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Oil platforms seem to sustain damage due to waves more often than standard theories would predict. Ocean waves are dispersive and directionally spread changing size and shape as they propagate. Therefore the maximum crest height over an area in a given length of time will be larger than the maximum crest at a single point. Extreme crest heights are usually calculated from single point statistics but the designer of a platform is really interested in the probability of a wave crest reaching any part of the deck area. Statistics for the maximum crest over an area have been developed using a combination of analytic theory and numerical simulations. A sophisticated theory for the maximum of a multi-dimensional Gaussian process is reviewed. Simulations are used to verify the theory and calibrate simple formulas for engineering use. Next it is shown how the linear crest heights can be corrected up to second order. Then the area inundated by 2D wave crests is calculated by a applying a 2D version of the NewWave method that finds the most probable shape of an extreme wave. These calculations show that although the maximum crest over an area is higher than given by the usual method of calculation the force on a platform from that crest is not necessarily very high and only a small fraction of the deck may be inundated. Finally conclusions are drawn.

New production facilities require accurate metering of produced fluids for optimal reservoir and facilities management. The need for cost and size reduction and the severe effects of high watercut production on accuracy are forcing careful evaluation of multiphase metering methods. A process of custom design of multiphase metering systems from commercially available components is being used selected to optimally perform in accuracy and cost for the production design basis. Software models of conventional and compact separation have been developed which allow comparison in cost and size for equal performance. These models demonstrate that separation can rarely be considered to be perfect and that optimal system design must take realistic incomplete separation of gas and liquid into account. Software and data have been developed for design and implementation of partial separation multiphase metering applicable to surface floating and subsea contexts. These products allow design engineers to input their field conditions and obtain within minutes performance cost and size expectations for hundreds of combinations of separation rate metering and watercut metering for further review.

The problem of classification of underwater targets involves discrimination between mine-like and non-mine-like objects as well as the characterisation of background clutter. To improve the performance of a given classifier usually multiple aspects are fused together in some fashion. In this work an HMM (hidden Markov Model) is used to make the overall decision. This is a very powerful tool for using multiple observations to make a decision as no decision is made until all the evidence is presented. In recent years much attention has been given to the area of automatic speech recognition using MLP (multi-layer perceptron) networks for estimating certain probabilities in the HMM framework. Here several approaches are taken to this MLP-HMM idea and the results are compared. The test results presented are obtained on a wideband acoustic backscattered data set collected using four different objects with one degree of aspect separation for two different bottom (smooth and rough) conditions. The advantages and disadvantages of an HMM scheme in classification of mine-like objects are presented. Several connectionist approaches are discussed and their impact upon the HMM classifier is shown. The idea is to exploit both HMM and MLPs to improve the performance of multi-aspect schemes within the realms of the classification problem. The HMM model is discussed together with the possible training techniques. Various connectionist approaches are explained. The data set used for this paper is described and pre-processing and feature extraction schemes are given. The results of the var87880 Multi-attribute concept design model of search and rescue vessels

With the approach of the 200th anniversary of the Royal Navy's greatest battle off Cape Trafalgar on October 21st 1805, much attention will be given to our most tangible symbol of that most ferocious engagement, Nelson's fully preserved flagship HMS Victory. Much has been written about HMS Victory but it is often simplistic and romanticised or clearly aimed at the technical requirements of the naval historian. In Nelson's Victory: 101 Questions & Answers about HMS Victory, Nelson's Flagship at Trafalgar 1805, Peter Goodwin adopts a fresh approach to explain the workings of the only surviving 'line of battle' ship of the French Revolutionary and Napoleonic Wars. As Victory was engaged in battle during only two per cent of her active service, Peter Goodwin also provides a glimpse into life and work at sea during the other ninety-eight per cent of the time. As technical and historical advisor to the ship in Portsmouth, he is in a unique position to investigate an interpret not only the ship's structure but also the essential aspects of shipboard life: victualling, organisation, discipline, domestic arrangements and medical care. In his role as Keeper and Curator of the ship, the autho

Prediction of VIV (vortex-induced vibrations) is one of the main topics in the design of deepwater risers. The understanding and modelling of the complex fluid-structure interaction requires advanced analysis techniques coupling in a correct manner both structural and fluid dynamics aspects. This study aims to develop optimise and calibrate a numerical code to provide reliable results within a reasonable analysis timeframe and without or very limited need of experimental verification. For this purpose the unsteady RANS (Reynolds Average Navier-Stokes) code Navis is applied to solve a typical riser VIV problem and compute the 3D riser-fluid dynamics interaction. During a preliminary analysis phase the 2D flow past (1) a bare circular cylinder and (2) a straked riser at high Reynolds numbers is simulated (different incidences flow-strake vanes are analysed). Numerical results are validated and calibrated against published test data. The core analysis phase is then focused on the numerical investigation of the unsteady flow over a 3D helical strake. In this phase the 3D flow field turbulent structures and response frequency patterns are analysed. Spectral analysis of data is carried out to identify carrier frequencies deemed to be critical due to the induced vibration of the whole structure and helical strakes efficiency in reducing the riser vibrations is also addressed. Finally comparison between numerical and experimental results shows that the complexity of a 3D model is indeed compensated by a significantly improved accuracy of the obtained results.102069

Coherence time of sound is modeled for a 3250 km section in the Pacific at 75 Hz 0.03 s resolution between a source and receiver both moored high above the ocean floor. The model is based on the temporal evolution of a standard spectrum of internal gravity waves and an accurate approximation for the acoustic wave equation. The probability is 0.6 that the signal-to-noise (s/n) ratio first decreases at times of 13 min or less. Afterward the s/n usually increases reaching a peak near 40 min. This is longer than the experimentally reported coherence time of 12.7 min. The discrepancy could be due to the fact that the experimental value was obtained assuming that movement between the source and receiver could be accounted for using a single Doppler speed correction for each transmission lasting between 10 and 40 min. However accelerations of the source and receiver appear to be too large to use the single Doppler speed correction. Coherence times from the data should be re-analyzed with a variable Doppler scheme to see if they are consistent with the 40 min coherence time predicted from the model.

The behaviour of floating objects such as debris of plants seaweed man-made objects foam etc is determined by surface current. In particular surface convergence results in the concentration of floating objects often along fronts. Surface convergence may also form even without fronts. In this case the area of surface convergence is called 'streak'. Fronts and streaks play an important role in the physical environment of coastal region and the distribution of floating objects may provide useful information about the position and strength of the fronts and streaks. In this study visual observation of floating objects was carried out in The Ariake Sea to establish the relation between fronts and streaks and concentration of floating objects. The Ariake Sea is a partially enclosed bay located in the centre of Kyushu Island Japan. One of the most serious problems was the damage to cultivated seaweed in 2001. Although the main cause of damage was allegedly the reclamation of tidal flat in Isahaya Bay such a connection is still unproved because of the lack of knowledge concerning both the physical and biological environment in the Ariake Sea. Therefore the estimation of water mass distribution and water circulation in the Ariake Sea can have a significant impact on coastal management. The relationship between the distribution of floating objects and water mass distribution in Ariake Sea

Increases in both the use of fertilisers for agriculture and the use of industrial and household detergents have led to increasing concern about the fate of nitrates and phosphates in natural rivers and estuaries and on possible increases in the occurrence of eutrophication problems in estuarine areas. Much of the recent literature has highlighted the importance of understanding the nutrient balance in estuaries in identifying the root causes of eutrophication problems. It is therefore important to investigate the patterns of distribution of nutrients within these lagoons in order that this effect may be better predicted and mitigation measures undertaken. Results of nitrate and phosphate concentrations are shown measured both over individual tidal cycles and over longer-term deployments at Pagham Harbour West Sussex UK. In particular the effects of fresh water-salt water stratification over two tidal cycles are presented. It is shown how obtaining periodic vertical profile measurements during the tidal cycle helps to quantify the flux of nutrients from the tidal limits into the main body of the lagoon. Also of key interest is the interaction between sediment bound nutrients with the surrounding water in which the sediment is suspended during parts of the tidal cycle. Synthesis of these results with existing knowledge about sediment-water-nutrient interactions reveals how it is possible for nutrients to become trapped at the muddy tidal limits of the lagoon.

Research into ship performance in actual seas have been taken up recently. The aim of this research is to estimate ship performance in actual seas and to apply this to the building of a good performance ship. Oceangoing simulation is one of the methods used to estimate a ship's performance in actual seas. In this simulation sea states and ship conditions have to be simulated more exactly and rationally. The nominal loss of ship speed induced by added resistance in waves and other forces acting on ship hull is usually taken into consideration. The deliberate loss of ship speed and course change is often ignored. This study proposes a new oceangoing simulation considering deliberate speed loss and course change. A captain changes ship speed and course for safety in rough seas when the occurrence probability of the critical condition of the ship e.g. deck wetness propeller racing and slamming is higher than the critical probability. The occurrence probability of the critical condition is clarified from ship motions in an encounter sea condition calculated by using the EUT method. The joint probability distribution of ship speed and course can be plotted as a polar diagram in any sea conditions consisting of two different wave directions of wind wave and swell. Using this polar diagram a new method is proposed of oceangoing simulation with ship handling as the ship goes toward the original course as fast as possible. The oceangoing siX36881

Conventional merchant and military applications of diesel and gas turbine marine main propulsion plant are compared the high-power availability of the gas turbine is identified as the main reason for its selection for military ships fast ferries and yachts while the availability high efficiency and relatively low fuel consumption of 2 and 4 stroke diesels determine their choice for the majority of merchant ships. A detailed discussion examines the characteristics and advantages of gas turbines (including savings in weight and space the optimisation of hull form single unit installation competitive life-cycle costs vibration-free operation environmentally friendly) and of diesel engines (notably high efficiencies for low fuel consumption rates). Particular attention is paid to the features of a new combination power plant COGES (Combined Gas Turbine And Steam Turbine Integrated Electric Drive System) developed by General Electric Marine Engines and to be fitted in 6 new Millennium-class cruise vessels on order for Royal Caribbean International (RCI)/Celebrity Cruises - the COGES system is described in comparison with the well established diesel-electric drives usually used for cruise ships - it is anticipated that the high fuel costs of a turbine power plant will be offset by revenue from additional passenger carrying capacity.

High-resolution sea surface temperature (SST) fields are crucial for modelling upper ocean circulation and estimating air-sea fluxes. To meet these critical needs SST products are often constructed by combining measurements from a variety of sources. One such application is described that produces a regional SST product for the Gulf of Maine and results are provided from an ongoing study to validate this product. These SST fields are derived using measurements from the geostationary operational environmental satellite (GOES) and analyses from the real-time global sea surface temperature (RTG_SST) and the ocean surface temperature and ice (OSTIA) systems over the Gulf of Maine region. This algorithm has been implemented into a prototype near-real time production system that since May 2007 has produced SST fields four times per day on a 4km grid. This system also provides daily validation data constructed by collocating estimated SST values with in-situ measurements from buoys. The average bias in the domain from May to August 2007 is found to be 0.02±0.8°C. The system was applied to analyse diurnal variability in the region which revealed significant amplitudes and complex spatial distribution during summer.

A detailed procedure is described for the design of marine screw propellers in combination with stators (also known as fixed guide vanes or pre-post swirl devices). This procedure is based on lifting line theory with selection of the best among generated propulsors using a genetic algorithm procedure. This design procedure involves the realistic representation of the propeller slipstream which is a contracted form of helical vortices. As slipstream deformation is the key parameter in the design of reaction type performance improvement devices the design methodology is applied to a stator device behind the propeller and then the hydrodynamic performance of the combined propulsor is analysed. Design studies for a SWATH Bessel and a conventional ship are carried out to demonstrate the effect of the slipstream contraction as well as the efficiency and gain by the systematic variation of the number of stator blades and the axial distance between the propeller and stator. The use of GA (genetic algorithm) for the optimisation involves a further study in which various combinations are analysed to determine the main design parameters of the propulsor system. The use of the GA optimisation method allows a greater number of design parameters to be explored and provides an efficient methodology for determination of a true global near-optimal solution.

The contribution of non-linearities to tension leg platforms (TLPs) has been investigated. A rigid body with three degrees of freedom was selected to represent a TLP hull that consists of four columns and four pontoons. The tendons were modelled as elastic springs to allow for the variation in axial forces and the effect of setdown. The lateral forces were computed with Morison's equation in the hull's instantaneous position and up to the wave-free surface. The longitudinal forces on the bottom of the columns were computed using diffraction and radiation results for truncated cylinders. The analyses were performed in the time domain and the time histories of the motions and the tendon forces were obtained. A parametric study investigated the effects of wave frequencies and heights water depth and column spacing. Using frequency-dependent wave heights instead of a constant wave height for different wave frequencies or a constant wave frequency for different wave heights produced different relations between the response and the parameters of the applied waves from those previously published. Maintaining a constant axial stiffness in the tendons for any water depth kept the same force level in the tendons.

Phytoplankton form he base of nearly all marine foodwebs. Therefore a detailed study of their abundance structure and function is central for understanding the basics of marine ecology and global elemental cycles. The phytoplankton division Haptophyta is one of the most abundant and geographically widespread components of natural phytoplankton assemblages. The pigment approach is described followed by pigment analytical procedures. These procedures can be used to study distribution abundance and composition of natural phytoplankton populations using a chemotaxonomic approach. Pigment detection in the Haptophyta is overviewed from a historic perspective and new data on their distribution in cultured coccolithophores is given. A study is presented that was carried out with the largest and most diverse haptophyte sample set ever subjected to a comparative study. The methods are described and results presented and discussed. The extraordinary diversity in the pigment composition observed appears closely related to current taxonomy and published phylogeny. HFx (open-ocean and non-littoral coastal environments) is shown to have recovered its previously questioned status as a straightforward marker for haptophyte distribution in offshore habitats. Haploid and diploid lifecycle stages yielded identical pigment compositions. This provides further evidence for an evolutionary origin of pigment content rather than short-term temporal adaptations to environmental conditions.

As emission limits become ever tighter the development of low emission combustion systems becomes more and more important. In recent years several technologies have been established which have the potential to improve the NOx-sfoc-PM-trade-off without using external engine methods. These are: the Miller-cycle; high compression ratio; retarded injection; optimised (not maximised!) injection intensity. These measures require certain prerequisites e.g. high compressor pressure ratio combined with high T-C-efficiency and high injection pressures. They can be used to reduce sfoc as well as to comply with today's emission limits as shown by MAN B&W with the 48-60 B. In the future these measures will be combined with the possibilities of electronically controlled fuel injection systems. MAN B&W have carried out comprehensive experimental studies on the research engine 1L 32-40 with their in-house developed common rail system which is presented elsewhere. Using this system significant improvements of the NOx-sfoc-PM-trade-off could be achieved. Some of the results of these tests are reported. Theoretical considerations show that for the achievement of a good NOx-sfoc-trade-off a high compression ratio and Miller-valve timing are effective measures. Unfortunately

Proceedings of the International Maritime Defence Conference - 'Creating the Naval Task Force' London 28-31 March 1995 Volume 3. Includes papers relating to Platform technologies: ship radar and IR signatures, electromagnetic design of ships, Fire-safe materials R & D for Canadian ships, surface combatant stealth, use of CFD in today's ship design, Ship resistance prediction tools using computational fluid dynamics, methods of submarine atmosphere control and monitoring. Papers relating to cost effective requirements: Combined operational effectiveness and investment appraisal for future naval systems, Assessing competing options in defence procurement using risk management techniques, impact of formal safety assessment on prime contract management, SAVIUS: an integrated system for assessment of vulnerability of naval surface vessels, Weapon system co-ordination demonstrator, Developing advanced submarine combat systems, AUV concept assessment model. Papers relating to Cost effective maritime research of materials, components and performance: Modelling of fibre reinforced visco-elastic composites for noise reduced ship and submarine structures, application of GRP pipework systems, Systems engineering support methodology and tools applied to naval combat management systems, Proposal for a frigate innovative propulsion system.

The electro-magnetic actuator is a brushless permanent magnet based technology that offers the opportunity to extend the range of capabilities already available from electro-hydraqulic and electro-mechanical actuators. Suitable for linear and rotary applications and capable of operating in hostile environments the electro-magnetic actuator offers a unique combination of hifh force or high torque and speed at response times unachievable by equivalent technologies. A demonstration programe established by the Ministry of Defence' Marine Auxiliary Systems Integrated Project team (MXS IPT) is now leading towards trials of a full scale prototype. Investment by the MXS IPT is focused on the introduction of these actuators into naval platforms using relatively low levels of MoD investment at Technology Readiness Level (TRL) 4 to ensure that the commercially available actuators are manufactured to meet a range of military requirements. At their present state of development the actuators can achieve a mean thrust of 20kN power levels over 100kW speeds of up to 8ms-1 a stroke of 2m and a bandwidth of over 400Hz. Possessing a transient peak of load of 10 times the mean thrust electro-magnetic actuators can be operated at ratings significantly lower than their hydraulic equivalent. they are currently offering high performance solutions for High Voltage (HV) switchgear and this application is used to demonstrate their potential for other markets.

During Spring 2008 a subset of the WATER Institute's GLUCOS (Great Lakes Urban Coastal Observing System) was deployed to demonstrate the ability of the observatory to remotely monitor in real time the seasonal transition from a mixed state to a stratified state in coastal Lake Michigan. A prominent feature of the transition is the spring thermal front also known as the 'thermal bar' a boundary of 4 Centigrade water that extends from top to bottom and separates near-shore stratified water from colder mixed water further off-shore. Three Pioneer 2 buoys were deployed in an east-to-west line at 20 m 40 m and 60 m depths and at distances of 2 km 6 km and 12 km from shore respectively. Each buoy was equipped with a string of temperature sensors spaced one meter apart from the bottom to about 3 meters below the surface. The buoys communicated with shore station using 900 MHz radio modems. An Internet connection was established between the WATER Institute and the buoys via the shore station permitting two-way communication for real-time data retrieval and control of the buoys. The spring thermal transition was remotely observed at the 20 m buoy along with its characteristic 4 thermal bar. This paper presents the data on the spring thermal evolution of the lake as measured by the GLUCOS observatory and describes the design of the new Pioneer 2 buoy that made up the buoy array for this experiment.

Location and geologic conditions contribute significantly to the earthquake-tsunami vulnerability of ports and harbours along the US Pacific Northwest coast. Although this area has not experience major earthquake-seismic-related events in recent years scientific studies show that there is about a 10 to 20 per cent chance of such an event before 2050. When the next major earthquake strikes transportation lifelines could suffer severe impacts and take many months or even years to re-establish. Therefore there must be sound hazard mitigation practices. A partnership has been formed to address seismic hazards with an emphasis on tsunamis with the ultimate goal of increasing the resilience of ports harbours and their surrounding communities to earthquakes and local and distant tsunami hazards. The project is called 'Protecting our Ports and Harbours' and its principal objectives include the identification of earthquake-tsunami issues relevant to ports and harbours in the US Pacific Northwest region. Information and data will be studied to assess the region's risk and vulnerability. Project work will culminate in the development of an educationally focused Internet site and a GIS (geographic information system)-based hazard mitigation model. The project will also undertake demonstration projects one each in Oregon and Washington to develop test and evaluate various mitigation strategies and trade-offs to help increase the resiliency of lifelines infrastructure and facilities in anX17634

Table of Contents Frank Broeze, "Introduction: Maritime History at the Crossroads: A Critical Review of Recent Historiography " / ix-xxi Contributions Malcolm Tull, "Maritime History in Australia" / 1-29 Lewis R. Fischer, "The Enterprising Canadians: An Assessment of Canadian Maritime History since 1975" / 31-52 Chi-Kong Lai, "The Historiography of Maritime China since c. 1975" / 53-79 Paul Holm, "Danish Maritime History, 1976-1992: A Review" / 81-112 Lars U. Scholl, "German Maritime Historical Research since 1970: A Critical Survey" / 113-133 Gelina Harlaftis, "The Maritime Historiography of Greece in Recent Decades" / 135-149 Jorge Ortiz-Sotelo, "Ibero-American Maritime History: Recent Advances in Research, 1975-1994" / 151-170 Mariam Dossal, "Indian Maritime Historiography: West Coast Merchants in a Globalizing Economy" / 171-192 Jaap R. Bruijn, "Recent Developments in the Historiography of Martime History in the Netherlands" / 193-211 Murat Çizakça, "The Ottoman Empire: Recent Research on Shipping and Shipbuilding in the Sixteenth to Nineteenth Centuries" / 213-228 Jesús M. Valdaliso, "The Progress of Maritime History in Spain since 1975" / 229-247 William Henry Flayhart III, "Oceanic Historiography: The American Dimension" / 249-276 Luke Trainor, "The Historians and Maritime Labour, c. 1850-1930" / 277-294