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Current IMO regulations require life rafts to be tow tested only in calm water. In real evacuation situations life rafts are deployed in the prevailing environmental conditions with wind and waves. Added wave resistance is small at low wave heights but increases non-linearly with increased wave height. If life rafts are to be towed in moderate seas (up to 4 m significant wave height) tow force estimates based only on calm water tow resistance become less reliable. Tow patches towline towing craft etc. also need to be designed to withstand dynamic wave loading in addition to mean load. Therefore mean tow force tow force variation and maximum tow force are important. A full-scale 16-person commercially available SOLAS-approved life raft was towed in the tank in upwind head seas with significant wave height of 0.5 m. The measured tow force showed that it could be treated as a linear system with wave amplitude by demonstrating that tow force is mainly inertial and follows a Rayleigh distribution. Therefore extreme-value statistics used for waves can be applied to developing equations for predicting tow force. A method is proposed to predict life raft tow force at different tow speeds and in various sea states

Fretting is a process of material damage which results from the rubbing of two contacting components with small-amplitude oscillatory movement. Fretting is known to cause premature fatigue failures in structural elements such as riveted or bolted lap joints steel ropes and cables and the contact region of dovetail joints of gas turbines. In addition to material properties the fretting damage is governed by factors such as contact geometry normal load slip behaviour loading frequency and surface roughness. Fretting results in a scar oxides and debris and leads to material transfer surface plasticity and surface cracking. The possibility of fretting damage in pressure armour wires of flexible pipes has been investigated. A novel experimental facility which is capable of simulating nub-valley contact conditions with dynamic slip representative of actual pipe loading has been developed. The test setup is equipped with a state of the art data acquisition system and a controller with transducers to measure and control the normal load slip amplitude and friction force at the contact in addition to the hoop stress in the wire. Tests were carried out with selected loading and the fretted regions were examined using an optical microscope. Results show that the magnitude of contact loading and the slip amplitude have a distinct effect on surface damage. Surface cracks originated from fretting scar were observed at very high contact loads in mixed slip sliding while surface damage predominantly due to wear was observed under gross slip. The position of surfaX44612

Petrobras is going deeper and some fields are feasible only if the production platforms are installed in ultra deep waters close to the wells. In one case in Campos Basin for example the platform will be installed at 1255 m water depth and the solution to allow the production is based on the evolution of flexible lines for high pressure and high loads. For the oil export line however a steel rigid line was chosen due to the large diameter. Some analyses were performed in order to make feasible the installation of an 18-inch SCR export oil line. Due to fatigue loads the free hanging catenary configuration did not match with API RP 2RD recommendations so Petrobras decided to change the original shape to Lazy Wave in order to reduce the top loads and increase the fatigue life. But some configurations are not feasible to install. This article presents the steps made to reach a configuration that will make feasible the installation of this riser in parallel to the static and dynamic analysis to maintain the stresses in an allowable level in accordance with API RP 2RD.

Petrobras is going deeper and some fields are feasible only if the production platforms are installed in ultra deep waters close to the wells. In one case in Campos Basin for example the platform will be installed at 1255 m water depth and the solution to allow the production is based on the evolution of flexible lines for high pressure and high loads. For the oil export line however a steel rigid line was chosen due to the large diameter. Some analyses were performed in order to make feasible the installation of an 18-inch SCR export oil line. Due to fatigue loads the free hanging catenary configuration did not match with API RP 2RD recommendations so Petrobras decided to change the original shape to Lazy Wave in order to reduce the top loads and increase the fatigue life. But some configurations are not feasible to install. This article presents the steps made to reach a configuration that will make feasible the installation of this riser in parallel to the static and dynamic analysis to maintain the stresses in an allowable level in accordance with API RP 2RD.

During the past few decades the need for electric power and fresh water requirements has turned man to using temperature difference in deep sea around the world. The design of a 0.25 MLD (Million Litres per Day) low-pressure desalination plant in 150 m water depth using a TLCP (tension leg counterweight platform) consisting of a 10 m diameter hull 1 m diameter cold water pipe with counterweight and vertical taut mooring has been carried out. A 1:50 scale model of the TLCP is tested in the 30 m x 30 m x 3 m wave basin. The tensions in mooring lines are measured using load cells. The coupled analysis of the TLCP is studied using the NOAS (non-linear analysis of offshore structures) program developed at IIT MADRAS. The measured tension response of mooring line compare well with numerical results. The Surge Heave Pitch and Tension response amplitude operators for the TLCP obtained from numerical study are observed to be within the permissible limits for the operational wave condition whereas the TLCP performs satisfactorily for the survival wave condition. The numerical and model studies are carried out for regular waves. The effect of counterweight and pretension on platform motions is studied.

Statistical methods are adopted to understand the wind and wave characteristics over the Hsinchu Water where there are three observing pots: the coastal wind station the Hsinchu data buoy station and the Kuokwang oil platform station. Field data from 1998 and 1999 are used for analysis. The wind speeds in the file were measured at the land-based Hsinfung weather station Hsinchu data buoy station and Kuokwang oil platform while the field wave data were measured at Hsinchu data buoy station and Kuokwang oil platform. In order to investigate the variation of wind directionality and wind speed due to the topographic effects in the offshore region near shore region and coastal zone wind rose analysis is firstly applied to the field data measured in different stations. Secondly the comparison of the 3m-wind speed which has been transformed according to the wind profile equation in different stations is carried out. The statistical analysis of waves is mainly focused on the discussion of the statistical wave heights and periods distributions in Hsinchu region. Comparison of wave heights and joint wave heights and periods distributions in different stations are made. Regression analysis and Markov Chain analysis are also made to establish the correlation of wave heights in Hsinchu data buoy station and Kuokwang oil platform.

Roll motion is one of the most important responses of a ship in waves. Potential flow base theories although they reproduce the heave and pitch motions very well are much less effective in predicting the roll motion due to the negligence of fluid viscosity. This shortfall is usually compensated for by introducing a viscous roll damping component. However it is not even simple because of non-linear characteristics due to the effect of fluid viscosity and strong dependence on the forward speed of a ship. Moreover the appendages such as bilge keels and rudders make the problem much complicated. The present study shows URANS (Unsteady RANS)-based approach to simulate the free roll decay motion for a ship. The WAVIS (Ver. 2.0) code is extended to simulate roll decay motion which is originally developed for the predictions of resistance and propulsion performance of a ship in MOERI. The numerical simulation is applied to the DTMB 5512 model ship which has the experimental results obtained in INSEAN (Italian Ship Model Basin) towing tank. Roll decay motions are simulated both at the Froude number zero and 0.138 with and without bilge keels. The results show that CFD-based approach is very promising to predict the roll damping force.

Risk based inspection of process plant is a technique where inspection is concentrated on those areas which are most likely to fail and create problems if they do. The type of inspection carried out is in direct relation to the anticipated failure mode. In 1994 British Gas determined that the application of a risk based inspection approach to the two installations in the Rough Gas Field would have several benefits including improved operational efficiency. During 1994 and 1995 British Gas and the author's company worked closely together to implement the riskbased inspection approach in the Rough Field. This has required (1) the preparation of written schemes of examination; (2) an authoritative review of the pressure systems including the assignment of grades and conditions to all of the piping and pressure vessels; (3) an Operational Critically Assessment of all piping and vessels to determine the consequences of failure probability of failure and the failure mode for each item; (4) development of new inspection schedules and intervals; (5) development of a review and feedback system so that inspection results may be used to alter the grades of piping and equipment and the subsequent inspection intervals. This development has been agreed with the certifying authority and has resulted in some inspection intervals being greater than the traditional five year certification limit.

The Global Ocean Data Assimilation Experiment (GODAE) has addressed the necessary technological development for data assimilation which is a critical choke point within the process of providing meaningful information to many people encompassing a wide range of applications. One of these application areas is for Navies throughout the globe. Major use by operational Navies of oceanographic information through numerical model forecasts initialized by analysis of global satellite and in situ data sets has allowed substantial advancement in the safety of operations and search and rescue. The importance of the information relayed to ships across the globe is reflected in the dedication of large resources to daily production and dissemination. Not including the costs of observational systems there are large investments associated with personnel required to ensure that each step of the processing is properly conducted every day. The communications and computational hardware requirements to ensure products are delivered require enormous effort and costs to implement. The importance of the information on which decisions are made daily by the worlds Navies throughout the worlds oceans is reflected by the commitment of these substantial resources to ensure the GODAE technology enables a new level of capability. Some of the major applications that are common throughout Navies of the globe are examined in this paper.

The Pacific Ocean Shelf Tracking (POST) array was initially conceived and planned as a single continental scale acoustic tracking system for direct measurement of the marine movements and survival of animals in the ocean. With the success of the demonstration phase POST is now transitioning into a single integrated global system of compatible arrays distributed throughout the continental shelves of all continents. In summary POST has demonstrated that a large-scale system to track fish in the ocean is feasible. Equally important the fates of multiple fish stocks (migration routes and speed of movement plus survival) were simultaneously accounted for during their downstream and early ocean migrations demonstrating that the system can be made economical because of its ability to support many studies at once. Having demonstrated the technical feasibility and biological importance of the data collected POST's near-term goals are to deploy units that can permanently stay on the seabed for long-term monitoring along the continental-shelf and to increase the scientific understanding and need for the information that will be collected.

The recreational boat market is becoming global. Many countries that used to have protective tariffs for their internal market are slowly decreasing their important rates and becoming more attractive markets for worldwide powerboats and sailing yacht builders. The Boat-2000 database is introduced. This database was created to gather and stord information from manufacturers and trade publications dealing with recreational boats. It is not a commercial system and was created to integrate recreational boat information and commercial design software for academic research. Its applications in market study as well as power and sailboat design are used to show the system capability for integrated design. The database includes specific naval architecture software and other functional software. It was developed in Microsoft Access and has four main objectives: to be a simple and useful tool for boat market analysis; to have the ability to arrange the design process; to include different sorts of boat information as test results and survey reports and; to integrate commercial software in the boat design process. The focus here is on database systemisation and shows the Boat-2000 application in two case studies. Graphs and tables illustrate the actual available dates. Some future implementations are identified.

FRP laminated plates are widely used in high-speed ships and aircrafts as: they have high specific stiffness and strength. In particular GFRP laminated plates are frequently used because their production costs are relatively cheaper than that of CFRP. However GFRP laminated plates are characterized by easily allowing delamination to take place. Therefore it is important to investigate the reduction in compressive strength of GFRP plates caused by the delamination. The buckling tests and FEA (FEM analyses) of the GFRP laminated plates with initial delamination under thrust are carried out. The GFRP plates which consist of E-glass fibers (chopped strand mat and balanced woven roving) and unsaturated polyester resins are considered. The buckling test is carried out for the clamped rectangular plate with the initial delamination at the centre or the corner of the plate. Elastic buckling behaviour is simulated by FEA using shell elements and the energy release rate along delamination tip is calculated to examine the growth of delamination. The applicability of FEA is investigated through a comparison with buckling test results. A series of FEA is carried out considering various size and location of delamination and the influences of initial delamination on the buckling-fracture behaviour of GFRP plates are discussed.

In the coming years there will be a growing demand for FPSOs (floating production and storage units) for ultra deep waters. In the Gulf of Mexico the process will be accelerated by the technical and economical limitations inherent to other type of concepts the lack of pipeline infrastructure in such deep areas and the wide acceptance of the FPSO concept by Shelf Authorities. One of the most critical issues in the design of FPSOs for ultra deep waters will be the selection of the most cost-efficient station-keeping system for the specified operational requirements. Standard solutions based on internal turret and thruster-assisted mooring systems are already being offered by the industry. However beyond certain water depths the technical and economical constraints associated with the use of mooring systems may favour other concepts potentially more attractive and cost-efficient such as a fully dynamically positioned FPSO (DP-FPSO). This DP-FPSO concept is proposed. It provides an innovative and cost-effective solution to meet the challenges of ultra deepwater production by using existing and proven technology in the offshore industry. The paper shows the technical feasibility of the concept by analysis model testing detailed engineering of the various sub-systems and risk and reliability studies. This concept marries state-of-the-art FPSO technology and latest generation drill ship technology for dynamic positioning and operation in ultra deep waters. This system can either be u

CCS (carbon capture and storage) is recognised as having a significant role to play in reducing CO2 (carbon dioxide) emissions and tackling climate change. In CCS schemes CO2 is captured from anthropogenic sources and transported to suitable sites either for EOR (enhanced oil recovery) or storage. Globally the largest source of CO2 is from power generation therefore the initial projects proposed for CCS in the UK are from power plant. There are various technologies for capturing CO2 from power stations however the captured CO2 can contain significant amounts of impurities. The presence of the impurities in the CO2 stream has an effect on the requirements for pipeline transportation and can change such factors as the flow properties the decompression characteristics and the solubility of water in the mixture. Although transport of CO2 by pipeline is not new technology and has been implemented in the USA for over 30 years the effect of these impurities is not fully understood. The UK is in the advantageous position of having natural sinks for CO2 available offshore in the North and Irish Sea which can be used for either EOR or storage. Therefore CCS implementation in the UK will involve transport of anthropogenic carbon dioxide from power stations to offshore sinks.

The fundamental role of a classification society is to develop publish and maintain standards the Rules for the design and construction of ships and to implement these standards within a system of classification. The success of the international maritime safety regime depends on the technical contribution of the classification societies. The continual advance in maritime technology is accompanied by a demand for specialised technical expertise and knowledge and the maritime industry looks to the classification societies for support. The classification societies must therefore be responsive to change and keep their own technology up to date. The expectations and perceptions facing the maritime industry are reviewed and some specific research and development activities of Lloyd's Register are considered in relation to naval architecture engineering systems environmental protection and human factors. Some current activities show the contribution that is being made to maritime safety. The current programme is compared to achievements of the past reflecting the changes within the marine industry. Working with industry universities and research institutes is a key part of the research and development activity of the modern classification society and some experience is described. The challenges that will be presented in the forthcoming years are discussed briefly.

A way to use finite element models to determine the effect of fatigue cracks in ship structures is proposed. Cracks of different lengths are modelled and the maximum nodal stress at the crack tip is used to estimate the stress intensity level. The calculated stress intensity factor is substituted into fracture mechanics equations to calculate the rate of crack growth and the critical crack length. The main advantage to calculating the stress intensity factor from an appropriate finite element model is that load redistribution effects are included. Since most ship structures develop fatigue cracks it is important to know how fast these cracks propagate and at what length they present a danger to ship safety. It is also possible to study the crack's impact on the stress levels in the surrounding structure. The use of modal crack tip stresses directly from the finite element model circumvents the problem of determining a nominal stress level in an often complicated stress field. Practical examples are presented to demonstrate how load shedding and multiple load paths improve ship structural safety. The examples shown are independent of the type of structural failure hence this type of analysis can be used to investigate the effect of cracks created by fatigue collision or grounding damage. Type of analysis can be used to estimate appropriate inspection periods and to assist in the design process. Conclusions are drawn.

The inclusion of high-resolution multi-beam and digital side scan sonar systems along with state-of-the-art positioning and attitude sensors and other ancillary sensors on ships and HSL (hydrographic survey launches) has provided NAVOCEANO (the US Naval Oceanographic Office) with the finest-equipped survey fleet in the world. This tremendous increase in bottom-mapping capability brings with it a corresponding increase in the amount of data that must be validated prior to inclusion into the various shallow- and deep-water hydrography bathymetry and imagery products that NAVOCEANO produces. The key to meeting the challenge of the massive data volumes was to change the approach that required every data point to be viewed and validated. This was achieved with the replacement of the traditional line-by-line editing approach with an automated cleaning module and an ABE (area-based editor) integrated with existing COTS (commercial off-the-shelf processing) and visualisation packages. An overview of the new approach is presented together with data results and metrics of the effort required to process data including editing quality control and product generation for multi-beam data using targets from digital imagery data and automated techniques. 90701 Dealing with rigid beds in saturated bed load transport equations

The book starts with the basic thermodynamics of compressors and then discusses the selection of compressor size and type. Modern compressor design and construction aspects are covered with particular emphasis on component descriptions, valves, multistage compression, cooling options, oil and moisture separators. This section finishes with an examination of rotary screw unit construction. A study of installation details typical problems and their avoidance, including clean air to unit suctions, correct lifting procedures, bedplate types and details, piping, Vee belt drives, couplings, prime movers and packaged units. In line with modern practice, the automation and control of reciprocating air compressors is considered together with advantages over manual control. Detailed items include unloading, starting/stopping, running condition, automatic drain operation, safety shutdowns and 'master and slave' operation. The chapter is rounded off with information regarding screw compressor controls. Air system fittings considers air quality, different air dryer types, air receivers with fittings, various type line valves and oil removal filters. Operating instructions cover new machines, initial starting, running in periods, stopping, lubrication, cooling, care of compressor fittings, lay up and corrosion protection. Planned maintenance schedules are illustrated in tabular format.

The further development and application of CFD (computational fluid dynamics) simulation for combustion system optimisation of large MD (marine diesel) engines suffers from a lack information about actual characteristics of spray combustion and emissions formation processes at conditions relevant for those engines. In particular the models commonly available for these processes have been developed for considerably smaller engines running at higher speeds and on substantially higher fuel quality. These models have usually been validated against data from reference experiments in small spray combustion chambers operated at conditions which are far from the ones applied to MD engines during fuel injection and combustion. Moreover such experiments are hardly capable of providing sufficiently detailed data for typical marine fuel quality. In order to overcome this a new spray combustion chamber was developed to allow the optical investigation of flow spray combustion and emissions formation at conditions typical of the combustion system in large two-stroke diesel engines. In particular the pressure temperature and swirl was close to the levels experienced in those engines and the arrangement of the injectors allowed the investigation of interactions of sprays originating from different injectors. In addition it had to cope with a wide range of fuel qualities.

The temporal variability of coastal and oceanic bioluminescence remains largely unknown. Few studies have attempted to measure this phenomenon over any appreciable timescale because of the limitation of the number of available instruments the platforms from which to measure for an extended period of time and the cost in terms of time. Similarly the seasonal and annual characteristics of bioluminescence have been observed in only a handful of studies. Bioluminescence is important because it is a sensitive indicator of marine environmental health. The distribution of bioluminescence has been of interest to the US Navy because of its potential impact on operational issues. Bioluminescence correlates with toxicity biomass and even red tides an important coastal phenomenon that can be associated with bioluminescent plankton (dinoflagellates). Recently a buoy mounted oil spill sensor was modified to house a bioluminescence sensor and a transmissometer. The materials and methods are described. The buoy measures bioluminescence by activating a small electric pump that pulls seawater into a light-tight chamber. The agitation and shear associated with the water flow stimulates the bioluminescent dinoflagellates to emit light. Water clarity is also measured with a red (680 nm) transmissometer. Data is automatically collected twice an hour transmitted by a spread spectrum (900 MHz) RF link to a lab-based computer and posted to a secure Internet browser. The buoy is providing for the first time autonomous long-term bioluminescence measurements in San Diego Bay. Results are presented together with101480 The development of an autonomous underwater powered glider for deep-sea biological chemical and physical oceanography