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The most closely related attribute to the actual building cost of a new ship is its structural arrangement. Other particulars related to that cost such as the pay load capacity the propulsion installation the endurance of the ship etc. are more or less defined in the specification document. On the other hand the structural integrity of the vessel is not in any case directly considered by the ship owner. It is responsibility of the designer to analyse it in depth and within the limits of a given budget. The latter feature directly implies that the strength and production cost of a new vessel are closely related and require special attention in the design stage since this is the time to make substantial changes with the least cost penalty. Considering the above a method is proposed for the estimation of structural integrity of the hull in terms of production cost. The potential of this method lies in the fact that strength and cost virtues are expressed as functions of the same fundamental variables. As a result the method is particularly useful in the early design stages. Despite the simplistic approach the foundation is set for a more rational approach of cost analysis in ship design.

CCS (carbon capture and storage) has been receiving increasing recognition as a short-to-medium term measure for closing the energy gap whilst a portfolio of carbon neutral technologies is developed to provide power for the UK. This has been accompanied by an increasing political will and a developing policy framework to achieve it. If the UK is serious in its intentions the necessary economic drivers will also be put in place. It remains to identify and resolve the technical issues that apply peculiarly to the UK. In recent years the capture technology has developed to the point of viability and storage has been accepted to be safe and ecologically sound but relatively little work has been carried out on CO2 transport. In the US naturally occurring CO2 is routinely transported considerable distances overland through mostly sparsely populated regions for the purpose of enhanced oil recovery. There is also some limited transport of anthropogenic CO2. In the UK a number of suitable offshore CO2 sinks have been identified in the North and Irish Seas for EOR or simply for storage. It has been commonly assumed that the transport of CO2 from UK sources to offshore sinks is straightforward and may even be able to make widespread use of existing infrastructure.

Several contaminants have been found in groundwater and the behaviour of contaminants in the subsurface involves several different and simultaneous phenomena. Advection and dispersion which are of significance in solute transport phenomena play an important role in assessment or prediction of groundwater contamination. Additionally adsorption of contaminants to a soil particle is also key to understanding the fate of the contaminant. Laboratory tracer experiments are carried out in homogenous and two-layered flow fields under various hydraulic gradient conditions. NcCl solution dyed with Brilliant Blue FCF is used as a tracer to measure NaCl breakthrough curves and to obtain images of dye tracer movement. Inverse analysis through genetic algorithm and image analysis are used to estimate dispersivity dispersion coefficient and retardation factor. The results show that dispersivity estimated from image analysis is about one order smaller than that of GA estimates. Moreover it is revealed that tracer is slightly retarded relative to pore water velocity. As for parameter estimation in two-layered media the values of equivalent dispersivity to he entire flow region exist between the values estimated in each layer. Estimated dispersivity in layered media depends on transport pathway of contaminant suggesting the importance of observation location in parameter estimation problem.

In the future offshore LNG terminals tugs are planned to help LNG carriers during berthing and offloading operations. A model test study is presented which was carried out to better understand the tug behaviour in waves and to make a first step in the quantification of the related weather limits. Scale 1:35 model tests were carried out in the two important 'modes' of a tug during this type of operation: the 'push' mode and the 'pull' mode. Realistic weather conditions were used and the tugs worked at the unshielded and shielded sides of the LNG carrier. Results are presented. Based on these it is concluded that the motions of tugs in waves are significant even in wave conditions that are considered to be mild for the berthing and offloading LNG carriers. The resulting push or pull loads may hamper these tug operations significantly. Special measures are necessary to take this behaviour into account in tug design LNG carrier design and development of operational procedures and equipment. An insight is given to the typical tug behaviour in different weather conditions. The tug behaviour in waves was also simulated numerically. Considering the complex behaviour of the tug in the push mode the comparison between the tests and simulations is shown to be remarkably good.

The design construction and management of pipelines poses a series of unique geotechnical problems. The problems are unique primarily because of i) the geometric character of a pipeline and ii) the fact that the pipelines are commonly placed near to the ground surface within the unsaturated portion of the soil profile. The geometric character of the pipeline is linear resulting in an enormous area for which geotechnical information must be assembled. Unsaturated soil properties functions must be measured or predicted in order to model the soil-structure interaction behavior of the pipeline. The availability of increased computational capabilities has provided several powerful options for addressing both of the above problems. Solutions arise from the application of database technologies and knowledge-based systems to various aspects of pipeline design construction and management. This paper describes the application of the new computer based technologies. In particular emphasis is placed on the use of a knowledge-based system in the assessment of suitable unsaturated soil properties. This paper will describe the functionality and application of such a knowledge-based system.

Any device that aims to harness the abundant clean and renewable energy from ocean and other water resources in the USA must have high energy density be unobtrusive have low maintenance be robust meet lifecycle cost targets and have a 10-20 year life. The VIVACE (vortex-induced vibration aquatic clean energy) Converter satisfies those criteria. It converts ocean or river current kinetic energy to electricity using VIV successfully and efficiently for the first time. VIVACE is based on the simple idea of maximizing rather than spoiling vortex shedding and exploiting rather than suppressing VIV. It introduces optimal damping for energy conversion while maintaining VIV over a broad range of vortex shedding synchronisation. VIV occurs over very broad ranges of Re (Reynolds) number. Only two transition regions suppress VIV. Thus even from currents as slow as 0.25m per second VIVACE can extract energy with high efficiency making ocean or river current energy a more accessible and economically viable resource. The underlying concepts of the VIVACE Converter are discussed.

Since the 1960s and over the last two decades in particular the coastal zone has experienced an unprecedented increase in the volume and variety of water-based recreation. This has partly been driven by Governmental initiatives but also by rising standards of living greater spending power and the aspiration and willingness of people to devote spare time to participate in CAS (coastal aquatic sport). However while increased involvement in sports is part of government strategy since participation in such activities is generally perceived as being beneficial to society there is nonetheless potential conflict in the use of the water space. A report of the UK Government's Inter-Departmental Working Party detailed by the Department of the Environment Transport & Regions (1998) acknowledged the problems associated with recreation on the coast and noted that there were few comparative statistics available from which to assess the scale of the problem. The 1998 launch of the MCA (Maritime and Coastguard Agency) also highlighted the fact that there were specific risks associated with the marine and coastal environment from the human use of the coastal zone. Further a large number of organisations involved in coastal issues have evolved somewhat 'piece-meal' around coastal planning and policy. Hence for CAS management an extensive mesh of intricacy exists that is not conducive to clear and effective management. In addition because of the complications associated with inter-organisational communications the House of Commons Environment Committee (1992) stated that these types of issues have88577

NIWA (the National Institute of Water and Atmospheric Research Limited) integrated a 30kHz Kongsberg Simrad EM-300 multibeam echosounder on their research ship to help meet the mapping and charting requirements of LINZ (Land Information New Zealand) and to support NIWA's science and consulting activities. Installation of the hull-mounted multibeam system was carried out and it was put through a series of stringent calibration and acceptance tests by LINZ prior to its performance of hydrographic charting in the Western Ross Sea of Antarctica. The LINZ Hydrographic Survey Standards are detailed together with their specifications for the Western Ross Sea survey NIWA's evaluation and selection of a multibeam system to meet these standards and specifications and the system's integration upon the research ship. Predicted error budgets are provided for the echosounder's vertical accuracy and feature detection capabilities. An evaluation of the calibration and acceptance testing and a comparison with the predicted performance of the multibeam echosounder are provided. Conclusions resulting from the Western Ross Sea 2001 voyage together with the mapping data collected by multibeam echosounder are presented. Experiences and issues associated with surveying in the harsh Antarctic environment during the February-March 2001 voyage are also detailed.

Corpus Christi (CC) Bay in Texas USA is a shallow wind-driven bay which experiences hypoxia (dissolved oxygen (2 mg/L)) during the summer months in the southeast region of the bay. Real-time monitoring systems have been developed and installed in the bay to measure various water qualities meteorological and hydrodynamic parameters. These systems can help determine the extent and frequency of hypoxic events in this energetic bay. DO (dissolved oxygen) is an important indicator of aquatic ecosystem health. Hypoxia develops when DO concentration in the water column dips below 2 mg/l ad most aerobic aquatic organisms cannot survive under these conditions. A 3D mechanistic dissolved oxygen model has been developed to investigate the key processes that induce hypoxia in CC Bay. This model includes variable advection and dispersion coefficients so that it can be driven by real-time monitoring hydrodynamic data. The results from model simulations indicate that hypoxia may occur at the lower depths of the bay when both stratification and higher biological activity conditions exist. The water column in the southeast part of the bay becomes stratified during calm wind conditions when there is inflow of hyper-saline water from the neighbouring Laguna Madre waterbody. This condition when combined with higher biological activity during the summer months induces hypoxia at the lower depths of the bay. The simulation results also point out that physical transport processes have more pronounced effect on the DO distributX36275 Mechanistic features of short fatigue crack growth kinetics for high strength steels in sea water

The fatigue life of a welded joint is sensitive to welding residual stresses remained in the joint. A new fatigue life prediction model for welded joints is presented. The effects of residual stresses are assumed to be equivalent to those of mean stresses. The keystones of the present model are hot-spot stress equivalent stress model to take account into the effects of residual stresses and residual stress relaxation model. Hot-spot stress is a very effect reference stress because the fatigue test data from many kinds of joints can be plotted on one curve by this stress. The residual stress relaxation model decreases residual stresses cycle by cycle and the equivalent stress is updated also cycle-by-cycle by hot-spot stress and residual stress. The fatigue damage is calculated by Miner's linear damage rule with the equivalent stress. This fatigue life prediction model needs two kinds of fatigue test with different residual stresses. Once being tuned by two specific fatigue tests this model can be applied to arbitrary stress ratio and many kinds of joints. Finally the present model was conceived by a couple of experiments as promising one.

An innovative float-over topside mating concept is presented that can be applied offshore for floating platforms. Float-over topside installation enables fabrication of a fully integrated deck to proceed in parallel with fabrication of the hull and therefore provides significant improvements in the construction schedule. Moreover as the topsides are built as a completely pre-commissioned stand-alone unit in one construction yard the offshore commissioning is reduced to its minimum. The designed system has been applied to the installation of two fully integrated decks to be installed on the OCTOPLUS. The OCTOPLUS is a new generation FPSO (Floating Production Storage and Offloading Platform) with two independent decks that weigh between 10000 and 12000 t at installation. The basic principle is to connect the Barge carrying the topsides to the offshore site with the Platform using a system of tensioned members to synchronise the two floating structures. Once they are connected together the relative movements between the Barge and the Platform disappear and a passive system can be used to carry out the final load transfer. The tension members are provided with an adjustable top connector that can move downward under its own weight but cannot move upwards again. When released it drops down the steel member to make a rapid initial connection between the Barge and the Platform. As the waves continue to induce some relative motions between the two structures the connector will continue to ratchet dX27517 New offshore tanker proposed by Statoil

It has now become paramount to find sources of sand for beach replenishment and maintenance that will be both environmentally and economically sustainable. Recent discoveries by the USGS (United States Geological Survey) and others have indicated a potentially very large source of clean sand on ancient beaches between 70-130 m deep. These beaches are part of the Makua Shelf system formed some 40000 years ago. They are outside the reef at depths below the impact of storm waves and the removal of sand should not affect the present shoreline in any way. It now appears that these deep water beaches just beyond the reef cliff might be found Pacific-wide. The depth is however considerably greater than normally anticipated and the characterisation of the deposits using traditional vibracoring tools has been shown to be time consuming and expensive. This paper describes a new tool to measure in situ the engineering and environmental characteristics of unconsolidated seabed materials particularly carbonate tropical sands as much as 15 m thick in water depths of up to a maximum of 20 m from a small unanchored vessel. Although conceived for the characterisation of offshore carbonate sand deposits

SWATH (small waterplane area twin hull) vessels are becoming increasingly popular in many areas of the marine transport industry. Their superb characteristics in sea keeping overall stability ride comfort and quality are unique and attractive to those industry professionals who seek to maintain cruise speed and comfort in rough seas. 'Pipe Dream' a model SWATH is the product of two semesters worth of design and construction. The work was done in an effort to satisfy a challenge that required first a working SWATH whose design addressed those fundamental aspects of naval architecture marine engineering and ocean engineering which pertained to the boat. Second the challenge required a demonstrated method for measuring and correcting for pitch instability while the third part involved quantifying the performance of the model boat in rejecting wave disturbances. Using a detailed analysis of the Charles River 'sea state' and the traditional engineering theory associated with ship design Pipe Dream was physically designed to operate at natural periods in roll and heave which allowed for sufficient stability in its intended environment and also to withstand the structural stresses imposed thereby. Focusing more on the implementation than the design process the construction of Pipe Dream involved the development of the SWATH structure propulsion and steering systems pitch control scheme and the electronics used to read the sensors and drive the vehicle. Complex machining was required in many areas of the construction for waterproofing and design requirements and an even more complex electronics layout was engineered in order to meX25967

Compliant offshore structures like TLPs (tension leg platforms) are usually subjected to considerable uplift forces. These structures require foundations that can anchor them to competent strata. It has been common in the past to use piles to provide such a foundation. However there are difficulties associated with the installation of the long piles that are usually necessary particularly in deep waters. Largely because of these difficulties a new type of foundation the suction caisson has been developed and used to provide uplift resistance for a variety of in situ soil conditions. An extensive theoretical investigation has been carried out of suction caissons subjected to vertical uplift loading for cases where the behaviour of the seabed soil is undrained partially drained or drained. Theoretical solutions for the uplift capacity are derived based on the results of a finite element study and then validated by previous field experiments and model test results. The expressions developed in this paper for the uplift capacity take into account the influence of the aspect ratio of the caisson the shear strength parameters of the soil the soil permeability and the loading rate. Conclusions are drawn about the behaviour of suction caissons subjected to vertical pullout loads.

The ability to scientifically predict the performance degradation resistance and usable lifetime of marine cables and connectors is highly desired and valued by design engineers and program managers. Historically the most frequently encountered failure mechanism for marine cables and connectors has been delamination of the polymeric over-molding compound from metal connector backshells. Over the years several testing protocols have been developed. The purpose of these ALT (accelerated life test) protocols is to determine the resistance to degradation of various metal-primer-polymer combinations used on cables and connectors in a marine environment. Unfortunately many of the existing ALT protocols show technical and-or scientific deficiencies that compromise their ability to provide meaningful data for the prediction of service life and the understanding of the cause(s) of hardware failure in the marine environment. These problems include but are not limited to: choice of failure mechanism model; differences in activation energy for materials or reactions or processes; maintenance of the proper corrosion current density and voltage; and maintenance of the proper ALT fluid medium chemistry. All of these issues are important for the successful completion of an ALT yet ALTs are often carried out without addressing one or more of these critical issues. After presenting the problems and pitfalls some suggestions for improvements are made. Conclusions are drawn.

A computer-aided decision support system should use all available knowledge about the design space and should adapt to changing knowledge and allow for more detailed input later in the design phase. By combining this with the ability to build upon the results from the first iterations in the design spiral the overall design-time will be decreased and the confidence in the decisions made in initial design will be improved. Different ways to generate 3D models are described at a time when there is little knowledge about the design object. Having a 3D model available right from initial design means that there is a set of calculation packages available. Initially the concept of 'adaptive programs' is discussed. It is argued that by using these programs more reliable estimates will be achieved in early design phases. Next it is described how 3D ship models can be used in early design by applying the principles of adaptive programs. Different ways of producing 3D ship models based on the limited knowledge in the early design phases are described. After this it is explained how rule-based design can be used to help the ship designer to generate 3D ship models. Finally it is shown how some of the theories in this paper are used to develop a new tool which is intended for the initial design of FPSOs.

The water depth for offshore oil and gas installations has been steadily increasing over the last decade. It is expected that within the next ten years the industry will be developing fields in water depths approaching 10000 feet. The associated increases in weight pressure dynamics and fatigue loading put severe demands on the riser systems. An integrated approach must be adopted early in deepwater risers projects that accounts for all stages of modelling analysis design and fabrication of the riser system to guarantee the required quality and performance. The key drivers for the successful development of deepwater top tensioned riser systems are discussed together with the need for a high degree of front-end engineering. The need for an integrated approach between the different stages of analysis design and fabrication to achieve the desired quality is also stressed. Riser performance monitoring in recognition of the fact that much of the deepwater design work is plowing new territories is highlighted. This paper also serves as a primer for a comprehensive design basis for the development of deepwater risers. The discussion is limited to production and water injection TTRs (top tensioned risers) and does not include drilling risers.

In recent years oil and gas mining has moved into increasingly deeper water in search of undeveloped fields. As water depths approach and exceed 500 m conventional offshore foundation systems become inefficient and ineffective in stabilising platforms and floating production storage units. Consequently many types of alternative anchoring systems are being developed and used in order to withstand large mooring forces. Plate anchors have attracted much attention in offshore deepwater development. Over the last 40 years a number of researchers have proposed approximate inexact correlating techniques to estimate the uplift capacity of plate anchors in various types of soils. Most of the results from the studies of anchors in clay consist of either simplified analytical solutions or empirically derived formulations from laboratory scaled model tests. Here the bearing capacity and rotational behaviour of plate anchors subject to inclined pullout in clay are investigated. Both centrifuge tests and numerical simulations are conducted. Both anchor rotation and chain reaction are studied during plate anchor inclined pullout when the anchor is installed vertically in clay. Both numerical simulation of strip plate anchor and centrifuge model tests on square anchor are carried out in uniform and NC (normally consolidated) clay. In the numerical analysis RITSS (remeshing and interpolation technique with small strain model) is used to simulate large movements of the anchor. In the centrifuge model tests a transparent 'soil' is used to observe anchor rotation and chain reaction during anchor pullout.

A naval ship is said to be in class when the published Rules and Regulations which pertain to it have been complied with to the satisfaction of the Classification Society. The role of the human element in classing and maintaining a naval ship in class is not clearly defined in the Rules and Regulations. The human element needs to be considered in meeting the principles of classification for example to inform design and test with an understanding of the context of use. The focus here is on the interface with the equipment and systems that are required to be operated with proper care and conduct to ensure the safety and reliability of machinery and related engineering systems. HFI (human factor integration) [or in the US HIS (Human Systems Integration)] is a complex and multi-dimensional issue that requires activity by a wide range of stakeholders. There is now a standard to provide usability assurance at a management level. A range of technical standards and guidance can be used to define project activity and design criteria. The role of usability assurance is a new one. The usability assurance approach meets the human element needs of a number of stakeholders including design safety manpower and training. In the early stages of a project and during design and development usability assurance provides risk management. Later in the project the evidence gathered can be used to reduce the effort involved in meeting the requirements of classification.

A turret-moored FPSO under harsh conditions is supposed to align with wind-driven waves due to its weathervane capability. However the ship can find herself beam on to the seas in mild environments as a result of a combination of wind-driven waves and swell condition. This means that a misalignment between ship's heading and waves can happen leading to large amplitudes of roll motion for a reasonably long time. This really gets worse in the case the FPSO is at low draft and the roll natural period is in the vicinity of the peak period associated with the swell condition. It is well known that one of the most effective devices to reduce the roll motion of ships is the bilge keel. The importance of the bilge keel increasing the roll damping moment stands out for resonant conditions. The results of free decay tests for various bilge keel arrangements are presented regarding roll damping coefficients. Tree representative drafts were considered for the FPSO and the bilge keel configuration varied from bare hull (no bilge keel) to bilge keel. Finally a tailor-sized bilge keel is defined for a typical F(P)SO operating at Campos Basin.