplane' catamaran (United States)

    Liebenberg, L.; Bunt, E. A.


    Tests conducted on a model ‘Busemann biplane’ catamaran in a towing basin qualitatively showed that the form of the wave drag coefficient curve followed the typical drag curve for a single unswept supersonic wing, but on this was superimposed that of the Busemann wave drag curve (giving a local minimum near the design Froude number).

  9. Parametric system identification of catamaran for improving controller design (United States)

    Timpitak, Surasak; Prempraneerach, Pradya; Pengwang, Eakkachai


    This paper presents an estimation of simplified dynamic model for only surge- and yaw- motions of catamaran by using system identification (SI) techniques to determine associated unknown parameters. These methods will enhance the performance of designing processes for the motion control system of Unmanned Surface Vehicle (USV). The simulation results demonstrate an effective way to solve for damping forces and to determine added masses by applying least-square and AutoRegressive Exogenous (ARX) methods. Both methods are then evaluated according to estimated parametric errors from the vehicle’s dynamic model. The ARX method, which yields better estimated accuracy, can then be applied to identify unknown parameters as well as to help improving a controller design of a real unmanned catamaran.

  10. The overall motion sickness incidence applied to catamarans (United States)

    Piscopo, Vincenzo; Scamardella, Antonio


    The Overall Motion Sickness Incidence is applied to the hull form optimization of a wave piercing high-speed catamaran vessel. Parametric hull modelling is applied to generate two families of derived hull forms, the former varying the prismatic coefficient and the position of longitudinal centre of buoyancy, the latter instead the demi-hull separation. Several heading angles are analysed in a seaway, considering all combinations of significant wave height and zero-crossing period under two operating scenarios. The optimum hull is generated and vertical accelerations at some critical points on main deck are compared with the parent ones. Finally a comparative analysis with the results obtained for a similarly sized monohull passenger ship is carried out, in order to quantify, by the OMSI, the relative goodness in terms of wellness onboard of monohulls and catamarans, as a function of sea states and operating scenarios.

  11. SPIV measurements around the DELFT 372 catamaran in steady drift (United States)

    Falchi, M.; Felli, M.; Grizzi, S.; Aloisio, G.; Broglia, R.; Stern, F.


    The present work concerns the experimental measurements of the velocity field around a catamaran advancing in static drift. The main aim of the paper was to investigate the dynamics of the vortices generated by catamaran hulls with particular emphasis on the mechanisms of generation, detachment, downstream evolution and destabilization. In this context, a Stereo-PIV campaign has been performed to map the velocity fields on some cross-planes along and downstream of the catamaran. Froude numbers equal to 0.4 and 0.5 at drift angles as large as 6° and 9° have been selected as testing conditions. In all the tests, the model has been fixed at the dynamical values of trim and sinkage, measured in a preliminary static drift experiments. Major geometrical and kinematical characteristics of the keel vortices have been documented in the paper through the analysis of the mean and fluctuating components of the velocity and vorticity field. Vortex interaction with the wave pattern has been investigated as well through the use of a conditional average technique of the velocity snapshots with the free surface elevation. As a secondary, but important, outcome, a valuable experimental dataset for CFD benchmarking in severe off-design conditions has been collected.

  12. 46 CFR 171.057 - Intact stability requirements for a sailing catamaran. (United States)


    ... 46 Shipping 7 2010-10-01 2010-10-01 false Intact stability requirements for a sailing catamaran. 171.057 Section 171.057 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION... stability requirements for a sailing catamaran. (a) A sailing vessel that operates on protected waters must...

  13. Investigation of the viscous resistance components of catamaran forms (United States)

    Utama, I. Ketut Aria Pria

    Research into the breakdown of resistance components of catamaran hull forms has been carried out over a number of years. The components consist of viscous and wave resistance as well as viscous and wave resistance interference. Significant investigation of wave resistance has been carried out. Less effort, however, has been dedicated to determining viscous resistance and viscous interference resistance, which can be important elements in the estimation of power for a new design. Investigations into the components of viscous resistance have been carried out experimentally using a low-speed wind tunnel and numerically using a commercial CFD code (CFX). The investigations used representative reflex models of multihull ships and investigated the components of viscous resistance and viscous interaction effects between the hulls. The experimental work was carried out on a single ellipsoid and a pair of ellipsoids in proximity and the CFD investigations were carried out on (1)a single ellipse and a pair of ellipses in proximity, (2)a single ellipsoid and a pair of ellipsoids in proximity and (3)single and twinhull configurations of round bilge/transom stern ship forms. In the experimental work, the tests were carried out without and with turbulence transition strip at separation to length (S/L) ratios of 0.27, 0.37, 0.47 and 0.57, and at Reynolds number values of 1.6 × 106, 2.4 × 106 and 3.2 × 106. In the numerical work, the investigations were conducted at the same S/L ratios, two- and three-dimensional, under turbulent flow condition and at a Reynolds number of 2.4 × 106. The CFD work was extended to a higher Reynolds number in order to investigate the scale effect. The results of the experimental and CFD investigations are presented and discussed. Reasonable correlation between the approaches is achieved. Both approaches demonstrate form effect on the slender hull forms and the presence of viscous interaction in the catamaran mode. The investigation has

  14. Estimation of Directional Surface Wave Spectra from a Towed Research Catamaran

    National Research Council Canada - National Science Library

    Hanson, Kurt


    During the High Resolution Remote Sensing Main Experiment, wave height was estimated from a moving catamaran using pitch rate and roll rate sensors, a three axis accelerometer, and a capacitive wave wire...

  15. Performance Evaluation of Leading Edge Slats on Rigid Wing Sail Catamarans (United States)

    Johnson, Chelsea; O'Neill, Charles


    Rigid wing sails have created the fastest catamarans in history, however with the addition of a leading edge slat higher lift and faster speeds may be achieved. Slats are currently used on airplane wings to increase lift, but have not been implemented on a rigid wing sail catamaran. Using 3D modeling and computational fluid dynamics software, this research investigates the effect that slats have on the performance of rigid wing sail catamarans. Aerodynamics and hydrodynamics form the basis of the research. The preliminary results show an increase in the coefficient of lift for sail models with slats over sail models without slats, allowing the catamaran to perform at higher speeds. The ability of the slat to rotate has also been identified as a key factor in increasing the benefit of the slat. This work was supported by NSF site award 1358991.

  16. Anti-slamming bulbous bow and tunnel stern applications on a novel Deep-V catamaran for improved performance


    Mehmet Atlar; Kwangcheol Seo; Roderick Sampson; Devrim Bulent Danisman


    While displacement type Deep-V mono hulls have superior seakeeping behaviour at speed, catamarans typically have modest behaviour in rough seas. It is therefore a logical progression to combine the superior seakeeping performance of a displacement type Deep-V mono-hull with the high-speed benefits of a catamaran to take the advantages of both hull forms. The displacement Deep-V catamaran concept was developed in Newcastle University and Newcastle University's own multi-purpose research vessel...

  17. Catamaran or semi-submersible for floating platform – selection of a better design (United States)

    Qasim, Idrees; Gao, Liangtian; Peng, Duojin; Liu, Bo


    With nonstop advancement in marine engineering, more and more new structures are being designed and explored for tidal current energy. There are three different kinds of support structures for tidal current power station mostly in use, which are sea-bed mounted/gravity based system, pile mounted system and floating moored platform. Comparing all of them, the floating mooring system is most suitable for deep water systems and the application of this arrangement is widely usable. In this paper, a semi-submersible and a catamaran as floating platforms for tidal current power stations are studied are compared on the basis of its economics, efficiency of turbine and stability of the station. Based on basic ship theory and using software MAXSURF, the stability of Catamaran tidal current power station is also calculated. It is found that the catamaran design is optimal choice.

  18. Analysis of structural dynamic characteristics of a high speed light special catamaran (United States)

    Sun, Li-Ping; Nie, Wu; Zhang, Wei


    In this paper, structural dynamic characteristics of a high-speed light special catamaran-wave piercing catamaran are analyzed using the FEA software MSC-NASTRAN. The dynamic reduction method is introduced to eliminate the local vibration modes in order to obtain the whole ship’s mode shapes. In the post-processor, a lot of accessorial methods are adopted to eliminate the local vibrations, so that the whole ship’s mode shapes can be identified. The modal analysis indicates that the dynamic reduction method fits for mode shapes identifying. In the end, the test results of a catamaran named Frederick G. Greed are used for reference to validate the obtained results. The comparison process shows that the results are credible. A special mode shape, which is quite different with that of conventional monohull ship, is also pointed out. The obtained results provide a valuable reference for the coming computation of catamaran’s vibration characteristics.

  19. Analysis and Optimation Hydrofoil Supported Catamaran (HYSUCAT Size 25 Meter based on CFD Method

    Directory of Open Access Journals (Sweden)

    Hari Prastowo


    Full Text Available In the field of transportation, ship is relatively cheap then others transportation. However, the ship still has constraints on speed and fuel consumption. Therefore, the ship has many variations of shape to achieve optimal condition. For example the body of ships with double hulls (catamaran or three (trimaran, that using foil to make ship can have a smaller resistance to achieve optimal efficiency. The purpose of this research in order to plan the maximum foil shape which can produce high force of buoyance on the catamaran boat (25 meters and also to determine the type of hydrofoil that produces maximum buoyance force using CFD method.

  20. Preliminary study of a very large catamaran freighter as a derivative of a current wide-body aircraft (United States)

    Heyson, H. H.


    The development of a very large cargo aircraft by combining, in catamaran fashion, two existing wide body transports was studied. Advantages of this system include: lighter weight and increased payload; increased fuel economy; and reduction in direct operating costs.

  1. Sea Surface Scanner: An advanced catamaran to study the sea surface (United States)

    Wurl, O.; Mustaffa, N. I. H.; Ribas Ribas, M.


    The Sea Surface Scanner is a remote-controlled catamaran with the capability to sample the sea-surface microlayer in high resolution. The catamaran is equipped with a suite of sensors to scan the sea surface on chemical, biological and physical parameters. Parameters include UV absorption, fluorescence spectra, chlorophyll-a, photosynthetic efficiency, chromophoric dissolved organic matter (CDOM), dissolved oxygen, pH, temperature, and salinity. A further feature is a capability to collect remotely discrete water samples for detailed lab analysis. We present the first high-resolution (< 30 sec) data on the sea surface microlayer. We discuss the variability of biochemical properties of the sea surface and its implication on air-sea interaction.

  2. The Low-Noise Potential of Distributed Propulsion on a Catamaran Aircraft (United States)

    Posey, Joe W.; Tinetti, A. F.; Dunn, M. H.


    The noise shielding potential of an inboard-wing catamaran aircraft when coupled with distributed propulsion is examined. Here, only low-frequency jet noise from mid-wing-mounted engines is considered. Because low frequencies are the most difficult to shield, these calculations put a lower bound on the potential shielding benefit. In this proof-of-concept study, simple physical models are used to describe the 3-D scattering of jet noise by conceptualized catamaran aircraft. The Fast Scattering Code is used to predict noise levels on and about the aircraft. Shielding results are presented for several catamaran type geometries and simple noise source configurations representative of distributed propulsion radiation. Computational analyses are presented that demonstrate the shielding benefits of distributed propulsion and of increasing the width of the inboard wing. Also, sample calculations using the FSC are presented that demonstrate additional noise reduction on the aircraft fuselage by the use of acoustic liners on the inboard wing trailing edge. A full conceptual aircraft design would have to be analyzed over a complete mission to more accurately quantify community noise levels and aircraft performance, but the present shielding calculations show that a large acoustic benefit could be achieved by combining distributed propulsion and liner technology with a twin-fuselage planform.

  3. Comparison of streamflow between pre and post timber harvesting in Catamaran Brook (Canada) (United States)

    Caissie, Daniel; Jolicoeur, Serge; Bouchard, Mireille; Poncet, Emmanuel


    The forest industry plays a major role in the economy of eastern Canada. The recreational fishery also represents an important source of revenue for this area. Therefore, there is concern over the potential economic effects and ecological impacts from logging operations on aquatic habitats. The present study deals with the comparison of streamflow between pre and post timber harvesting at Catamaran Brook (New Brunswick, Canada) to identify any potential changes to the hydrological regime. Studies were carried out on two sub-basins of Catamaran Brook, namely the Middle Reach (mid-basin) and the Upper Tributary 1. The harvested area at the Middle Reach represented 2.3% of this sub-basin while 23.4% of Upper Tributary 1 was harvested. It was noted that during both the calibration and timber harvesting phases, meteorological conditions (e.g. precipitation, runoff) contributed to relatively high natural variability. When studying changes on an annual and seasonal basis for the basin cut at 2.3% (i.e. Middle Reach) and using a control basin for comparison, no changes were detected to the annual water yield, seasonal runoff and streamflow timing between the calibration and timber harvesting phases. On a summer rainfall event basis, no changes were detected at the Middle Reach and the Upper Tributary 1 when studying relations between precipitation and stormflow (obtained through hydrograph separation). Alternatively, changes were detected in relations between peak flows and precipitation (pCatamaran Brook, changes could only be detected on a summer storm event basis for the most affected site (Upper Tributary 1) and for peak flow only.

  4. Injuries sustained during major evacuation of the high-speed catamaran St Malo off Jersey. (United States)

    Lockey, D; Purcell-Jones, G; Davies, C T; Clifford, R P


    The difficulties and injuries sustained during the emergency evacuation of 308 passengers and crew from the fast passenger catamaran M.V. St Malo are described. The vessel had hit a rock off Jersey and was listing severely. Fifty-three passengers were injured, 32 requiring hospital admission; one with a myocardial infarction and 31 with musculoskeletal injuries. Eighteen patients required operation for severe lower limb injuries. Increased numbers of emergency exits and the introduction of evacuation chutes to this type of twin-hulled vessel are recommended.

  5. Analysis of the wave system of a catamaran for CFD validation

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    Souto-Iglesias, A.; Zamora-Rodriguez, R.; Fernandez-Gutierrez, D.; Perez-Rojas, L. [Technical University of Madrid (UPM), Model Basin Research Group (CEHINAV), Naval Architecture Department (ETSIN), Madrid (Spain)


    This paper describes the investigations carried out in the towing tank of ETSIN (UPM), where the influence of the distance between catamaran hulls on interference resistance was studied. Resistance, trim and wave cuts were measured for several situations and a device for measuring the wave cuts in different positions between the hulls was built. In order to ascertain the accuracy of the measurements taken, an uncertainty analysis is included. The relation between the interference resistance and the inner wave cuts shapes is analyzed. This analysis provides some insight into the phenomenon but further work is yet to be done. (orig.)

  6. Analysis of the wave system of a catamaran for CFD validation (United States)

    Souto-Iglesias, A.; Zamora-Rodríguez, R.; Fernández-Gutiérrez, D.; Pérez-Rojas, L.


    This paper describes the investigations carried out in the towing tank of ETSIN (UPM), where the influence of the distance between catamaran hulls on interference resistance was studied. Resistance, trim and wave cuts were measured for several situations and a device for measuring the wave cuts in different positions between the hulls was built. In order to ascertain the accuracy of the measurements taken, an uncertainty analysis is included. The relation between the interference resistance and the inner wave cuts shapes is analyzed. This analysis provides some insight into the phenomenon but further work is yet to be done.


    Directory of Open Access Journals (Sweden)

    Amin Najafi


    Full Text Available Determination of high-speed crafts’ hydrodynamic coefficients will help to analyze the dynamics of these kinds of vessels and the factors affecting their dynamic stabilities. Also, it can be useful and effective in controlling the vessel instabilities. The main purpose of this study is to determine the coefficients of longitudinal motions of a planing catamaran with and without a hydrofoil using RANS method to evaluate the foil effects on them. Determination of hydrodynamic coefficients by experimental approach is costly, and requires meticulous laboratory equipment; therefore, utilizing numerical methods and developing a virtual laboratory seems highly efficient. In the present study, the numerical results for hydrodynamic coefficients of a high-speed craft are verified against Troesch’s (1992 experimental results. In the following, after determination of hydrodynamic coefficients of a planing catamaran with and without foil, the foil effects on its hydrodynamic coefficients are evaluated. The results indicate that most of the coefficients are frequency independent especially at high frequencies.

  8. Introducing a mini-catamaran to perform reflectance measurements above and below the water surface (United States)

    Froidefond, Jean-Marie; Ouillon, Sylvain


    An innovative platform is tested to perform reflectance measurements at sea. This platform is a mini-catamaran with two hulls 1m long and set 0.7m apart, fitted with optical sensors. It can be used far away from an oceanographic ship to avoid its hull influencing the measurement. Reflectance measurements were performed with a TriOS radiance sensor placed +2cm or -2cm from the water surface and a TriOS irradiance sensor. Tests were carried out in calm seas and with cloud cover. The processing to derive marine radiances from raw measurements is detailed. When the radiance sensor is above the interface, it limits the sky reflections on the targeted surface and the radiance is identical to that deduced from measurements below the surface. When the sensor is placed at +3cm abovewater or higher, glint affects the measurements. The mini-catamaran shows a good ability to measure marine reflectance with an adapted measurement protocol. Except for very turbid waters, it seems preferable to perform upwelling radiance measurements below the surface.

  9. Anti-slamming bulbous bow and tunnel stern applications on a novel Deep-V catamaran for improved performance (United States)

    Atlar, Mehmet; Seo, Kwangcheol; Sampson, Roderick; Danisman, Devrim Bulent


    While displacement type Deep-V mono hulls have superior seakeeping behaviour at speed, catamarans typically have modest behaviour in rough seas. It is therefore a logical progression to combine the superior seakeeping performance of a displacement type Deep-V mono-hull with the high-speed benefits of a catamaran to take the advantages of both hull forms. The displacement Deep-V catamaran concept was developed in Newcastle University and Newcastle University's own multi-purpose research vessel, which was launched in 2011, pushed the design envelope still further with the successful adoption of a novel anti-slamming bulbous bow and tunnel stern for improved efficiency. This paper presents the hullform development of this unique vessel to understand the contribution of the novel bow and stern features on the performance of the Deep-V catamaran. The study is also a further validation of the hull resistance by using advanced numerical analysis methods in conjunction with the model test. An assessment of the numerical predictions of the hull resistance is also made against physical model test results and shows a good agreement between them.

  10. Anti-slamming bulbous bow and tunnel stern applications on a novel Deep-V catamaran for improved performance

    Directory of Open Access Journals (Sweden)

    Mehmet Atlar


    Full Text Available While displacement type Deep-V mono hulls have superior seakeeping behaviour at speed, catamarans typically have modest behaviour in rough seas. It is therefore a logical progression to combine the superior seakeeping performance of a displacement type Deep-V mono-hull with the high-speed benefits of a catamaran to take the advantages of both hull forms. The displacement Deep-V catamaran concept was developed in Newcastle University and Newcastle University's own multi-purpose research vessel, which was launched in 2011, pushed the design envelope still further with the successful adoption of a novel anti-slamming bulbous bow and tunnel stern for improved efficiency. This paper presents the hullform development of this unique vessel to understand the contribution of the novel bow and stern features on the performance of the Deep-V catamaran. The study is also a further validation of the hull resistance by using advanced numerical analysis methods in conjunction with the model test. An assessment of the numerical predictions of the hull resistance is also made against physical model test results and shows a good agreement between them.

  11. A CFD Study on Aerodynamic Characteristics of a Middle Wing for WIG Catamaran During Ground Effect (United States)

    Priyanto, A.; Maimun, Adi; Jamei, Saeed; Suharyanti, Ike


    In this paper the influence of ground effect on the aerodynamic character of NACA 6409 were numerically studied. The simulations of the wing were performed by three dimensional Computational Fluid Dynamic (CFD). The important aerodynamic characters such as lift and drag coefficient, lift to drag ratio were determined with variation in some principle aerodynamic parameter, for instance the angle of attack and aspect ratio. The ground clearance ( h/c ) in CFD simulation was 0.1. This simulation showed that there was enhancement on lift coefficient and reduction on drag coefficient related to incremental of aspect ratio when a aircraft flying in proximity to the ground. The κ-ɛ turbulent model was used in CFD model. Numerical results were compared with experimental data of another researcher. As a application of this CFD simulation was calculating the lift-drag coefficient and lift to drag ratio from middle wing of WIG Catamaran.

  12. Friction induced irreversible stretching of substrate films by recording with a catamaran glider on thin film floppy disks (United States)

    Schildberg, Hans-Peter; Hibst, Hartmut


    The tribological interaction between a commercial floppy disk catamaran glider and flexible magnetic thin film media is investigated on a tribometer under floppy disk drive conditions. Apart from the usual wear scars which develop in the metallic thin film due to abrasion and microploughing, one observes elevations of the medium (up to 15 μm) along the track of the head. The profile of these elevations in directions perpendicular to the track reflects the two rails of the catamaran glider and strongly depends on the thickness of the polymer substrate, its elastic properties and on the frictional force between head and medium. The observations are explained by the distribution of shear forces in that region of the polymer substrate which is directly underneath and besides the rails of the sliding R/W-head. Consequences for magnetic recording, the selection of substrate films and the head/tape interface are considered.

  13. Design of Catamaran Propulsion System with Demihull Distance Variation on Hospital Ship

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    Amiadji Amiadji


    Full Text Available Various problems faced by health services in the area of remote islands based on survey data Ministry of Health, that limited human resources in health and treatment facilities, as well as the difficult geographical conditions causing problems transport and communication are the main problem. From the above, the problems faced by means of a mobile hospital in the form of vessels operating from one small island to another small island is the solution of health problems for the people living within the island of MaduraIn this thesis the work will be done planning catamaran ship propulsion system with a variety of distances and determine the power demihull hospital equipmen. From the calculation results in a variation within demihull get with B = 19.51 m, 0,1B = 21.46, 0,2B = 23.41, 25.36 resulting 0,3B = 97.8 kN after the engine power of 812.71 kW obtained. From the selection of the engine 10 criteria obtained type Caterpillar 3508B engines.Power generators are required for a hospital ship is 75kW for 4 gensets.

  14. Estimation of directional surface wave spectra from a towed research catamaran (United States)

    Hanson, K.A.; Hara, T.; Bock, E.J.; Karachintsev, A.B.


    During the High-Resolution Remote Sensing Main Experiment (1993), wave height was estimated from a moving catamaran using pitch-rate and roll-rate sensors, a three-axis accelerometer, and a capacitive wave wire. The wave spectrum in the frequency band ranging roughly from 0.08 to 0.3 Hz was verified by independent buoy measurements. To estimate the directional frequency spectrum from a wave-wire array, the Data-Adaptive Spectral Estimator is extended to include the Doppler shifting effects of a moving platform. The method is applied to data obtained from a fixed platform during the Ris?? Air-Sea Experiment (1994) and to data obtained from a moving platform during the Coastal Ocean Processes Experiment (1995). Both results show that the propagation direction of the peak wind waves compares well with the measured wind direction. When swells and local wind waves are not aligned, the method can resolve the difference of propagation directions. Using the fixed platform data a numerical test is conducted that shows that the method is able to distinguish two wave systems propagating at the same frequency but in two different directions.

  15. System identification for precision control of a wingsailed GPS-guided catamaran (United States)

    Elkaim, Gabriel Hugh

    This thesis details the Atlantis project, whose aim is the design, development, and experimental testing of an autonomous wind-propelled marine craft. Functionally, such a vehicle is the marine equivalent of an unmanned aerial vehicle (UAV), and would serve similar purposes. The Atlantis project has been able to demonstrate an advance in control precision of a wind-propelled marine vehicle from typical commercial autopilot accuracy of 100 meters to an accuracy of better than one meter with a prototype based on a modified Prindle-19 light catamaran. The project involves substantial innovations in three areas: wind-propulsion system, overall system architecture, and sensors. The wind-propulsion system is a rigid wing-sail mounted vertically on bearings, mass balanced to allow free rotation in azimuth about a stub-mast. Aerodynamic torque about the stub-mast is trimmed using a flying tail mounted on booms aft of the wing. This arrangement allows the wing-sail to automatically attain the optimum angle to the wind, and weathervane into gusts without inducing large heeling moments. The sensor system uses differential Global Positioning System (DGPS) augmented by a low-cost attitude system based on accelerometer- and magnetometer-triads for position and velocity measurements. Accurate attitude determination is required to create a synthetic position sensor that is located at the center-of-gravity (c.g.) of the boat, rather than at the Global Positioning System (GPS) antenna location. A high-performance estimator/controller was implemented and tested on the full-scale prototype. The identified controllers were able to perform remarkably well, in the presence of wind and waves, tracking the desired line to within 0.3 meters (˜1 foot).

  16. Numerical estimation of interactions between foils and hulls of hydrofoil catamaran; Suichu yokutsuki sodosen no sentai to suichuyoku no sogo kansho

    Energy Technology Data Exchange (ETDEWEB)

    Kataoka, K.; Ando, J.; Nakatake, K. [Kyushu University, Fukuoka (Japan)


    The hydrofoil catamaran model which is built up with the twin Wigley hulls and the tandem fore and aft set of hydrofoils is used for the numerical calculation and the experiments of this model was performed at Kyushu University. In this paper, combining with a Rankine source method, the SQCM (a simple panel method) is applied to the unsymmetrical flow problem around catamarans. And the running attitude of the model is not fixed in both the calculation and the experiments. Comparing with the experiment we show the interaction between hulls and the hydrofoils for the lift and the wave-making resistance in the high speed range. 6 refs., 11 figs.

  17. Conference on the Physics and Chemistry of Semiconductor Interfaces (26th) Held in the Catamaran Resort Hotel in Pacific Beach, San Diego, California on 17 January 1999 to 21 January 1999. Microelectronics and Nanometer Structures: Processing, Measurement, and Phenomena

    National Research Council Canada - National Science Library

    Schulte, C


    ...) are contained in this volume. The Conference was held at the Catamaran Resort Hotel in Pacific Beach, San Diego, California from Sunday evening, 17 January 1999 to noon on Thursday 21 January 1999 A total of 18 invited and 69...

  18. Método dinamométrico para avaliação da escora em barcos tipo Catamaran Dynamometric method for the evaluation of hiking in Catamaran boats

    Directory of Open Access Journals (Sweden)

    Gustavo Ricardo Schütz


    Full Text Available Este estudo tem como objetivo propor e validar um método de medição da distância de escora ("De" e do momento de escora ("Me", através do uso de plataformas de força para barcos tipo Catamaran. O novo método propõe a medição por dinamometria, com o posicionamento de plataformas de força abaixo de cada casco, e a mensuração das Forças de Reação do Solo (FRS. Com base nas equações clássicas da estática são determinadas as variáveis "De" e "Me". Para validar o método proposto, foi utilizada a validação concorrente, através da comparação com os valores obtidos por cinemetria através do sistema "Peak Motus". Para correlação entre os dois métodos optou-se pelo coeficiente de correlação intraclasse (ICC. Foram analisadas diferentes posturas em duas diferentes inclinações do barco, simulando o adernamento do barco. Os resultados encontrados apontaram alta correlação (ICC > 0,99 e pequeno erro médio (1,00% para "De" e 0,96% para "Me" entre os métodos. Com isto, o método proposto se mostrou válido e eficiente, pois mensurou as variáveis de maneira rápida e precisa e se torna importante à medida que facilita a análise e auxilia a velejadores e técnicos na tomada de decisõesThis study aimed to propose and to validate a method for the measurement of hiking distance (Hd and hiking moment (Hm in Catamaran boats, through the use of force plates. This new method proposes the measurement by dynamometry, with the positioning of a force plate below each boat hoof to measure the Ground Reaction Forces (GRF. Based on the classic static equations Hd and Hm were determined. In order to validate the method a validation of competing was carried out through the comparison with kinematic values measured through the Peak Motus system. Intraclass correlation coeficient was used. Different positions in two different inclinations of the boat, simulating the boat heeling, had been analyzed. The results showed a high correlation

  19. Method for calculating wave resistance in a catamaran by using a simple panel method; Kanbenna panel ho ni yoru katamaran no zoha teiko keisanho

    Energy Technology Data Exchange (ETDEWEB)

    Kataoka, K. [Kyushu University, Fukuoka (Japan). Faculty of Engineering


    This paper describes a method for calculating wave resistance in a catamaran by using a simple panel method. Two Wigley models were put side by side to make a catamaran, speccular images were taken on a face symmetrical in the left and right sides, and only one side (the demi-hull) was used as a region to be calculated. Considering blow-out onto the demi-hull surface and still water surface, a model was constituted, in which discrete vortices were distributed on the demi-hull camber to flow the vortices out to an infinitely distance place from the stern. A free surface condition according to double model linearization by Dawson was derived for this model in terms of numerical analysis. The Kutta`s condition is incorporated when SQCM is used concurrently with the Rankine source method, but not incorporated when not used. Calculations were performed on both conditions. Wave resistance was derived by using pressure integral on the hull surface. It is better to consider the Kutta`s condition when the distance between the demi-hulls is small. However, if the distance is large, or speed is great for the boat length resulting in less interference between the demi-hulls, there is very little difference due to the Kutta`s condition. Difference in the wave shapes causes how waves are made to vary. 11 refs., 8 figs.

  20. Progress in the development of the surface effect catamaran (SECAT) (United States)

    Durkin, J. M.; Paraskevas, N. M.


    Twin-cushion surface effect ship technology development includes analytical and experimental investigations in the areas of hydrodynamics, seakeeping, and structures. This paper reviews the progress achieved in hydrodynamic drag prediction and correlation, and craft motions, and identification of passive motion reducing devices. A 33-foot demonstrator has been constructed to further extend the technology data base.

  1. Salinity, Temperature, and Optical Characterization of a Tidally Choked Estuary Connected to Two Contrasting Intra-Coastal Waterways (United States)


    B.  MINI CATAMARAN OBSERVATIONS .....................................................6  III.  RESULTS...9  B.  MINI CATAMARANS -MAIN CHANNEL AND SIDE BAYS .................12  C.  MINI CATAMARANS -ICWN...16  D.  MINI CATAMARANS -ICWS

  2. Solving Wave Flow Energy Propagated by Twin-Hull Ships (Catamarans) (United States)

    Salim Kamil, Md; Muslim, Mazlan; Ali, Ishak


    The main objective of this paper is to put forward a method of solution of wave flow energy propagated by twin-hull ships utilizing ship wave resistance integral equation by Tuck-Lazauskas [8]. The underlying principle of the governing equation is based on the linear thin ship theory pioneered by Michell. The ship wave resistance integral equation by Tuck-Lazauskas is improvised in which the upper limit of the mathematical integration of the governing equation is set to the final root instead of π/2 as in the original equation to eliminate the problem of solving such a divergent improper integral. The method of solution and the theoretical results are validated against works of others experimentally and theoretically. The results obtained by the proposed method are found to be very consistent and more closely fit to the experimental results in comparison with those obtained by other theoretical method as presented in this paper.

  3. Improving the Efficiency of a High Speed Catamaran Through the Replacement of the Propulsion System

    Directory of Open Access Journals (Sweden)

    German de Melo Rodriguez


    Full Text Available The high speed vessels are primarily designed for short distances services as public transport of passengers and vehicles. The range of high speed, according to the Code of high-speed vessels begins at 20 knots, which depends on the cruise speed you desire for your vessel; you will have to use the most appropriate type of propellant. In general, in the past 20 years, they have been building high-speed vessels with speeds above 33 knots, which meant installing water jet propellants coupled to powerful engines and therefore of high consumption of fuel, increasing operating costs and causing increased air pollution. Although the prices of fuel have been reduced to half, due to the sharp fall in oil prices, the consumption of fuel and the air pollution remains high at these speeds and powers used, in addition to that the reduction of the time spent on each trip is not excessive, mainly in short routes that are less than an hour . This article is about adapting a ship of high-speed service, with a maximum speed in tests of 34 knots and to reduce its operating costs (fuel, maintenance, etc. and make it economically viable; before the transformation, this vessel was operating with a service speed of 22 knots, and with a consumption per mile of 135 litters of MGO. The transformation process has consisted by: – Replacement of the two original water jet with four shaft lines with fix pitch propeller. – Replacement of the two original main engines (2 x 6500 kW = 13000 kW by four engines (4 x 1380kW = 5.520 kW. – Changing the underwater hull shape to fit the new propellers and maximize its efficiency. – Relocation of auxiliary engines, to achieve the most efficient trim. – Installation of two lateral propellers to improve maneuverability and shorten the total time of journey. After the reform and the return to service of the vessel with a service speed of over 22 knots, it has been verified that the consumption per mile is of 45 litters MGO, representing a reduction of 65% of consumption and even more reduction of emissions as the new engines comply with the latest regulations.

  4. Dynamic Response of a Catamaran-Hull Ship Subjected to Underwater Explosions

    National Research Council Canada - National Science Library

    Ucar, Hakan


    .... While these trials are necessary in order to evaluate the vulnerability and survivability of the ship, they are very expensive, require extensive time for planning and coordination, and pose serious...

  5. Sensitivity analysis of a deterministic water temperature model to forest canopy and soil temperature in Catamaran Brook (New Brunswick, Canada) (United States)

    St-Hilaire, André; El-Jabi, Nassir; Caissie, Daniel; Morin, Guy


    A coupled deterministic hydrological and water temperature model, CEQUEAU, was modified to include soil temperature and crown closure in its calculation of local advective terms in the heat budget. The modified model was than tested to verify its sensitivity to these modifications. An analysis of the heat budget of a small forested catchment in eastern Canada revealed that the advective term related to interflow plays a significant role in the daily water heat budget, providing on average 28% of the local advective budget (which also includes advective heat terms from surface runoff and groundwater) and nearly 14% of the total heat budget (which includes all radiative terms at the water surface, convection and evaporation, as well as the local advective terms).Relative sensitivity indices (RSIs) were used to verify the impact of the newly introduced parameters and variables. Among them, parameters related to the forest cover (crown closure and leaf area index) have a maximum RSI of -0·6; i.e. a 100% increase in value produces a 60% decrease in the local advective term. Parameters with the greatest influence are the volume of water contributing to interflow and the amplitude of the net radiative flux at the soil surface, which, if doubled, would double the contribution of the local interflow advective term to the heat budget.

  6. 75 FR 8370 - Center for Scientific Review; Notice of Closed Meetings (United States)


    .... Agenda: To review and evaluate grant applications. Place: Catamaran Resort, 3999 Mission Boulevard, San... grant applications. Place: Catamaran Resort, 3999 Mission Boulevard, San Diego, CA 92109. Contact Person...

  7. A Comparative Analysis of Computed and Measured SAR Images of Complex Targets (United States)


    catamaran ferry, “HSC Alboran”, showing the actual configuration. Figure 5: CAD model of the catamaran ferry HCS Alboran; top: original model, bottom...range 4.4 “Alboran”, a catamaran ferry Figure 21: Two measured SAR images of the catamaran ferry, “Alboran”; image captured at

  8. 77 FR 13694 - Requested Administrative Waiver of the Coastwise Trade Laws: Vessel CHANGING CHANNELS; Invitation... (United States)


    ... of Vessel: ``The vessel is a 38-foot sailing catamaran owned by our sailing club. The vessel will be... teach group sailing lessons on the catamarans.'' Geographic Region: ``California.'' The complete...

  9. 77 FR 13695 - Requested Administrative Waiver of the Coastwise Trade Laws: Vessel IN THE SHELTER; Invitation... (United States)


    ... catamaran owned by our sailing club. The vessel will be used for teaching sailing lessons and for sailboat... Sailing. A waiver will allow us to teach group sailing lessons on the catamarans.'' Geographic Region...

  10. Conference on the Physics and Chemistry of Semiconductor Interfaces (26th) Held in the Catamaran Resort Hotel in Pacific Beach, San Diego, California on 17 January 1999 to 21 January 1999. Microelectronics and Nanometer Structures: Processing, Measurement, and Phenomena (United States)


    borophosphosilicate glass films Tomoyuki Yoshida,a) Koyu Aoki, and Yasuichi Mitsushima Toyota Central Research and Development Laboratories, Inc...PA, 1978). 18K. Krishnan, P. J. Stout , and M. Watanabe, in Practical Fourier Trans- form Infrared Spectroscopy, edited by J. R. Ferraro and K


    Directory of Open Access Journals (Sweden)

    Samuel Samuel


    Full Text Available RESISTANCE COMPONENT ANALYSIS OF TRADITIONAL FISHING BOAT IN CILACAPMonohull fishing boats used to catch fish is modified into a catamaran boat. The purpose of this modification is to get more fish. Catamaran ship has a double hull, but with the double hull ships resulted in increasingly complex resistances. It is interesting to study in depth about the resistance components of Catamaran boat. Resistance Components not only consist of surge resistance, frictional resistance, and the form resistance but with the distance between demihull causing interference waves. There are many research results of Catamaran boat in that aspect, but the data and information obtained from the experiment is still inadequate. In addition, there is still lack of accuracy particularly in predicting interference resistance component in calm water (calm-water resistance as a result of the distance between the demihull. This study aims to describe the resistance component at Catamaran boat by using slender body method. Keywords: catamaran, Cilacap, slender body method ABSTRAK Kapal ikan monohull yang biasa digunakan untuk mencari ikan dimodifikasi menjadi kapal catamaran. Tujuan modifikasi ini untuk mendapatkan muatan ikan yang lebih banyak. Kapal Catamaran mempunyai dua lambung, tetapi dengan adanya dua lambung mengakibatkan hambatan kapal semakin kompleks. Menarik untuk dikaji lebih lanjut tentang komponen hambatan kapal Catamaran. Komponen hambatan tidak hanya terdiri dari hambatan gelombang, hambatan gesek, dan hambatan bentuk namun dengan adanya jarak antar demihull sehingga menimbulkan interferensi gelombang. Sudah banyak dijumpai hasil riset kapal Catamaran pada aspek tersebut, tetapi data dan informasi yang diperoleh dari eksperimen masih kurang memadai. Disamping itu, masih ditemukan ketidak-akurasian khususnya dalam memprediksi interferensi komponen hambatan pada air tenang (calm-water resistance akibat dari adanya jarak antar demihull tersebut. Penelitian

  12. COLREGS-Compliant Autonomous Collision Avoidance Using Multi-Objective Optimization with Interval Programming (United States)


    41 2-4 Clearpath M200 Catamaran AMV . . . . . . . . . . . . . . . . . . . . 42 2-5 Geometry of CPA Calculations...and starboard sides as shown in Figure 2-3. The M200 variant is a catamaran with water jet propulsion used as a second hull type for in-water AIS. 41 Figure 2-4: The Clearpath M200 autonomous marine vehicle is a catamaran , water jet driven design used for testing on the Charles River

  13. Waterway Equipment - Boat, Barge, Motor (United States)


    cargo they are designed to carry. These vessels include high speed wave-piercing catamarans and beaching craft. Non-propelled Barges, Conversion...Bulkhead A term applied to the vertical partition walls that divide the interior of a ship into compartments. Catamaran A boat with twin side-by-side

  14. Stratified Fronts in Well-Mixed Estuaries (United States)


    the repeated deployment of six small catamarans (“mini-cats”) that were anchored to the seabed. Each mini-cat was equipped with a robust suite of...downward-oriented Nortek Aquadopp Acoustic Doppler Current Profiler (ADCP) transmitting at 2 MHz was attached to the underside of each catamaran hull

  15. Development and Testing of an Engineering Prototype for a Marine Version of the Berkeley Unexploded Ordnance Discriminator (BUD) (United States)


    shown in Figure 29. The test steel ball was lowered to preset stops in this tube at depths beneath the platform. The custom catamaran shown in...Figure 31 was constructed to hold the platform assembly and to lower the assembly into the water. Figure 31 The catamaran and MBUD system were

  16. Seabed Characterization for SW2013 Mid-Frequency Reverberation Experiment (United States)


    incidence reflectivity was measured as shown in Figure 3 where the source and receiver were suspended below a small catamaran (about 2 x 2 m) which was...That is, the source and receiver trailed slightly (an unknown distance) behind the GPS sensor fixed on the back of the catamaran . Positional errors on

  17. The Axis and the Intended Invasion of Malta in 1942: A Combined Planning Endeavor (United States)


    catamaran barges), six Type 39 Pionierlandunsboote (small engineer boats), six Type 40 Pionierlandunsboote (a larger version of Type 39), 81 with German crew - 200 assault boats without crew - 12 catamaran barges - 170 small and 100 large inflatable crafts - 21 motorbarges 120 tons

  18. Design of Eco Friendly Shallow Draft Fishing Vessel

    Directory of Open Access Journals (Sweden)

    Sunardi Sunardi


    Full Text Available One of the main problem of inland waterways fisheries is the transportation of fish from ponds to fish market during low tide trough inland waterways with 0.6m water depth.The boat is experiences grounding due to water depth of the river is not sufficient for the fishing boat to carry fish at it’s maximum2 tones capacity or experience dead freight . This condition forces fisherman to wait until the high tide from the sea, this delay causes the quality of the fish is decreasing.Besides the problem dead freight  problem the existing vessel is causes environmental problem such as erosion of the river bank due to wake wash. The other important issue is the increases of fuel price and it’s scarcity.  This paper presents the results of comparison of existing monohull fishing boat and two other alternativecatamaran designs. The catamaran design alternatives are is ordinary catamaran and flat side catamaran.  Both of the catamaran fishing boat design shows that the catamaran boat with 0.5m draft is able to carry more than 2 tonnes payload during low tide water depth.  The CFD simulation results shows that flat side catamaran resistance is more than 17.7% lower compared to ordinary catamaran and 44% lower compared to monohull. It means that the consumption of flat side catamaran is lowest compared to two other type of hull design. The flat side catamaran also produces lowest wake wash compared to o two other design. The low wake wash means more friendly to environment.

  19. A Preliminary Ship Design Model for Cargo Throughput Optimization (United States)


    16.46 11454 LCS-2 [15] 3,084 3,009 44 22.64 50120 JHSV [16] 2,362 2,304 43 22.12 36400 LCS-1 [17] 2,862 2,792 47 24.18 72000 Low-Wash Catamaran ...1.3618 50.218 HST-1 1.6799 40.975 MV Fairweather 1.7470 31.340 LCS-2 1.9020 20.734 JHSV 1.9433 19.274 LCS-1 2.0572 25.688 Low-Wash Catamaran ...Low-Wash Catamaran % % HSV-2

  20. Large Scale Visual Recognition (United States)


    CalNet200, Rand200 – 50 2 0 6 5 5 Sailboat 1 1 Catamaran Trimaran 1 Catboat Sailing vessel 5 Watercra 6 2 Galleon Ship Cra Aircra 62 Figure 3.6...classifying it as any of its (more specific) descendants. As an example, in Figure 3.6, for an image labeled as “sailboat,” classifying it as “ catamaran ” or... catamaran .” This is a limitation of intermediate level ground truth labels. 54 Barred owl (16) Ba ng helmet (3)Boater Speedometer Salp (16) Hematocrit (4

  1. Integrated Life-Cycle Framework for Maintenance, Monitoring and Reliability of Naval Ship Structures (United States)


    the HSV-2 high speed naval craft, wave piercing catamaran [2, 4]. The second application is a joint high-speed sealift ship (JHSS) [2, 3, 5]. Data for...this article are illustrated on a HSNC, HSV-2. The HSV-2 is a 98-m long, high speed, all aluminum, wave-piercing catamaran designed by Revolution...naval craft, wave piercing catamaran [I, 8j. ’Ihe second application is a joint high-speed sealift ship (JHSS) [4,5]. Data for this application

  2. Radiated Sound of a High-Speed Water-Jet-Propelled Transportation Vessel. (United States)

    Rudd, Alexis B; Richlen, Michael F; Stimpert, Alison K; Au, Whitlow W L


    The radiated noise from a high-speed water-jet-propelled catamaran was measured for catamaran speeds of 12, 24, and 37 kn. The radiated noise increased with catamaran speed, although the shape of the noise spectrum was similar for all speeds and measuring hydrophone depth. The spectra peaked at ~200 Hz and dropped off continuously at higher frequencies. The radiated noise was 10-20 dB lower than noise from propeller-driven ships at comparable speeds. The combination of low radiated noise and high speed could be a factor in the detection and avoidance of water-jet-propelled ships by baleen whales.

  3. High Speed Vessels to Market : Comparative Case Studies in the Passenger Trade (United States)


    The Volpe Center chose to study several existing catamarans and high speed monohulls in comparison to representative SWATH family craft, including the SLICE 400 (passenger) and SLICE 600 (passenger/90 car) variants, the former similar in size and per...

  4. IEEE Conference Record - Abstracts. 1997 IEEE International Conference on Plasma Science, 19 - 22 May 1997, San Diego, California

    National Research Council Canada - National Science Library

    Hyman, Julius


    This 360 page softbound publication includes the following major sections. An invitation to ICOPS'97, Catamaran Resort Hotel Floor Plnas, Officers of the IEEE Nuclear and Plasma Sciences Society, Conference Information...

  5. Research in Advanced Surface Effect Ships

    National Research Council Canada - National Science Library

    Leonard, Douglas C


    .... An experimental 42 ft lwl (50 ft oa) air-cushioned, composites constructed, catamaran is designed, built and tested to serve as a demonstrator and test bed for proprietary technology that could deliver the desired capabilities...

  6. Conference Proceedings for 1997 IEEE 24th International Conference on Plasma Sciences, 19 - 22 May 1997, San Diego, California

    National Research Council Canada - National Science Library

    Hyman, Julius


    This 360 page softbound publication includes the following major sections, An invitation to ICOPS'97, Catamaran Resort Hotel Floor Pinas, Officers of the IEEE Nuclear and Plasma Sciences Society, Conference Information...

  7. IEEE Conference Record - Abstracts. 1997 IEEE International Conference on Plasma Science, 19 - 22 May 1997 San Diego, California

    National Research Council Canada - National Science Library

    Hyman, Julius


    This 360 page softbound publication includes the following major sections. An invitation to ICOPS'97, Catamaran Resort Hotel Floor Pinas, Officers of the IEEE Nuclear and Plasma Sciences Society, Conference Information...

  8. Cost Earnings Data 2001 - American Samoa Longline (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In 2001, 25 vessels > 50 feet in overall length joined the American Samoa longline fleet, which previously had consisted of local, small catamaran-style vessels...

  9. Hybrid propulsion for sailing boats; Propulsion hybride pour voiliers

    Energy Technology Data Exchange (ETDEWEB)

    Dougin, Y.


    Lagoon, a French catamarans maker (Beneteau group), launches the very first cruise catamaran fitted with an electric propeller. Two permanent magnet motors supplied by a 72 V battery set allow an autonomy of 2.5 hours of operation. Batteries charging is performed by the screws while the ship uses its sails to navigate. When batteries charge state is below 20%, a diesel generator set ensures their charging. Short paper. (J.S.)

  10. Observations and computations of narrow Kelvin ship wakes

    Directory of Open Access Journals (Sweden)

    Francis Noblesse


    Full Text Available Computations of far-field ship waves, based on linear potential flow theory and the Hogner approximation, are reported for monohull ships and catamarans. Specifically, far-field ship waves are computed for six monohull ships at four Froude numbers F≡V/gL=0.58, 0.68, 0.86, 1.58 and for six catamarans with nondimensional hull spacing s≡S/L=0.25 at two Froude numbers Fs≡V/gS=1 and 2.5. Here, g is the gravitational acceleration, V and L denote the ship speed and length, and S is the separation distance between the twin hulls of a catamaran. The computations show that, although the amplitudes of the waves created by a ship are strongly influenced by the shape of the ship hull, as well known, the ray angles where the largest waves are found are only weakly influenced by the hull shape and indeed are mostly a kinematic feature of the flow around a ship hull. An important practical consequence of this flow feature is that the apparent wake angle of general monohull ships or catamarans (with arbitrarily-shaped hulls can be estimated, without computations, by means of simple analytical relations; these relations, obtained elsewhere via parametric computations, are given here. Moreover, the influence of the two parameters Fs and s that largely determine the ray angles of the dominant waves created by a catamaran is illustrated via computations for three catamarans with hull spacings s=0.2, 0.35, 0.5 at four Froude numbers Fs=1, 1.5, 2, 2.5. These computations confirm that the largest waves created by wide and/or fast catamarans are found at ray angles that only depend on Fs (i.e. that do not depend on the hull spacing s in agreement with an elementary analysis of lateral interference between the dominant waves created by the bows (or sterns of the twin hulls of a catamaran. The dominant-waves ray angles predicted by the theory of wave-interference effects for monohull ships and catamarans are also compared with the observations of narrow Kelvin ship

  11. Seacoaster advanced marine vehicle. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Burg, D.


    The Seacoaster combines the high efficiencies of Surface Effect Ships (SES) with simple catamaran hull construction. It has blower pressurized air cushions that support some 80-90 percent of displacement and hence the high efficiencies. However, unlike the SES, there are no expensive and high maintenance flexible seals. Each catamaran sidehull has a simple recess molded or built into its underside. Powered blowers direct pressurized air into such recesses and thereby create lifting air cushions. There are no flexible seals of any kind and there is no air cushion between the sidehulls. Extensive towed model tests were conducted that showed the viability of the invention.

  12. Socio-économie de la pêche artisanale dans les eaux burundaises ...

    African Journals Online (AJOL)

    L'étude estime la capture par unité d'effort de l'unité Appolo à 152 kg/nuit de pêche, 80 kg/nuit de pêche pour le catamaran motorisé et 50 kg/nuit pour le catamaran non motorisé. Après la vente des produits de la pêche, le profit net estimé (PNE) par unité de pêche artisanale s'élève à 8 300 ± 222 $US. avec un revenu ...

  13. Design of 360° moveable and uniform feeding system (United States)

    Zhang, Lizhen; Ma, Dihong; Yang, Mengmeng; Hu, Qingsong


    In order to solve the feeding problem in shrimp aquaculture which is high labor intensity, low automation and non-uniform feed distribution, a 360° moveable and uniform feeding system was proposed. The feeding system uses turbine worm mechanism to realize the quantitative feeding, and the turbine is conveying plate which can adjust the conveying speed according to catamaran’s cruise speed. Casting plate can achieve 360° uniform cast feed. A catamaran is used as carrier platform for feeding machine, and BeiDou satellite positioning system installed on the catamaran helps to automatic cruise. So the moveable and uniform of shrimp pond feeding can be realized in this way.

  14. New River Inlet DRI: Observations and Modeling of Flow and Material Exchange & Field and Numerical Study of the Columbia River Mouth (United States)


    analyze the MCR drifter, in situ mini-catamaran, pressure, and USGS tripod observations; • describe the tidal chocking behavior at New River Inlet ( NRI ...describe the generation mechanisms for fronts at NRI through observations and modeling; • evaluate the optical properties of NRI through ins situ

  15. 77 FR 10802 - Requested Administrative Waiver of the Coastwise Trade Laws: Vessel SILVER MOON; Invitation for... (United States)


    ... DEPARTMENT OF TRANSPORTATION Maritime Administration [Docket No. MARAD 2012 0012] Requested Administrative Waiver of the Coastwise Trade Laws: Vessel SILVER MOON; Invitation for Public Comments AGENCY... SILVER MOON is: Intended Commercial Use of Vessel: ``Catamaran Sailing Charters, both term and day...

  16. Experimental Investigation into the Fatigue Life of Hybrid Joints Under Fully Reversed Flexure Loading (United States)


    7 1.4 Literature Review ...Sea FlyerI one example vessel called the MIDFOIL where a hydrofoil and a parabolic lifting body shape are combined with a catamaran hull to achieve...integrity. *6 I 1.3 Scope of Work IA literature review of previous work relating to the present research is presented in the remainder of this section. A

  17. A whispering boat on photovoltaic energy; Een fluisterboot op zonnestroom

    Energy Technology Data Exchange (ETDEWEB)

    Vaessen, M.; Robles, M. [eds.


    A brief impression is given of the newly developed solar energy-driven catamaran `Blaustirns`. The boat is developed for excursions in the nature reserve `De Alde Feanen` in the Dutch province Friesland. The boat must make no noise and not pollute the nature reserve

  18. Floating terminal as an alternative to shore terminals

    Energy Technology Data Exchange (ETDEWEB)

    Terenzio, M. [CoeClerici Logistics S.p.A. (Italy)


    Transfer vessels, floating terminals, catamaran type or Floating Transfer Stations (FTSs) are some of the latest alternative solutions to standard floating cranes. The CoeClerici 'Bulkwayuu' and 'Boca Grande' floating terminals are described and their advantages over shore-based structures are itemised. The text is accompanied by 17 overhead/slides. 1 fig.

  19. Verstorings- en Verslechteringstoets Zwitserleven Ronde om Texel (Zwitserleven Zeilweek)

    NARCIS (Netherlands)

    Baptist, M.J.


    De Zwitserleven Ronde om Texel is ’s werelds grootste catamaran race. Het evenemententerrein ligt in meerdere Natura 2000 gebieden en aangetoond zal moeten worden dat het evenement geen significante gevolgen heeft voor de natuur‐ en instandhoudingdoelen voor deze gebieden. De organisatie en de

  20. Process development, nutrition and sensory characteristics of spiced ...

    African Journals Online (AJOL)

    Harvesting of dagaa is a demanding activity and the methods used include scoop net, seine net and catamaran or lift net. The harvesting of dagaa employs a lot of people along the lake carrying out the activities of fishing, preserving and selling. It is therefore considered to be a very important sector for job creation, income ...

  1. X-joints in composite sandwich panels

    NARCIS (Netherlands)

    Vredeveldt, A.W.; Janssen, G.Th.M.


    The small structural weight of fast large ships such as fast mono hulls or catamaran type of ships is of extreme importance to their success. One possible light weight structural solution is the sandwich panel with fibre reinforced laminates and a balsa, honeycomb or foam core. A severe obstacle for

  2. Direct Adaptive Rejection of Vortex-Induced Disturbances for a Powered SPAR Platform (United States)

    VanZwieten, Tannen S.; Balas, Mark J.; VanZwieten, James H.; Driscoll, Frederick R.


    The Rapidly Deployable Stable Platform (RDSP) is a novel vessel designed to be a reconfigurable, stable at-sea platform. It consists of a detachable catamaran and spar, performing missions with the spar extending vertically below the catamaran and hoisting it completely out of the water. Multiple thrusters located along the spar allow it to be actively controlled in this configuration. A controller is presented in this work that uses an adaptive feedback algorithm in conjunction with Direct Adaptive Disturbance Rejection (DADR) to mitigate persistent, vortex-induced disturbances. Given the frequency of a disturbance, the nominal DADR scheme adaptively compensates for its unknown amplitude and phase. This algorithm is extended to adapt to a disturbance frequency that is only coarsely known by including a Phase Locked Loop (PLL). The PLL improves the frequency estimate on-line, allowing the modified controller to reduce vortex-induced motions by more than 95% using achievable thrust inputs.

  3. Seacoaster trials

    Energy Technology Data Exchange (ETDEWEB)

    Burg, D.


    The Seacoaster combines the high efficiencies of Surface Effect Ships (SES) with simple catamaran hull construction. It has blower pressurized air cushions that support some 80-90 percent of displacement and hence the high efficiencies. However, unlike the SES, there are no expensive and high maintenance flexible seals. Each catamaran sidehull has a simple recess molded or built into its underside. Powered blowers direct pressurized air into such recesses and thereby create lifting air cushions. There are no flexible seals of any kind and there is no air cushion between the sidehulls. Extensive towed model tests were conducted that showed the viability of the invention. The video shows the 65 foot open demonstrator Seacoaster underway at approximately 40 mph.

  4. Radiated noise from commercial ships in the Gulf of Maine: implications for whale/vessel collisions. (United States)

    Allen, J Kaitlyn; Peterson, Michael L; Sharrard, George V; Wright, Dana L; Todd, Sean K


    To understand mysticete acoustic-based detection of ships, radiated noise from high-speed craft, cruise ships, catamarans and fishing vessels was recorded June-September 2009. Calibrated acoustic data (fishing vessel had the lowest. Ship noise radiated asymmetrically and varied with depth. Bow null-effect acoustic shadow zones were observed for all ship classes and were correlated with ship-length-to-draft-ratios. These shadow zones may reduce ship detection by near-surface mysticetes.

  5. UV Sentry: A Collaborative Approach to Creating a Collaborative System (United States)


    0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions...searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send... Hydrofoil Supported Catamaran Length Overall 11 m Beam 4.7 m Draft 0.8 m Displacement 7.8 tonnes Speed (S.S. 4) 40 knots Duration 6 days

  6. Estudio de la viabilidad de los hovercrafts como embarcaciones de alta velocidad en el transporte marítimo de pasajeros y vehículos


    Ferrer Frau, Jaime


    Through a detailed study about what hovercraft has represented in the field of the very short sea carriage, I intend to find out its economic viability as passenger & vehicle transportation means far certain sea passages, justifying the reason for its very low deployment by shipping lines as an option to the current high speed crafts (catamarans & mono-hulls) that nowadays monopolize the short sea passenger traffic. In this thesis, it is described how they arose, how they are kept hovering...

  7. Is the change of heart in matters of energy consumption a twinaround towards solar energy Ecological innovations and natural science education. Documentation on a technical meeting. Energiewende = Sonnenwende Oekologische Innovationen und naturwissenschaftliche Bildung. Dokumentation einer Fachtagung

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, A.; Staeudel, L. (comps.)


    The compiled facts and examples are evidence that education itself is already heading for a kind of ''solar turnaround''. Under the aspects of ecological innovation and natural science education, the conference volume documents, inter alia, the following lectures given and workshops held: the energy policy of federal Germany; Greenpeace's solar campaign with reference to the solar energy school project; construction of a solar catamaran; and small and big energy projects realized at schools. (GL)

  8. Sustainable Oceanographic Vessels - Setting an Example (United States)

    van Leer, J. C.


    In response to climate change, global warming and post “peak oil” fuel scarcity, the oceanographic community should consider reducing its carbon foot print. Why should scientists operate inefficient vessels while lecturing the general public on the need to reduce CO2 emissions? We have already seen curtailment of ship schedules and ship lay-ups, due in part to rising fuel costs, following $140/barrel crude oil. When the global recession ends, upward pressure on oil prices will again commence. Who can forecast how high fuel prices may ultimately rise during the typical 25-30 year lifetime of a research vessel? Are we to curtail future work at sea when oceanic climate research is becoming ever more important? A catamaran research vessel has been designed which can be electrically propelled from by a combination of high efficiency generators, photovoltaic panels and/or sails. Sail produced power is transformed with propellers and motor/generators into electric power which is stored in battery banks. This vessel could operate as the first true hybrid oceanographic research vessel. It could even continue operations without fuel in cases of a severe fuel shortage or fueling denial. Since the power produced by any water turbine increases with the cube of the velocity flowing over its propeller, the low fluid friction and high stability of a catamaran, with reasonably slender hulls, provide an important boost to efficient hybrid operation. The author has chartered a 42’ hybrid catamaran sailboat and found it efficient and extremely easy to operate and control. A 79’ motor sailing catamaran research vessel by Lock Crowther Designs will be presented as one example of a sustainable research vessel with excellent speed and sea-keeping. A center well makes operation as a small drilling/coring ship for coastal climate investigation possible. The center well also supports a host of remote sensing and robotic gear handling capabilities.

  9. Fifth International Conference on High Energy Density Physics

    Energy Technology Data Exchange (ETDEWEB)

    Beg, Farhat


    The Fifth International Conference on High Energy Density Physics (ICHED 2015) was held in the Catamaran Hotel in San Diego from August 23-27, 2015. This meeting was the fifth in a series which began in 2008 in conjunction with the April meeting of the American Physical Society (APS). The main goal of this conference has been to bring together researchers from all fields of High Energy Density Science (HEDS) into one, unified meeting.

  10. China Naval Modernization: Implications for U.S. Navy Capabilities Background and Issues for Congress (United States)


    combatants. The HOUBEI design integrates a high-speed wave- piercing catamaran hull, waterjet propulsion, signature-reduction features, and the YJ-83 family...Department is investing in new cutting -edge capabilities, deploying our finest maritime capabilities forward, and distributing these capabilities more...Missile Hits Targets, Spooks USAF Generals,” Popular Science, September 22, 2015. 191 David A. Fulghum, “USAF: Slash And Burn Defense Cuts Will Cost





    Semi-SWATH ship design is a result of combining the good features of SWATH and Catamaran designs. However, the disadvantage of semi-SWATH is that she has low restoring force at bow that causes a tendency to bow-dive when running in following seas. In some critical conditions, the foredeck was found to be immersed underwater. One of the efforts to improve the ship???s performance is to install fin stabilizers at bow and stern. The fin stabilizers are used to compensate for the low restoring fo...

  12. Concept of navigation and automatic steering of the measuring dolphin

    Energy Technology Data Exchange (ETDEWEB)

    Majohr, J.; Buch, T.; Korte, C. [Rostock Univ. (Germany). Inst. fuer Automatisierungstechnik


    The Catamaran - Measuring Dolphin (MESSIN) is an unmanned and independently operated craft having been designed for carrying out multiple measuring tasks in the field of marine research and water monitoring especially in shallow waters. An introduction to the navigation, steering and safety systems is given. Furthermore the main components of the track control system and the electronic chart system used here are shown. Results of manoeuvring tests of the MESSIN are represented. This paper gives a contribution to the field of research ''autonomous and full automated vehicle''. (orig.)

  13. Developments in skirt systems for air cushion vehicles (United States)

    Inch, Peter; Prentice, Mark E.; Lewis, Carol Jean

    The present evaluation of the development status of air-cushion vehicle (ACV) skirts emphasizes the materials employed, with a view to the formulation of materials-performance requirements for next-generation AVCs and, in particular, an 'air-cushion catamaran' surface-effect ship (SES). Attention is given to novel skirt-design features which furnish substantial savings in maintenance costs. The employment of extant test rig data and the use of CAD methods are discussed, and the features of a novel system for the direct fixing of a bow finger onto an SES structure are noted.

  14. Tracking an oil slick from multiple natural sources, Coal Oil Point, California

    Energy Technology Data Exchange (ETDEWEB)

    Leifer, Ira [Marine Sciences Institute, University of California, Santa Barbara, CA 93106 (United States); Luyendyk, Bruce [Department of Geological Sciences, University of California, Santa Barbara, CA 93106 (United States); Broderick, Kris [Exxon/Mobil Exploration Company, 13401 N. Freeway, Houston, TX 77060 (United States)


    Oil slicks on the ocean surface emitted from natural marine hydrocarbon seeps offshore from Coal Oil Point in the Santa Barbara Channel, California were tracked and sampled over a 2-h period. The objectives were to characterize the seep oil and to track its composition over time using a new sampling device, a catamaran drum sampler (CATDRUMS). The sampler was designed and developed at UCSB. Chromatograms showed that oil originating from an informally named, very active seep area, Shane Seep, primarily evolved during the first hour due to mixing with oil originating from a convergence zone slick surrounding Shane Seep. (author)

  15. Versatility the key for new heavy lifters

    Energy Technology Data Exchange (ETDEWEB)



    This article gives details of the design of recent ships for offshore lifting projects covering the Dynamic Lifter and Dynamic Carrier which incorporate dynamic positioning, are capable of transporting heavy loads, and can be configured to operate in catamaran mode. The operation of the new vessels, their use to carry a wide range of cargoes such as mobile drilling rigs and offshore structures, and design features and propulsion systems are described. The provision of sample transport manuals providing information on voyages, loading, stability, and marine operations is discussed.

  16. Do-it-yourself bulk handling

    Energy Technology Data Exchange (ETDEWEB)



    Vessels with self-unloading gear are nothing new. But the self-unloader concept has wider potential in coal handling as the work and the vision of one of the world's leading designers of self-unloading vessels shows. Seabulk Systems Inc. has worked on self-unloaders since 1989 and has gone on to develop the semi-submersible transhipment vessel (SST), the Sea Bulk Transhipper vessel (SST), the Sea Bulk Transhipper (SBT), the Catamaran Transfer Vessel (CTV) the Seabulk Cape Unloader (CSU), and the transhipment barge - the Sea Bulk Transfer Vessel (STV). 6 photos.

  17. New tender for Alvin (United States)

    Richman, Barbara T.

    This month the Atlantis II will become the new tender ship for the Deep Submergence Research Vehicle (DSRV) Alvin. The Woods Hole Oceanographic Institution's 64-m refitted ship replaces the 32-m catamaran Lulu, which has been Alvin's tender and escort for 19 years. Originally constructed as a temporary support vessel from two surplus mine sweeping pontoons, Lulu cannot move quickly enough or traverse the large distances required to support priority research. In the next three months, two workshops will review letters of intent to use the new ship/submersible team.

  18. Dynamic characteristics of a WPC—comparison of transfer matrix method and FE method (United States)

    Chen, Guo-Long; Nie, Wu


    To find the difference in dynamic characteristics between conventional monohull ship and wave penetrating catamaran (WPC), a WPC was taken as an object; its dynamic characteristics were computed by transfer matrix method and finite element method respectively. According to the comparison of the nature frequency results and mode shape results, the fact that FEM method is more suitable to dynamic characteristics analysis of a WPC was pointed out, special features on dynamic characteristics of WPC were given, and some beneficial suggestions are proposed to optimize the strength of a WPC in design period.

  19. Yachting Club

    CERN Multimedia

    Yachting Club


    Under a cloudless sky, the YCC ran its traditional Traversée du Lac for dinghies and catamarans last Sunday. The turn-out was not good, surprisingly: do we all take longer or more frequent holidays than your Committee anticipated? Never mind, we had a final fleet of six, even with no catamarans: three Laser 1’s (now that is a popular boat and surely a wise recent purchase for the Club), and three RS’s, respectively 400, 500 and 800 (private). Winds were light, but even with a slightly delayed start, they were strong enough for Race Officer Tom Wilkins and ResQ driver Tim Hancox to fit in two complete circuits/races. In older times, that would have been one race of two circuits, but the scoring is fairer if you get a chance to recover your first start in a second heat! Adjacent is a photo (thank you Loic Le Canderff, also doing important work on ResQ) of one of the final winners, Sandrine on Laser 1, joint first with overall regatta coordinator, Sanja: yes, surprisingly, th...

  20. Yachting club

    CERN Multimedia

    Yachting club


    WARNING: your C key is about to expire... Good, we hoped that would draw your attention! A gentle reminder that, following the purchase of our fast, sophisticated racing catamaran Hobie Tiger Meerkat last season, your Committee decided to create a new key to reflect this, the EC (Experienced Catamaran). Those taking a C course will be assessed during a test as to whether they will gain the C key or the C plus EC key, so need only practise hard. Those - and we are many - who possess the C key from past years need to refresh our knowledge and prove our competence to sail Meerkat effectively with the EC key. This requires a few attested outings under good wind conditions, use of the gennaker, general control. And if it’s any consolation, we (remembering the Darts and then the Mysteres, and now both SL16 and Tiger) can confirm that she is really a pussycat, and really very willing to tack if you treat her right... Plan on trying for her or indeed Catapult on Thursdays, then talk to your Committee (f.i...

  1. Basement of Structure, Main Power and Design Parameters of Mechanism of Removing Sections of Mechanized Sets of Knife Plane Installation (United States)

    Sysoev, N. I.; Turuk, Yu V.; Kolesnichenko, I. Y.; Lugantsev, B. B.


    The reasons for the failure of the pitch stability of the knife-plane installation due to the action of extreme effort in the plane of the seam from the conveyor side on the mechanism of removing sections of mechanized sets are shown. The technique for determining this effort is presented. The constructions of the adaptive mechanisms of the removing sections of mechanized sets with the basements of catamaran type, in the constrictions of which elastic elements (rods) are used, are considered. The constructions of the mechanism of removing a section of the mechanized set with the basement of catamaran type in which the stock of the hydraulic jack is connected with the band loop through the movable rods intermediate basement with a link are worked out. The intermediate basement unloads the stock of the hydraulic jack of the moving installation from the side curving efforts, caused by the action of lateral forces in the plane of the seam on the conveyor side. It increases the reliability and efficiency of work of the knife plane mechanized complex.

  2. Influence of a conservative sleep management strategy during a solo Pacific Ocean crossing on anxiety and perceived fatigue: a case study. (United States)

    Hagin, Vincent; Gonzales, Benoît R; Candau, Robin B; Groslambert, Alain


    The aim of this case study was to determine whether a sailor's deliberate choice of a conservative strategy to manage sleep deprivation would allow him to cross the Pacific Ocean and to minimize his state of anxiety and perceived fatigue. The participant, who had more than 10 years' sailing experience in severe conditions, was tested on a small catamaran without any living quarters during a solo Pacific Ocean crossing. Estimations of sleep hours, state anxiety, and perceived fatigue were self-reported by the sailor on a daily basis using a specific questionnaire. The most important finding is that the sailor's deliberate sleep strategy, 5.4 h sleep per day (24% less than on-shore), was enough to keep his anxiety and perceived fatigue within acceptable limits and enabled him to achieve his goal, which was the first crossing of the Pacific Ocean on a catamaran of less than 6 m. In conclusion, our results suggest that the sailor observed in the present case study was able to minimize anxiety and perceived fatigue with adequate sleep to optimize his performance, security, and to achieve his goal.

  3. Development of the ride control system (RCS) for the JETPIERCER; JETPIERCER no side ride control system (RCS) no kaihatsu jitsuyoka

    Energy Technology Data Exchange (ETDEWEB)

    Onoda, K.; Tanaka, I.; Yamase, Y.; Ebira, K.; Ogawa, M. [Kawasaki Heavy Industries, Ltd., Kobe (Japan)


    Ride control system (RCS) is developed to improve on the quality of riding aboard a wave piercing catamaran high-speed car ferry Jet Piercer. The boat is an economically excellent buoyancy-supported high speed wave piercing catamaran, suitable for carrying heavy goods. It has its own shortcoming, however, in that it experiences much motion when exposed to waves, and this deteriorates the quality of riding. This is the reason why an RCS is developed, which utilizes as the motion suppressing force the lift generated by fins and trim tabs installed on the hull. Rate gyros sense the motion of the ship, and a control calculation unit, working on the basis of the obtained data, issues instructions for actuators to change the angle settings for fins and trim tabs so that the lift they generate may serve the purpose of damping the motion. The control system consists of a pitching system and rolling system, both responding to angular velocity signals they receive from respective, independently operating rate gyros. With the RCS in operation, the roll rate is approximately 47%, and the vertical acceleration rate approximately 36%, lower than without. 2 refs., 12 figs.

  4. Multipurpose stabilization of the advanced marine surface crafts

    Directory of Open Access Journals (Sweden)

    Sevostyanov Ruslan A.


    Full Text Available Advanced marine surface crafts, such as SWATHs, catamarans or hovercrafts become more and more popular for a great range of various tasks. They usually operate at much higher speed than conventional ships. Moreover, in the open sea there are a lot of requirements and restrictions concerning the quality of such crafts’ dynamics, especially in case of the wind or waves. This paper considers application of the control law with a special multipurpose structure for autopilot design for amphibious air cushion vehicles. Such control law allows to decompose the autopilot task into simpler optimization subtasks. Efficiency of this approach is shown in the task of stabilizing yaw angle of the air cushion vehicle in the different weather conditions.

  5. High Performance Marine Vessels

    CERN Document Server

    Yun, Liang


    High Performance Marine Vessels (HPMVs) range from the Fast Ferries to the latest high speed Navy Craft, including competition power boats and hydroplanes, hydrofoils, hovercraft, catamarans and other multi-hull craft. High Performance Marine Vessels covers the main concepts of HPMVs and discusses historical background, design features, services that have been successful and not so successful, and some sample data of the range of HPMVs to date. Included is a comparison of all HPMVs craft and the differences between them and descriptions of performance (hydrodynamics and aerodynamics). Readers will find a comprehensive overview of the design, development and building of HPMVs. In summary, this book: Focuses on technology at the aero-marine interface Covers the full range of high performance marine vessel concepts Explains the historical development of various HPMVs Discusses ferries, racing and pleasure craft, as well as utility and military missions High Performance Marine Vessels is an ideal book for student...

  6. Sea breeze forcing of estuary turbulence and air-water CO2 exchange (United States)

    Orton, Philip M.; McGillis, Wade R.; Zappa, Christopher J.


    The sea breeze is often a dominant meteorological feature at the coastline, but little is known about its estuarine impacts. Measurements at an anchored catamaran and meteorological stations along the Hudson River and New York Bay estuarine system are used to illustrate some basic characteristics and impacts of the feature. The sea breeze propagates inland, arriving in phase with peak solar forcing at seaward stations, but several hours later at up-estuary stations. Passage of the sea breeze front raises the water-to-air CO2 flux by 1-2 orders of magnitude, and drives turbulence comparable to spring tide levels in the upper meter of the water column, where most primary productivity occurs in this highly turbid system. Modeling and observational studies often use remotely-measured winds to compute air-water fluxes (e.g., momentum, CO2), and this leads to a factor of two flux error on sea breeze days during the study.

  7. Resistance and seakeeping numerical performance analyses of a semi-small waterplane area twin hull at medium to high speeds (United States)

    Vernengo, Giuliano; Bruzzone, Dario


    The hydrodynamic analysis of a new semi-small waterplane area twin hull (SWATH) suitable for various applications such as small and medium size passenger ferries is presented. This may be an attractive crossover configuration resulting from the merging of two classical shapes: a conventional SWATH and a fast catamaran. The final hull design exhibits a wedge-like waterline shape with the maximum beam at the stern; the hull ends with a very narrow entrance angle, has a prominent bulbous bow typical of SWATH vessels, and features full stern to arrange waterjet propellers. Our analysis aims to perform a preliminary assessment of the hydrodynamic performance of a hull with such a complex shape both in terms of resistance of the hull in calm water and seakeeping capability in regular head waves and compare the performance with that of a conventional SWATH. The analysis is performed using a boundary element method that was preliminarily validated on a conventional SWATH vessel.

  8. Stretching the HM200 series SES (United States)

    Tattersall, E. G.; Gee, N. I.

    The HM200 series SESs are discussed and compared with respect to design specifications, cost, and performance specifications such as speed loss in waves, and vertical accelerations. Structural modifications for the HM221, demonstrating a capacity increases of 33 percent over the HM218 for only a 22 percent increase in first cost, include small increases on bottom shell thickness and a 30 percent lift power increase (by using the turbo charged version of the HM218 naturally aspirated engine). It is shown that the HM200 series requires about half the HP and fuel consumption of the catamaran, and about 30 percent less than the surface piercing hydrofoils, in the same speed range.

  9. Note: Development of a small maglev-type antirolling system (United States)

    Park, Cheol Hoon; Park, Hee Chang; Cho, Han Wook; Moon, Seok Jun; Chung, Tae Young


    Various passive and/or active antirolling devices have been used for suppressing the rolling motion of ships in the ocean. In this study, a maglev-type active mass driver (AMD) is developed for controlling the rolling motion of a shiplike structure. No friction is generated during the motion of this maglev-type AMD, as the moving mass is floated by the magnetic levitation force and displaced by the propulsion force generated by the linear motor. For verifying the feasibility of the proposed method, a small AMD having a moving mass of approximately 4.0 kg is constructed and used in a small-scale model of a catamaran. This paper presents the detailed design procedures and obtained experimental results. Our results show that the developed maglev-type AMD has the potential for use in controlling the rolling motion of ships and other oceanographic vessels.

  10. Damage Stability Assessment of an HSC after Grounding

    DEFF Research Database (Denmark)

    Ravn, Erik Sonne; Simonsen, Bo Cerup; Baatrup, Jan


    Currently a substantial effort is done within the International Maritime Organisation (IMO) on revision of the High Speed Craft (HSC) Code. A main issue is the extent of bottom damage and raking damage due to grounding on hard rocks and the corresponding requirements to the damage stability.......In the present paper a detailed grounding and damage stability analysis is carried out for two specific HSC, a mono-hull (86 m) and a catamaran (69 m). First various grounding scenarios are considered with different values of the forward speed and ground geometry. The results indicate that 100% bottom damage...... is likely for grounding on sharp-pointed rocks. In the second part of the paper the damage stability is determined for the two craft damaged according to the proposal by the IMO working group. The results show that the two ferries cannot comply with the regulation unless modified either with a double bottom...

  11. Streambed temperature dynamics and corresponding heat fluxes in small streams experiencing seasonal ice cover (United States)

    Caissie, Daniel; Kurylyk, Barret L.; St-Hilaire, André; El-Jabi, Nassir; MacQuarrie, Kerry T. B.


    Streambed temperature and heat fluxes are important for aquatic habitats as well as in the development and improvement of water temperature models. In the present study, measured streambed temperatures at different depths were used as a tracer to predict the magnitude and direction of groundwater flow using an advection-conduction heat transport model. This analysis was carried out under different conditions, namely under natural surface water temperature conditions (i.e., as measured in the field), under steady-state conditions (e.g. under stream ice cover) and for conditions where the surface water temperatures followed a sinusoidal function. In Catamaran Brook, results from the advection-conduction numerical model showed good agreement between predicted and observed streambed temperatures with root-mean-square errors (RMSEs) ranging between 0.07 °C to 0.6 °C. A comparison of streambed fluxes showed that the heat flux by conduction was more important during the summer period for upwelling conditions (mean value 96 W m-2 at 25 °C), but was also present in winter (-20 W m-2). Variability in heat flux by conduction was also greater when the diel surface water temperature variability was high (e.g. range of 6 °C). The heat flux by advection varied between -120 and 145 W m-2 (for typical water temperatures and vertical flow conditions within Catamaran Brook, 0-25 °C and ±0.005 m h-1). Short-term heat exchange (diel) occurred within the thermally active depth, typically <0.7 m. The long-term annual streambed heat flux by conduction was also calculated and daily mean was generally less than ±11 W m-2. Winter conditions provided a unique opportunity to analyse streambed heat fluxes under steady-state conditions when both conduction and advection fluxes were present.

  12. Promising propulsion technologies for the water vehicles of the EXPO.01; Zukunftsweisende Antriebstechniken fuer die Wasserfahrzeuge der EXPO.01. Schlussbericht 1998

    Energy Technology Data Exchange (ETDEWEB)

    Minder, R. [Minder Energy Consulting, CH-8917 Oberklunkhofen (Switzerland); Renaud, P. [Planair, CH-2314 La Sagne (Switzerland)


    In the year 2001 (Note of the reviewer: effectively, it will be 2002) the Swiss National Exhibition EXPO.01 will take place at four sites in the region of the lakes of Biel/Bienne, Neuchatel and Murten. A large part of the transportation of the visitors from one site to the other will be made by ships. Since the currently available fleets of passenger ships on these lakes have not the capacity needed, some off-shore fast ferries will be leased during the EXPO. The present project aims at demonstrating the feasibility of advanced energy-efficient and environmentally benign propulsion systems for inland waterway passenger ships at the EXPO.01. In the report various technical concepts such as advanced internal-combustion engines and electric drives powered by fuel cells, batteries and solar cells are discussed. The authors came to the conclusion that the concept of a solar-electric-driven catamaran would be technically feasible and a very attractive solution. Based on these findings a preliminary engineering study for 'SolarCat' has been made. 'SolarCat' is a 200-passenger catamaran-type ship of 30 m length by 10 m width, powered by electric motors. The energy is provided by some 200 m{sup 2} of photovoltaic modules installed on the roof. For energy storage, lead-acid batteries with some 320 kWh capacity will be used. The cruising velocity of the vessel will be 15 to 18 km/h (8 to 10 knots), peak velocity some 25 km/h (14 knots) which is comparable to conventional ships. The construction of the ship will cost approximately 3 million CHF (about 1.5 million US D). In order to obtain the financing, negotiations with public institutions as well as with private sponsors have been started. (author)

  13. A Floating Ocean Energy Conversion Device and Numerical Study on Buoy Shape and Performance

    Directory of Open Access Journals (Sweden)

    Ruiyin Song


    Full Text Available Wave and current energy can be harnessed in the East China Sea and South China Sea; however, both areas are subject to high frequencies of typhoon events. To improve the safety of the ocean energy conversion device, a Floating Ocean Energy Conversion Device (FOECD with a single mooring system is proposed, which can be towed to avoid severe ocean conditions or for regular maintenance. In this paper, the structure of the FOECD is introduced, and it includes a catamaran platform, an oscillating buoy part, a current turbine blade, hydraulic energy storage and an electrical generation part. The numerical study models the large catamaran platform as a single, large buoy, while the four floating buoys were modeled simply as small buoys. Theoretical models on wave energy power capture and efficiency were established. To improve the suitability of the buoy for use in the FOECD and its power harvesting capability, a numerical simulation of the four buoy geometries was undertaken. The shape profiles examined in this paper are cylindrical, turbinate (V-shaped and U-shaped cone with cylinder, and combined cylinder-hemisphere buoys. Simulation results reveal that the suitability of a turbinate buoy is the best of the four types. Further simulation models were carried out by adjusting the tip radius of the turbinate buoy. Three performance criteria including suitability, power harvesting capability and energy capture efficiency were analyzed. It reveals that the turbinate buoy has almost the same power harvesting capabilities and energy capture efficiency, while its suitability is far better than that of a cylindrical buoy.


    CERN Multimedia

    Yachting Club


    TRAVERSEE DU LAC MEETS BOL D’OR It is not entire coincidence that your ever-attentive YCC Committee schedules our Traversée du Lac (dinghies, catamarans, windsurfs - although admittedly not many of the latter these last few seasons) for the same weekend as the rather larger-scale Bol d’Or: it enables our intrepid crews to practise their priority rules as Dona Bertarelli sweeps past with LadyCat and gives you something to watch should the wind drop momentarily ... The rest is history, as we say and your scribe will not repeat here the results, either of the Traversée or of the Bol - go find them on our respective Webs! But many thanks to John and Sarah Fullerton for organising this event and to Wolfgang Adam for ably skippering our new Q-boat. And a gentle reminder to us all, please, that we are fairly short of volunteers on all fronts: not merely routine maintenance, remembering to clean the boat you enjoy from time to time but also - urgently - Q-boat skippers (she&...

  15. Summary of the papers of the 95th Meeting of the West Japan Society of Naval Architects. Joint meeting of three shipbuilding societies in fall, fiscal 1997; Seibu Zosenkai dai 95 kai reikai ronbun gaiko. 1997 nendo shuki zosen sangakkai rengo koenkai

    Energy Technology Data Exchange (ETDEWEB)



    The paper summarized the papers on the following: estimation of the propulsion performance by the surface vortex lattice method using model ship flow field data; wave-making resistance calculation and performance estimation by the Rankine source method; calculation method of wave-making resistance of Catamaran and solution method of the hydrofoil problem using the convenient panel method; study of estimation of hydrodynamic forces acting on ship in maneuvering motion; study of the combined plant using generator use diesel exhaust heat; mathematical structure of the ocean container transport system; developmental OTEC plants in Indonesia. In relation to structural dynamics/strength problems, reports were made on the hull longitudinal strength theory, FEM modeling in analyses of buckling/plasticity collapse of deflection panels, etc. Further reported were a consideration of the use classification of hull use steel sheets considering fracture toughness, and changes of aspect ratios of small surface cracks emanating from a toe of corner boxing. Concerning ocean structures, there are experimental studies on vibration in water of a semi-spherical shell fixed in water, and a behavior of huge floating structures in regular waves

  16. New approaches to the design optimization of hydrofoils (United States)

    Beyhaghi, Pooriya; Meneghello, Gianluca; Bewley, Thomas


    Two simulation-based approaches are developed to optimize the design of hydrofoils for foiling catamarans, with the objective of maximizing efficiency (lift/drag). In the first, a simple hydrofoil model based on the vortex-lattice method is coupled with a hybrid global and local optimization algorithm that combines our Delaunay-based optimization algorithm with a Generalized Pattern Search. This optimization procedure is compared with the classical Newton-based optimization method. The accuracy of the vortex-lattice simulation of the optimized design is compared with a more accurate and computationally expensive LES-based simulation. In the second approach, the (expensive) LES model of the flow is used directly during the optimization. A modified Delaunay-based optimization algorithm is used to maximize the efficiency of the optimization, which measures a finite-time averaged approximation of the infinite-time averaged value of an ergodic and stationary process. Since the optimization algorithm takes into account the uncertainty of the finite-time averaged approximation of the infinite-time averaged statistic of interest, the total computational time of the optimization algorithm is significantly reduced. Results from the two different approaches are compared.

  17. High Resolution Marine Magnetic Survey of Shallow Water Littoral Area

    Directory of Open Access Journals (Sweden)

    Jacob Sharvit


    Full Text Available The purpose of this paper is to present a system developed for detection andaccurate mapping of ferro-metallic objects buried below the seabed in shallow waters. Thesystem comprises a precise magnetic gradiometer and navigation subsystem, both installedon a non-magnetic catamaran towed by a low-magnetic interfering boat. In addition wepresent the results of a marine survey of a near-shore area in the vicinity of Atlit, a townsituated on the Mediterranean coast of Israel, about 15 km south of Haifa. The primarypurpose of the survey was to search for a Harvard airplane that crashed into the sea in 1960.A magnetic map of the survey area (3.5 km2 on a 0.5 m grid was created revealing theanomalies at sub-meter accuracy. For each investigated target location a correspondingferro-metallic item was dug out, one of which turned to be very similar to a part of thecrashed airplane. The accuracy of location was confirmed by matching the position of theactual dug artifacts with the magnetic map within a range of ± 1 m, in a water depth of 9 m.

  18. Retrospective assessment of macrophytic communities in southern Lake Garda (Italy from in situ and MIVIS (Multispectral Infrared and Visible Imaging Spectrometer data

    Directory of Open Access Journals (Sweden)

    Claudia Giardino


    Full Text Available In situ and hyperspectral MIVIS (Multispectral Infrared and Visible Imaging Spectrometer images acquired over a period of 13 years are used to assess changes in macrophyte colonization patterns in the coastal zones of the Sirmione Peninsula in the southern part of Lake Garda (Italy. In situ data (abundance, cover density and diversity of macrophyte communities and MIVIS-derived maps of colonized substrates are analyzed by considering the variability of the main hydrological and physicochemical variables in order to indicate the main factors that explain the spatiotemporal variability of macrophyte communities. The results show a considerable modification in terms of macrophyte structural complexity and colonized areas. Almost 98% of macrophyte meadows (in particular communities with a density of over 70% are lost and subsequently replaced by moderate to extremely rare communities with density from 10% to 40%. Well-established submerged macrophytes are replaced by de-structured communities characterized by moderate to scarce density: on average lower than 30%. The study indicates that macrophyte distribution along the littoral zone of the Sirmione Peninsula is certainly linked to water transparency and water level fluctuation. The results also indicate that the worsening of eutrophication may be associated with the gradual disappearance of macrophyte meadows, but may also be accelerated by herbivorous aquatic birds grazing there. Lastly, the increasing frequency and number of catamaran tours could be considered a threat for the stability of these valuable communities.

  19. Hydrogen fuel in a marine environment

    Energy Technology Data Exchange (ETDEWEB)

    Veldhuis, I.J.S.; Richardson, R.N.; Stone, H.B.J. [School of Engineering Sciences, University of Southampton, Southampton SO17 1BJ (United Kingdom)


    Hydrogen may offer considerable potential as a marine fuel. The lower fuel mass when compared with existing hydrocarbon fuels can usefully increase payload which in turn benefits the economics of oceanic transport and provides the opportunity to compete in new markets. The potential to virtually eliminate pollution at the point of use may prove significant at a time when exhaust emissions from shipping are becoming a matter of global concern. The potential for hydrogen in the marine environment, the current state of transferable technologies and the particular technical and economic issues that need to be addressed are considered in the context of a design study being conducted on a high-speed foil-assisted catamaran capable of transporting 600TEU at speeds of up to 64 kn (118.5 km/h) over trans-Pacific and trans-Atlantic trade routes. It is concluded that such a vessel is technically feasible and could achieve door-to-door delivery times, as part of an integrated transport chain, otherwise only possible by airfreight but at a fraction of the cost. (author)

  20. MobiCat - a solar-electrical passenger boat; MobiCat solar-elektrisches Passagierschiff

    Energy Technology Data Exchange (ETDEWEB)

    Minder, R.


    This final report for the Swiss Federal Office of Energy presents the results of the 'MobiCat' project which included the design, construction and operation of a solar-electric powered passenger ship for inland waterways. The vessel is of a catamaran with a length of 33 m and a width of 11 m. The electrical energy is produced by a 20 kW{sub p} array of photovoltaic panels and stored in two 480 V lead-acid battery blocks rated at 240 Ah each. The ship is powered by two 81 kW industrial AC drives. With a passenger capacity of 150 persons MobiCat is the largest solar-powered ship world-wide. The report discusses the generally positive operational experience and the wide interest both by the public and the media that the project has attracted. The MobiCat has become the most popular charter ship on the lake of Biel/Bienne in Switzerland. The author states that the ultimate goals of the project - to demonstrate the feasibility of large solar-powered passenger ships and to present new sustainable mobility solutions on inland waterways - have been fully reached.

  1. WAGO IPCs manage energy on unique solar-powered boat

    Energy Technology Data Exchange (ETDEWEB)



    This article described WAGO's contribution to the world's largest solar-powered boat, the Turanor PlanetSolar, a catamaran research vessel that was developed for solar power research. The boat has over 500 square metres of photovoltaic (PV) panels and 11 tons of batteries, including the 388 V lithium ion (NCA) battery. WAGO provided three 758 Series IPCs with control functionality and electrical components. The IPCs control charging for 3 batteries and 10 Drivetek Maximum Power Pick Trackers by way of 13 CAN buscouplers. The high-end DC/DC converters improve the solar absorption of the PV panels, which are fixed and mounted on the deck. For dependability in severe marine environments, WAGO's electrical components feature gas-tight connections that are vibration and thermal-cycling resistant. The Turanor accommodates a crew of four and has no gasoline back-ups for steering or propulsion. In 2011, the Turanor will embark on the first solar-powered circumnavigation of the globe by any means of transport. 1 fig.

  2. High-fidelity global optimization of shape design by dimensionality reduction, metamodels and deterministic particle swarm (United States)

    Chen, Xi; Diez, Matteo; Kandasamy, Manivannan; Zhang, Zhiguo; Campana, Emilio F.; Stern, Frederick


    Advances in high-fidelity shape optimization for industrial problems are presented, based on geometric variability assessment and design-space dimensionality reduction by Karhunen-Loève expansion, metamodels and deterministic particle swarm optimization (PSO). Hull-form optimization is performed for resistance reduction of the high-speed Delft catamaran, advancing in calm water at a given speed, and free to sink and trim. Two feasible sets (A and B) are assessed, using different geometric constraints. Dimensionality reduction for 95% confidence is applied to high-dimensional free-form deformation. Metamodels are trained by design of experiments with URANS; multiple deterministic PSOs achieve a resistance reduction of 9.63% for A and 6.89% for B. Deterministic PSO is found to be effective and efficient, as shown by comparison with stochastic PSO. The optimum for A has the best overall performance over a wide range of speed. Compared with earlier optimization, the present studies provide an additional resistance reduction of 6.6% at 1/10 of the computational cost.

  3. Ship motion control system; Sentai shisei seigyo

    Energy Technology Data Exchange (ETDEWEB)

    Yamaga, H. [Mitsui Shipbuilding and Engineering Co. Ltd., Tokyo (Japan)


    Techno-super-liner is a large object combining with catamaran in application of an amphibious principle of a hover craft, called as the air pressure type complex support from (TSL-A form). In this paper, the driving device in the ship motion control system (RCS), equipped with `HISYO` developed as an experimental ship of TSL-A 70m type in the marine area, was mainly introduced. This RCS was a motion control system for a propose to reduce swing of a ship body when high speed navigation in the opening sea, this structural device consisted of the control calculation device, the swing detection device, the operation monitoring device, the underwater fin flip driving device, the lopper driving device, and the hydraulic power unit. As investigation results on the effectiveness of RCS in the HISYO through the marine experiments and general experiments, it was proved that the expected effect was obtained, high speed navigation was possible in a worse weather. 1 figs., 4 tabs.


    CERN Multimedia



    INTERNAL RAGATTE - BEST EVER ! If you missed Internal Regatta III on Sunday 11 July, you missed one of the best we can recall! The winds were about perfect, fairly stable Bf 2 with periodic gusts higher and the resulting capsizes to keep crews concentrating. It was extremely hot but we ran the usual three heats for keelboats and a record four for dinghies, catamarans - where there was another record, surely: a total of 11 boats in that class, of which three privately owned by members. And a final record: we calculate five boats were competing in their first-ever regatta. Results on the webpage. Surprisingly for those who remember regattas of a couple of years back, only three keelboats competed, so there would have been plenty of scope for less experienced members to come along regardless and probably find themselves a place. It is also noteworthy that the keelboat winner was Andrea Messina with an - ummm, may I say - less experienced crew himself! We hope this win bodes well for his forthcoming Transl&am...

  5. Resistance analysis of unsymmetrical trimaran model with outboard sidehulls configuration (United States)

    Yanuar; Gunawan; Talahatu, M. A.; Indrawati, Ragil T.; Jamaluddin, A.


    The application of multi-hull ship or trimaran vessel as a mode of transports in both river and sea environments have grown rapidly in recent years. Trimaran vessels are currently of interest for many new high speed ship projects due to the high levels of hydrodynamic efficiency that can be achieved, compared to the mono-hull and catamaran hull forms. The purpose of this study is to identify the possible effects of using an unsymmetrical trimaran ship model with configuration ( S/ L) 0.1-0.3 and R/ L=0.1-0.2. Unsymmetrical trimaran ship model with main dimensions: L=2000mm, B=200 mm and T=45 mm. Experimental methods (towing tank) were performed in the study using speed variations at Froude number 0.1-0.6. The ship model was pulled by an electric motor whose speed could be varied and adjusted. The ship model resistance was measured precisely by using a load cell transducer. The comparison of ship resistance for each configuration with mono-hull was shown on the graph as a function of the total resistance coefficient and Froude number. The test results found that the effective drag reduction could be achieved up to 17% at Fr=0.35 with configuration S/ L=0.1.

  6. Development and problems in liquid hydrogen tankers; Ekitai suiso tanker no kaihatsu to kadai

    Energy Technology Data Exchange (ETDEWEB)

    Abe, A.; Seki, N. [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)


    This paper summarizes studies on liquid hydrogen transportation tankers in the international clean energy system technologies for hydrogen utilization (Word Energy Network: WE-NET) at which research and development has begun under the initiative of NEDO since fiscal 1993. The amount of liquid hydrogen required to generate electric power by using hydrogen burning turbines at a power plant with an output of one million KW on the ground is about 1,200 tons a day. If two vessels are assumed used to unload the liquid every ten days to supply this quantity, the amount to be transported by one vessel will be 12,000 tons. It was assumed that an amount of about 14,000 tons would be required if evaporation loss during transportation is considered, so that the tank capacity of a liquid hydrogen transportation tanker was set to 200,000 m{sup 3}. Attention should be paid in designing a tanker that, since liquid hydrogen has very small specific gravity making assurance of draft difficult, an optimal vessel type must be selected, including a catamaran. Thickness of aluminum plates for tanks and heat insulation structures would be 20 to 33 mm as maximum. A heat insulation system having a structure capable of following tank shrinkage is required. The heat insulation system must be discussed on a normal pressure system and a vacuum system for the hold section. Loading and unloading work is another important problem to be solved. 5 refs., 7 figs., 3 tabs.

  7. Hydroelastic responses of cross deck panel to slamming; Slamming ni taisuru cross deck panel no dansei oto ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Toyama, Y. [Mitsui Engineering and Shipbuilding Co. Ltd., Tokyo (Japan)


    An analysis and a study were performed on deformation and stress response occurring in a structure when a high-speed catamaran ship is subjected to wave slamming on the lower face of the cross deck. The study proposed a method to analyze response to water slamming, which can consider elastic effects by utilizing solution of potential flow around a flat plate having perpendicular speed distribution of a triangle form. A dynamic response simulation was performed by using this method on a problem that a flat cross deck slams wave crests of parabolic shape. As a result, the following points were made clear: the maximum bending and bending moment at the center of a span of the panel show a trend of becoming proportional to the drop speed as the curvature radius on the water surface increases, where the proportion constant shows a trend of not depending on the curvature radius of the water surface; the peak value of impact pressure is thought not to give large effect directly to the dynamic response; and the reason for the maximum bending at the span center becoming proportional to the drop speed can be explained by reduction in magnification of the dynamic response. 10 refs., 14 figs., 1 tab.

  8. Fabrication of submerged caissons for constructing the west route tunnel of the Tokyo Port Coastal Road, and construction of ventilation shafts using the pneumatic caisson process; Tokyowan rinkai doro nishi koro tunnel kensetsu koji ni okeru chinmaikan no seisaku oyobi pneumatic caisson koho ni yoru kanki tatekui no seko

    Energy Technology Data Exchange (ETDEWEB)

    Muranaka, T. [Tokyo Metropolitan Office, Tokyo (Japan); Kishimoto, T.; Hayashi, N.; Koyama, F. [Taisei Corp., Tokyo (Japan)


    This paper introduces fabrication of submerged caissons for an ocean bottom tunnel for the Tokyo Port Coastal Road, and construction of ventilation shafts (on either side of the tunnel) using the pneumatic (pressurized air) caisson process. With regard to the submerged tunnel, eleven submerged caissons made of reinforced concrete with a width of 32.3 m, a height of 10m and a length of 120 m were fabricated in a nearby dock. The both ends of the ducts were covered with iron lids, and the dock was filled with sea water to float the ducts. Then, the ducts were towed and submerged by using a catamaran submerging work ship, connected under water pressure, and laid on the sea bottom. The ventilation shafts were structured from above the sea surface by using the pneumatic caisson process. After foundation piles of the caissons were driven, the factory-fabricated steel shell caissons were transported on the sea; pulled into beam stands having already been constructed; and then settled onto the sea bottom by using weight of the concrete of the bottom slabs. Thereafter, while the ducts were subsided at a subsiding speed of 10 to 30 cm per day, the main body construction was completed in the prescribed sequence. Remote ground controlled drilling system was used to operate a drilling machine by radio from a ground operating room to load and unload the earth automatically. The construction was completed maintaining the construction environment safely and reliably. 9 figs., 2 tabs.

  9. Imaging Karst Aquifers with Multichannel Seismic Data in Biscayne Bay: Conventional Wisdom Defied (United States)

    Walker, C.; Cunningham, K. J.


    Conventional wisdom reasons that acquisition of useful seismic data in shallow-marine carbonate environments is not possible because: (1) water-bottom multiples will dominate; (2) receiver offsets will be too short to image deep reflectors; (3) normal move out is too small to effectively calculate velocities; (4) air-gun source arrays are not appropriate or frequency band-limited; and (5) it is folly to over-sample the seismic data and process very large digital data sets. In 2007, about 108 km (17 individual profiles) of marine, multichannel, high-resolution, seismic data were acquired almost entirely inside Biscayne National Park in water depths ranging from 0.9 to 100 m. The data were collected using a 48-trace, towed-streamer array; an interdependent air-gun as the seismic source; and a proprietary 52-channel, 24-bit recording system. The seismic vessel was a fast, shallow-draft catamaran capable of continuously acquiring data in water as shallow as 0.7 m. The set of seismic images from 17 profiles show well-defined reflections from near surface to the Eocene Oldsmar Formation (including the karstic Boulder Zone in the Lower Floridan aquifer). The profiles also display distinctive geologic features that include karst, clinoformal prograding strata, unconformities, fractures, stratal truncation, and evidence for breaching of confining units.

  10. Sea Breeze Forcing of Estuary Turbulence and Air-Water Exchanges (United States)

    Orton, P. M.; McGillis, W. R.; Zappa, C. J.


    The sea breeze is often a dominant meteorological feature at the coastline, but little is known about its estuarine impacts. It arises on sunny days with weak synoptic weather forcing, due to O(100 km) scale atmospheric pressure differences that develop as a result of the different solar absorption properties of sea and land. Here, measurements at an anchored catamaran and meteorological stations along the Hudson River and New York Bay estuarine system are used to illustrate some basic characteristics and impacts of the feature. The sea breeze propagates inland, arriving in phase with peak solar forcing at seaward stations, but several hours later at up-estuary stations. Passage of the sea breeze front raises the water-to-air CO2 flux by 1-2 orders of magnitude, and drives turbulence comparable to spring tide levels in the upper meter of the water column, where most primary productivity occurs in this highly turbid system. Modeling and observational studies often use remotely-measured winds with quadratic parameterizations to compute air-water fluxes (e.g. momentum, CO2), and this leads to a factor of two flux error on sea breeze days during the study. We conclude with a survey of how common these features are in the Hudson as well as other estuaries.

  11. Surface wave observations during CoOP experiments and their relation to air-sea gas transfer (United States)

    Hara, Tetsu; Uz, B. Mete; Wei, Hua; Edson, James B.; Frew, Nelson M.; McGillis, Wade R.; McKenna, Sean P.; Bock, Erik J.; Haußecker, Horst; Schimpf, Uwe

    Gas exchange between the ocean and the atmosphere is strongly influenced by physical processes in the near-surface waters. Surface waves are particularly important for gas fluxes because they enable faster transfer of gases across the diffusive sublayer by causing more frequent renewal of the skin layer. During the CoOP air-sea gas exchange experiments (1995; 1997), we obtained one of the most comprehensive data sets of physical processes at the air-sea interface in both near-shore and off-shore waters. During these experiments simultaneous measurements of short wind waves, surface films, wind stress, and transfer velocity were made from a towed or self-propelled catamaran with a wide range of wind stress and with varying surface film conditions. The results show that the wave spectra at higher wavenumbers are significantly reduced by surfactant at wind friction velocities below 0.2 m s-1. The surfactant effect may be quantified using the surface enrichment (difference between the CDOM fluorescence in microlayers and that in bulk water) with reasonable accuracy. During rain events the wave spectra are raised at higher wavenumbers (above 200 rad m-1) but are not affected at 100 rad m-1. The surfactant effect is also reduced during rain. The air-sea gas transfer velocity is roughly proportional to the wave spectra at higher wavenumbers but appears to be less sensitive to spectra of longer waves.

  12. Yachting Club

    CERN Multimedia

    Yachting Club


      Sailing course lottery Potential learners still have a couple of days to sign up to the Lottery for places in this season’s sailing courses. Yes, it is already quite heavily oversubscribed - as every year: we must run good courses! - but the draw is completely fair so you stand as good a chance as anyone else. Among questions we have been asked is which course is least oversubscribed - and might therefore offer a better chance of a place? Probably Surprise, since you ask, but then that is also one of the most demanding, both in terms of requisite keys you already need even to sign up in the Lottery and also likelihood of passing the test. Well, one was our most expensive boat purchase ever, and she is a boat that revels in being sailed well (even while being forgiving of the rest of us). The picture alongside is a loosely connected explanation to another question we get: how did catamaran Meerkat get named? We convinced ourselves that Meerkats are friendly, sociable, fast, intell...

  13. CERN Yachting club

    CERN Multimedia

    CERN Yachting club


    Surely among the most active sports clubs within CERN, the Yachting Club has had a steadily increasing membership over a decade; it is now around 350 but new members are always welcome, especially now at the beginning of a season. Indeed, with the Lottery for places in courses which are one of our highlights, membership has jumped since mid-March. The Lottery is always heavily oversubscribed, which we like to think represents its good reputation for quality of teaching and good fun at the same time. Now those lucky new students are in contact with their teachers, will be buying wetsuits in some cases (dinghy and catamaran courses), joining us for the launch of the fleet (see calendar on website at ) and  – in many cases – learning sailing as complete beginners. Those Lottery-unlucky can still plan a fun season, with our Thursday Practice evenings, where we can almost always place everyone on a boat for an outing.   ...

  14. 92nd Meeting of West Japan Society of Naval Architects. Summary of papers; Seibu zosenkai dai 92 kai reikai. Ronbun kogai

    Energy Technology Data Exchange (ETDEWEB)



    The 92nd Meeting of West Japan Society of Naval Architects was held at Shimonoseki city on May 9 and 10, 1996, and 27 papers were made public. As for hydrodynamic force, the following were reported: Hydrodynamic interference between hull and submerged foils; An experimental research on maneuvering hydrodynamic force interference coefficients; A research on the method to estimate maneuvering hydrodynamic force at swirl motion; An experimental research on the method to estimate hydrodynamic force added to floating offshore structures, etc. As to the high-speed hydrofoil catamaran, Cabin connected to hull by spring and its riding comfort in waves, and Cabin connected to hull and vibration response. Relating to fundamental experiments, An experiment on vibration in water of the cylinder shell fixed in water; An research on fracture behavior of rectangular waves under water pressure; Buckling of the continuous stiffened plate under in-plane compressive loads; An research on plasticity decay behavior, etc. In addition, The aesthetics of ship design and the dynamic symmetry; Spilt oil pollution preventive measures and effects of the ocean preservation, etc.

  15. Feasibility of using Big Area Additive Manufacturing to Directly Manufacture Boat Molds

    Energy Technology Data Exchange (ETDEWEB)

    Post, Brian K. [ORNL; Chesser, Phillip C. [ORNL; Lind, Randall F. [ORNL; Sallas, Matthew R. [ORNL; Love, Lonnie J. [ORNL


    The goal of this project was to explore the feasibility of using Big Area Additive Manufacturing (BAAM) to directly manufacture a boat mold without the need for coatings. All prior tooling projects with BAAM required the use to thick coatings to overcome the surface finish limitations of the BAAM process. While the BAAM process significantly lowers the cost of building the mold, the high cost element rapidly became the coatings (cost of the material, labor on coating, and finishing). As an example, the time and cost to manufacture the molds for the Wind Turbine project with TPI Composites Inc. and the molds for the submarine project with Carderock Naval Warfare Systems was a fraction of the time and cost of the coatings. For this project, a catamaran boat hull mold was designed, manufactured, and assembled with an additional 0.15” thickness of material on all mold surfaces. After printing, the mold was immediately machined and assembled. Alliance MG, LLC (AMG), the industry partner of this project, experimented with mold release agents on the carbon-fiber reinforced acrylonitrile butadiene styrene (CF ABS) to verify that the material can be directly used as a mold (rather than needing a coating). In addition, for large molds (such as the wind turbine mold with TPI Composites Inc.), the mold only provided the target surface. A steel subframe had to be manufactured to provide structural integrity. If successful, this will significantly reduce the time and cost necessary for manufacturing large resin infusion molds using the BAAM process.

  16. Estimation of performance of a high-speed boat by using the Rankine source method; Kosokutei no rankinsosuho ni yoru seino suitei ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Eguchi, T. [Mitsui Engineering and Shipbuilding Co. Ltd., Tokyo (Japan)


    This paper describes estimation of performance of a high-speed boat by using the Rankine source method. An orthogonal coordinate system is considered, which uses the center of a hull as the zero point, and is made dimensionless by using the hull length. The catamaran boat or the single hull boat being the subject of the discussion is supposed to have a transom stern, and to be sailing at a constant speed in the -X direction. A governing equation and a border condition were formulated using disturbance speed potential and X-direction speed differentiation. An inverse specular image was employed as a specular image system upon considering attitude change in the high-speed boat. As to the division of hull surface, the portions protruded above the static water surface were cut off from among the panel data of boat CAD. Considering a high speed condition in which the water surface is completely separated at the transom section, the water level at the transom section was supposed to be at the same height as at the rear end of the hull. Blow-out intensity at the water surface was derived in such a way that a CAD panel of the rear end of the hull is searched and wave height agrees with the height of the transom in the Z direction. A resistance curve may be obtained easily by using a personal computer. 4 refs., 8 figs.

  17. Intelligent Control for USV Based on Improved Elman Neural Network with TSK Fuzzy

    Directory of Open Access Journals (Sweden)

    Shang-Jen Chuang


    Full Text Available In recent years, based on the rising of global personal safety demand and human resource cost considerations, development of unmanned vehicles to replace manpower requirement to perform high-risk operations is increasing. In order to acquire useful resources under the marine environment, a large boat as an unmanned surface vehicle (USV was implemented. The USV is equipped with automatic navigation features and a complete substitute artificial manipulation. This USV system for exploring the marine environment has more carrying capacity and that measurement system can also be self-designed through a modular approach in accordance with the needs for various types of environmental conditions. The investigation work becomes more flexible. A catamaran hull is adopted as automatic navigation test with CompactRIO embedded system. Through GPS and direction sensor we not only can know the current location of the boat, but also can calculate the distance with a predetermined position and the angle difference immediately. In this paper, the design of automatic navigation is calculated in accordance with improved Elman neural network (ENN algorithms. Takagi-Sugeno-Kang (TSK fuzzy and improved ENN control are applied to adjust required power and steering, which allows the hull to move straight forward to a predetermined target position. The route will be free from outside influence and realize automatic navigation purpose.

  18. Archive of side scan sonar and swath bathymetry data collected during USGS cruise 10CCT01 offshore of Cat Island, Gulf Islands National Seashore, Mississippi, March 2010 (United States)

    DeWitt, Nancy T.; Flocks, James G.; Pfeiffer, William R.; Wiese, Dana S.


    activity for that project in that calendar year. Refer to for a detailed description of the method used to assign the field activity ID. Data were collected using a 26-foot (ft) Glacier Bay Catamaran. Side scan sonar and interferometric swath bathymetry data were collected simultaneously along the tracklines. The side scan sonar towfish was towed off the port side just slightly behind the vessel, close to the seafloor. The interferometric swath transducer was sled-mounted on a rail attached between the catamaran hulls. During the survey the sled is secured into position. Navigation was acquired with a CodaOctopus Octopus F190 Precision Attitude and Positioning System and differentially corrected with OmniSTAR. See the digital FACS equipment log for details about the acquisition equipment used. Both raw datasets were stored digitally and processed using CARIS HIPS and SIPS software at the USGS St. Petersburg Coastal and Marine Science Center. For more information on processing refer to the Equipment and Processing page. Post-processing of the swath dataset revealed a motion artifact that is attributed to movement of the pole that the swath transducers are attached to in relation to the boat. The survey took place in the winter months, in which strong winds and rough waves contributed to a reduction in data quality. The rough seas contributed to both the movement of the pole and the very high noise base seen in the raw amplitude data of the side scan sonar. Chirp data were also collected during this survey and are archived separately.

  19. Archive of single-beam bathymetry data collected during USGS cruise 07CCT01 nearshore of Fort Massachusetts and within Camille Cut, West and East Ship Islands, Gulf Islands National Seashore, Mississippi, July 2007 (United States)

    DeWitt, Nancy T.; Flocks, James G.; Reynolds, B.J.; Hansen, Mark


    identifier to each cruise or field activity. For example, 07CCT01 tells us the data were collected in 2007 for the Coastal Change and Transport (CCT) study and the data were collected during the first (01) field activity for that project in that calendar year. Refer to for a detailed description of the method used to assign the field activity ID. Data were collected using a 26-foot (ft) Glacier Bay catamaran. The single-beam transducers were sled mounted on a rail attached between the catamaran hulls. Navigation was acquired using HYPACK, Inc., Hypack version 4.3a.7.1 and differentially corrected using land-based GPS stations. See the digital FACS equipment log for details about the acquisition equipment used. Raw datasets were stored digitally and processed systematically using NovAtel's Waypoint GrafNav version 7.6, SANDS version 3.7, and ESRI ArcGIS version 9.3.1. For more information on processing refer to the Equipment and Processing page.


    Directory of Open Access Journals (Sweden)

    Aulia Widyandari


    Full Text Available There are lot of research done to develop a patrol boat, from the modification of hull model until propulsion system equipment. For example the model ship type AMV (Advanced Marine Vehicle was developed starting from the Catamaran, Trimaran and  Pentamaran model. Everything is aimed at obtaining the ship design that has the speed and stability. In addition to achieving high-speed vessel must be equipped with propulsion (Main Power is great, that means the main engine dimensions, auxiliary equipments and fuel tanks is too large. Many Limitations of space on the ship's engine room trimaran vessel is the main obstacle in designing propulsion system. Beside that Patrol boat should have many missions speed, so propulsion system should be designed at that conditions.   Hybrid propulsion is a combination of Diesel Mechanical Propulsion (DMP with Diesel Electric Propulsion (DEP. DMP system is connected directly to the propeller shaft (or through a reduction-gear. DMP has provide more efficiency rate of 95%. While DEP is only able to provide efficiency by 85% - 89% is slightly lower than DMP, but the DEP offers many advantages such as simplicity and suitability in the rotational speed settings, control systems, engine power production Redundancy, Flexibility in the design of equipments layout in engine rooms, noise, vibration and fuel consumption efficiency which affects the lower pollution.   Design of Hybrid Propulsion system can be satisfied and achieved the Power requirements and optimally at all speed condition of patrol boat. Therefore the author made using modeling Maxsurf-11.12 software and carried out various optimization of the choice of main engine, propeller and system conditions for fast patrol boat cruise. 

  1. Inter-comparison of hydro-climatic regimes across northern catchments: Synchronicity, resistance and resilience (United States)

    Carey, S.K.; Tetzlaff, D.; Seibert, J.; Soulsby, C.; Buttle, J.; Laudon, H.; McDonnell, J.; McGuire, K.; Caissie, D.; Shanley, J.; Kennedy, M.; Devito, K.; Pomeroy, J.W.


    The higher mid-latitudes of the Northern Hemisphere are particularly sensitive to climate change as small differences in temperature determine frozen ground status, precipitation phase, and the magnitude and timing of snow accumulation and melt. An international inter-catchment comparison program, North-Watch, seeks to improve our understanding of the sensitivity of northern catchments to climate change by examining their hydrological and biogeochemical responses. The catchments are located in Sweden (Krycklan), Scotland (Mharcaidh, Girnock and Strontian), the United States (Sleepers River, Hubbard Brook and HJ Andrews) and Canada (Catamaran, Dorset and Wolf Creek). This briefing presents the initial stage of the North-Watch program, which focuses on how these catchments collect, store and release water and identify 'types' of hydro-climatic catchment response. At most sites, a 10-year data of daily precipitation, discharge and temperature were compiled and evaporation and storage were calculated. Inter-annual and seasonal patterns of hydrological processes were assessed via normalized fluxes and standard flow metrics. At the annual-scale, relations between temperature, precipitation and discharge were compared, highlighting the role of seasonality, wetness and snow/frozen ground. The seasonal pattern and synchronicity of fluxes at the monthly scale provided insight into system memory and the role of storage. We identified types of catchments that rapidly translate precipitation into runoff and others that more readily store water for delayed release. Synchronicity and variance of rainfall-runoff patterns were characterized by the coefficient of variation (cv) of monthly fluxes and correlation coefficients. Principal component analysis (PCA) revealed clustering among like catchments in terms of functioning, largely controlled by two components that (i) reflect temperature and precipitation gradients and the correlation of monthly precipitation and discharge and (ii


    Directory of Open Access Journals (Sweden)

    Parlindungan Manik


    Full Text Available Jatiluhur had the very big tourism potency so that it was required the supporting mean such as the tour ship which was better than the wooden ship. The research about the tour ship design having a catamaran hull form was expected to help the development of potencial tourism in Jatiluhur reservoir. In conducting this research, there were several research designs used those were the principle dimension, lines plan, general arrangement, hydrostatic analysis, stability analysis and ship motion analysis. Furthermore, it was used the selection of ship equipments and main engine which is based on result of motor power calculation appropriate for resistance against ship.  The result of this tourist ship design was in the form of hydrostatic analysis, general arrangement, the analysis of stability and ship motion. The resulth shown by the hydrostatic analysis was that the buoyancy located behind the midship as far as 0.469 m. In addition, the result of general arrangement indicated that this tour ship had enough rooms to store all the ship equipment and it was able to carry the passangers with the maximum capacity of twenty people. In a review analysis of stability, it was shown that the largest GZ value was 2,009 m in the ten condition in which it carried ten passangers on the left side with a consumable weight of 100%. This tour ship had a good ship motion in which the deck wetness was not occurred when the wave happened as 0,70 m with the wave heading of 90° having a value of amplitudo heave motion of 0,176 m, the pitchmotion of 1,04 °, and roll motion of 2,99 °.

  3. Preparing for the America's Cup: A technological and a human challenge

    KAUST Repository

    Fischer, Martin


    The America\\'s Cup is the pinnacle event in sailing and it is the oldest sports trophy in the world. The trophy was originally awarded in 1851 for a race around the Isle of Wight, which was won by the schooner ムAmericaメ. It was subsequently renamed after the yacht and was donated to the New York Yacht Club under the terms of the Deed of Gift, which made the Cup available for perpetual international competition. The 35th America\\'s Cup will be held in May / June 2017 in Bermuda. The races will be sailed in 50-ft foiling catamarans. Instead of a main sail the boats feature a rigid wing. These boats are capable of sailing 3 times the wind speed, with top speeds reaching 45 knots. The lecture describes the technological and human endeavor to develop and prepare the boat and the crew. Developing an America\\'s Cup boat is a multidisciplinary effort. Excellence is required in such different fields as aerodynamics, hydrodynamics, structural analysis, advanced composite engineering and building, design of mechanical control systems, hydraulics, electronics and flight control, to name the most important ones. Since automatic control systems (autopilots) are forbidden in the America\\'s Cup rules there is a strong two-way feedback between sailing practicalities and the technological choices being made. Combine this with the management of a very tight build schedule for hulls, beams, foils, rudders and the wing and you get an idea what it means to prepare for the America\\'s Cup.

  4. Hydrodynamic and hydroelastic analyses of a plate excited by the turbulent boundary layer (United States)

    Ciappi, E.; Magionesi, F.; de Rosa, S.; Franco, F.


    Recent studies have demonstrated that the characterisation of wall-pressure fluctuations for surface ships is of great interest not only for military applications but also for civil marine vehicles. A ship model towed in a towing tank is used to perform pressure and structural measurements at high Reynolds numbers. This facility provides ideal flow conditions because background turbulence and noise are almost absent. Free surface effects are naturally included in the analysis, although in the particular section chosen for the present study do not have significant consequences on pressure spectra. Scaling laws for the power spectral density are identified providing the possibility to estimate pressure spectra for different flow conditions and in particular for full-scale applications. The range of validity of some theoretical models for the cross-spectral density representation is analysed by direct comparison with experimental data of wall-pressure fluctuations measured in streamwise and spanwise direction. In a second phase, an indirect validation is performed by comparing the measured vibrational response of an elastic plate inserted in the catamaran hull with that obtained numerically using, as a forcing function, the modelled pressure load. In general, marine structures are able to accept energy mainly from the sub-convective components of the pressure field because the typical bending wavenumber values are usually lower than the convective one; thus, a model that gives an accurate description of the phenomenon at low wavenumbers is needed. In this work, it is shown that the use of the Chase model for the description of the pressure field provides a satisfactory agreement between the numerical and the experimental response of the hull plate. These experimental data, although acquired at model scale, represent a significant test case also for the real ship problem.

  5. IOP from reflectance measurements to obtain the Kd coefficient: application to the Gabon and Congo coastal waters (United States)

    Schmeltz, M.; Froidefond, J.-M.; Jourdain, F.; Martiny, N.


    During the "Optic-Congo" oceanographic survey which took place in 2005 on board the "Beautemp-Beaupré" SHOM vessel, different optical measurements of the surface water were acquired using a TRIOS radiance sensor fixed onboard a mini-catamaran. Hydrological measurements (CTD, fluorescence, attenuation, scattering) and water samples were simultaneously collected in order to measure SPM, Chlorophyll-a and CDOM concentrations. Four types of surface water colours (blue, green-yellow, dark and brown) were identified. The main characteristics of these waters were the very low Chlorophyll-a concentrations for this period of the year (March), and the very high CDOM concentrations along the Congo coast, and particularly in the turbid plume of the Congo River. The attenuation and scattering measurements highlighted the predominance of organic matter at the water surface. These observations were documented using a beam electron microscope and by microanalysis. This data set was used to classify the water bodies along the Gabon and Congo coasts. We propose here to use the remote sensing reflectance (Rrs) measurements to invert the IOP (absorption (a) and backscattering (bb)) using the WASI numerical bio-optical model. The model is iterative: the Rrs WASI simulations are computed given initial values of ocean constituents' concentrations and iteratively adjusted to the Rrs in-situ measurements. The IOP computations are satisfying when the correlations between simulated and measured Rrs are optimized. Then, the attenuation coefficients (Kd) are computed from the IOP coefficients. These results are compared with measurements of Ku carried out during the survey.

  6. Investigations into Ebb Tidal Fronts Using in Situ Acoustic Backscatter and Optical Satellite Imagery (United States)

    Sun, D.; Ortiz-Suslow, D. G.; Haus, B. K.; Laxague, N.; Graber, H. C.; Hargrove, J.; Williams, N. J.


    The Office of Naval Research sponsored the Riverine and Estuarine Transport (RIVET) experiment during May 2012 at New River Inlet, North Carolina, in an effort to better understand the complex wave-current-wind interactions typical of tidal inlets. Over the course of a month, this highly sheared zone was intensely sampled with an array of Eulerian and Lagrangian instruments, in part, as a means of creating a synoptic, three-dimensional data set for validating various satellite remote sensing platforms. A component of this project was to deploy the Surface Physics Experimental Catamaran (SPEC), which is a mobile vessel designed specifically for collecting detailed meteorological and oceanographic data in coastal waters. Among its suite of instruments, SPEC was outfitted with a pair of acoustic doppler velocimeters (ADV), an acoustic doppler current profiler (ADCP), and an optical backscatter sensor (OBS). This instrument package allowed for high resolution mapping of the acoustic signature of the ebb tidal plume and the sub-surface, two-dimensional flow field. On May 8th, at 18:40 UTC, a panchromatic satellite image with a 0.6 m resolution, covering 122 km2, was taken of the New River Inlet Estuary and the inner shelf waters just off-shore. Numerous interesting features are visible in the image, such as the river outflow plume, surface streaks and slicks, a complex wave-field, and a remnant frontal edge from the past ebb tide. Interpretation of the surface features in these types of optical images remains a significant challenge and we have used data collected by SPEC immediately after the image acquisition to help illuminate the processes underlying these signatures.

  7. The optimal access system for future far-offshore wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Obdam, T.S.; Rademakers, L.W.M.M.; Savenije, L.B. [ECN Wind Energy, Petten (Netherlands)


    Operation and maintenance (O and M) of offshore wind turbines is one of the main cost drivers of offshore wind energy. One of the aspects critical for an efficient and cost-effective O and M strategy is the selection of the access system which is used to transfer technicians and, optionally, small spare parts. Currently, most offshore wind farms are located close to shore, and their size is relatively small. For these farms the typical access system consists of catamaran-like workboats, which are used to transfer both technicians and small spare parts. As wind farms move further offshore this O and M concept might no longer be cost-effective. Currently, different alternative O and M concepts are being considered for the future far-offshore sites. In this paper an extensive and holistic comparison of different O and M concepts including different access system solutions is presented. This analysis has been performed using the OMCECalculator, ECN's software for advanced O and M cost modelling. Different sites have been considered, which are typical for the future offshore wind farms that will be commissioned during the next five years. The results of the performed analyses indicate that when moving further offshore harbour-based O and M strategies are no longer economical, even when helicopters are added to the mix. Looking at farm-based O and M concepts a supply vessel with a compensated access gangway offers great potential. However, the calculations also indicate that its ability to transfer small spare parts, in addition to technicians, is crucial.

  8. Wind Stress Variability Directly Measured at a Tidal Inlet from a Mobile Vessel (United States)

    Ortiz-Suslow, D. G.; Haus, B. K.; Laxague, N.; Williams, N. J.; Graber, H. C.


    Tidal inlets are characterized by a dynamic coupling of waves, currents, wind, and topography and to better understand these processes the Riverine and Estuarine Transport (RIVET) experiment was conducted during the month of May 2012 at New River Inlet, North Carolina. As a part of that effort, the Surface Physics Experimental Catamaran (SPEC) was outfitted with a suite of concurrently sampled atmospheric and oceanographic sensors. These included a meteorological mast capable of measuring the air-sea momentum flux, paired subsurface ADV's, a downward looking ADCP, and a bow-mounted wave-staff array. Using a mobile platform enabled capturing the fine-scale dynamical features across this highly sheared zone, without compromising spatial or temporal resolution. The SPEC was deployed, in part, to make direct wind stress measurements and the eddy covariance method was used to calculate the 10 m neutral drag coefficients from the observed wind shear velocities. In general, for any given wind speed, measured drag coefficients were about 2.5 times greater than those derived from bulk relations (e.g. Smith, 1988). Observations of the wind stress angle show significant wind stress steering, up to about 70o off the mean wind direction, within 2 km off-shore of the inlet mouth. The causes for the departure of these observations from conventional open ocean results remains under investigation, although it is highly likely that these findings highlight processes unique to coastal waters that are not regarded in the well-established algorithms (e.g. depth-limited wave breaking and wave-current interactions). Preliminary results from the second installment in the RIVET campaign, which took place at the Mouth of the Columbia River during the spring of 2013, will also be shown.

  9. Multi-tiered sensing and data processing for monitoring ship structures

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, Charles [Los Alamos National Laboratory; Salvino, Liming [NSWCCD; Lynch, Jerome [UNIV. OF MICHIGAN; Brady, Thomas [NSWCCD


    A comprehensive structural health monitoring (SHM) system is a critical mechanism to ensure hull integrity and evaluate structural performance over the life of a ship, especially for lightweight high-speed ships. One of the most important functions of a SHM system is to provide real-time performance guidance and reduce the risk of structural damage during operations at sea. This is done by continuous feedback from onboard sensors providing measurements of seaway loads and structural responses. Applications of SHM should also include diagnostic capabilities such as identifying the presence of damage, assessing the location and extent of damage when it does occur in order to plan for future inspection and maintenance. The development of such SHM systems is extremely challenging because of the physical size of these structures, the widely varying and often extreme operational and environmental conditions associated with the missions of high performance ships, the lack of data from known damage conditions, the limited sensing that was not designed specifically for SHM, the management of the vast amounts of data, and the need for continued, real-time data processing. This paper will discuss some of these challenges and several outstanding issues that need to be addressed in the context of applying various SHM approaches to sea trials data measured on an aluminum high-speed catamaran, the HSV-2 Swift. A multi-tiered approach for sensing and data processing will be discussed as potential SHM architecture for future shipboard application. This approach will involve application of low cost and dense sensor arrays such as wireless communications in selected areas of the ship hull in addition to conventional sensors measuring global structural response of the ship. A recent wireless hull monitoring demo on FSF-I SeaFighter will be discussed as an example to show how this proposed architecture is a viable approach for long-term and real-time hull monitoring.

  10. Cross-Regional Assessment Of Coupling And Variability In Precipitation-Runoff Relationships (United States)

    Carey, S. K.; Tetzlaff, D.; Soulsby, C.; Buttle, J. M.; Laudon, H.; McDonnell, J. J.; McGuire, K. J.; Seibert, J.; Shanley, J. B.


    The higher mid-latitudes of the northern hemisphere are particularly sensitive to change due to the important role the zero-degree isotherm plays in the phase of precipitation and intermediate storage as snow. An international inter-catchment comparison program North-Watch seeks to improve our understanding of the sensitivity of northern catchments to change by examining their hydrological and biogeochemical variability and response. The catchments are located in Sweden (Krycklan), Scotland (Mharcaidh, Girnock and Strontian), the United States (Sleepers River, Hubbard Brook and HJ Andrews) and Canada (Catamaran, Dorset and Wolf Creek). For this study, 8 catchments with 10 continuous years of daily precipitation and runoff data were selected to assess the seasonal coupling of rainfall and runoff and the memory effect of runoff events on the hydrograph at different time scales. To assess the coupling and synchroneity of precipitation, continuous wavelet transforms and wavelet coherence were used. Wavelet spectra identified the relative importance of both annual versus seasonal flows while wavelet coherence was applied to identify over different time scales along the 10-year window how well precipitation and runoff were coupled. For example, while on a given day, precipitation may be closely coupled to runoff, a wet year may not necessarily be a high runoff year in catchments with large storage. Assessing different averaging periods in the variation of daily flows highlights the importance of seasonality in runoff response and the relative influence of rain versus snowmelt on flow magnitude and variability. Wet catchments with limited seasonal precipitation variability (Strontian, Girnock) have precipitation signals more closely coupled with runoff, whereas dryer catchments dominated by snow (Wolf Creek, Krycklan) have strongly coupling only during freshet. Most catchments with highly seasonal precipitation show strong intermittent coupling during their wet season. At

  11. Marketing aspects of solar technologies

    Energy Technology Data Exchange (ETDEWEB)

    Kindlimann, A. [MW-Line SA, Yvonand (Switzerland)


    The substantial market potential for small craft using PV propulsion technology has been outlined together with the associated problems. The growth of PV propulsion is largely dependent on the ability of small companies to overcome problems that are typically associated with their available resources and facilities rather than with the availability of technical solutions. To promote the use of solar energy for the propulsion of small craft it is vital to have well run projects that are able to attract a wider audience. In practice it has been shown that this kind of propulsion is not only feasible but also reliable. It stands as an option, available to be considered seriously when thinking about buying a new small craft. Richard Mesple, Mark Wuest and their team from MW-Line have realised several such projects. Two of the most recent ones are outlined below. Transatlantic21 is a project well under way where a 14m catamaran will cross the Atlantic Ocean from Seville to New York powered only by solar energy. The boat has been built by MW-Line and is currently on its way to Spain. (Further info on Planetsolar is a project that has been running several years and intends to circumnavigate the globe in 120 days powered also only by solar energy. A second trip will take it again around the globe, this time in only 80 days along the southern route, powered by clean energy (solar and fuel cells). (Further info on The two projects above, together with many others, strengthen the image of solar energy as a serious and viable option for boat propulsion and will be important factors in the growth of this sustainable technology. (orig.)

  12. Movements and behaviour by juvenile Atlantic salmon in relation to ice conditions in small rivers in Canada and Norway

    Energy Technology Data Exchange (ETDEWEB)

    Linnansaari, T.; Cunjak, R.A. [New Brunswick Univ., Saint John, NB (Canada). Canadian Rivers Inst., Dept. of Biology; Stickler, M.; Alfredsen, K. [Norwegian Univ. of Science and Technology, Trondheim (Norway). Dept. of Hydraulic and Environmental Engineering; Arnekleiv, J.V. [Norwegian Univ. of Science and Technology, Trondheim (Norway). Museum of Natural History and Archeology; Fjeldstad, H.P.; Halleraker, J.H.; Harby, A. [Sintef Energy Research, Trondheim (Norway)


    Ice dominates aquatic habitats in temperate and polar regions for a large part of the year. Different ice formations below and above the water surface occur depending on the river characteristics and the local climate. Aquatic microhabitats are influenced by rapidly changing ice conditions which redistribute the flow pattern and cause water velocities and depths to change. In shallow streams significant variation occurs in the physical habitat even within a 24-h cycle in early winter. Increased movements of fish have been observed in response to declining water temperatures. In particular, salmonids may have problems acclimatizing to these rapidly changing conditions during early winter. Passive Integrated Transponder (PIT) technology was used in this study to track the individual movement and behaviour of 144 tagged Atlantic salmon parr during two winters from 2003-2005. This method has proven to be efficient even during the most challenging winter conditions. It allows for accurate spatial positioning of the fish across different mesohabitat classes in shallow headwater streams. The movements of PIT-tagged juvenile Atlantic salmon were followed under various ice conditions in 3 small streams: 1) Catamaran Brook in northern New Brunswick, 2) Dalaa River in Norway, and 3) Sokna River in Norway. The physical characteristics of the study sites were presented. All of the study sites were affected by variable ice formations between October and April and most of the surface area was ice covered by January. The water temperature regime during the study period was also presented. Juvenile Atlantic salmon was the dominant fish species in all of the study sites, with small populations of trout. The primary objective was to identify any causal mechanisms between ice formation and fish movement. Their behaviour and site fidelity was also investigated. The study revealed that fish often chose positions under ice cover if the ice was near to the initial territory of parr, but

  13. Estuary Turbulence and Air-Water Carbon Dioxide Exchange (United States)

    Orton, Philip Mark

    The mixing of constituents between estuarine bottom and surface waters or between estuarine surface waters and the atmosphere are two topics of growing interest, in part due to the potentially important role of estuaries in global carbon budgets. These two types of mixing are typically driven by turbulence, and a research project was developed to improve the scientific understanding of atmospheric and tidal controls on estuary turbulence and airwater exchange processes. Highlights of method development and field research on the Hudson River estuary include several deployments of bottom mounted current profilers to quantify the turbulent kinetic energy (TKE) budget, and construction and deployment of an instrumented catamaran that makes autonomous measurements of air-water CO2 exchange (FCO2), water TKE dissipation at 50 cm depth (epsilon50), and other physical properties just above and below the air-water interface. On the Hudson, wind correlates strongly with epsilon50, but surface water speed and airwater heat flux also have moderate correlations with epsilon50. In partially mixed estuaries such as the Hudson, as well as salt wedge estuaries, baroclinic pressure forcing typically causes spring ebb tides to have much stronger upper water column shear than flood tides. The Hudson data are used to show that this shear leads to local shear instability and stronger near-surface turbulence on spring ebbs. Also, buoyancy budget terms are compared to demonstrate how water-to-air heat fluxes can influence stratification and indirectly influence epsilon50. Looking more closely at the role of wind forcing, it is demonstrated that inland propagation of the sea breeze on warm sunny days leads to arrival in phase with peak solar forcing at seaward stations, but several hours later at up-estuary stations. Passage of the sea breeze front raises the air-water CO2 flux by 1-2 orders of magnitude, and drives epsilon50 comparable to spring tide levels in the upper meter of the water

  14. Enhanced mixing downstream of a pile in an estuarine flow (United States)

    Lass, H. U.; Mohrholz, V.; Knoll, M.; Prandke, H.


    We studied the impact on stratification and mixing of a bridge pile in a stratified shear flow at the Western Bridge of the Great Belt Fixed Link, Denmark, in January and April 2006. Stratification was measured with high horizontal resolution by towed CTD chains and dissipation of turbulent kinetic energy was measured by a free-falling MSS 90 microstructure profiler equipped with shear probes. Background stratification and current were measured by standard CTD and a bottom-mounted ADCP, respectively. The spatial and temporal variability of the flow field close behind a single pile was measured by an ADCP mounted on a small catamaran tethered to this pile. A shear background flow of varying strength was observed with an inflow of up to 80 cm s - 1 in the surface layer and an outflow of 10 cm s - 1 in the bottom layer. The brackish surface layer was separated from the saline Kattegat water in the bottom layer by an intermediate layer resulting in a Brunt-Väisälä frequency of up to 100 cycles per hour (cph). The maximum Reynolds number ( Re) and internal Froude number ( Fr) were 4.6 × 10 6 and 1.3, respectively. Eddies occurred downstream of a pile with a characteristic diameter of the pile and a frequency corresponding to a von Kármán vortex street when near-surface Fr > 0.7. Enhanced mixing was observed in the von Kármán vortex streets, which caused an increase in salinity by a few psu in the surface mixed layer of the eddy up to 400 m downstream of the piles. Differential advection by cross-channel circulation smeared out laterally from the wakes' salinity anomalies and turbulence. The dissipation of turbulent kinetic energy in the intermediate layer increased by an order of magnitude downstream of the piles as a function of Fr when Fr > 0.7. This enhanced mixing reduced the mean potential energy anomaly downstream by some 10 Jm - 3 in the upper 15 m depth and caused an upstream-directed baroclinic pressure gradient of the same order as the barotropic

  15. Development and Characteristics of a Mobile, Semi-Autonomous Floating Platform for in situ Lake Measurements (United States)

    Barry, D.; Lemmin, U.; Le Dantec, N.; Zulliger, L.; Rusterholz, M.; Bolay, M.; Rossier, J.; Kangur, K.


    In the development of sustainable management strategies of lakes more insight into their physical, chemical and ecological dynamics is needed. Field data obtained from various types of sensors with adequate spatial and temporal sampling rate are essential to understand better the processes that govern fluxes and pathways of water masses and transported compounds, whether for model validation or for monitoring purposes. One advantage of unmanned platforms is that they limit the disturbances typically affecting the quality of data collected on small vessels, including perturbations caused by movements of onboard crew. We have developed a mobile, semi-autonomous floating platform with 8 h power autonomy using a 5 m long by 2.5 m wide catamaran. Our approach focused on modularity and high payload capacity in order to accommodate a large number of sensors both in terms of electronic (power and data) and mechanical constraints of integration. Software architecture and onboard electronics use National Instruments technology to simplify and standardize integration of sensors, actuators and communication. Piecewise-movable deck sections allow optimizing platform stability depending on the payload. The entire system is controlled by a remote computer located on an accompanying vessel and connected via a wireless link with a range of over 1 km. Real-time transmission of GPS-stamped measurements allows immediate modifications in the survey plan if needed. The displacement of the platform is semi-autonomous, with the options of either autopilot mode following a pre-planned course specified by waypoints or remote manual control from the accompanying vessel. Maintenance of permanent control over the platform displacement is required for safety reasons with respect to other users of the lake. Currently, the sensor payload comprises an array of fast temperature probes, a bottom-tracking ADCP and atmospheric sensors including a radiometer. A towed CTD with additional water quality

  16. A Coastal Bay Summer Breeze Study, Part 1: Results of the Quiberon 2006 Experimental Campaign (United States)

    Mestayer, Patrice G.; Calmet, Isabelle; Herlédant, Olivier; Barré, Sophie; Piquet, Thibaud; Rosant, Jean-Michel


    The Quiberon 2006 experiment was launched to document the onset and development of land and sea breezes over a semi-circular coastal bay propitious to inshore sailing competitions. The measurements were taken during the 2 weeks of 16-28 June 2006. Micrometeorological variables were recorded at three shore sites around the bay using turbulence sensors on 10-30-m high masts, on four instrumented catamarans at selected sites within the bay, and at a fourth shore site with a Sodar. Synoptic data and local measurements are analyzed here from the point of view of both micrometeorologists and competition skippers, testing in particular the empirical rules of breeze veering and backing according to the wind direction with respect to the coastline orientation at the mesoscale (the quadrant theory). Our analysis focuses on the patterns of lower-altitude wind direction and speed around the bay and over the water basin, and the temporal variations during the periods of the breeze onset, establishment and thermal reinforcement. In offshore synoptic-flow conditions (quadrants 1 and 2), the clockwise rotation of the surface flow had a very large amplitude, reaching up to 360°. The breeze strength was negatively correlated to that of the synoptic wind speed. In conditions of onshore synoptic flow from the west (quadrant 3) at an angle to the mainland coast but perpendicular to the Quiberon peninsula, the rotation of the flow was backwards in the early morning and clockwise during the day with a moderate amplitude (40°-50°) around the synoptic wind direction. As the surface wind speed was much larger than the synoptic wind speed, such a case we have designated as a "synoptic breeze". The breeze onset was shown to fail several times under the influence of weak non-thermal events, e.g., the passage of an occluded front or clouds or an excess of convection. Finally, several local-scale influences of the complex coastal shape appeared in our measurements, e.g., wind fanning in the

  17. Paradigm change in ocean studies: multi-platform observing and forecasting integrated approach in response to science and society needs (United States)

    Tintoré, Joaquín


    -platform approach in ocean observation. Three examples from the integration capabilities of SOCIB facilities will be presented and discussed. First the quasi-continuous high frequency glider monitoring of the Ibiza Channel since 2011, an important biodiversity hot spot and a 'choke' point in the Western Mediterranean circulation, has allowed us to reveal a high frequency variability in the North-South exchanges, with very significant changes (0.8 - 0.9 Sv) occurring over periods of days to week of the same order as the previously known seasonal cycle. HF radar data and model results have also contributed more recently to better describe and understand the variability at small scales. Second, the Alborex/Perseus project multi-platform experiment (e.g., RV catamaran, 2 gliders, 25 drifters, 3 Argo type profilers & satellite data) that focused on submesoscale processes and ecosystem response and carried out in the Alborán Sea in May 2014. Glider results showed significant chlorophyll subduction in areas adjacent to the steep density front with patterns related to vertical motion. Initial dynamical interpretations will be presented. Third and final, I will discuss the key relevance of the data centre to guarantee data interoperability, quality control, availability and distribution for this new approach to ocean observation and forecasting to be really efficient in responding to key scientific state of the art priorities, enhancing technology development and responding to society needs.

  18. CHIRP survey of the submerged harbors of King Herod's Caesarea, offshore Israel - looking for evidence of ancient disasters (United States)

    Austin, J. A.; Goodman-Tchernov, B.


    on the starboard flank of a ~8 m-long catamaran. Data acquisition was generally conducted from dawn to mid-day, when wind/wave conditions were most favorable. A dense (5-10 m average profile spacing) grid of profiles, both along-strike (spanning the entire harbor complex) and across-strike (from intermediate harbor to ~10-15 m of water), was acquired. Total track length is ~126 line-km. In certain places, multiple sub-bottom horizons can be traced and mapped; sub-seafloor penetrations up to ~ 4-5 m were occasionally achieved, particularly in deeper water. However, sub-bottom penetration is spatially variable in sand-prone sediments. Correlation difficulties relate both to uneven acoustic penetration and to the presence offshore of "kurkar" ridges, calcareous sandstone ridges paralleling the modern shoreline that represent now-submerged Pleistocene dune complexes. These ancient dunes can produce physical barriers that both alter the depositional regime as well as complicate the acoustic mapping task. Mapped horizons within the survey area will be shown, along with preliminary correlations to the stratigraphy described from previously cored sediments (e.g., interpreted "tsunamites").

  19. Immersive, hands-on, team-based geophysical education at the University of Texas Marine Geology and Geophysics Field Course (United States)

    Saustrup, S.; Gulick, S. P.; Goff, J. A.; Davis, M. B.; Duncan, D.; Reece, R.


    The University of Texas Institute for Geophysics (UTIG), part of the Jackson School of Geosciences, annually offers a unique and intensive three-week marine geology and geophysics field course during the spring/summer semester intersession. Now entering its seventh year, the course transitions students from a classroom environment through real-world, hands-on field acquisition, on to team-oriented data interpretation, culminating in a professional presentation before academic and industry employer representatives. The course is available to graduate students and select upper-division undergraduates, preparing them for direct entry into the geoscience workforce or for further academic study. Geophysical techniques used include high-resolution multichannel seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, sidescan sonar, sediment coring, grab sampling, data processing, and laboratory analysis of sediments. Industry-standard equipment, methods, software packages, and visualization techniques are used throughout the course, putting students ahead of many of their peers in this respect. The course begins with a 3-day classroom introduction to the field area geology, geophysical methods, and computing resources used. The class then travels to the Gulf Coast for a week of hands-on field and lab work aboard two research vessels: UTIG's 22-foot, aluminum hulled Lake Itasca; and NOAA's 82-foot high-speed catamaran R/V Manta. The smaller vessel handles primarily shallow, inshore targets using multibeam bathymetry, sidescan sonar, and grab sampling. The larger vessel is used both inshore and offshore for multichannel seismic, CHIRP profiling, multibeam bathymetry, gravity coring, and vibracoring. Field areas to date have included Galveston and Port Aransas, Texas, and Grand Isle, Louisiana, with further work in Grand Isle scheduled for 2014. In the field, students work in teams of three, participating in survey design, instrument set-up, field deployment

  20. Introduction (United States)

    Narlikar, J. V.; Sathyaprakash, B. S.


    colleague Kumar (S.M.) Chitre and the younger one, Ajit Kembhavi, and the organizational infrastructure of TIFR. In particular, the then administrator dealing with scientific meetings, Parelkar enthusiastically joined me to set up the local boundary conditions in Goa. To get our priorities right, we first picked upon Hotel Mandovi in Panjim (Capital of Goa) as the nodal hotel for catering, accommodation, and arrangements of the academic sessions. We were expecting around 100 participants with 50% from abroad. Kamat, the Manager of Hotel Mandovi, promised all help including beds in nearby hotels to make up any shortfall. Regarding the quality of food, for which Hotel Mandovi was justly famous, its in-charge, Satish Prabhu took care of all our worries. Delegates may still recall the various Goan delicacies featured on the conference menus. Parelkar negotiated the basic deal with the hotels to extract the maximum benefits for the conference. But we were still rather vulnerable in lack of the local conditions. An unexpected helping hand came to make up for our lack of local knowledge. The amateur astronomer organization, called ''Friends of Astronomy in Goa'', led by their venerable President, Percival Noronha offered to run errands for us and play the role of local volunteer. Noronha had been associated with the state government of Goa, since the days when it was a Portuguese colony. His 'inside knowledge' came in useful, especially when he advised us to request the Chief Minister, Pratapsingh Rane to entertain the conference participants in the state catamaran. Somewhat hesitatingly, I wrote a request letter, and to my delightful surprise, the CM agreed. Indeed, the boat-ride followed by the CM's riverside banquet was the entertainment high point of the conference. The food, Goan drinks, and musical entertainment were well appreciated by the participants, and an uninitiated person might be forgiven for thinking that ICGC stood for ''International Conference on Goan