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The flow around supercavitating hydrofoils is studied. These hydrofoils have cavities which start on the suction side of the foil away from the leading edge (mid-chord detachment) or on the pressure side of the foil in front of the trailing edge (face detachment). This type of cavitation is likely to occur in propellers which are cavitating at design conditions. First the linearised supercavitating hydrofoil problem with arbitrary cavity detachment points is formulated in terms of unknown source and vorticity distributions. The corresponding integral equations are inverted analytically and the results are expressed in terms of integrals of quantities which depend only on the hydrofoil shape. These integrals are computed numerically in an accurate and efficient way to produce cavity shapes and pressure distributions on the foil and cavity. He effect of the cavity detachment points on the shape of the cavity and the foil pressure distribution is investigated. An inviscid flow criterion for the cavity detachment point is derived for the case where the cavity detaches in front of the trailing edge on the pressure side of the hydrofoil. Finally the accuracy of the linearised cavity theory is assessed for different foils and flow conditions by analysing the produced cavity shapes with a non-linear panel method. Conclusions are drawn and future research is identified.

Lubricants are essential design elements in the complex systems of marine diesel engines. It is essential that designers of marine diesel engines and of marine lubricants should co-operate to design an interface between engine and lubricant for the benefit reliability and efficiency of the entire system. The WG (working group) 'Lubricants' was established in 1987 with the aim of generating a user language on the lubrication of large diesel engines and on the technology of designing and using lubricants and lubrication systems. It is described how this WG was established and how it was able to develop its structure working style methods and its unique efficiency. Current work is on the treatment of lubricants an update of Recommendation Number 13 the impacts of emission controls and the lubrication of engines running on non-standard fuels. Work published and recommendations-guidances given by this WG through publication has been positively received by the industry and is used as a reference within the industry (users operators) and. A future key problem will be the lubrication of marine diesel engines running for prolonged periods on LSFO (low sulphur fuel oil). This and the inflammability of lubricant-fuel vapours in the crankcase will need a dedicated input from all members. WG concentrates on core tasks team and networking and leaves jobs others can do to them. This has enabled the WG to work successfully and this style should ensure that they remain successfully.

In December 1980, IEA Ministers decided that publication of more comprehensive information on historical trends and prospects for coal use, production and infrastructure development would help to reduce uncertainties constraining the role of coal in the IEA energy system. Based on recommendations form the Coal Industry Advisory Board, identification of information needs and review of available information, a decision was reached to implement a comprehensive IEA Coal Information system. This was intended to provide both IEA Member countries and those employed in all sectors of the coal industry with information on current world coal market trends and long-term prospects. This is the fourth publication based on the IEA Coal Information System. It differs from the previous one in that the IEA has improved on the concept of 'solid fuels' by separating out coal from all other primary solid fuels. It includes data on coal reserves, production, trade, demand, prices, transport infrastructure, coal-fired power stations and for the first time, emission standards for coal-fired boilers. Part 1 provides an overview of world coal market developments and prospects and Part 2 provides, in tabular form, a more detailed and comprehensive picture of coal developments and future prospects for the OECD by regions and countries.

A computational tool was applied based on a two-dimensional linear method to predict the hydrodynamic loads for damaged ships. Experimental tests on a ship model have also been carried out to predict the hydrodynamic loads in various design conditions. The results of the theoretical method and experimental tests are compared to validate the theoretical method. The extreme wave-induced loads have been calculated by short-term prediction. For the loads in intact condition, the prediction with a duration of 20 years at sea state 5 is used, while for loads in damaged conditions, the prediction with 96 hours of exposure time at sea state 3 is used. The maximum values of the most probable extreme amplitudes of dynamic wave-induced loads in damaged conditions are much less than those in intact condition because of the reduced time. An opening could change the distribution of not only still-water bending moment but also wave-induced bending moment. It is observed that although some cross-sections are not structurally damaged, the total loads acting on these cross-sections after damage may be dramatically increased compared with the original design load in intact condition.

North Carolina has more than 2500 square miles of land within one meter of spring high water. Despite the State's vulnerability it has few policies that deal directly with the economic and environmental ramifications of sea level rise. The State does have policies that require oceanfront setbacks for new development based on historical erosion rates and coupled with this there is a prohibition on hardened-permanent erosion control structures on ocean beaches and inlets. However along the estuarine shoreline policies regulating development are far fewer. In 1999 the State established a buffer zone along much of the State's coastal rivers and estuarine shoreline. Although this buffer may delay some of the impacts of rising sea level the primary motivation for action was water quality protection - not protection from sea level rise or storm events. Finally the State's CAMA (Coastal Management Act) requires land-use planning in the State's 20 coastal counties and the State's planning guidelines require local governments to address the issue of sea level rise. However most of the current plans only lightly touch on the issue and defer action to the state's coastal management program. This study develops maps depicting three shore protection scenarios that reflect potential responses to sea level rise. The three scenarios are based on alternative policy responses to sea level rise. The scenarios are visually depicted on 12 maps (technically not feasible to present them in the conference materials). Creating these maps required existing coastal policies to be analysed and interviews to be carControl No

Quantifying the fatigue crack growth and remaining life in joints making up jacket structures forms one of the basic requirements of a sub sea structural integrity assurance scheme. The accurate prediction of the likely failure time of welds allows a realistic estimate of the risk of structural collapse at any stage in a structure's life. It is current practice to consider the welds making up the member as individual components rather than looking at the whole compliant system of welds joints members and structural framing arrangement. In this approach the nominal loads in any one member are determined from an analysis of the undamaged structure and are then applied to a crack growth solution using handbook stress intensity factor solutions to determine the fatigue life of that component. This method assumes that the applied load is purely load-controlled whereas in reality it is a combination of both load and displacement controlled. A study was carried out to investigate the influence of the surrounding structure on crack growth in tubular members located in jacket structures. The aim of the study was to verify whether the traditional approach which uses stresses from undamaged structures to evaluate crack growth in individual components is appropriate. The findings of the study showed that structural compliance has only a beneficial effect on fatigue growth in the latter stage of the crack growth process with crack lengths greater than 40 percent circumference. It was shown that the beneficial effect of structural compliance on fatigue crack growth in the later100254 Effect of structural member uncertainties in the jacket-type offshore platform assessments

The movement of offshore gas transportation pipelines to deeper and deeper waters has generated new challenges. In order to reach depths greater than 2000 m even with X70 grade wall thicknesses of nearly 30 mm are required for 24-inch diameter line-pipe. The resulting lay tension requirements on the pipe-laying vessel are enormous. For this reason any ability to reduce the pipe wall thickness and still resist the external pressure at these depths would be quite attractive. Line pipe is often coated prior to installation in order to achieve some protection against the environment. Many of the coatings used today require the pipe to not only be cleaned and degreased but also to be pre-heated to a temperature of 200-240 degrees C during application of the coating material. A typical coating thermal cycle involves rapid heating of the pipe using induction coils application of the coating and quenching to cool the pipe for handling purposes. It is generally understood that this thermal treatment on UOE line pipe which can last from a couple to as many as ten minutes has an effect on the pipe yield and to a lesser extent tensile strength. For ultra-deepwater offshore applications where collapse is often the controlling design case the increase in hoop-compressive yield strength is viewed as desirable because of the corresponding increase in collapse pressure. For onshore applications however bending due to differential ground movements can be the primary design consideration. In this case

The paper presents a comprehensive investigation into the effect of incidence on the current loading of a mini TLP by means of three-dimensional CFD computations. The robustness of the code is demonstrated by validation against established experimental benchmark data and by extensive convergence and sensitivity testing. The computational results show significant effects from shielding indicating that for a TLP type of floating structure the most critical heading with respect to current loading is in the range of 20" to 30". Comparisons carried out with design code recommendations suggest that if shielding effects are not accounted for current loading will be overestimated by as much as 30% by a traditional "engineering" approach.

This is a book about the development of ships and boats which have affected the history of Western civilisation. It concentrates on the ships themselves rather than on literary descriptions or artistic representations. It takes in the earliest seafarers in the Mediterranean and Near East; Greek, Etruscan and Phoenician ships and shipping; Romans on the sea; Greek and Roman harbourworks; ships of the Roman period and after in Britain; Byzantium 330-641; Scandinavian ships from earliest times to the Vikings; the Vikings and the Hanseatic merchants 900-1450; the maritime republics: medieval and Renaissance ships in Italy; the influence of British naval strategy on ship design 1400-1850; traders and privateers across the Atlantic 1492-1733; and waterways opening the New World.

A test program has been conducted using a geotechnical centrifuge to examine methods for improving the sliding capacity of spudcans by modifying the spudcan footing. The tests were performed on medium dense dry sands applying different kinds of spudcan geometry. A computer controlled loading system was used to simulate the load path a spudcan is subjected to in a storm. First the test program is outlined. Next the test technique is discussed. Finally test results are given indicating that the most significant improvement to the sliding capacity can be obtained by using a skirt.

With the advent of ECDIS (electronic chart display and information systems) the US Army Corps of Engineers began efforts to publish chart data on the inland waterways. Executive Order 12906 directed Federal agencies to make geospatial data holdings available to the public and the National Transportation Safety Board recommended that the Corps promote the use of electronic chart technology on inland waterways for safety of navigation. The data initiative began with the publication of data in CADD (computer-aided design and drafting) files. However the various formats layer structures and geographic projections proved unsuitable for electronic charting applications. Therefore the Corps committed to use the S-57 exchange standard and carried out pilot projects on the Atchafalaya River in Louisiana and a 200-mile section of the Mississippi River. These projects established a mapping scheme of Corps waterway data to S-57 format to produce the river data product known as IENCs (inland electronic navigation charts) and initial coverage of broader areas followed. Currently 30 IENC cells covering some 1000 miles of river are available for public access on the Internet.

The monotonic and cyclic shear behaviour of a volcanic soil Shirasu as a reclamation material is investigated. Shirasu usually has a high coefficient of uniformity and typically contains 20-30% non-plastic fines formed from the crushed remains of larger particles. A series of monotonic and cyclic triaxial tests was carried out on samples of Shirasu to assess the influence of the fines on the monotonic shear and liquefaction susceptibility. Tests were carried out both on the original particle size distribution and on the soil which had the fines washed out. The existence of the fines was shown to dictate the mechanical properties of Shiiasu when used as a till material. Shirasu is shown to have a low liquefaction strength and underwent flow deformation at low confining stresses.

As passenger ships become ever larger many authorities and operators have been forced to examine the stability and safety of the people on board passenger vessels including ROPAX and cruise ships. The design of these vessels has changed significantly. However prescriptive stability rules do not represent these developments. As a result the application of the IMO Weather Criterion for intact stability based on the effects of a severe wind and rolling to modern passenger vessels can result in requirements higher than the values that should be applied if correct parameters are used. The experimental study carried out by the Ship Stability Research Centre on the effect of Pod structure on roll damping and roll motion is presented. Results are presented and discussed and are followed by some concluding remarks.

Sigrist has installed more than 100 on-line UVF (UV fluorescence) OIW (oil-in-water) monitors in the past ten years for continuous monitoring of the oil content in produced water from offshore platforms. Various reports indicate that different specific parameters are affecting the fluorescence reading. Separation systems that were not working properly were investigated in particular sample preparation. There was also concern about the influence of droplet size and this was also investigated. The possible influence of chemicals and the use of a rotor-stator homogeniser for sample pre-treatment were tested. The results are presented. These show that the combination of chemicals and the use of a homogeniser may help improve the oil droplet size distribution which leads to higher fluorescence readings and possibly to better correlation with laboratory methods.

Wave-current interactions have considerable practical interest in coastal engineering and related disciplines. A 1D wave-current numerical model is presented for the simulation of irregular wave characteristics in a current field. The model is based on the Madsen-type extended Boussinesq equation and a wave-current dispersion relationship. The model is applied to the following current and adverse current fields. Numerical results show the modification of spectral density in a current field and it is also found that modification of spectral density depends on the current direction and its magnitude. Spectral densities decrease in a following current field and increase in an adverse current field. In an adverse current field the spectral peak shifts towards to the higher frequency but there is no substantial shift of the spectral peak for waves on following currents. For the same magnitude of current velocity an adverse current field has significant impact on spectral densities than a following current field.

Tsunami-induced coastal inundation is of great concern to civil defense agencies in Pacific Rim countries. Currently two questions related to tsunami run-up on rough coastal terrain need to be investigated. The first is whether terrain roughness has a significant effect on wave run-up and the second is what is the proper mathematical formula to model the roughness effect. An experimental study is carried out to investigate the maximum run-up of non-breaking solitary waves on both smooth and rough plane beaches. Artificial beaches with different slopes and bottom roughness are studied. The results show that for waves running up relatively steep slopes (eg 20 °) viscosity and roughness have little effect on the maximum run-up. In this case the inviscid long wave theories are adequate for predicting the run-up height. However for waves running up over mildly sloped beaches the viscous and roughness effects are found to be very significant and can reduce the maximum run-up by more than 50% compared with the inviscid predictions.

SMC (submerged moored cylinders) can be used for transporting oil gas and dredged slurry. They can also be used as tunnels for crossing deep-waterways. The costs of such structures are independent of water depth and thus are cheaper compared to the fixed directions. A SMC consists of a buoyant tube supported on tethers as mooring lines which are anchored to the seafloor at suitable intervals. The hydrodynamic behaviour of a SMC due to the action of oblique random waves is studied in a wave basin in a water depth of 3m. Open type mooring was applied and the model was moored with linear taut moorings. The pressures around the cylinder were measured. The horizontal and vertical forces on the cylinder were obtained by integrating the pressures and resolving. The experimental set-up and program are described. Results are presented and discussed. The effect of wave direction and the relative submergence of the model below the still water level on the forces on the SMC and the mooring forces are reported. Conclusions are drawn.

The Indus delta in Pakistan supports a diverse ecosystem and serves as a sanctuary for a variety of waterfowl and migratory birds. It is reported that the terrestrial wildlife has decreased in diversity due to reduction of freshwater into the delta from the River Indus. This is due to a severe tropical Cyclone 2A which landed in the lower Indus region of Pakistan in May 1999. A study to assess the environmental impact of the cyclone on the area is presented. A tidal surge caused seawater to spill into the brackish water lakes. The aquatic living resources wildlife local coastal fauna and flora have come under physiological stress. Remote sensing techniques are used to detect morphological changes in the area. The SPOT satellite Panchromatic and Multi spectral full scene data of the area for three different periods is obtained. The Satellite data is processed on ER Mapper 6.2. The analysis shows very prominent morphological changes on the wetlands of the area caused by the landfall of cyclone. The major impacts on the coastal wetland environment are discussed and imagery with the field data collected during the study is compared. Conclusions are also presented.

An attempt is made to determine some aspects of the inter- relationship between wake field propeller design cavitation and dynamic load. Theoretical procedures are presented for propeller design for determining the dynamic propeller load and for determining cavitation performance. The use and need for these theoretical calculation methods are discussed. Five-hole pitotube measurements carried out on a group of large tankers and container ships are analysed to determine if it is possible to derive properties of wake fields that are typical for certain types of ships. Based on this propellers are then designed for the vessels and conventional design procedures are critically reviewed. The combinations of nominal wake fields and designed propellers are analysed with respect to the dynamic load due to the inhomogenity of the wake field and the occurrence and extent of cavitation. Calculation programs based on unsteady lifting surface theory are used for the dynamic load. Programs based on quasi-steady propeller theory are used for the cavitation prediction. It is concluded that a detailed knowledge of the wake structure is required for accurate calculation of the dynamic load distributions and that it is necessary to incorporate cavitation minimisation criteria in propeller design procedures.

Int semn held in Tokyo Japan 3 - 9 February 1976 Papers are A bibliography of wave resistance of ships Linearized wave resistance theory Line integral uniqueness and diffraction of wave in the linesarised theory On nonlinear wave resistance theory Wave breaking resistance of ships Wave analysis State of the Art 1975 Application of wave analysis to tank experiment Hull form design derived from wave analysis Wave theory applied to practical hull forms Hull form design - its practice and theoretical background Catamaran hull form design Added resistance and propulsive performance of ships in waves Ship waves and wave resistance in a viscous fluid An approximation to Michells integral The line integral term in the wave resistance On the contribution of line integral to the wave resistance of surface ships On the second order velocity potentials of the thin ship theory by centreplance source distributions Non linear wave resistance and coordinate straining The sheltering effect of ship waves Some consideration on the sheltering effect of a ship with a long parallel middle body