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This paper describes a series of experimental studies on the dynamic behaviour of buried pipe in liquefied ground by using a shaking table model test. The test was performed to examine the external forces acting on the pipe of which one end was connected to a stationary structure during the liquefaction of ground. The connection joint of pipe to the structure was either a ball type flexible joint or a fixed joint. Also in the test the direction of shaking was varied from the longitudinal direction to the direction normal to the pipe.

In this paper the influence of the transverse location of the rudder on lift drag stall and on the interaction phenomena is discussed including the effects of the wake field and the propeller induced velocity field on the flow conditions in the rudder plane. Analysis on the relevant frequency range of rudder motions for fast non-planing monohulls operating in waves is presented. The dynamic effects of steering on the rudder forces are studied.

The protective behaviour of chromia-rich scales grown on stainless steels is mainly dependent on their chemical and mechanical properties. In situ growth and thermal stresses measurements on chromia-rich scales grown on ferritic stainless steels are reported as well as adhesion measurements of these scales on their substrate. Experimental procedures are described and results are presented and discussed. Finally conclusions are drawn.

It is expected that construction work on a very large floating structure similar to the MEGA-FLOAT will increase. The working characteristic and the effect on board of oscillating ships by measuring the finger pulse is investigated. The effect of oscillating working conditions on the human body is investigated. Experiments are carried out to analyse the trend of decreasing work efficiency and the effect on workers' motion using various methods. The first experiment investigates the effect of oscillation upon physical motion. This experiment considers walking motion on the passage. The next experiment examined considers the effect on sensitive work. In this experiment the amount of the water poured into the empty bottle from the kettle is observed. The third experiment evaluates the relation between oscillation and thinking capability resulting from a simple test of calculation. Results of this study have shown that the decrease in work efficiency is closely connected to the delayed reaction of the human body with the oscillation.

Biofuels are already influencing the shipping trade but are designers and ship owners thinking far enough ahead to accommodate their influence on the world fleet of the future? The impact of biofuel industrial growth with relation to shipping is not well analysed and there is much contradictory information making the future very difficult to predict. This lecture performs a multidisciplinary analysis of biofuels covering their background the economic political and social drivers for their use and the consequential impact on ship design and operation with the intention of promoting further debate on both the effects of biofuels as a fuel and a cargo for ships. Biofuels are described under the commonly referred to three generations. And comparison with the automobile and aviation industries use of biofuels is drawn Analysis of the demand of both the European and Asian sectors is covered. The impact of these new technologies on shipping routes and port facilities is also discussed. This analysis finds that current political legislation on biofuel use is dependent on technology not economically available.

This paper presents experimental results of vortex-induced oscillations of an inclined circular cylinder mounted on an elastic base. Models are mounted on an air-bearing elastic base instrumented with strain gages accelerometers and a load cell. The experiments were carried out on a water channel facility at NDF-EPUSP. New measurements on the dynamic response oscillations of this inclined cylinder due to vortex-induced vibrations (VIV) are compared with previous experiments on a vertical cylinder. VIV is investigated by conducting experiments in two ways. First the cylinder is maintained vertical on the elastic base with a uniform current normal to its axis and the response curve is obtained. Subsequently the investigation is carried out changing the angle of inclination from 0 to 45 degrees in relation to vertical.

The RST (rotary separator turbine) and skid package is used in the first offshore field trial of this technology on the Ram-Powell TLP (tension leg platform) located in the Gulf of Mexico. The RST is a compact gas-liquid separation and power generation device designed to operate on process fluid pressure. It offers a potential 50% weight and space savings over conventional vessel separators and is under development for use on minimum footprint facilities. The purpose of the trial is to verify the separation and mechanical characteristics in actual production conditions. An integrated test package installed on the Ram-Powell TLP in June 2000 tested the RST on actual well production. Photographs and diagrams appear on pages 5 to 6.

Bottom properties have a major influence upon shallow water acoustics especially for very low frequencies. The use of broadband low frequency signals received on sparse arrays has been shown to lead to robust and efficient estimations of seabed properties. The results of a geoacoustic inversion process both on simulated data and on the INTIMATE'96 experimental data set is presented. The process is based on the use of the measured impulse response on a single hydrophone and aims to build a geoacoustic representation of the bottom which is sufficient to predict acoustic losses for sonar purposes. Firstly the INTIMATE'96 data set is presented. Then the process on simulated data is presented and the validity of the approach is examined. It is then applied to the experimental data set and finally the basis of an equivalent medium concept is derived.

River dykes and road embankments are often damaged during earthquakes. The main cause is considered to be the liquefaction of the foundations the behaviour of which is not yet fully understood. Based on the results of past studies an embankment's foundation is divided into three areas to examine the failure modes. One-dimensional on-line seismic tests conducted by a combination of element tests and computer seismic response analyses are carried out on areas of actual river dykes damaged by earthquakes. The cumulative lateral displacement values obtained by the tests are compared with the measured embankment-crest settlement data. This shows that the sliding failure due to liquefaction under the toe of slope of such an embankment is the most detrimental of all failure modes.

This paper summarizes the objectives and some progress of an on-going research project related to mechanical buckling collapse testing on aluminium stiffened plate structures sponsored by Alcan Marine France and Ship Structure Committee USA. unlike stell structures the experimental test data on buckling collapse of aluminium stiffened plate structures is very lacking. Existing test data has mostly been obtained for plate-stiffener combination models or column type models rather than single or multi-bay stiffened panel models with the focus on some specific types of collapse modes. No specific information regarding the fabrication related initial imperfections and softening in the heat affected zone (HAZ) due to welding is found in the literature. To address these issues a research project which involves an extensive test program is on-going under the responsibility of the first author. Design of the test structures and the methods for measuring fabrication related initial imperfrections are addressed in the present paper. Some preliminary results are presented although the test program is on-going and the detailed test results will be reported separately in near future.

When a ship with a wide immersed transom stern runs on a deeper draft than its design draft forward-oriented wave breaking often occurs just behind the transom. This accompanies large loss of momentum and accordingly large hull resistance. One of the most important factors affecting this is the bottom profile form of the transom stern. However this part of the hull has not been afforded a great deal of attention as it is regarded as only a limited local part of a hull. An analytical method is developed to estimate the effect of the factor on stern wave resistance. Next model tests on typical bottom profile forms are carried out to verify the method and to obtain data for discussion of the effect. Finally characteristics and mechanism of the effect are clarified.

The wave force on a seawater intake well model consisting of a perforated circular caisson (500mm diameter) encircling a vertical suction pipe (50mm dia) is measured experimentally. The effect of porosity of the caisson wall incident wave height and wave period on the in-line forces on the caisson and suction pipe is investigated. The porosity of the caisson was varied from 4.54% to 19.15%. Waves of wide ranges of heights and periods were used. The wave forces on the outer caisson & inner cylinder water surface fluctuations in the interior & exterior of the caisson and wave run-up on the outer caisson & inner cylinder are studied. The present paper includes the wave forces on the outer perforated circular caisson and inner circular cylinder due to regular waves only.

Symposium held in Newcastle 15 October 1974 and in London on 17th October, 1974, on Automation in Ships.

Inmarsat regularly puts its FleetBroadband service through stringent maritime field evaluation (MFE) and earlier this year FB150 was put through its paces on board Skagern a coaster that found it could not depend on 3G connectivity alone.

The coastline of Bangladesh is one of the areas of the world that is most exposed to extreme meteorological and hydrological conditions. Cyclones and tidal surges cause devastating effects. Forests are always considered a low-cost and natural protection to the lands subjected to attack of current and surge. Here development of mangrove forests is being considered as one of the measures of coastal protection for this area. The pilot model developed for this study is used to assess the effect of afforestation on the storm surge height and to develop a basis for having the necessary engineering judgement in designing the minimum amount of forest cover to reduce the height of the embankment system. The study was done based on the results of a 2D nested surge model. The model has been developed based on the general numerical model named MIKE 21 and specific information on the area that the model covers. The model has been calibrated for normal hydrological condition as well as for cyclonic condition. The model results show that the laid afforestation has reduced the surge height around the southern end of the island to some extent. But a reverse impact has been found at the north-eastern corner of the island due top afforestation.

There are an increasing number of liquefied natural gas ships and oil tankers that are intended for navigation in ice and cold climates, and as such, there is a necessity to assess the risk of fatigue damage to these ships. A significant aspect of the fatigue assessment is the performance of steels when subject to low temperatures. This paper presents the results of an investigation on the fatigue strength of welded steel joints at low temperatures and discusses some of the associated issues. The paper presents the results of cyclic tension fatigue testing of welded specimens made from AH36 and DH32 steel grades under room and cold temperature conditions. Nominal fatigue curves for these specimens and crack lengths as a function of loading cycle number are also provided. The fatigue strength of welded specimens of DH32 and AH36 steel grades has been obtained. The data can be used for the evaluation of the fatigue life of ship structures manufactured from the specified steel grades and can be used for establishing whether measures need to be taken to reduce the risk of fatigue damage in the structural elements of ships trading in cold climates.

Coral reefs in tropical and subtropical ocean systems have recently experienced severe environmental problems due to mass coral bleaching events which occurred worldwide in 1997 and 1998. Water temperature is known to be a main factor of coral bleaching and so it is therefore important to clarify thermal environments and heat balance in coral reefs. The thermal environments in coral reefs are significantly influenced by heat fluxes through sea surface and bottom due to shallow water depth and high transparency of water in coral reefs. Thermal influences from inland and offshore also have a major effect on the heat balance for reef water. The focus here is on the effects of sea bottom on thermal environments in a coral reef. An intensive field observation was carried out at Shiraho reef on the southeast coast of Ishigaki Island Okinawa Japan. The heat budget analysis for reef water was performed with special attention to the sea-bottom effects. The heat balance for reef water shows that the sea bottom is of crucial importance to thermal environments in a coral reef. The heat budget analysis of reef water shows that the treatments of the sea-bottom effects can appreciably affect the results of the heat budget analysis.

Shallow water and surf zone target detection-localisation is very problematic due to severe sensor limitations imposed by the environment. The Navy is relying more and more on AUVs (autonomous underwater vehicles) to accomplish this difficult shallow water task and to keep human divers out of harms way. To augment the AUV's detection and localisation capability various sensors and sensor suites are being investigated. One technology that is minimally affected by the harsh shallow water environment is magnetics. The early stage efforts to augment the AUV with an enhanced magnetic detection-localisation capability that is inherently unaffected by environmental conditions found in the shallow water environment is considered. The focus here is therefore on the collection of magnetic noise data from various candidate platforms. The first and major objective is to document the setup and conditions surrounding the collection of the data and to compile a gross comparison of the magnetic characteristics exhibited by these platforms. A secondary objective is to begin to look at techniques that are useful in mitigating the magnetic noise generated by the platform and detected by the proposed magnetic sensors that will be integrated on the AUV. The emphasis during this phase is to determine which mitigation techniques are viable and to identify potential locations for the auxiliary mitigation sensors. Based on the findings during the initial measurements phase suitable auxiliary sensors are placed at select locations and signals from these sensors are processed and used for noise reduction dX36627 Measurement of marine environment around Mega- Float model in Tokyo Bay M Fujino ; Y Kyozuka ; S Tabeta et al.

It is very important in pipeline design to investigate the stability of an unburied offshore pipeline under severe storm conditions. The cyclic movement of pipeline due to drag and lift forces caused by waves and currents will lead to pore pressure build up in the seabed around the pipeline. The pore pressure accumulation will reduce the effective strength of the seabed soil and degrade its bearing capacity. In particular an increase of horizontal displacement of the pipeline may lead to a sudden breakout which has a serious influence on the safe operation of the pipeline. It is therefore very important for design engineers to evaluate the stability of an unburied offshore pipeline by considering pore pressure accumulation in the seabed soil around the pipeline under severe storm condition. Therefore this paper investigates the stability of an unburied offshore pipeline resting on carbonate sand under severe storm conditions. Pore pressure accumulation and pipeline movement during cyclic loading caused by waves and currents are numerically investigated. Both drag and lift forces are numerically obtained for 100 years return period storm condition using the Fourier decomposition method. Non-linear spring element is used to simulate a slip phenomenon between pipeline and seabed. The effects of both bi-linear and tri-linear spring element models on pipeline movement and pore pressure response are numerically investigated. Pipeline movement during cyclic loading greatly depends on the mechanical properties of non-linear spring element. In addition pore water pressure response as wellX31721 Stability and Ballast Control M Hancox

When considering maritime safety marine simulation training and maritime casualty investigation are interlinked key issues. Marine simulation can contribute to effective realistic training depending on data gathered from marine casualties. Marine casualties on the other hand can be studied in simulators where solutions for existing safety gaps can be developed. Both issues - simulation and casualty investigation - have an important impact on MET. Improved realistic training contributes significantly to the elimination of human failure. The links between simulation casualty investigation and MET are highlighted. Safety issues to be investigated in more detail in engine room simulators are listed and approaches as to how this can be done are suggested. Firstly the paper focuses on how simulators are used in MET. This is then followed by a short introduction to the creation of simulation scenarios together with an analysis of data needed for this purpose. This data analysis is underlined by some examples from casualty reports. Suggestions are made as to how simulation can contribute to investigating those issues. These suggestions are followed by conclusions in which reference is made to existing networks and initiatives that can be used e.g. for data and experience exchange to facilitate research and training.