Search our collections

High-speed craft are increasingly being pushed to the limits of design technology. Within improved efficiencies in propulsion machinery and propellers the constraining factors on high-speed operation now include dynamic operations and safety in addition to the traditional cal water performance. When operating in a seaway high-speed planing hulls exhibit strong non-linearities. The vertical plane dynamic stability and response associated with such craft is investigated. Explicit expressions for the hydrodynamic forces are developed and modern methods of dynamical systems analysis are applied. An illustrative example is given in which the forced and unforced motions are examined. Parameter studies relating to the following topics are made: the onset of porpoising the magnitude of motions while porpoising and forced motions due to regular waves. It is found that while non-linear effects can reduce the response over that predicted by linear theory these same effects can also be responsible for sudden extreme behaviour.

The book explains all of the welding processes, and assists in selection of the optimum process of any metal-joining situation. The major emphasis is on the arc welding processes since they are the most widely used in industry and construction, and relates all the arc welding processes to manual covered electrode welding which is still the most popular, and explains the similarities and differences. The safety, training, testing and qualification of welding personnel receive much attention. The book explains the different equipment required to use the arc welding processes and assists in selecting and specifying the equipment. Weldability of metals is discussed along with the selection of filler metals and shielding methods for joining them. The development of welding procedures and the use of welding schedules for automatic welding is explained. Design considerations for welds are covered and cost estimating and calculating is presented in detail. Weld quality and evaluation including non-destructive examination, testing and quality control and weld problems are given broad coverage. Finally, the special application and the use of welding by different industries is included.

Traditional Failure Mode and Effects Analysis (FMEA) uses the Risk Priority Number (RPN) ranking system which has been criticised for having several drawbacks. This paper addresses these drawbacks by proposing a modified method using fuzzy approximate reasoning with the integration of expert judgement and grey relation analysis to rank the risks. A fuzzy rule base is generated using the fuzzy multi-expert weighted system. Grey relation analysis is then used to obtain a risk priority based on the relative importance of causes. The proposed method is demonstrated for a fishing vessel and the fuzzy rule base is developed using selected experts within the fishing industry.

The engineering of control systems for ship propulsions is becoming more and more complex. To realise the variability in functions a special software has to be developed. A new approach for a modular control system for ship propulsions is presented. This is based on modular intelligent hardware devices which can communicate with each other via an electrical bus system. Using these modular devices it is possible to design a cost-optimal hardware to control the different types of applications. Software variability is achieved by the development of a modular control software. Adaptations to different kinds of propulsion systems are carried out by simply adjusting a set of parameters. Replacing the software development by a simple parameter adjustment saves engineering costs. Failure analysis and diagnosis of this system as well as the parameter adjustment is carried out with service PCs. Remote service functions are included to guarantee maintenance worldwide.

Transcript of the tenth Seatrade Conf held in London 30 - 31 March 1982 Papers are Shipbuilding technology for safety and economy of marine transportation Risk an inevitable factor in maritime safety Regulate or not the unregulated regulations An oil companys view - the penalties of being responsible Cooperation and development in Arab shipping Vessel finance and the open registry system Anatomy of a developing fleet Caribbean trade and shipping development - a Trinidad and Tobago perspective US shipping policy in an international environment US shipping policy and the worldwide scene American shipping and its effect on the international liner industry Developments and new directions in ship design - a ship owners point of view Residual fuel - an oil company perspective A shipbuilders view of fuel economy Marine propulsion - what scope exists for further fuel economy

Long-term high resolution sea water temperature data sets are essential in studies involving for example fish growth rates changes in marine population densities and fish mortalities as well as in assessing large-scale environmental changes. An examination is presented of variations between satellite derived surface sea water temperatures from the National Climatic Data Center (NCDC) charts and sea water temperatures obtained in situ at 7m and 14m the depth of many Caribbean inshore benthic communities. Significant differences were found between these data which increased with depth. Consequently extrapolation of subsurface sea water temperature from NCDC charts based on AVHRR measurements must be used with caution in shallow coastal Caribbean tropical waters.

Viscous damping due to drag on mooring lines and risers is seastate dependent and significantly affects the motion of a floating platform in deep water particularly in everyday seastates. This in turn impacts design of the risers which are typically controlled by fatigue. The dynamic interaction between the platform mooring and risers cannot be evaluated using conventional uncoupled analysis tools where each is analyzed separately. Rather coupled analysis is required to provide a consistent way to model the drag-induced damping from mooring lines and risers. A description is given of a coupled frequency domain approach (RAMS - Rational Approach to Marine Systems) for calculating the dynamic response of vessel mooring and risers.

In this paper it has been shown that slowly-varying wave drift forces may affect the nonlinear dynamics of mooring systems in numerous qualitative ways. Based on the design methodology developed at the University of Michigan it has been possible to identify seven different response phenomena. One of those is resonance which has been reported in the literature for many years. The university's approach has revealed such phenomena as destabilization of the principal equilibrium genesis of limit cycle around the principal equilibrium genesis of alternate equilibria as well as their destabilization and appearance of limit cycles around the alternate equilibria. The reverse effects have also been revealed that is stabilization of unstable equilibria and disappearance of limit cycles. The list of phenomena revealed is by no means complete. The next logical step in revealing such complex nonlinear dynamic phenomena is to develop the method of harmonic balance for mooring systems which was briefly introduced in this paper.

For high-resolution radars (as the ones used for radar imagery tasks are) sea clutter is difficult to characterise especially for low grazing angles. According to the physical model of sea surface the echo signal is best described as the product of a Gaussian process with rapid variation (the speckle component) and of a slow varying component (the underlying component). The K-compound distribution is used for the statistical characterisation of the clutter echo. Standard target complex signature simulations techniques (based on the well-known scattering centre model or using geometric primitives) are combined with synthetic sea clutter allowing us to generate realistic signals. The MUSIC 2D super-resolution reconstruction method presented in the paper is used to generate ISAR target images. A comparative study of robustness of MUSIC and Fourier type images is then performed. The obtained results show the validity of both clutter simulation engine and super-resolution reconstruction methods. The problem of naval targets subject to particular simulation conditions is also discussed in detail.

The multidisciplinary conversion of ocean wave power for a site off the Australian East Coast is considered. An OWC (oscillating water column) capture device with a parabolic collector wall converts incident wave power to pneumatic power while subsequent conversion to electricity is facilitated by a new air turbine-generator unit. A simple methodology is presented for estimating the air turbine's output and longer-term productivity according to its sizing. Consequently a methodology is defined which can be used in determining the optimal turbine diameter for a given wave climate and capture device performance. It is predicted that a 0.73 m turbine on the 10 m wide Australian plant will have a rated capacity of 300 kW and will export 770 MWh annually at an average rate of 86 kW.

Pipeline bundling is an attractive solution for deepwater development due to its insulation performance and cost effectiveness. However the multiphase flow and thermal analysis of bundle systems are very complicated and the information available in the open literature is limited. The aim of this paper is to understand the thermal interaction among the flowlines and to investigate its effect on the characteristics of multiphase flow in the product line. A computer model is developed for analyzing steady and transient multi-phase flow and heat transfer in a three-flowline bundle with active heating. The bundle system used for modeling is a pipeline bundle system installed in the Gulf of Mexico.

Detailed visualization of three-phase oil/water/gas flows has been carried out in a l0-cm ID acrylic pipe with four 9-D 90o clear PVC vertical bends. The experimental system simulates multiphase flow in pipelines experiencing topography changes such as road or river crossings. Flow regimes and characteristics have been studied to determine the effect of abrupt elevation changes on multiphase flow. The flow characteristics have been noted at different velocities for nine locations along the system. Different flow regimes are observed in each location for a given flow rate. Corrosion rates in these regions have been determined and have been found to be signiticantly higher than that for horizontal flow at the same conditions.

The first application of multiphase meter technology in Brazil happened in June 1997 when a unit was deployed inside of a guidelineless deployable/retrievable module in the subsea production manifold MSP-DL3 (circa 450 m of water depth - WD) in the Albacora field; a second happened on a deck of the P-34 Floating Production Storage and Off-loading (FPSO) vessel and future meters (subsea and topside) are already planned. The expected success of such deployments specially the deep water one shall not only set a milestone in Brazil's industry but also pave the way for a wide use of this technology. This paper will deal with what has been carried out in Brazil for the multiphase flow metering application the main aspects that drives PETROBRAS in contributing to the implementation of such a route and in some extent information related to the subsea pioneer deployment made as a result from the non-exclusive PETROBRAS and FLUENTA (Norway and USA) Technological Co-operation Agreement in this technological route.

The development of NEPTUNE (the north east Pacific time-series underwater networked experiment) is presented. This is being designed as a long-lived highly reliable underwater observatory to instrument the Juan de Fuca tectonic plate. NEPTUNE will use standard telecommunication fibre optic cable to provide a communication and power infrastructure. A high- speed data link and high power will be available at nodes spaced over the tectonic plate. Each node will act as a local relay point for scientific instruments and experiments that will be deployed on the sea floor and in the water column above it. A current design of the observatory is presented including descriptions of the key subsystems. Innovative approaches are being developed to provide high power broadband communications data archiving and accurate timing and control. The methodology for ensuring the reliability and affordability of the observatory is discussed.

During the lifetime of the National Science Foundation's Coastal Ocean Processes program four experiments were conducted on the US West Coast in the northern California Current System. Although each project had a unique scientific focus all four addressed the mechanisms causing eastern boundary current systems in general and the California Current System in particular to be biologically rich from phytoplankton to apex predators. Taken together findings from these projects provide new insights into the canonical view that upwelling systems are simple wind-driven "conveyor belts" bringing cold nutrient-rich waters to the well-lit surface ocean where biological organisms flourish. In this article new insights and advances gained from these programs are highlighted. After some introductory information a look is taken at the role of nutrients followed by nitrogen supply the importance of retention over the shelf and plankton community structure.

A series of F-PAHs (monofluorinated polycyclic aromatic hydrocarbons and dibenzothiophenes) are synthesised and it is found that they provide a promising set of internal standards for environmental and petroleum analysis. An additional important advantage is that there are no known natural sources of these compounds. Due to the comparable physico-chemical properties of F-PAHs and their parent PAHs F-PAHs have a potential use as surrogate standards to monitor recoveries during extraction clean-up and other sample-handling steps in PAH analysis. The chromatographic behaviour of monofluorinated PAHs in LC and GC can be explained on the basis of dipole moments and London forces. The suitability of F-PAHs as internal standards in GC-MS and HPLC-UV is shown.

The use of devices to prevent the passage of flames on tanker vessels and barges is discussed. Modern tankers usually feature either common venting or individual venting systems while more advanced tanker design might have duplicate systems. One requirement in the IMS standards concerning flame arresting equipment is the elimination of hammering in high velocity vents as it can cause damage to equipment and failure in the nature of flame passing through the vent. To this end guidelines are provided for the design of venting systems to suit tankers with extensive vent piping typically chemical carriers. Certification of flame arresters is also discussed.

Contents I J van Loo, 'For Freedom and Fortune: The Rise of Dutch Privateering in the First Half of the Dutch Revolt, 1568-1609' p.1 Neil Ashcroft, 'British Trade with the Confederacy during the American Civil War' p.15 Edgar Martin, 'Shipping, Politics and the River Danube: The Commissions of the Danube, 1856-1948' p.23 Riccardo Busetto, 'Captain Edward Chichester and HMS Immortalite in Manila Bay during the Spanish American War' p.31 Lynn Dunning, 'The Shipping Company Poster' p.39 Elizabeth M Bardolph, 'Power, Prejudice and Putrefaction: The Elimination of Scurvy from the Royal Navy, 1747-1796' p.59 Rodney H Taylor, 'Cholera and the Royal Navy' p.59 Colin Singleton, 'The Competence of Nineteenth Century Masters and Mates' p.69 R Mumby-Croft, 'The Working Conditions on UK Trawlers, 1950-1970' p.77

Wartsila has a range of technology solutions to meet the challenge of future emissions control for Sulzer low-speed engines. These new technologies in the fields of fuel efficiency exhaust emissions reduction and cylinder lubrication are reported. They have either recently been introduced or are currently under development by Wartsila for Sulzer low-speed two-stroke marine diesel engines. The improved waste heat recovery of the newly developed Total Heat Recovery Plant can contribute fuel savings of more than 11% through adapting engine tuning to provide more exhaust energy which is then recovered in both a steam turbine and an exhaust gas turbine. The first Total Heat Recovery Plants are already in service. Waste heat recovery also has a major impact on reducing exhaust emissions including CO2.

The technical and economical advantage for fast ferries that are powered by lightweight medium-speed diesel engines is shown by a comparison of two identical vessels powered by either typical medium-speed engines with a specific weight of approximately 15 kg per kW or by the new MAN B&W engines type 16V 40-50 with a specific weight of 9.5 kg per kW. While fuel oil consumption rises drastically with increased speed requirements on NOx reduction technologies become more demanding. The HAM (humid air motor) provides a very attractive solution and this technology is discussed.