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Coldwater reefs are comparable in size and structural complexity to the warm-water coral reefs of the tropics. Various cold-water coral ecosystems are described together with their known and potential global geographical distribution and their similarities to warm-water coral reefs. Observations from several locations around the world illustrate the state of these reefs and highlight their vulnerability to threats caused by human activities which have already destroyed or affected a large number of cold-water coral reefs. Key cold-water coral species are described followed by some consideration of their distribution and status regulations and measures. The aim is to raise awareness about cold-water coral reefs. Some recommendations are put forward for action to conserve protect and sustainably manage these fascinating but fragile ecosystems. Because of their extreme vulnerability there is a need for urgent and precautionary action to conserve and sustainable manage these cold water coral reefs. Such action includes the prohibition of destructive fishing practices including bottom trawling and the establishment of MPAs (marine protected areas). Conclusions are drawn and recommendations made. A scientist's statement is presented on protecting the world's deep-sea coral and sponge ecosystems. Recommended websites are listed.

Compared to connections between CHS (circular hollow sections) less attention has been devoted to multi-planar connections between RHS (rectangular hollow sections). Because of a lack of sufficient experimental and numerical evidence there is no sufficient information available for such connections. The strength of multi-planar overlap KK-joints in RHS and their counterparts uni-planar overlap K-joints are studied in more detail in order to determine the multi-planar effect. In this study the RHS sections are square. Based on this study the relationship between the strength of multi-planar overlap KK-joints and uni-planar overlap K-joints is determined. Further comparisons are made with existing design recommendations. An initial conclusion is that when using the formulae of the strength of uni-planar overlap K-joint to determine the strength of multi-planar overlap KK-joints no multi-planar correction has to be included if the strength is governed by the brace effective width criterion. However this investigation has also shown that for medium to higher chord slenderness chord face failure by yielding or buckling may occur and this failure mode is not covered in the current recommendations.

Designers of HSV (high-speed vessels) resort to light-weight design concepts since the hull weight plays a crucial role in the performance of such ships. Aluminium alloys appear certainly to be the best choice. However such material may be more prone to fatigue collapse and therefore aluminium alloy welded joints can be considered to be areas of weakness in a ship's structure. The fatigue behaviour of these joints is considered. The traditional methods for fatigue assessment of welded joints have some limitations and are extremely time consuming. In order to overcome these difficulties Risitano's method based on thermographic analysis is applied to predict the fatigue behaviour of welds. Experimental tests have been carried out to assess and compare the high-cycle endurance limits of different welded joints obtained by means of FSW (friction stir welding) and MIG techniques. The results obtained resorting to the TM (Thermographic Method) show good agreement with those derived from the experimental data represented through S-N curves. This is the first step in a research programme for the fatigue strength assessment of light alloy welded joints used in ship construction. Further research developments are outlined.

Long flexible circular cylinders known as marine risers linking the seabed to an offshore platform are exposed to strong sea currents which cause the flow around the risers to separate and initiate vortex shedding. Due to low structural damping the resultant lift and drag forces induce forced oscillations of the cylinder known as VIV (vortex-induced vibrations). High amplitude vibrations of the riser could potentially result in a high level of fatigue damage in a relatively short period of time. Design principles for deepwater risers are typically drawn from empirical knowledge and existing experimental data. These databases would further benefit from reliable computational studies on fluid-induced motions of structures. In an effort to gain a better understanding of the VIV phenomena 3D numerical simulations of VIV of circular cylinders are presented. Operating conditions that correspond to high Reynolds number flow low structural damping and allow for two-degree of freedom motion are considered. The numerical implementation makes use of overset (Chimera) grids in a multiple block environment where the workload associated with the blocks is distributed among multiple processors working in parallel. The 3D grids around the cylinder are allowed to undergo arbitrary motions with respect to fixed background grids eliminating the need for tedious grid regeneration at every time step.

All floating production systems must rely on some kind of marine risers for transport of the well stream from the seafloor to the platform and in many cases also for transport of processed oil and gas down to a pipeline. Among the many proposed riser concepts the SCR (steel catenary riser) is particularly promising due to its simplicity and low costs. This is in particular true if the heave motions of the floater are moderate as for TLPs (tension leg platforms) SPAR buoys and deep draught floaters. A key issue in design of catenary risers is to control stresses and fatigue damage in the touch down area. Vessel motions and waves will cause time varying stresses and because of restrictions from the seafloor contact bending stresses will often have peak values in this area. Another phenomenon that may contribute significantly to fatigue is VIV (vortex induced vibrations) in constant current. Although amplitudes are small compared to wave and motion induced stresses fatigue damage can be high because of the large number of stress cycles that may occur. Reliable prediction of bending stresses in the touchdown area from VIV is therefore desirable. Modelling aspects and analysis methods are discussed for calculating fatigue damage close to the touchdown point due to VIV. The method that is applied has previously been used for calculating VIV for free spanning pipelines - see Larsen et al. (2004) and Larsen and Koushan (2005).

For mooring chains of offshore floating production units API (American Petroleum Institute) recommends the use of its TxN fatigue curve considering the MBL (minimum breaking load) of an ORQ (oil rig quality) chain even if the chain has a higher grade. DNV (Det Norske Veritas) recommends the use of SxN fatigue curve where the stress is taken using the tension over the nominal area of the chain or wire rope. So it is easy to convert this SxN curve to a TxN curve or vice-versa. The geometry of the chain or wire rope and the material are implicit considered. To develop SxN curve for new accessories design it is necessary the using of FEM (finite elements method) to obtain the distribution of stresses and strains and the stress concentration factor and the SxN curves of the material. The analysis of the tension and the stress concentration factor will be used to obtain the slope and intercept parameters of the fatigue curve. The study developed for KS hook is presented together with how to obtain the fatigue curve for this accessory based on published papers rules and recent tests.

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.