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The emulsified fuel combustion method is recognised as improving combustion efficiency and reducing pollutant emissions. The combustion process of an emulsified fuel droplet is explored. The experimental procedure is described. The oil-in-water emulsion is tested. Photographic observation and temperature measurement are made of the suspended emulsion droplet during the heating-up and combustion processes under microgravity. Primary attention is to the phase- separation in the droplet and the time histories of droplet temperature and the amount of water in the droplet during the time prior to disruptive microexplosion. The effects of the emulsion properties on the onset rate of microexplosion are also shown using statistical analysis. Results are presented and discussed. Primary conclusions are drawn.

This paper proposes a navigation scheme of an Autonomous Underwater Vehicle (AUV) for photo mosaicing of a shallow vent area with bubble plumes. While bubble plumes disturb acoustic positioning systems they can be detected by sonars. So the method takes advantage of the plumes as landmarks using a profiling sonar. By adopting the concept of Simultaneous Localization and Mapping (SLAM) the method achieves drift-free accurate and independent positioning without using conventional acoustic transponders. The high positioning accuracy enables complete data acquisition as well as position based mosaicing without relying on pictorial correlations of the photos. Some artificial acoustic reflectors are also deployed to enhance positioning performance. The scheme was implemented at the testbed AUV "Tri-Dog 1" and the performance was verified through sea experiments at Tagiri vent area Kagoshima Bay in Japan.

Data collection and documentation of shipwreck sites involves a variety of methods and techniques depending on the location of the site the size of the site the time constraints of the survey and the technology available. Photo mosaics of underwater sites are useful tools for interpreting sites and increasing the level of detail for areas too large for conventional photography. While this tool has been used for years at deepwater sites using camera platforms such traditional devices are difficult to use in areas that are too shallow or too rough to maintain a consistent distance to the site. In addition some sites notably large shipwrecks cannot by photographed at a well-maintained distance given the time constraints of many projects. Finding alternative methods to collect data and create photo mosaics is necessary. The history of photo mosaics in underwater photography is briefly overviewed and its relevance to underwater archaeological sites in particular ship and aircraft wreckage found in shallow water areas is discussed.

In orientation experiments it is common procedure to displace a group of 10-15 pigeons and release them singly at a distant location and note their vanishing bearing. Based on the mean vectors the initial orientation of the pigeons can be classified into three categories. One of these is showing a release site bias where the bearings are non-random. This case is discussed. Such release site biases their temporal constancy and their spatial distribution are documented. Various hypotheses attempting to explain this phenomenon are discussed namely hypotheses assuming global distance-depending or direction-depending patterns and hypotheses attributing biases to local causes. It is concluded that among these hypotheses the one attributing biases to local irregularities of the navigational map appears to be the most plausible.

The present paper presents estimates of the rate of declines of live coral cover - an acknowledged sign of coral reef degradation - on Caribbean reefs before and after coral bleaching events which an enhanced rate of coral loss as a result of high sea temperatures. In addition the rates of post bleaching coral losses are compared for reefs under severe and less severe human pressures as well as for reefs within and out of marine protected areas. The three lines of evidence presented here suggest that when placed empirically in the context of other threats global climate change is indeed a significant threat to coral reefs.

A theoretical method for plate tearing by a rigid wedge is developed in this paper. The studied model is an idealization of ship-grounding and collision damage. The analysis model postulates that the plate curls up into two curved surfaces behind the wedge tip and that the plate material ahead of the wedge is tensioned and ruptured due to the direct pushing. Based on a parametric study, a semi-empirical formula is proposed for determining grounding force in the event of a ship running onto rocks in a high-energy grounding. The bottom strengths of single hull structures and double hull structures in ship-grounding incidents are compared. Finally, simple formulae for determining damage resistance and the extent of damage in ship grounding, expressed in terms of the ship principal particulars, are developed.

In the commercial marine industry there is considerable interest in electrical shore supplies for large vessels such as cruise liners container ships and tankers or LNG carriers. The QEC (Queen Elizabeth Class) aircraft carriers will be the first RN warships to have HVSC (high voltage supply connection). This paper defines why the HVSC is necessary to meet environmental maintenance and alongside manning aspirations and describes some of the constraints that channel the resulting technical solution. In particular the geometry of the vessel makes it difficult to use directly the systems developed in the commercial world for cruise ships container vessels and ferries. The paper describes the shipboard design for cable handling and routeing that minimises manual effort and interference with access to operational areas. Information on shoreside equipment options and the dockyard supply system is given.

First Conf held in Brighton in 1980 Papers are Oil terminal support - practical criteria for their selection in the light of operational conditions in remote areas Development of hydrographic surveying for ports and their approaches The development of shallow draught workboats for civilian and military use propelled by steerable right angle gear drives Design trends in aluminium patrol craft Recent developments in polyester matrices and reinforcements for marine applications in particular polyester/Kevlar composites Workboat insurance Wheelhouse design for fast boats Noise and vibration control in workboats Electrostatic risks and explosion hazards The selection of propulsion systems for workboats Sailing workboats - practical propositions based on experience with a sailing tug Propeller design for fuel economy Low voltage DC marine electrical system for work boats Traffic control and enforcement in international waters

The potential conflict between ports and the environment is addressed. The importance of the coast is presented alongside the environmental duties of ports and the growth of the ports. It is widely accepted that although there is pressure on important wildlife sites from ports wishing to expand not all existing port capacity is fully used at least in certain sectors at certain locations. The RSPB are concerned about this apparent anomaly and about the risk to the environment. A report was commissioned to: establish the existing capacity of the ports industry for different types of trade; establish trends in ship size for different trades; establish trends in growth of different types of trade; estimate whether current capacity accounting for increased ship size can meet predicted future trade. Results of the report are presented. This begins to answer some of the questions but clearly further work is required. It is hoped that this work will contribute to a debate aimed at reducing the conflicts between port and environmental interests in the years to come.

Non-indigenous species (NIS) can have significant impacts on the economy and ecology of coastal marine environments. Ships' ballast water and hull fouling are the primary vectors for the translocation of NIS and as a consequence ports and shipping areas are constantly at risk from their introduction. Mitigation of NIS impacts is underpinned by their early detection which allows management and eradication procedures to be implemented. However much of Australia's marine fauna is still being described contributing to the difficulty of correctly identifying whether taxa are native or introduced. A number of new initiatives in taxonomic networks (eg the Australian marine invertabrate taxonomists network the Online Zoological Collections of Australian Museums) and methods for survey and detection are assisting in providing the best possible mechanism for the early detection and therefore management of NIS incursions. The importance of utilising these techniques for successful NIS management will be discussed.

Progress is reported toward achievement of a new magnetic tensor gradiometer technology being developed with support from the Strategic Environmental Research and Development Program (SERDP). The aim is to provide a man-portable magnetic tensor gradiometer for real-time point-by-point detection localization and classification (DLC) of Unexploded Ordnance (UXO). The portable gradiometer processes data from triaxial fluxgate magnetometers to develop sets of rotationally invariant "gradient-contraction-type" scalar parameters. The scalar parameters provide the basis for a unique Scalar Triangulation and Ranging (STAR) method that determines the UXO's position and magnetic signature. The paper presents a review of the magnetic STAR concept details of construction and operation of the portable STAR-type gradiometer and results of computer simulations of the effects of fluxgate noise on the gradiometer's target-tracking performance. Also results are given of experimental measurements of uncorrelated fluxgate noise and correlated gradient channel imbalance errors. Preliminary results from a gradient imbalance noise compensation algorithm are provided.

One step towards improving the design and production engineering processes is to introduce CAD-CAM- or Product Model-based systems. However to be able to compete successfully in today's market each shipyard has to take advantage of its own unique possibilities. This means that a customisation and extension of the standard functionality offered by design systems will be required. Amongst potential application areas where major benefits can be obtained are for instance design automation. Customised software will be different from one shipyard to another because of different product types design standards production facilities and general ways of working. This introduces the requirement for using a publicly available API (application programming interface) based on the functionality of the design system thus enabling the shipyard to develop its own customised software. The characteristics and possible benefits of a shipbuilding-orientated API are evaluated and compared to other APIs such as those available from general purpose systems.

Installing jack-up platforms at sites where previous installations have left seabed craters can be problematic. The difficulties are magnified if the new spudcan locations do not coincide with the existing craters. Possible solutions to the problem are stomping and infilling. A numerical soil-structure investigation is presented of two potential solutions to the problem of installing a jack-up platform at the North Everest North Sea site where prior operations had left unmatched set of spudcan craters in the seabed clay layers. The first potential solution considered was infilling the craters with granular material while the second solution involved capping the in-filled craters with gravel loading platforms. This numerical investigation shows that for the eccentric cases examined both options are likely to lead to unacceptable platform leg forces and moments developing during installation to the desired pre-load level. The findings of this study led to further examination of stomping which was combined with seabed excavation to achieve a successful solution on site.

An economical way of improving the operation of a power station burning heavy fuel oil is presented. This improvement was achieved by introducing fuel treatment chemicals. The chemical background is presented as well as the situation before and after the trial; including all data collected during the trial period. The objective of the test was to establish and compare performance patterns between both units. The main reason for adding the fuel additive was to observe how the reduction of carbon deposits in the combustion chamber on the valves in the turbo charger and the exhaust gas system positively effects all the other operational parameters such as exhaust gas temperature turbo charger efficiency and the specific fuel consumption.

The paper presents improved methods and new results on the introduction of formal optimization strategies into the design of offshore structures. The hull design stage is singled out from the overall design process and automated by introducing parametric shape generation numeric hydrodynamic analysis and assessment tools as well as Nonlinear Programming algorithms for process control. The investigation compares the performance of three different optimization algorithms within a shape optimization framework. The classical deterministic Sequential Quadratic Programming method competes with two so called global optimization algorithms: The popular Genetic Algorithm and the more exotic Adaptive Simulated Annealing. The applications show that significant improvements of seakeeping qualities are obtained in either case. Guidelines for an efficient application are given in the conclusions.

This paper addresses the feasibility of retaining pre-construction primer (PCP) as the permanent primer for protective coatings systems applied in high performance areas such as exterior hull underwater bottom and most importantly ballast tanks. Should the retention of PCP be proven as a viable option the process of coatings application can be improved resulting in significant cost savings. Spending of new construction dollars will not be necessary to remove the PCP prior to the application of high performance coating and lining systems. The test program discussed in this paper was based on work sponsored by the National Shipbuilding Research Program Advanced Shipbuilding Enterprise (NSRPAES) and the U.S. Navy

The design of high-speed planning craft presents special challenges for the practising naval architect. A 2D low-aspect ratio strip theory proposed by Zarnick is reviewed. The method was implemented in a computer program called POWERSEA. POWERSEA is a predictive tool a time domain planing hull simulator. It can create regular and irregular waves and includes a simple wake model that can approximate the Kelvin diverging wake waves. A POWERSEA model was created of a test boat and simulations were carried out under conditions that matched the physical test conditions. The results of the simulation are presented and comparisons are made between the physical data and the simulated data. Finally recommendations are given for collecting accurate physical data together with comments on the validity and usefulness of the simulation results.

Optimising the performance of an escort tug is an important part of the design process but the impact of tug performance on total system performance is the critical issue. Tug performance can be predicted with model experiments but this is an impractical method for evaluating the combined tug-towrope-tanker system. Numerical simulation of the total system is a much more practical option since numerical manoeuvring models for ships are well established and can easily include the predicted trajectory of the tanker under the action of a force generated by the tug. A method for predicting the trajectory of a tanker assisted by an escort tug is presented. The development of the method is described. Equations of motion for the tug tanker and towrope are given together with the experiment methods for obtaining the tug's hydrodynamic coefficients. The results of the simulations are validated against model experiments. The simulation is used to illustrate how forces and dynamics of the system can be varied. Some operating practices and the associated safety considerations are also discussed.

The effect of Busan New Port on the future bathymetric changes of the deltas at Nakdong Estuary was studied in three main directions - the tidal current wave and wave-induced current and river flood. A description is given of the tidal current environment and the consequent bathymetric change before and after the construction of the Busan New Port and the Nakdong Tidal Barrage. After some introductory information a look is taken at the tidal system at the site. Next the numerical model is described. Lastly model results are given.

To analyze the dynamic response of the pipelaying system and the subsequent stresses custom-made software has been developed and validated by model tests. From vessel motions calculated by standard diffraction software it determines bending and tension stresses resulting from these motions imposed to the top of the suspended pipe span. The paper demonstrates that environmental conditions laying vessel characteristics stinger type and pipe dimensions interact with each other in a complex manner. Limiting seastates can be evaluated on the basis of maximum permissible stresses. The relative motion between pipeline and stinger may be significant for the operational safety of a laying system. The validated numerical simulation can serve to predict the limiting environmental conditions for specific pipelaying operations.