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To comply with oil pollution abatement regulations OWSs (oil water separators) are being installed onboard all Navy surface ships. More stringent oil pollution regulations are anticipated. In anticipation of this CDNSWC carried out an influent maximisation test on the Navy's OPB-10NP OWS system to determine its maximum operational capabilities. The influent parameters that were varied are flow rate oil concentration and oil droplet size distribution - that is the basic design parameters of an OWS system which operates on the principle of gravity separation. During the test the effects of the various influent oil concentrations on the performance of the OPB-10NP OWS were determined. Different methods of analysing oil droplet size distributions in oily wastewater samples were also evaluated. The test set up is described and the method of evaluation is described. Test results are presented and discussed. Conclusions are drawn and recommendations are made.

On 3 December 1994 the fishing vessel Heather Bloom with a crew of six snagged her fishing gear on an underwater obstruction causing her to heel heavily to port and to take on water. The vessel sank 60 miles north of Cape Wrath. Five of the crew were rescued. A significant contributory factor to her loss was the lack of a safe operational procedure for manually releasing the winch after hydraulic power was lost.

In 1998 the Association for Structural Improvement of the Shipbuilding Industry (ASIS) initiated a three-year research and development project on large-scale recovery systems for collecting highly viscous oil with a minimum kinematic viscosity of 100000 centi-stokes under severe sea conditions. This paper focuses on the design and evaluation of a newly developed oil skimmer system suitable for the recovery of highly viscous spilled oil emulsified under rough sea states. Furthermore synthesized model experiment was carried out in a water tank and oil basin using a large-scale model of a developed oil skimming system to acquire the performance data on the constituent technologies and to confirm synthetic function as an oil skimming and treatment system.

Two series of numerical simulations based on the discrete element method were carried out to study the interaction of both multi-year sheet ice and multi-ridge ice with a proposed six-sided faceted conical structure. In the first series two physical tests were simulated one using sheet ice and the other using ridge ice with a small neck model of the faceted structure. The approach was verified by comparison of simulation results with those from tests. The ice failure process was analysed. In the second series of simulations a large neck structure was used. Comparison of the results showed the effect of neck size on both the sheet ice loads and the ridge ice loads exerted on the structure.

Chevron UK Ltd has increased the number of well slots on Alba Northern Platform (ANP) by over 20% at minimum cost. ANP is using four 46 inch OD caissons each housing two 20000 bpd wells. The close proximity well project (CPW) is a refinement of an application seen in some Gulf of Mexico and mud-slide areas whereby multiple wells are drilled from the same caisson. The CPWs will facilitate the drilling of 28 wells efficiently and economically from a platform originally equipped with 24 slots. Conductor sharing technology provides an additional 4 well slots on Alba Northern platform and the provision of these extra slots has helped remove the need for a second platform to develop the field which has had a major impact on project economics. The first CPW system was successfully installed during May and June 1995. The installation of two wells in the space reserved for one shows that it should be possible to design smaller lighter and cheaper platforms and so reduce a major item of capital expenditure.

Energy conversion systems applied in the marine environment require higher performance and efficiency. It is very important to understand the mechanism and corresponding correlation of the boiling heat transfer for the effective use of existing energy conversion technology so we need to accumulate a fundamental database of CHFs (critical heat fluxes) on energy conversion. The purpose of this work is to clarify the transition phenomena to film boiling in several liquids having different wetability by the photographic approach on the vapour bubble and vapour film behaviour on the cylinder surface by using a high-speed video camera. Experimental apparatus and method are presented and results given and discussed and conclusions drawn.

Evidence for the natural seepage / migration of gas and low density fluid through seabeds particularly in hydrocarbon rich regions of the world is presented with discussion of: seabed erosion features associated with the escape of gas / fluid notably "seabed pockmarks" and "mottled seafloor"; characteristics processes and mechanisms of migration and seepage; the effects on seabed installations both indirectly on soil properties and directly on structure behaviour; and methods (model and full-scale field trials) for the assessment of seepage processes prior to seabed construction pipeline gravity based and piled structures are considered. Particular attention is paid to areas of gas / fluid escape in the North Sea especially the densely pockmarked Norwegian Trench across which pipeline construction is intended.

Sub-Plate VLFS (a new type of VLFS using submerged plates) has been proposed for extending the operational area of VLFS to deeper sea with reducing environmental problems. The system consists of a FBSP (floating breakwater using submerged plate) and a VLFS with submerged plate. FBSP not only decreases incident wave height for VLFS but also generates a steady flow which enhances the exchange of seawater around VLFS; and is thus very friendly to sea environment. Here the focus is on the submerged plate built into the VLFS with the partial openings being 5 m long thus enabling the reverse flow on the plate. First extensive experiments are carried out to make clear the characteristics of the wave exciting forces and moments acting on the submerged plate and the fore part of VLFS.

Nowadays huge amounts of petroleum chemicals are transported by ocean-going chemical tankers in particular aromatics - materials of various petroleum products. As these chemicals are low density than water and non-water solubility once a chemical spill has occurred it forms a massive chemical film on the ocean as well as petroleum oil. These chemicals are also toxic and shouldn't be touched or inhaled at high levels. The chemicals are limpid and hard to identify on the ocean with the naked eye even in good daytime light. Also the speed of volatilisation of these chemicals is higher than that of petroleum oil and the pollution is not only in the ocean but also extends to the atmosphere. All this means that these chemical pollutants are more difficult to treat than petroleum oil. Currently there is no practical application for monitoring chemical spill on the ocean.

The investigation into the fire and sinking of the Bahamian passenger ship Sun Vista was conducted by the Bahamas Maritime Authority as flag state of the vessel under the provisions of the Merchant Shipping Act. The Bahamas Maritime Authority investigates incidents at sea for the purpose of discovering any lessons which may be learned with a view to preventing any repetition. It is not the purpose of the investigation to establish liability or to apportion blame, except in so far as it emerges as part of the process of investigating that incident.

During 1980 there were two severe accidents in the Swedish shipping industry, directly or indirectly caused by the shifting of cargo on board ships. This report is the result of research carried out concerning securing cargo at sea. It gives a survey and state conclusions of some accidents due to the shifting of cargo; the rules and recommendations concerning securing cargo on board ships; calculations of accelerations compared for different classification societies; full scale measurements of ship movements; an analysis of material properties in different types of securing equipment; conclusions regarding occurring loads and required safety factor; a survey of securing systems and equipment; calculations of lashing forces for some types of goods and covers securing of road trailers on board ro/ro ships.

This paper describes the models of redundant systems and dependability of power systems which are redundant engine sets with multi-cylinders for propulsive primemover and power generating station of ships and their running data and designing and manufacturing ones. Two kinds of surveyed data show the average number of generating sets per vessel is between 2.5 and 3.5. The JSRIC database is analysed during more than 7 million propelling hours and four kinds of evaluation indices are obtained. (Please note that the poor English used in this paper makes the content almost incomprehensible.)

Challenging emissions legislation requires manufacturers to comply with the decreasing levels of NOx and other exhaust emission species. An Emission Strategy Group has been set up between the three UK diesel engines companies to develop technologies for emission control to enable the group products to comply with current and future legislation. The methodology used both in experimental and predictive techniques is briefly described and the results achieved based on the 6-cylinder RK215 engine are discussed. This medium-speed engine is extensively instrumented and has been modified to enable high-speed in-cylinder combustion photography and gas sampling. A CFD (computational fluid dynamics) program has been adapted and validated by the engine to examine all influencing parameters on NOx control. The results show that significant NOx reduction can be achieved with minimum deterioration in fuel economy by using the appropriate injection system and by optimising the design of piston bowl to improve air/fuel mixing and combustion. Diagrams photographs and graphs appear on pages 10-15.

Subject to the 1982 UN Convention on the Law of the Sea the seas and oceans are classified into the following areas: internal waters territorial sea contiguous zone archipelagic waters straits used for international navigation exclusive economic zone continental shelf high seas and international sea-bed. These areas have international legal status and legal regime of passage for ships. Subject to the Convention the ship's right of navigation can be categorised as follows: right of innocent passage; right of archipelagic sea-lanes passage; right of transit passage right of free navigation; right of concessional navigation. Based on these a brief study on the ship's right of passage is presented. It is concluded that to grasp these legal regimes is of great importance to make good use of the oceans' resources to protect national interests of the sea and to maintain the safety of navigation.

A detailed analysis of causes resulting in phase errors in SAS (synthetic aperture sonar) is used to point out that the primary factors to affect developing SAS can be ascribed to the shifts of doppler centre and doppler rate for the irregular motion of the underwater carrier. Successively and estimating methods in image field based on multi-look processing are analysed and it is proved that these approaches are the better selections for SAS in the presence of both Range Migrant and Partial Aperture. A compensating and imaging complete SAS systemic design based on the auto-focusing method is provided together with a modified Range-Doppler imaging algorithm and a refined compensating step based on the PGA algorithm. Finally it is proved that this design is effective by real lake trial results.

Contents of the book comprise of the following chapters: Moving axes and relative motion (including theories and equations), Oscillations about equilibrium (Lagrange, Bernoulli), Oscillations about a state of motion (steady motion, Watt's governor), Motion of a body under no forces (Euler's and Kirchoff's solutions, the polhode, MacCullagh's construction), Motion of a body under any forces, Nature of the motion given by linear equations and the conditions of stability, Free and forced vibrations (Herschel's theorem, oscillations), Determination of the constants of integration in terms of the initial conditions (method of multipliers, Fourier's rule), Calculus of finite differences (agitation, Sturm's theorems), Calculus of variations (Hamilton, Jacobi, Helmholtz, Poisson theories), Precession and nutation, Motion of the moon about its centre (Cassini's theorem), Motion of a string or chain and Motions of a membrane.

There is a rapidly growing interest in MPAs (marine protected areas) as a tool for fishery management and ecosystem conservation. Evaluation of MPAs plays a crucial role in their management and redesign. This paper attempts to assess biological implications following the establishment of closed areas off East Iceland more than a decade ago with a focus on two for which sufficient data were available. The main question addressed here is whether the area closures have had any effect on the structure of the demersal fish community. The effect of reduced fishing effort on the demersal fish community following area closures in 1993 was analysed for two protected areas off the east coast of Iceland. The observed changes in the fish community in Breiddalsgrunn were reversed within 7 years of the reopening of the area to fishing. The possible causes for the observed patterns of response to area closures are discussed. Materials and methods are presented and results presented and discussed.

The effect of the homogenization heat treatment at 990C for 2h and 50 minutes on the mechanical properties and microstructural banding elimination of the API 5L X65 microalloyed steel was investigated. The investigated mechanical properties were the tensile strength the hardness the impact toughness and the fracture toughness (CTOD). After the homogenization heat treatment a normalization heat treatment at 940°C for 30 minutes was performed in order to refine the microstructure. The specimens in the “as received” condition were extracted from the plate on the L-T orientation longitudinal to the rolling orientation. The homogenization was effective on the banding reduction in spite of the ocurrence of a discrete undesirable ferritic grain growth. Tension and impact toughness properties after homogenization were below those properties in the “as received condition” but fracture toughness was improved.

Surface frost deposition takes place when humid air comes into contact with a surface whose temperature is below the dew point of water vapour in air and below the freezing point. Frost growth behaviour is difficult to model mathematically. A transient inverse geometry heat conduction problem (shape identification problem) is solved using CGM (conjugate gradient method) and BEM (boundary element method)-based inverse algorithm to estimate the unknown irregular frost thickness and shape. Frost growth is estimated using CGM and the results are justified using numerical experiments. It is concluded that frost shape can be estimated using CGM except for the first and last time. The reason for this and the improvement of this are addressed. Finally the effects of reducing the number of sensors and increasing the measurement errors on the inverse solutions are discussed. Results show that the accuracy of inverse solutions obtained by CGM remain acceptable as the measurement errors are increased and the number of sensors are reduced. Frost shape tables and diagrams appear on part of page 860 and continue on pages 861 and 862.

The Nautical Institute is an independent professional body for qualified mariners, whose principal aim is to promote a high standard of knowledge, competence and qualification amongst those in control of sea going craft. This book on pilotage and shiphandling includes an introductory chapter with definitions of terms and a brief history of pilotage, and succeeding chapters on pilotage organisation (including law, training schemes, economics and safety), planning pilotage and pilotage techniques (including optimising instrument navigation, balancing radio and visual navigation, charts and hydrographic publications, operating in ice and using tugs), traffic management (including traffic systems, legal and liability aspects and training), ship handling (including turning corners and manoeuvring, rudder design, performance, thrusters, ship and boat handling in surf and heavy weather, emergencies and notes on handling unusual vessels), bridge design and ship control (including classification of bridges, key factors in design, and propulsion systems and their control).