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This paper presents the fatigue life assessment procedure for the welded joint of ship structure. In this study the fatigue test is performed for the boxing fillet specimen an idealized welded joint model of longitudinal members and transverse members. Experimental data is presented in the fatigue resistance S-N curves based on hot spot stress (HSS) approach regarding the stress concentration due to structural discontinuities of the welded joints. As a result S-N data for each crack length is appraised to provide detailed data for the damage tolerance fatigue design of welded joint.

A trial project for the improvement of seawater quality was carried out in the New Nagasaki Fishery Port from the end of May 2001. 60 units of 3D asymmetrical bottom roughness with directional resistance properties were to be installed in order to enhance tidal residual currents around the existing breakwater. Before installing these bottom structures field observations were carried out to identify the characteristics of the tidal currents waves water qualities and sediment from May 2000 to March 2001. These field observations on tidal currents and water qualities are summarised.

When considering offshore monopile foundations designed for wind turbine support structures a grouted connection between the monopile and an overlapping transition piece has become the de facto standard. These connections rely on axial loads being carried primarily by the bond between the steel and grout as shear. Given the critical nature of the grouted connection in a system with zero redundancy the current design verification requirement is that a finite element analysis is performed to ascertain the viability of the connection with respect to combined axial and bending capacity whilst pure axial capacity is handled as a decoupled phenomenon using simple analytical formulas. This paper addresses the practical modeling aspects of such a finite element model covering subjects such as constitutive formulations for the grout mesh density and steel/grout interaction. The aim of the paper is to discuss different modeling approaches and where possible provide basic guidelines for the minimum requirements valid for this type of analysis.

The current emphasis on littoral warfare increases the possibility of joint operations with allied naval land and air forces. Severe helicopter landings during these operations pose a hazard to the ship structure and could interfere with the mission. Operational Commanders need a quick method of analysing the capability of ships to safely land visiting helicopters in emergencies and during joint air operations. LLDs (landing load diagrams) provide that method. A methodology to develop flight deck LLDs is presented together with an explanation of the risk associated with their use. The principles of load development introduced may provide ship designers with a method to design flight decks with a range of capability. With probabilistic-based criteria flight deck design and assessment can move from arbitrary pass-fail assessments to specific consideration of expected extreme loads.

High-speed ships are very sensitive to weight. In order to reduce the structural weight thin stiffened plate is used. The imperfection of bulkhead stiffened plate occurs because of the effect of welding. The frequency of contact with water and the vibration of the plate are linked with fatigue damage. Discrete fluid and structure kinetic equilibrium equations are deduced on the basis of the Galerkin method and the Hamilton variation principle. A modal analysis about fluid-structure interaction system of bulkhead stiffened plate is conducted. Through the model experiment interaction vibration modal with different depth of water is obtained. The result has guidance meaning to the dynamical design of bulkhead stiffened plate.

Conf held in London on 3 - 5 Nov 1980 Papers are Atmospheric fluidised bed boilers (shell and small industrial) - The development of a range of water tube fluidised bed boilers Development of a commercial fluid bed package boiler Development and commercial application of liquid - fuelled fluidised combustion The development of a commercial range of multi - fuel fluidised bed combustion packaged boilers Corrosion studies in coal - fired fluidised bed combustors by the national coal board Development and operating experience of coal fired industrial fluidised bed boilers Atmospheric fluidised bed boilers (water tube) - operation of the Georgetown University fluidised bed steam generator The CFB Summerside project - an AFBC boiler for high sulphur coal and wood chips First experimental results of the Flingern demonstration plant Experience in the design and control of water tube AFBC boilers Fluid bed gasification of coal and heavy fuel oil for clean and power generation

The reduction of the occurrence of tanker drive-off and the reduction of the probability of recovery failure should drive-off happen are two basic principles in reducing FPSO and DP shuttle tanker collision in tandem offloading. This paper focuses on measures to reduce recovery failure. Previous analyses revealed that recovery failure probability is high due to lack of time for DP operator to initiate the recovery action in tanker drive-off scenario. Therefore increasing time window and reducing operator reaction time are two main principles of recovery failure reduction. Substantial increase of the separation distance between FPSO and tanker and possible reduction of the main propeller(s) forward thrust that can be used by tanker DP system are two measures to increase the time window. Effective reduction of operator reaction time can be achieved by a number of measures (i.e. training procedure crew resource management and automation support) which are designed to improve early detection as well as effectively reduce operator's time in diagnosis and situation awareness.

The potential use of semi-submersible crane vessels (SSCVs) is highlighted together with the results of past experience. HeereMac's proposal to use a multi-purpose SSCV as a deepwater development unit is described. On its own the vessel has the capability to drill test develop produce and create the infrastructure required to perform all phases leading to production. An additional structure called the Riser Support Floater (RSF) has been devised to optimise the multi-purpose SSCV. The RSF forms a drilling and/or production platform when connected to the SSCV and can support the risers and surface completions should the SSCV need to be disconnected in an emergency. The advantages of combining an SSCV with an RSF for deepwater development are listed.

Since modern pipelines usually display ductile fracture behaviour fracture assessments accounting for ductile tearing should be used. In this work a simplified strain-based fracture mechanics equation is used in the probabilistic fracture assessments. Furthermore there is use of the traditional tangency criterion between the crack driving force and the crack growth resistance in calculation of the onset of critical ductile tearing. Additionally two types of external load on the line-pipe are considered namely strains due to external bending moments and internal pressure. The probability is established of fracture for line-pipes with relevant diameter to thickness ratios and thicknesses for J-laid or S-laid offshore pipelines. The distinction between system effects in which all defects are likely to be subject to the same loading and cases where only a small part of the pipeline will experience high loading is also discussed.

Routine evaluation of fuel and lubricants can be effective tools for the shipowner to retard the ageing process of the machinery installed on his ships. Lubricating analysis including elemental analysis and particle recognition is an effective tool for predicting the health of closed circuit systems such as the sterntubes gearboxes or any hydraulic system. Lubricant analysis can only be used for diagnostic purposes when several samples are compared. In open circuit systems such as a diesel engine whether it be the system oil of a crosshead engine or that of a trunk piston engine lubricant analysis can give only a general indication of the change of conditions in the engine. Fuel analysis is also discussed.

Conf held 30 Sep - 2 Oct 1991 in Michigan USA Papers are Effects of oxygen enrichment and fuel emulsification on diesel engine performance and emissions Gas engines or fuel cells for future low emissions cogeneration A study of electronic engine control system structures for lean-burn natural gas operation in a spark ignition engine Low cost sensor for electronic fuel metering in small engine applications Closed loop engine control using multiple microprocessors Natural gas fuelling of a Caterpillar 3406 diesel engine Emission reductions through pre-combustion chamber design in a natural gas lean-burn engine Effects of spark plug number and location in natural gas engines Development of the Cooper-Bessemer Cleanburn gas-diesel (dual-fuel) engine

The market for diesel fuel is changing as the automotive sector seeks to include a biodiesel component to the fossil fuels it consumes. This will eventually affect the market for marine fuel although not in the short term. By 2050 the MGO (marine gas oil) offered at many ports may include biodiesel as a matter of course. This could particularly be the case in Africa and South America where the pressure to use indigenous biodiesel is greatest. UK warships and auxiliaries need to operate worldwide and any changes to the fuel infrastructure at ports needs to be considered early so that the necessary changes to onboard machinery and operations can be identified and their impact assessed. This paper considers the impact of storing and using blends of diesel with biofuels onboard warships. The key areas of study are the storage stability (hot and cold temperatures) onboard treatment and fuel management to ensure a fuel of sufficient quality is supplied to the engines. The impact of biodiesel fuels on ship performance is also assessed with specific reference to fuel consumption (endurance) and power (top speed).

Dynamic simulation results of thermal and hydraulic performance of the Gemini deepwater subsea production system of three wells and two pipelines are presented. An overview the challenges and results show how transient models such as OLGA are used to predict and alleviate the flow assurance problems associated with deepwater production of a gas condensate subsea system. The importance of flow modeling before and during production is addressed. Finally the results of this study can be applied to the design of new deepwater production systems in order to maintain flow assurance and to safely operate a subsea pipeline-riser system. Comparisons of predictions with measured production data are presented. Graphs appear on pages 8 to 10.

A recently completed Joint Industry Project (JIP) ‘Blast and Fire Engineering for Topside Structures’ has shown that severe explosions can be generated in large test rig (28 x 12 x 8m). However the data set was insufficient to provide advice with confidence on minimising the effects of gas explosion and in particular in relation to water spray mitigation. The HSE decided to sponsor an experimental programme to address these needs using the same test rig at the BG Technology Spadeadam test site. It is clear from the work carried out that the distribution of confinement equipment and water sprays is very important in determining the overpressures generated by explosions in offshore modules. Though this paper does not address risk assessment or actual offshore scenarios the analysis reported shows that the explosion process is complex particularly when accounting for the interaction with equipment of varying geometries. Also as the scale of the experiments was smaller than some offshore modules it should be realistic scenarios as there is a greater distance for flame acceleration.

In order to be able to exploit naturally occurring gas hydrates commercially two key issues need to be addressed from a production perspective: quantifying the reserve potential and identifying suitable methods for gas recovery. In broad terms these are the same issues that are considered when conventional hydrocarbon reservoir developments are being assessed. However for gas hydrates much of the technology needed is not yet available. If commercial exploitation is to become a reality in the future these gaps must be identified and filled. A new technology typically takes a minimum of ten years to move from being a concept to a market reality even with virtually no funding constraints. Since this rarely occurs in practice for methane derived from hydrates to be in widespread commercial production by 2025 the timeframe being considered at this event work on the missing technologies must start now.

GEOSTAR (GEophysical and Oceanographic STation for Abyssal Research) is an European project funded by the EU within the framework of the MArine Science and Technology Programme (MAST-III). The project has achieved the design and manufacturing of prototypes of a deep-sea intervention vehicle for heavy loads and an innovative benthic observatory capable of carrying out long-term geophysical geochemical and oceanographic observations. This enhanced system will provide an online data transmission unit using a mooring and satellite communication system. It will be shown that the deployment and recovery vehicle can be simply adapted to a lot of stations for in-situ experiments and measurements on the deep-sea floor thus allowing not only long-term measurements but to place sensor patterns during certain campaigns.

During the last 15 years operational oceanography systems have emerged in several countries around the world. This emergence has been largely fostered by the GODAE experiment during which each nation engaged in this activity have organised partnership and constructive competition. This trans-national coordination was very beneficial for the development of operational oceanography leading to economies of scales and more targeted actions. Today several systems provide routine real-time ocean analysis and forecast and/or reanalysis products. They are all based on (i) state-of-the-art primitive equation baroclinic Ocean General Circulation Model (OGCM) configurations either global or regional (basin-scale) with resolutions that range from coarse to eddy resolving and (ii) data assimilation techniques whose complexity ranges from simple analysis correction to advanced 4D variational schemes. They assimilate altimeter sea level anomalies remotely sensed SST such as GHRSST products and in situ profiles of T and S including ARGO. Some systems have implemented downscaling capacities in specific regions of interest including shelf/coastal seas. Some also have implemented coupling with the atmosphere and/or the prognostic sea ice in polar regions. They are the GODAE system in operation. They are reviewed in this paper.

Increasing public demand to experience parks like Isle Royale National Park (Michigan) inevitably leads to a decline or change in some resource conditions or visitor experiences. The question is how much decline or change should be accepted in recreational areas. Zoning approaches have been developed to help address this important question. For example managers often control land use by setting standards of quality in specified areas to provide recreational opportunities. They sometimes use GIS to divide outdoor recreational areas into regions that represent different physical social and managerial places. This approach can be effective when managing for recreational opportunities that exist within a zone e.g. camping in a backcountry area. However some recreational activities such as hiking and boating can take place across management zones e.g. hiking to a trailhead at the end of a trip or boating to a dock located in a developed setting. Vectors can be used to portray these events on maps. An approach to zoning events is demonstrated by presenting selected findings from an Isle Royale National Park visitor study. The study method is presented. Selected results are given and discussed.

Dredging is necessary to construct navigation channels and to maintain water depths for safe navigation at existing ports and harbours. Dredging is also required to build and maintain other important facilities such as water supply intakes bridges and utility crossings and in the remediation of contaminated sediments. Currently most material dredged from the Great Lakes is placed in CDFs (confined disposal facilities) discharged into open waters or deposited on or near shores for beach nourishment. However Great Lakes CDF capacity is diminishing and open water discharge is increasingly unacceptable to the public. The Great Lakes Commission is now investigating the beneficial use of dredged material. This allows for recycling of dredged material particularly that material that is not contaminated or only mildly contaminated reserving CDF capacity for the most contaminated dredged material. Presently however there is no national or basin-wide regulatory framework for beneficial use of dredged material. Under this project a regional Beneficial Use Task Force will serve as the vehicle for state and federal involvement in the development of a series of recommendations to advance beneficial use.

Automatic control systems have a dramatic impact on the reliability and performance of marine vehicles. Attention to their design and application is crucial. Using mathematical modelling and modern control theory, this comprehensive text looks at how optimal, adaptive, non-linear and self-tuning control work in relation to ocean vehicles. The book examines the modelling of marine vehicles in relation to the dynamics and stability of ships, navigation systems and sensors. This book will appeal to advanced students in electrical engineering, marine technology, mechanical engineering and computer science. Chapter content includes modelling of marine vehicles, environmental disturbances, stability and control of underwater vehicles, dynamics and stability of ships, automatic control of ships and control of high-speed craft.