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For this side-looking 200 kHz split-beam sonar application echo-envelope length has been shown to be predictive of fish size. In this paper this relationship is exploited to estimate the abundance of (large) chinook salmon in the presence of (smaller) sockeye salmon. The frequency distribution of echo-length measurements contains information on the relative abundance of chinook and sockeye salmon. The use of echo-length measurements in a mixture model is explored in order to estimate the proportion of total fish passage that comprised chinook salmon. The benefits of the mixture-model approach over threshold-based discrimination are discussed. Conditional maximum likelihood and Bayesian versions of the model are described.

A numerical model which describes the current system and transport processes of coastal ocean regions under wind field forcing is presented. The model has an active layer overlaying a deep inert layer where the pressure gradient is set to zero. The model includes the turbulent version of the momentum and continuity equations and transport equations to describe the thermodynamic changes of the sea surface temperature and the changes of pollutants. Solutions are found numerically on a uniform grid and the fundamental equations are approximated by the finite difference method taking the form of a Lax-Wendroff scheme.

The paper presents the development of BEM (Boundary Element Method) and FVM (Finite Volume Method) based models for the analysis of the flow around 2-D FPSO hull-sections fitted with bilge keels and subject to forced roll motions. Through these models an attempt is made to gain an insight into the two important aspects of the flow: separation around bilge keels and the effect of the free-surface. The effect of the free-surface and the resulting wave-body interaction is studied using a 2-D BEM model coupled with a Mixed-Eulerian-Lagrangian (MEL) time marching scheme for the free-surface boundary conditions. The separation around the bilge keels and viscous aspects of the flow are studied using a FVM based 2-D Navier Stokes (2DNS) solver with linear free-surface boundary conditions. The primary aim of the BEM model is to investigate the effects of the linear and nonlinear boundary conditions on the predicted flow within the scope of the parameters of the FVM model.

The computational fluid dynamics (CFD) modelling of wind interaction with an offshore platform and its relevance to the location of a helicopter deck and CFD modelling of gas turbine exhaust jets for a typical offshore production platform are presented. The flow resulting from the interaction between a single and double gas turbine exhaust stack was computed and compared with wind tunnel experience results. The flow over a helicopter deck was found to be sensitive to turbulence model. The low mesh density of the CFD models allows them to be easily simulated on standard workstations. There was better comparison between the experimental and CFD temperature distributions for the single stack than for the double jet. It was found that the application of the CFD results for gas turbine exhaust jets to the full-scale situation is less ambiguous than application of results of test from small-scale wind tunnel tests.

Survivability is of paramount importance to the RN. The government's military policy is one of expeditionary warfare to act as a force for good in the world. Within the joint force the RN is responsible for the safe passage of the majority of the men and material required for missions abroard as well as protecting itself as it provides power projection or deterrence from its ships and boats. The government's ambition for assured access to any theatre of operations requires a force that is inherently survivable. The challenge for procurement is to provide the maximum possible survivability within an inevitable restricted budget. Advice on how best to do this requires that all aspects of survivability should be considered together in a uniform and coherent manner. For this reason the MoD is developing the analytical tools and methods to do so. Susceptibility vulnerability and recoverability - the constituent parts of survivability - will be integrated in one modelling tool: the Maritime Integrated Survivability SimulatION-MISSION.

Tension Leg Platforms (TLPs) are predominately used for deep water oil and gas production. Due to non-linear wave loading effects it is possible for waves to create an output at their sum-frequency which may consequently equal the natural frequency of the platform. This phenomenon is more commonly known as 'springing'. The Volterra method is a technique used to model the behaviour of TLPs under these conditions. In this paper an orthogonalised Volterra series for use with both Gaussian and non-Gaussian input data is presented. The data used in the Volterra modelling was collected from tests conducted on a model TLP. The wave height and platform motion were measured at wave frequencies around one a half and a third of the model's heave natural frequencies. Both regular and irregular wave tests were performed to varying wave heights and frequencies. Using the Volterra method the transfer functions were calculated up to the third order. Difficulties encountered due to the use of discrete data were identified and where possible their effects minimized.

Nuclear weapons were tested by the French Government between 1966 and 1996. An international study to investigate the impact of the testing on the environment was carried out in 1997-1998. One aspect of this study to study the possible future outflow of radioactively contaminated sediments from the Mururoa lagoon into the Pacific Ocean is discussed. The problem is described. A three-dimensional HD (hydrodynamic) and sediment transport model is presented. This model was used to calculate the circulation and the sediment outflow from the lagoon. Two simulated cases are considered (normal and storm conditions) and the results are given. The outflow of raionuclides is covered. The conclusion states that even for the worst scenarios (earthquakes undersea landslides) the radioactive pollution due to underground tests is negligible.

Petrobras is conducting a research project to investigate the behaviour of pipelines with long corrosion defects. In the first phase of this project a database of corroded pipe tests was generated. In this paper the failure pressures of the Petrobras database are compared with those predicted by the ASME B31G the 085dL the Effective Area and the DNV RP-F101 (Part B) methods. The best fit to the tests results is achieved by the equation of the DNV RPF101 method. However as the length of the defect increases this equation has a trend to give results that depart from the test results. Based on the equation of the DNV RP-F101 method a new equation is developed. This equation fits well to the Petrobras laboratory tests and does not have a trend to give results that depart from the test results as the length of the defect increases.

On board naval ships the heating ventilation and air conditioning (HVAC) system is very important but due to the size and lay-out of the ships the design is more restricted than in other application. Using simulation models in the design stage can improve the system performance and give a good indication of system behaviour in off design conditions. A practical approach of modelling synamic process such as thermodynamic and fluid dynamic processes is to divide a system into smaller parts. A mean value first principle approach will then result in two main parts or modules: volumes and resistances with a predefined causality.This way of modelling is used to develop a model suitable for design evaluation of HVAC systems onboard marine objects both in design and off-design conditions. To be able to build models of various HVAC systems each HVAC component is modelled separately as either a volume or a resistance module. This paper discusses the potential and the limitations of this modular approach for modelling HVAC systems. Furthermore an example of a modular HVAC model is given. Finally the results of several tests performed with a prototype of a HVAC system model are discussed.

A method for modeling marine propulsion systems is presented. This uses a scalable and extendable building block approach with a well-defined interface between the modelled subsystems. By breaking down the propulsion installation into small elementary subsystems which are then individually modelled the resulting building blocks can then be reconnected through well-defined interfaces to implement various installations. The method has several uses in design. The method is tested in modelling a containership with a large two-stroke diesel engine. The results give good accuracy when compared with other simulation codes. The method is easily extendable on the interface level the element level and the mathematical model level.

The Argos system has provided satellite-based data collection and location for every major ocean monitoring initiative since 1978. It is also likely to be the system of choice for future ocean observing systems. Argos continues to make fundamental changes including increasing data transmission capacity (Argos-2 instruments flying today on the NOAA-15 and NOAA-16 satellites) adding a two-way communications capability (ADEOS-2 satellite in cooperation with NASDA) and fully customised access data and results. In the short-term the Argos-3 instrument featuring still greater capabilities is designated for satellites such as the European METOP series and the converged US NPOESS (National Polar Orbiting Environmental Satellite System). Specific new Argos capabilities are outlined that are evolving co-operatively with the ocean community. Consideration is also given to how they may be applied to improve the collection of real-time ocean observations.

Inflatable life rafts are commonly used today on oil installations cruise ships ferries military vessels merchant ships and small vessels as evacuation systems. Large passenger ships such as ferries are typically equipped with standby vessels to tow the life rafts to safety away from hazards such as fires explosions collisions and sinking vessels. While the stability of free-floating life rafts has been extensively studied life raft tow performance in waves and wind has not. The current project is part of a larger program aimed to address some of the knowledge gaps in life raft tow performance. Such information would be beneficial to marine operators rescuers life raft designers and training providers. A 16-person

Conf held March 1990 London Papers are - Ship of the future - the BCV 300 Criteria for the shipowner in choosing main and auxiliary machinery Liner wear and fuel particle concentration; some shipboard measurements Some insights into shipboard fuel system performance Lubricating oil analysis as an indictor of machinery health Dual-mode fluid controlled fuel injection system for diesel engines Turbocharger design for ease of servicing The CNC ship Machinery analysis and diagnosis by PC The shipowner and the environment; Seafox Research for more efficient operation The advantages of refurbishment re-engining and retro fitting An analysis of 35 years of Pielstick engines and some new developments The effects of wake interference on design criteria for triple-screw ships Designing for service The safety design concept The MC engines of MAN B&W Diesel entering the 90's Mitsubishi UE diesel engines in the 1990s Sulzer RTA84C - the modern containership engine

Contingency management facing an imminent oil spill is often a difficult task since the long-term consequences of decisions generally affect the interests of different stakeholder groups including the general public. A hybrid negotiation protocol is designed where multiple issues including money compensation are traded by parties. With the aim of examining appropriate designs of this process in multi-agent systems negotiations based on the Prestige oil spill response scenario is simulated. The hybrid negotiation protocol is shown to robustly depict basic features of real conflict mitigation. After some introductory information negotiation issues are addressed. Next a look is taken at the hybrid negotiation protocol followed by trading the response to the Prestige accident in simulated experiments. Lastly future works are outlined.

The powering issue of a high-speed marine vehicle with multi-hulls is addressed since there is an often need to quickly evaluate the effects of several configuration parameters in the early stage of ship design. For component hulls with given geometry the parameters considered include the relative locations of individual hulls and the relative volumetric ratios. Within the realm of linearised theory an interference resistance expression for hull-to-hull interaction is first reviewed and then a new formula for hull-and-pressure distribution interference is derived. Each of these analytical expressions is expressed in terms of the Fourier signatures or Kochin functions of the interacting components with the separation stagger and speed as explicit parameters. Based on this framework examples are given for assessing the performance of a di-hull as opposed to a tetra-hull system. Also examined is the wave resistance generated by an SSE (surface-effect ship) in comparison with that by a baseline catamaran subject to the constraint of constant total displacement.

The MAPLE (measuring the acoustic properties of the littoral environment) 2001 experiment is described. This used acoustic and non-acoustic sensors to acquire information on surficial bottom properties. The data is then used to support the development improvement and validation of new methods for remote segmentation classification and characterisation. Only a small portion of the results that followed MAPLE'2001 have been presented. The intension is to provide the reader with examples of research progress in the field of segmentation or classification and characterisation. An overview of some of the acoustic systems used during the experiment is presented. The ground truth methods used to measure the seabed properties are described. The classification methods associated with each acoustic instrument are reviewed and significant results are presented. The way ahead is discussed together with the multi-sensor approach to shallow water classification and characterisation.

HF (decameter wavelength) ground-wave radar is a useful tool for observing near-surface currents in the coastal ocean. About 20 HF systems are presently deployed along the US coastline. Although most systems operate at a single frequency the focus here is on MCR (multifrequency coastal radar) which has the capability of measuring currents at multiple depths in the top few meters of the ocean. We present three recent developments in multifrequency HF radar research that illustrate the consistency of HF radar observations of coastal surface currents the versatility of HF observations for air-sea interaction investigations and the use of HF radar for near-shore investigations in fresh water.

Deepwater multiphase pipelines are usually insulated to prevent hydrate formation and the need for hydrate inhibitor injection. In an unscheduled shutdown hydrate plugs are prevented using blowdown. Predicting the liquid movement during blowdown is critical for determining the remaining hydrostatic head at the seafloor when the blowdown ends so in 1997 blowdown field tests were carried out on an onshore gas condensate pipeline as part of the DeepStar project. Two different choke sizes were used to generate slow and rapid depressurisation and the transient multiphase flow simulator OLGA was used to model the tests. The OLGA simulation model is described and the simulation predictions are compared with field measurements. Good agreement between the two is demonstrated.

The static solution and its associated dynamic stability of a vertical riser situated in the wake of an upstream riser is investigated. The focus is on the multiplicity of static solutions of the downstream riser and the critical current velocity. The problem is formulated by taking account of the wake shielding effect. To trace the multiple solutions of the non-linear static problem a continuation analysis methodology is adopted. For each static solution its stability is further examined by finding the eigenvalues of linearised dynamic equations. A parametric study is also carried out in an attempt to find a universal non-dimensional parameter of the critical current velocity.

Reference is made to the UK/EC Assessors report published 12 March 1998 and awaiting testing by the forthcoming formal investigation. This colloquium publicly presents the technology and methodology used in the surveys and analyses with discussion of: features of the design construction and operation of the vessel; findings of the initial investigation (1987-1989) the International Transport Workers Federation (ITF) survey and Lord Donaldson's assessment; requirements of a detailed survey of the wreckage; overview of the Phase 1 survey; the Phase 2 survey (1996-1997) carried out by the Woods Hole Oceanographic Institution (WHOI) and comprising deployment and calibration of the seabed navigation system a DSL-120 sonar survey ARGO imaging using video and stills cameras with sidescan sonar JASON close-up and HiDEF imaging and physical sampling with systems for data acquisition handling archiving and on-board analysis; and the shoreside analysis and interpretation of the data set. The recommendations made in the main published report are reprinted in full.