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Norwegian oil companies have been investigating alternative electrical heating methods for prevention of hydrates and wax plugging the pipelines since 1986. A joint industry project 'Concept verification - direct heating of oil and gas pipelines' took place between 1996-1999. During this work the electrical heating system was proved to be feasible on several fields in the North Sea. The work is continued to implement electrical heating of rigid steel risers. Flexible risers with hot water heating (IPB (Integrated Production Bundles)) have been developed and tested for application in shallow and deep water. Electrical heating of flexible risers is being reviewed in this paper. Different configurations of steel risers are studied with individual and simultaneous heating of random selected risers. Some development work of cable and connector technology is scheduled for application in 2000 m water depth.

As more and more deep water wells are drilled and as the water depth increases hydrate blockages impairing well control equipment can no longer be ruled out. Chemical inhibition of drilling mud is only partially effective. Therefore a sound strategy to prevent and remedy hydrate incidents during drilling operations must be implemented. Various scenarios of hydrate blockage with their possible consequences are examined. Procedures methods and equipment modifications are proposed in order to avoid or to mitigate the problem. The possibility of hydrate formation involving nitrogen gas and the water content(s) of hydraulic control fluid inside subsea accumulators is also discussed. Depressurisation thermal chemical and mechanical methods to remove a hydrate plug are studied together with their pros and cons. The use of existing equipment and requirements for specific tool and well control equipment design is highlighted. Diagrams appear on pages 6 and 7.

Antenna structures towed on the ocean surface remain an important and disadvantaged component of submarine communication systems. The challenge inherent in a seawater environment is to mitigate the effects of seawater coupling with an antenna structure. This mitigation can be accomplished in several ways. One approach is to hydrodynamically shape the tow body in such a manner that seawater is systematically diverted away from electromagnetically active areas. This paper presents an empirically based definition of washover appropriate to towed bodies and further identifies three phases characteristic of most observed washovers. This definition is used as the basis for the development of several concepts intended to mitigate washover. The evolution and evaluation of these design concepts are discussed. A final design configuration of the tow body is presented.

The research and development project on the optimum hull form design of a cargo ship travelling along the Northern Sea Route (NSR) sponsored by Japan's Ship and Ocean Foundation (SOF) has been carried out since 1993. In this project three bow and two stern forms were designed and tested systematically at Mitsubishi Heavy Industries Nippon Kokan and the Ship Research Institute. These systematic experiments were conducted in ice-free water and associated numerical simulation was carried out to evaluate hydrodynamic performance both in calm water and at sea. The experiments are described. Results are provided. Resistance/propulsive performance and seakeeping performance are discussed.

Mathematical models using the linear barotropic hydrodynamic equations that are based on the Ekman theory have a wide range of applications in large-scale shallow water flow field simulations atmospheric boundary layer modelling and industrial rotating flows to described the phenomena of the hydrodynamic circulation. However for shallow water flow problems with complicated shoreline configuration and bathymetry numerical simulations are imperative as no exact solutions are available for complex cases. Only an appropriate 3D numerical model can include various shallow water parameters like wind stress the Coriolis force and tides and effectively simulate the hydrodynamics. In recent years the BIEM (boundary integral equation method) has been used successfully to analyse various types of fluid flow and solid mechanics problems. The fundamental solutions and BIEM model for the solution of 3D shallow water equations have recently been developed. The applications of the BIEM model are described for the analysis of 3D steady-state flow in large-scale shallow water flow field. The developed BIEM model has been compared with analytical and other numerical solutions and found to be feasible and accurate. The problem formulation is presented and results are presented and discussed. Conclusions are drawn.

The hydroelastic response of a floating runway under the action of waves is studied. The Elastic Module Flexible Connector (EMFC) method with frequency-dependent hydrodynamic coefficients is used. It is predicted that the motions are significantly suppressed at most wave frequencies. Predictions are compared with the available results based on the panel method and EMFC method with constant hydrodynamic coefficients. Morison's equation with constant coefficients over predicts the hydroelastic response. It is necessary to extend the present approach to multiple vertical cylinders and endplane forces. It is not clear how to model the three-dimensional flow between two neighbouring pontoon ends other than directly using the hydrodynamic coefficients obtained by the 3-D source distribution method (GFM).

Lidar hydrography has been in use worldwide since the mid 1980s with current systems providing to have unique capabilities particularly in shallow hazardous and remote areas. As the technology has evolved the data rates have increased and algorithms are being developed to extract more information from the data. To complement the higher volumes and variety of data there has been a parallel evolution of the approaches to processing. The whole data workflow of acquisition and processing is being automated and based on an area approach. An effective area-based approach needs to satisfy three important elements and these are identified. The development of the latest generation GCS (Ground Control System) software for the SHOALS-1000 ALH (Airborne Lidar Hydrography) system is described. This includes the background to the development and the modules of the new system.

Ophiolites provide a crucial dimension to understanding the generation of new oceanic lithosphere at mid-ocean ridges. There are some difficulties as ophiolities are no longer active so the evidence from them must be disentangled from the superimposition of all processes that modify new lithosphere and many ophiolites formed in supra-subduction zone environments rather than in open ocean basins. However there are advantages that offset these problems: they can be shown to have formed by seafloor spreading which can be examined by direct observation and sampling. In many ophiolites there is good evidence for high-temperature hydrothermal activity in the form of massive sulfide deposits and associated alteration zones but most have been metamorphosed to the extent that the products of lower temperature circulation are no longer preserved. In Cyprus the Troodos ophilite has for unknown reasons avoided these later changes. Not only is the upper part of the ophilite preserved almost undeformed but in addition low-temperature alteration minerals such as clays and zealites still survive from the time of their formation on the ocean floor.

The problem of image processing for the detection of mine-like targets from sonar data is addressed. This is a challenging problem because of the large variability in both background clutter and object appearance. The results are shown of applying Bulow and Sommer's hyper-complex signal (derived in a similar way to the complex or analytic signal) to texture detection in 2D image data. Three local phase components show the local texture within an image. These components are used to identify anomalies on the sea floor. The method is described. The effectiveness of this approach to texture anomaly detection with real data is explored. Anomalous textures appear as spatially predictable regions of extreme values in the phase components. The phase components are shown to be valuable in identifying regions of a sonar image that contain unusual texture when compared to the rest of the image. This method could be used in a real system as a practical human decision support identifying regions of interest (detections) in images where simple thresholding is ineffective.

ALTEX (Atlantic layer tracking experiment) is presented. This is a long-range AUV (autonomous underwater vehicle) which collects data on the changes that take place in the hydrography and ice cover of the Arctic Ocean. To solve both navigation and data retrieval issues a communication buoy and launcher section have been developed for the vehicle. The vehicle carries up to 12 buoys horizontally in the launcher section. These buoys are launched about once a day. Prior to launch data collected by the AUV is transferred to the buoy via an inductive link. After launch the buoy ascends to the surface and melts its way through the ice. Substantial engineering issues related to the melt-through process including stability and buoyancy have been solved. After the buoy penetrates the ice it uses GPS and ARGOS antennae. The positional information and the data stored in the buoy are then transmitted to a shore station via ARGOS. Planned modifications of the buoy include packaging it so that it could be used by manned submarines for communications and adding an acoustic modem. The latter would allow navigation data or commands to be downloaded to the underwater vehicle.

This paper describes the results of a second series of punch tests conducted on fresh water ice rubble at the University of Calgary. The main objective of the tests was to approximate the in-situ plunge tests in such a manner that failure behaviour of the ice rubble could be studied. The tests were conducted in a rectangular perspex tank which simulated the plane strain mode and made it possible to observe and record the failure process. The previous set of tests (Brown and Azarnejad 1997) provided considerable insight into the behaviour of rubble ice but it was clear that a more rigorous test program was required. For the present program the test equipment was improved so that it provided a better control over speed and less fluctuations in the recorded loads. The main variables were thickness speed and aging. A summary of the collected data regarding the strength properties is presented and the observed behaviour is discussed.

Ice shell is thin and its structural material is snow-ice. It is a kind of ice structure which may be considered to be a contemporary igloo or kamakura. The ice shell is thin and its structural material is snow-ice. It can cover a larger area compared with classical snow-ice structures. This paper describes the studies of structural and constructional engineering aspects of ice shell developed in Asahikawa over the last 20 years together with recent architectural applications for winter leisure spaces covered by many ice shells. A recent application (a large free- shape ice shell with a 20 m span ice dome) at Tomamu in Hokkaido is described. Based on the results of study for the past 20 years the realisation of a 30 m span ice shell is possible. However the reliability of its structural safety and improvement of the construction technique need further study.

A short outline of present profiling capabilities is presented in which important characterisations of acoustic scattering by an ice undersurface are identified and the development of the high-frequency sampling technique is outlined. The latter is an essential element in providing the detail and accuracy required for most modern applications. Quantitative data are provided on key issues determining instrument performance and their implications for optimal use of similar instruments for identifying suitable 'skylites' or patches of open water or thin ice suitable for bringing AUVs to the sea surface for recovery or to carry out operational tasks. Two fundamentally different identification approaches based upon respectively echo amplitude and range measurements are discussed and related to typical AUV operating constraints and needs. It is concluded that neither approach will in itself meet user needs necessitating future efforts toward development of a hybrid identification methodology in accord with suggested operating principles.

Electric Ship Technologies Fast-track initiative has been identified by the IEEE TAB (Technical Activities Board) as one of the ten emerging technological challenges that cut across the fields of multiple IEEE societies as well as engineering societies outside IEEE. The goal of this integrated initiative is to enhance technological advances and use all related applications by combining the collective expertise of various entities and engineering societies who otherwise individually address only part of overall problem. Implementation of this initiative proceeds in two different directions: firstly a bi-annual Electric Ship Technologies Symposium was established as the permanent forum for the exchange of broad spectrum of view points bringing together the knowledge of the entire scientific and technical community working in the field; secondly IEEE Marine Industries Sub-Committee formed new working groups for developing new electrical engineering standards for ships to compliment internationally accepted IEEE Standard 45 'IEEE recommended practice for electric installations on shipboard'. The ESTS symposiums are summarised and IEEE Marine Industries Sub-Committee activities in the development of the new IEEE standards are described.

Safe detection of mines is becoming increasingly important. Since MCM (mine counter measure) is regarded as a dangerous work good use can be made of unmanned platforms like ROVs (remotely operated) and AUVs (autonomous underwater vehicles). Therefore there has been a rapid development in new sensors to be adapted for these carriers in particular the development of SAS (synthetic aperture sonar). A side scan sonar was developed that uses SAS processing to image buried objects. The sonar was tested at a pontoon laboratory. Objects of various types were placed both on the bottom and in the sediment. A 20-30 kHz frequency modulated signal was transmitted from a small transducer and echoes were received by a 1.5 m horizontal linear array. SAS images of both proud and buried targets were shown indicating that SAS is an obvious choice for future mine-hunting sonar both penetrating and non-penetrating. The experiments are described and results are given and discussed.

GP (genetic programming) is used on acoustic backscatter data processing to classify different epi-benthos. The purpose is the provision of an improved classification capability that gives more reliable understanding of acoustic backscatter characteristics of different habitats. The results of this study prove that the acoustic classification capability for the recognition of different seafloor habitats can be enhanced by the adoption of GP in the data processing. With a suitable fitness criterion GP provides an automatic and alternative option to evolve from several initial candidate features into a final compound feature with improved classification performance. Different designs of initial candidate features are also tested to assess the final feature's performance. The execution of GP is illustrated by giving an example of data collected from different seafloor habitats in the Australian coastal waters.

A case study concerning the use of quick lime piles to improve the ground of marine clay for the building of Shin-Wha industrial complex in Korea is presented. Shear tests and model tests are conducted. First a look is taken at the characteristics of quick lime produced in Korea. Next the ground improvement theory of the quick lime pile and the strength properties of the quick lime pile are each considered in turn. After this the laboratory test is outlined followed by an analysis of the test results. Lastly an outline is given of the field test on the quick lime pile followed by an analysis of the field test results.

This paper presents a statistical method for developing a computationally efficient and simulation friendly approximation of a physics model of path loss. This method may also be used to adapt empirical data sets for use in network simulation in the same manner. The method was applied to the output of the Monterey-Miami Parabolic Equation model to assess its impact on the runtime performance of an OPNET-based simulation. Results of that simulation are compared to results from a previous OPNET simulation that simply used distance to determine reception. The simulation results confirm the incorporation of the MMPE approximation does not noticeably impact the runtime performance of the simulation. Anecdotally the simulation confirms earlier results that suggest contention-based access controls without collision avoidance techniques may outperform the typical access technique adapted from wireless radio networks that employs collision avoidance contrary to conventional wisdom.

Previously Platform Management Systems have consisted of centralised control interfacing to Platform Support Systems. Such highly distributed systems rely upon centralised control systems. DINCS (distributed intelligent networked control systems) is a technology that de-centralises the control functionality within Platform Support Systems providing reduced vulnerability and increased survivability through the ability to autonomously isolate and self-reconfigurate. DINCS technology will play a fundamental role in the affordable future fleet. Increasingly the autonomy of the control of essential Platform Support Systems and distributing control intelligence simultaneously increases survivability and reduces workload. Through demonstration on a Chilled Water System the objective is to de-risk DINCS technology and to deliver the benefits of increased survivability reduced workload and reduced through-life-cost to the affordable future fleet.

Comprehensive reference book covering all the industrial fuels and combustion processes as well as the associated machinery that has long been needed. Steam, diesel and gas turbines are dealt with in detail. The full range of distillate and residual fuels used in industrial and marine engines are covered. Coal as a fuel for boilers is covered. The book also examines fuel-related operational problems and also economics of fuels. Contents include the following chapters: Crude oil refining, Lab tests on fuels, Natural gas and LPG, Industrial and marine petroleum fuels, Coal, Steam boiler plants, Fluidised-bed combustion, Industrial furnaces, medium speed trunk piston engines, medium/high speed diesel engines, industrial and marine gas turbines, gas turbine operational problems and applications, fuel storage, handling and systems, liquid fuel treatment and cleaning, combustion of hydrocarbon fuels, deposit formation and corrosion in steam boilers and chimney stack emissions.