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The propulsion of Dutch Navy ships is predominantly by diesel (for LCF (air control frigates) or diesel-electric (for LPD (landing platform docks) and submarines). A new class of OPV (ocean-going patrol vessels) has a hybrid system. A new joint support ship related to the LPDs will also have electric propulsion. The debate about the merits of diesel and electric propulsion has led to an increasing share of AES (all-electric ship). The next step is AES with HTS (high temperature superconductivity) electric power generation and propulsion possibly in combination with other HTS systems like transformers and fault current limiters. HTS systems have geometric advantages as their size and weight is probably a factor 3 smaller than conventional equipment which is of great interest on board. Fuel efficiency is another important argument because of range and sustainability. A study was carried out to establish the fuel efficiency of diesel electric and HTS drive trains in the case of an LPD and OPV. Their design sailing profiles as well as an actually monitored sailing profile were applied to the three drive trains to compare the respective energy efficiencies. The results are presented. It is concluded that a set of various diesel generator sizes in combination with HTS generators and motors will be most efficient for both ship types.

The ESA (embedded suction anchor) is a type of permanent offshore foundation that is installed by a suction pile. The cross-sectional shape of the ESA is circular with its diameter being the same as that of the suction pile that is used to drive it into the seafloor. To increase the capacity against pullout three to four wings (vertical flanges) are attached along the circumference with equal spacing. During installation the ESA is attached at the tip of a suction pile and then driven as a unit with the suction pile by the applied reduced water pressure inside the suction pile. Once the ESA reaches the desired depth the suction pile is retrieved by applying a positive water pressure inside the pile and leaves the ESA permanently in the seafloor soil. The mechanism of suction pile installation is well described. The primary factors influencing the horizontal pullout capacity of an ESA include the loading point the soil type the embedment depth and the addition of flanges. An analytical solution is presented which is capable of estimating the horizontal pullout capacity of ESAs with the loading point anywhere along its length with or without the flanges. Validation of the analytical solution is made through comparisons with the centrifuge model test results. The results show that the horizontal pullout capacity of the embedded suction anchor in sand increases reaches its peak and then starts to decrease as the point of the load application moves downward. The effect of flanges on the horizontal pullout capacity is also found to be significant.

An AUV has been specifically designed to withstand the difficult environment in the Arctic and capable of collecting a variety of scientific data. This tool has the potential to replace capabilities previously supported by the US Navy SCICEX cruises which used submarines for measuring and monitoring Arctic oceanographic properties. Ice draft data was one important piece of data historically collected by the submarines that MBARI's AUV now has the potential to provide. This data has particular value to climatologists and Arctic scientists who are striving to evaluate the impact of global climate on the thickness and extent of the Arctic ice sheet. The basic AUV platform is described together with its performance during ice profiling missions. Present details about the science payload section of the AUV as well as specifications for the Ice Profiler ice profiling sonar are then presented. The modifications made to the system to support real-time ice sonar data acquisition and AUV operational decision-making are also presented. Finally the algorithms used to generate estimates of ice draft both in real-time and using post-processing software are outlined along with the presentation of the ice draft results from one the missions. Lessons learned and future plans for the ice profiling science payload are dealt with in the conclusion.

Systems of flexible lines and cables are frequently used in civil and oceanic engineering design. Recent activities in the offshore oil exploitation industry require new structural concepts using flexible lines (both mooring lines and risers). Such systems present increasingly complex configurations with dynamic non-linear behaviour. Therefore the use of efficient numerical solution procedures based on the Finite Element Method becomes mandatory for their analysis. The usual analysis procedure for flexible lines by the FEM is based in the calculation of an initial stable static equilibrium configuration in order to define the finite element mesh. Usually this configuration is obtained by the classic catenary equations. However in more complex problems these equations cannot be applied. Therefore the objective of this work is to present the use of a more general finite element approximation associated to dynamic relaxation algorithms. Such algorithms can be started from arbitrary configurations not necessarily in equilibrium. The resulting procedure is accurate and robust and avoids numerical problems such as the ill conditioning of the tangent stiffness matrix allowing the static equilibrium configuration to be obtained in an efficient way.

In the research field of sea-keeping qualities the short-term prediction method has been established on the assumption that the seaway can be considered as a stationary stochastic process. In actual ship operations however the ship motions in waves are regarded as non-stationary random processes because the ship's manoeuvres such as course and speed alterations change the encounter angle and encounter frequency with waves. The TVVAR (time varying coefficient vector autoregressive) modelling is applied to the cross-spectral analysis of non-stationary ship motion data. Introducing the instantaneous response a vector autoregressive model can be reduced to simple TVAR (time varying coefficient autoregressive) models for each ship motion and the required CPU time is effectively reduced. The TVVAR model and stochastic perturbed difference equations are transformed into a state space model. The vector-valued unknown coefficients can be evaluated and the instantaneous cross spectra of ship motions can be calculated at every moment. The results showed good agreements with one of the TVAR modelling and also with the SAR (stationary autoregressive) modelling analysis under stationary conditions. Furthermore the instantaneous relative noise contribution was also estimated using the TVVAR coefficients and illustrated how the structure of a spectrum changed according to the ship manoeuvres for the first time. Optimum order of the model and Akaike's information criterion were also examined for several changes of parameters. Moreover it is confirmed that the TVVAR modelling can estimate the instantaneous cross spectra and relative noise contribution ofX11884 Institute of Electrical and Electronics Engineers; Standard dictionary of electrical and electronics terms 3rd Edition.

The methodology for predicting sand production is in general constant across the industry. That is the determination of formation strength and field stresses and the application of them to a failure model. However the variety of models available and their applicability and accuracy can be confusing with the results not always representing what is experienced under production conditions. Here a more holistic approach to sand production prediction is presented. This not only uses numerical analysis but also includes a qualitative approach using geological information. With respect to the numerical analysis the determination of various parameters used in modeling sand production and their effectiveness for different reservoir and production conditions is discussed. An overview of the various tests considered useful in calibrating these parameters is also presented. The geological approach discusses the impact of mineralogical depositional structural and diagenetic factors which can impact on the propensity for sand but which are not fully taken into account by a purely numerical approach. The advantages and disadvantages of each of these aspects are presented and synergies identified between numerical and qualitative analysis. Case histories are presented which show that each of these methodologies

The inevitable computerisation and automation of shipboard propulsion systems has given rise to an increasing number of possibilities of improvements in its operation. The expert system developed for the diagnostics of the marine diesel engine conditions is based upon experimental data obtained by measuring the relevant performances of the shipboard engine and by continuously monitoring its operation. In this area the expert system has had an enormous impact on the use of computers elsewhere aboard ship. An optimum injection time has been achieved in a variety of operating modes by eliminating the camshaft and replacing it with a high-pressure VIT (variable injection timing pump). The VIT pump's various parameters can also be easily adjusted during engine operation to achieve optimum performance. A conceptual solution concerning VIT pump operation is sought by means of the expert system to determine an optimum angle of fuel injection. The results of imulation presented here clearly justify the use of such a system aboard ship. The fuel injection control sub-system is part of the entire shipboard propulsion system. It can make a significant contribution towards a better understanding of the functioning of other operating systems which makes it particularly suitable to be included in the marine engineering teaching curriculum primarily the courses dealing with marine engines.

Many high-speed displacement or semi-displacement marine vessels are designed with transom or cutoff sterns. The reason for choosing such an apparently unstreamlined form is subject to debate. An extensive set of experiments on a transom-stern ship model is described. The geometry of the free surface of the hollow in the water behind the model was measured for a large number of cases. This data has been recently re-analysed and a new regression formula for the progressive un-wetting of the transom has been developed. This formula takes into account both the transom beam-to-draft ratio and the Reynolds number. There is evidence that the Reynolds number plays an important role in this process. A similar regression equation has also been developed for the length of the transom-stern hollow. Using these two new formulas one can now predict the resistance components with greater confidence. Hence the total resistance of a high-speed vessel with a transom stern can be estimated accurately over the entire speed range. This theoretical approach is validated against resistance data for a longitudinally staggered catamaran. Future work directed towards a CFD (computational-fluid dynamic) study of the transom-stern flow is identified.

Deep-sea oil and gas fields can only be exploited by improving all involved components simultaneously. Steel structures are a vital part of this challenge so two recent steel developments directly linked with deep-sea extraction are considered. Going deeper means switching to new platform concepts such as the 4th generation TLPs (tension leg platforms) with stepped tendoners which will in the future attain depths of 5000 to 10000 feet enabling new and promising oil and gas fields to be reached. TLP platforms are connected to the seabed by strings of tendon pipes. For such water depths X70 pipes with a wall thickness up to 1.5 inches. (40 mm) are required. The demands put on steel pipes for tendons are different from those of riser pipes since they are subjected to longitudinal extension stress and hydrostatic pressure instead of internal pressure which means a different set of mechanical properties for steel plates and pipes. Of course high toughness values and proved weldability complement this profile. In order to fulfil those requirements a new specific steel grade with adjusted analysis and production route has been designed by Dillinger Hutte GTS in co-operation with Europipe GmbH. The latest experience and production data is presented. More generally the access to deep-sea resources is conditioned by the development of high strength steels with excellent weldability. A recent step towards this goal has been the production of a S500M grade with very low carbon equivalent - not higher than for S420M.X17398

Natural gas represents a source of clean energy for which global demand is increasing. Over three-quarters of the world's known offshore reserves of natural gas remain undeveloped due to the high cost of transportation. These reserves are found in far-off and remote locations. Therefore a new flexible easy-to-implement natural gas transportation method is required. The development of CGL (compressed gas liquid) is described. CGL is an alternative natural gas transportation system for which patent applications are pending. The system does not require the low temperatures of LNG or the high pressures of CNG and avoids costly shore-based assets required for the liquefication and regasification of LNG. For CGL gas is loaded by offshore pipelines and SPM or CALM-type buoys connected to offshore pipelines for delivery to a land-based gas grid. The CGL storage technology is suitable for either a purpose designed new built vessel or a conversion of existing tonnage particularly single-hull crude oil tankers facing phase-out. The gas is transported in liquefied form but production gas is conditioned aboard the CGL carrier and the neutral gas components (methane ethane propane and butane) are transported on the same gas carrier in liquefied form. The resulting volume is equivalent to about two thirds of LNG. The liquefied gas is transported at modest pressure and refrigeration temperature in a pipeline system mounted within the cargo area of the gas carrier. The technology and tanker design are discussed.

The new generations of diesel engines require a lube oil filter concept which meets the demand of finer filtration for the different lubrication points in an engine. Even if the quality of the oils has been adapted to keep all parts free from sediments and to minimise wear today not only the filter fineness should be considered but also how wear is mainly caused by the number of solids which pass the clearance of bearings and flow with very high velocity inside the hydraulic valves. The so-called cleanliness level of an oil system and the retention rate of the used filter mesh are the most important parameters for a maximum lifetime of the affected engine components. Comparisons of different filter media are presented and to what extent the valid ISO standards can be useful to compare the different solutions offered by the filter manufacturers. The questions considered are: whether one filter is sufficient for the safety of the bearing; how it ensures a long lifetime; and whether it is more economical to split the oil system to filter the oil according to the demand of the bearings turbochargers hydraulic pumps and valves. Boll & Kirch has equipped RT-Flex engines and MAN B&W ME engine with 6 and 10 micron filters. For a reliable system all filters installed: the main lube oil filter and the turbo charger filter and the hydraulic filter have to be evaluated by means of multi-pass testing or measurement of the mesh size. The balance of a well-performing lube oil system does not only depend on the filters although they do play a major role in the reliable operation of the propuX35998

In 1996 coldwater investigations at the US NMRI (Naval Medical Research Institute) in Bethesda Maryland demonstrated the inadequacy of existing diver thermal protection for combat swimmers in long-duration cold water missions. To address this deficiency by supplementing the insulation of divers' dry suits a suit liner system containing super-insulating aerogel materials is being developed. In 2005 the US NEDU (Navy Experimental Diving Unit) in Panama City Florida carried out a repeated measures series of 12 test dives each up to three hours in duration to compare the thermal performance of a prototype diving garment using a super-insulation aerogel fabric with that of a commercially available Thinsulate garment worn beneath a commercial dry suit. The thermal benefit of the experimental aerogel garment was determined by statistics describing psychological and physical thermal status data from the aerogel and the commercial Thinsulate garments. All tests were carried out to simulate long-duration cold-water conditions in the NEDU test pool where water temperature was maintained between 1.7 and 4.4 degrees C (35 and 40 degrees F). Divers remained immobile while either lying or sitting in chairs on the bottom of the test pool and they subjectively reported their thermal comfort at 30-minute intervals during each dive. Mean dive durations were found to be approximately 43 percent longer when divers wore the prototype aerogel garment than when they wore an M400 Thinsulate liner. The prototype aerogel garment also enhanced thermal protection to the fingers and toesX27293

Int symp held April 30 - May 2 1986 in Louisana USA Papers are Air Expendable oceanographic instruments Marine application of argos An overview of remote sensing technique for ocean application in China Oceanography from space - the TOPEX/POSEIDON mission Real time acquisition and interactive image processing of oceanographic satellite data Spatial and temporal statistics of significant waveheight and wind speed as measured by the GEOSAT altimeter Directional wave data acquisition and preprocesssing on remote buoy platforms Moored and drifting buoy data processing at NDBC - collection analysis and archival NDBC wave data products - present and future An evaluation of the WMO non real time marine data exchange system An archiving and analysis system for geophysical data A software package for processing conductivity temperature depth data Use of principal component methods to produce and compare large sets of hindcast and observed wave spectra Initiating an Arctic SOFAR programme Lifespan of Arctic data buoys Coast of California storm and tidal waves study - Observations from the San Diego region directional wave data network Cost 43 drifting buoy programmes Development of an operational mooored buoy network An ocean dumping surveillance system The Draper profiling current meter - A self contained open ocean profiler The ARE digital thermistor chain An advanced water sampling system for in situ concentration of trace compounds from water In situ sampling/concentration for hazardous ica chemical analysis in the marine environment VARIOSENS - a versatile in situ flurometer for fast measurement of fluorescent tracer substances Bioluminescent photometer system - hardware and capabilitiX47072 MDV 3000 JUPITER Service flexibility and profitability V Farinetti

Fishermen have the highest occupational risk of death and injury of any occupation in the United States. The main concern lies with vessels of less than 40 foot in length. Methods are being developed for the real-time assessment of ship stability with practical application to safety monitoring and early-warning instrumentation. Ship motion is reviewed together with the background of current models describing roll motion. The characteristics of the five craft used in this study are described. New instrumentation for measuring the kinematics associated with small vessel roll is described. An instrument for measuring and recording ship roll is presented on based semiconductor accelerometers used singly or in a linear array. The measured roll behaviour is presented for the five craft with different loading conditions. Two sets of experiments are carried out with six craft in a variety of sizes. Implications of the experimental results are subsequently discussed. The first experiments show that there is significant shift in the roll axis from the centre of gravity which is attributed to interaction with sway and pitch. The second experiments show that the change in BG accounts for most of the variation in roll period with different weight distributions. This is attributed to an intrinsic correlation between ship parameters and the shift in roll axis. A detailed analysis of the instrument response and methods for locating the roll axis are given in an appendix.

SHOALS (Scanning Hydrographic Operational Airborne Lidar Survey) operations have been used for some eight years and have proved that airborne lidar is an ideal tool for rapidly measuring shallow water depths. More recently SHOALS data has ben merged with hyperspectral imagery to provide such valuable information as bottom typing in Sarasota Bay and Biscayne Bay in Florida. Hyperspectral imagery was identified at a recent airborne hydrography workshop as a complement to SHOALS data collection for the quantification of water column properties like sediment concentration and identification of navigation hazards. Current research focuses on using hyperspectral imagery with SHOALS data to help accurately delineate the land-water interface. A new lidar system called SHOALS-1000 is presented. This is being developed to advance the data fusion effort by allowing topographic and hydrographic lidar to be flown from the same platform as a hyperspectral imager. An overview is presented of past and present efforts which aim to: fuse SHOALS airborne lidar bathymetry with spectral imagery; identify additional uses of hyperspectral imagery for airborne hydrography; and describe the advances in airborne lidar technology that will allow concurrent collection of topographic and hydrographic lidar and hyperspectral imagery.

a new model of a marine shafting is established in this paper in order to calculate dynamic bearing reactions. In this new model the hydrodynamic excitations of propeller the characteristics of the oil films of bearings and th rigidity of the pedestal-hull system of a specific type of ships are taken into cosideration. The modeling process of the marine shafting is as follows: Firstly the rational alignment model of the shafting is set up and the relativestatic reactions of the shafting bearings are calculated. Secondly the static and the dynamic rigidities of pedestal-hull system are calculated based on the finite element model (FEM) of the stern part of the ship and the bearing forces of the hydrodynamic excitations of propeller are also calculated according the wake data obtained from model tests. Thirdly the FEM of the oil films of shafting bearings is developed according to the Renault Equation in order to obtain their dynamic characteristics. The new dynamic model of the marine shafting is established. In order to verify the new model the movements of the shafts centers at three definite shaft sections are measured during the sea trial of the vessel and the test results are compared with those calculated theoretically according to the new dynamic model. It is found from comparison that the new dynamic model is credible.

Echoes from patches of fish fluctuate significantly from ping to ping as the sonar beam is swept across the patches. The fluctuations can be strongly non-Rayleigh because 1) there can be a small number of targets in the beam at a time 2) the distribution of fish can be inhomogeneous or 'patchy' and 3) the echoes are weighted by the non-uniform response of the sonar beam. Two distributions have previously been identified which describe the statistical behaviour of non-Rayleigh echoes from fish - the K-distribution for patches of multiple unresolved fish and a power law distribution for individual resolved fish. The K-distribution has been shown in previous studies to describe the statistics of targets with a Gamma distribution of echo amplitude. The power law distribution is based on the method proposed by Ehrenberg et al. for circular aperture transceivers where a more general physical interpretation to the K-distribution is provided and a generalised power-law distribution to include beam pattern effect is developed. In addition the data collected in the 2-10 kHz range with Atlantic herring are compared with the model predictions for two types of groupings of echoes -- within patches and across patches.

In recent years demands for transportation by ship have increased and there has been a demand for improved ship fuel efficiency due to environmental problems and increasing crude oil costs. For a tanker or a bulk carrier enlarged in the current design trend wind drag is expected to increase. Therefore the importance of design and technology for wind drag reduction is increasing. In order to investigate the wind drag reduction mechanism generated by a corner cut and a step-shaped design in the accommodation tower of a ship LES (Large-Eddy Simulations) of turbulent flow around the simplified models of accommodation tower are carried out. The results of the numerical simulations are compared with experimental measurements for a validation. The predicted reduction rates of wind drag in each model are in good agreement with the measurement. The visualised flow structures from the simulation results show cavity flows in the cut corner and the step. Such cavity flows can make the flow around the accommodation tower smoother than before and the wind drag can be reduced. The LES of the simplified models is carried out using hull geometry and the interactions between the flows around a hull and its accommodation tower are also discussed. In a crosswind condition with certain yaw angle the wind separates at the side edge of the hull. In this case the wind does not impinge on the lower level of the tower and wind dr90515

Petrels and albatrosses have an excellent sense of smell and routinely navigate over the world's oceans by mechanisms that are not well understood. Several recent studies have shown that a number of procellariiform species do not require magnetic cues to navigate over the open ocean suggesting the involvement of other sensory modalities. Since it is now well established that procellariiforms and burrow nesting species in particular rely heaving on olfactory cues for both foraging and nest relocation investigation is presented here into whether olfactory cues may also be used for orientation in other contexts. It has previously been suggested that DMS (dimethyl sulphide) may be an odour cue birds use for navigation in part because emissions reflect bathymetric features such as shelf breaks and seamounts. These features suggest an odour landscape that may provide birds with navigational information over a seemingly featureless ocean environment. DMS is produced by phytoplankton and emissions increase during zooplankton grazing. We have previously shown that seabirds are attracted to high source concentrations of DMS within a foraging context. Here we present the first physiological data demonstrating that unconditioned birds can detect DMS at biogenic concentrations.

Herring and sprat together formed approximately 90% of the prey of Baltic salmon feeding in the eastern and southern parts of the Baltic proper in samples collected from 1995-1997 although there were spatial and seasonal differences. Salmon have probably increased their feeding on sprat. It has been proposed that the rising frequency of the M74 syndrome is associated with the increase in abundance of sprat which have been supposed to have a high thiaminase activity that would result in an inadequate supply of thiamine for salmon. Thiamine deficiency has been connected with the M74 syndrome. There could be differences in thiamine content between herring and sprat. The aims of this study are to determine the PCB PCDD and PCDF congener and thiamine concentrations in sprat and herring sampled from 1994-1995 when the M74 mortality of salmon yolk-sac fry was high. A look is taken at materials and methods covering fish samples/preparation of homogenates analysis of organochlorines thiamine analysis and statistical analysis. This is followed by results and discussion of thiamine organochlorine levels and organochlorine bioaccumulation.