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NOx emissions from diesel engines are known to be a principal source of air pollution. In recent years global and local regulations for exhaust gas emissions in medium and large diesel engines used for power generation on land and propulsion system in vessels has become more stringent. Consequently engine makers have made every effort to meet the regulations. It is well known that when water is added to the combustion process NOx emissions are abated from decreased peak combustion temperature. Water can be introduced into the combustion chamber in various ways. A technique to moisturise charged air using water steam and packing block is studied. This offers a more effective means of moisturising charged air than the general water spraying method. This new water injection system is called a CAM (charged air moisturiser) system. The system is applied to SCDE and a medium-speed engine. The tests show very successful results. In applying the CAM system to the single cylinder diesel engine more than 66 per cent of NOx reduction rate was achieved with a maximum humidity of 66g per kg. The prototype CAM system for the HiMSEN engine showed a NOx abatement of 20 - 40 per cent with 20 - 39 g water per kg air humidity ratio. After the final optimising process the CAM system for HiMSEN engine is expected to show even better performance.

Throughout the oil industry vertical pipes are used to convey crude oil either offshore from the bottom of the sea or onshore from the depths under the soil. These pipes otherwise called risers are attached to a platform at one end and are buried under the seabed or in the ground at the other end. The stability of these pipes is the subject of this investigation. The history of such analysis dates back over five decades when the vibration and stability of fluid conveying Trans-Arabian pipeline network was first studied; albeit for an on-shore environment. For that case it was found that instability of the flow can be induced by vibration and that if such a horizontal conveyance pipe is supported at both ends it bows out and buckles when the flow velocity of the conveyed fluid exceeds a critical value. Because of the industrial relevance of such conveyance networks the problem has continued to generate interest over the years and especially now that deep waters offshore exploration is assuming increased importance in the Oil and Gas sector. When dealing with the stability of these pipes most workers usually assume the Euler-Bernoulli hypothesis which requires that plane sections perpendicular to the axis of the beam remain plane and perpendicular both before and after deformation. This essentially means that the deformation of such sections is neglected. However the Timoshenko hypothesis accounts for such deformation by including transverse shear which is usually neglected. In this paper the energy method is invoked to derive the governing equations including the effects of externa90509

Evaluation of hydrodynamic performance of two vessels in close proximity that are either stationary or advancing in waves is of paramount importance for many offshore and naval engineering applications. Hydrodynamic interactions between the vessels combined with non-linear mechanical interactions due to mooring and fendering systems make the problem more complicated. An efficient time-domain method is presented for evaluating the seakeeping and maneuvering performance of proximate vessels advancing with forward speed. The method computes the six DOF (degree-of-freedom) motions of a pair of hydrodynamically interacting vessels subject to wind waves currents and maneuvering effects at zero and non-zero speeds in regular or random seaways. Model tests carried out to validate the method are described and results presented. The validation efforts carried out so far have yielded satisfactory comparisons thereby reinforcing the confidence in the method and its applicability to such problems. The method has been used to predict safe operational limits of two vessels in skin-to-skin operations conducted by the US Navy. A similar analysis is presented for a different pair of vessels. Since it is based on time domain simulation this method also allows the inclusion of non-linear effects due to mooring lines fenders and effects of viscous roll damping which is not possible with two-body hydrodynamic interaction solutions in frequency domain.

In shipbuilding a ship hull structure is made of many ship hull blocks which consist of steel plates and stiffeners using welding in a shipbuilding dock. As one block weighs hundreds of tons holding it in a proper position with tolerable welding gaps and welding it to the neighbouring blocks take long time and many resources. Therefore the manufacturing accuracy of a block of a ship hull structure has a strong impact on the manufacturing costs. Accurate dimensions of a ship hull block with the minimal weld gap adjustment have been achieved in Japanese shipyards over the years using a knowledge database of weld shrinkage. However fierce competition in the shipbuilding industry is demanding a revolution of the conventional accuracy control system in Japanese shipyards in order to achieve weld-gap-adjustment free block erection in a dock. Research was carried out to develop an advanced accuracy control system. As a part of this coordinate measuring products were surveyed: a theodolite with a range meter; photogrammetry products with a film camera or with a digital camera; a laser scanner with an amplitude modulated laser beam; and a coordinate measuring machine using pattern recognition with a special probe. These products were evaluated by ease of use time required for measurement and measuring accuracy. Two measuring experiments revealed that a photogrammetry product the V-STARS system using a high-resolution digital camera is the best measuring method for ship hull production with some limitation in block size.

The longitudinal connections at the inner and outer hulls of ocean-going vessels often experience fatigue cracking as a result of dynamic stress fluctuations due to environmental loadings. A crack may begin at the area of stress concentration. It can then continue to grow through the longitudinal stiffener until it reaches the shell plate. Subsequently it creates a surface crack that goes through the plate. If this crack is not repaired it can grow to a critical size and may result in catastrophic structural failure. As a result it may induce structure failure and associated significant environmental impact and large financial losses. In view of previous studies on the fatigue analysis of ships and offshore structures shell elements are commonly used to calculate hot spot stress for complex connections. There are few studies using solid elements for longitudinal connections. Shell elements simulate only the mid-plane of a plate and weld is not modelled or modelled by some idealisations such as rigid links inclined shell element etc. This paper deals with a rigorous fatigue analysis using solid elements with full weld representation. A full-scale test of side longitudinal in FPSOs tested by DNV (Det Norske Veritas) is introduced and FE comparative studies are presented. After this effects of weld returns to connect two fillet welds and non-welded gaps in fillet weld are discussed. Finally

Continuing ocean experiments show specific applications in which a jellyfish-tracking ROV pilot assist enhances collection of scientific data. Recent results have repeatedly shown the tracker's ability to follow a jelly target for extended periods as long as 34 minutes. Thus far experimental demonstrations of the jelly tracker have incorporated a linear control law. The jelly-tracking controller is modified using extensions to the control law that enable two new capabilities. The first extension compensates for steady ROV disturbances. The second extension gives pilots full authority in the null space of the jelly-tracking regulation law. Bias compensation serves to smooth transition from human pilot to combined computer-human control and to establish a clear zero reference for supplementary pilot commands issued during tracking. Use of the regulator null space enables the pilots to view the target from multiple angles. The jelly-tracking system used in ocean trials is reviewed together with its linear control law and the results of recent ocean experiments with MBARI ROV Ventana. Then extensions to the fielded system are examined which are intended to improve interaction between automation and human control. Next the ROV dynamic equations are presented. An estimator is presented. This is based on these dynamic equations which can smooth transition during system initialisation. A control framework is proposed which allows the human pilot to command large motions in the regulation law null space.

Time-reversal techniques have been demonstrated in ultrasonics and underwater acoustics environments. A technique resulting from the analysis of the iterative time reversal process has been developed. This is called the DORT method (decomposition of the time reversal operator) is a scattering analysis technique using a source receiver array (SRA). The efficacy of this method for ultrasonic detection and selective focusing on different scatterers in an inhomogeneous media has been shown. Mordant et al have shown the robustness of the method in an ultrasonic waveguide. While the performance of classical detection methods usually decreases due to multiple reflections at the waveguide interfaces the DORT method takes advantage of the waveguide boundaries and multi-path propagation in order to improve spatial resolution. The first experiment in a realistic shallow water waveguide is presented. The experiment uses a 24-element source receiver array at 12 kHz central frequency. The DORT method is applied to detect two targets at 27 m distance. Numerical and experimental back-propagation of the dominant singular vectors of the array response matrix enable the localisation of the individual targets. After a brief description of the experimental set-up the measurement of the array response matrix K(ù ) is explained and the singular value distribution is shown revealing the apparent reflectivity of each scatterer.

Public awareness and understanding of ocean issues is key to generating the political will to address these problems. The case for the importance of an ocean literate public in moving from issues to solutions has been made in a series of reports by national commissions starting with the Stratton Commission in 1969. Since 2004 there has been a renewed interest in promoting ocean literacy both at the K-12 grade levels and of the general public. Aquariums and other informal science institutions are seen as key players. The Aquarium of the Pacific has focused on public ocean literacy and during its 10th anniversary year has embarked upon a major initiative to bring major ocean issues to the public in new and novel ways to evaluate the efficacy of these modalities and through a national conference in May 2009 to bring scientific experts together with experts in exhibit design film-making environmental journalism and story0twling to develop a portfolio of materials designed for different modalities of delivery for each of the major ocean issues that can be used widely to engage educate and enpower the public in moving from ocean issues to solutions. Participation by the MTS and its members is invited. In this paper the need for an ocean literate public is briefly explored together with what ocean literacy means the special roles that free-choice learning (informal science) institutions can play. The Aquarium's 10th Anniversary program is then described as well as its national conference in an attempt to elicit collaborators from MTS.

A full-scale field trial of a taut leg mooring was performed by Saga Petroleum in 1996 offshore Norway. The trial used suction anchors and two types of fibre ropes attached to a semi-submersible drilling unit. The aim was to qualify the technique as an effective mooring system for floating drilling units. The execution of the trial is described in detail. Fibre rope data obtained from other laboratory and field measurements are discussed and it is concluded that sufficient data are available to qualify these ropes for taut leg mooring. The benefits of taut leg moorings are presented in terms of their use on a congested seafloor in shallow water (200-400 m) and in terms of deep water (800-1500m). The trial successfully demonstrated effective installation and retrieval of suction anchors and fibre ropes from a standard AHTS vessel. It is concluded that this method of taut leg mooring is a viable alternative to conventional mooring and dynamically positioned units.

Recent developments in CFD (computational fluid dynamics) associated with increasing power of computer are able to offer further opportunities to realize CFD-based aerodynamic or hydrodynamic design optimisation. However the increasing complexity of engineering systems together with the inherent difficulty to deal simultaneously with a growing number of design goals and constraints has raised interest in the development of efficient global optimisation schemes which can be used with computationally expensive analysis tools such as RANS (Reynolds-averaged Navier-Stokes) solver. The main focus of the present work is on investigation and development of such optimisation schemes and demonstration for practical design problem. High-performance multi-objective evolutionary algorithms for CFD (computational fluid dynamics)-based design optimization are presented. In particular Binary Coded MOGA (Multi-Objective Genetic Algorithm) and RC-MOGA (Real Coded MOGA) are investigated. In order to overcome the limitations of classical approach for particular issues in CFD-based multi-objective design optimisation advantages of evolutionary algorithms are discussed in conjunction with parallel nature of the algorithm along with inherent efficiency of parallel processing. Message Passing Interface based parallel coding methods are also discussed so that capability of distributed-memory-model parallel computing environment is fu91918

Petrobras is developing new fields in Campos Basin offshore Rio de Janeiro - the main oil province in Brazil responsible for 85% of national production. The Petrobras HP-HT pipeline P-53/PRA will be installed at Marlim Leste field in Campos Basin. A numerical study for this pipeline is presented. It will connect P-53 platform in deep-water (1031m) to an Autonomous Platform for Intermediate Pumping (PRA-1) in shallow water (100 m). HP-HT pipelines resting on seabed can develop thermal buckling which is an important concern for the pipeline structural integrity. The aim of this study is to verify the P-53/PRA-1 pipeline behaviour during lateral buckling due to thermal cycles and pressure variations using a new approach for the pipe-soil interaction model in contrast with the traditional Mohr-Coulomb friction model. The pipe-soil interaction model considers soil berms formed due to pipe cyclic displacements representing different phases of the soil lateral reaction force versus displacement curve: breakout force suction release berm formation and residual resistance. The results presented compare the traditional Mohr-Coulomb model with the proposed one for several loads cycles analysing displacements stresses and strains behaviour during thermal buckling.

Conf held in Aberdeen 26 - 27 March 1985 Papers are Hook up and commissioning technology - the North Sea effect Historical lessons for future design and hook ups Hook up - where does it start? Hook up experience on statpipe development project platforms How to optimise an offshore hook up Approaching hook up and commissioning through management of risk Cost savings in hook up using big lifts The completion strategy for offshore hook up projects - the construction engineers role Cost planning integration during offshore hook up and commissioning Hook up minimisation programmes - recent experience from the Norwegian sector Site based materials management systems - a cornerstone of succesful hook up control Communications - the forgotten link in hook up and commissioning Gravity platforms and their hook up Some ways to reduce the cost of offshore hook up Buchan Alpha - offshore platform inshore refit Offshore logistics - an overview Supply bases - the future - an operators view A practical solution to cost control and analysis of logistics in the offshore environment using computer technologies Personnel The logistics of materials and documentation for an offshore development The future of the offshore vessel market The development of helicopter support to the offshore industry The role of the all cargo airline as a support to the oil and gas industry

Human factors practitioners working as part of a ship design programme face a set of problems on a scale to those involved with smaller stand-alone equipment. They have to address a wide range of often competing human factors issues across a ship. Usually the individual systems comprise off-the-shelf components whose design is outside the scope of the ship's programme. Components will be chosen and the systems designed by large teams of architects engineers and draftsmen with various degrees of appreciation of the human factors issues. Invariably professional human factors resources will be thinly spread and human factors practitioners will have to make hard choices about where to concentrate their efforts. This paper summarises practical techniques for maximising human factors influence derived from experience in real-life projects. It shows how techniques such as task analysis can be used to identify critical human factors risk areas and thus focus design effort. It explains how human factors practitioners can become properly integrated within ship design teams and can influence the design by educating assisting and monitoring the various technical specialisms. In particular it describes how human factors practitioners can contribute to design review and can sign-off procedures by managing the traceability of design back to critical operational and safety requirements. Also considered is how to carve the warship design problem into manageable portions and thus achieve effective human factors integration.

The extraction of hydrocarbons has recently moved to deeper water depths (in excess of 1000 m). The deepwater deployment of production systems has been associated with certain critical issues for example VIV (vortex induced vibration) of risers. VIV remains a largely unsolved problem. The recent requirement for deployment of marine risers in deep-water has provided an additional thrust to the VIV research. The effort to mitigate this problem has led to a number of solutions for VIV suppression. One of these solutions is to add a vortex suppression device such as helical strakes perforated shrouds fairings splitters guiding vanes spoiler plates etc. Helical strakes have been used for long time in civil structures such as chimneys funnels and tall towers as a means of suppressing wind-induced vibration and are now being widely used as a means of VIV suppression for marine risers. Hydrodynamic coefficients of cylinders fitted with strakes in oscillatory flows are investigated. Three different pitch ratios are tested - the pitch ratios of infinity 8 and 4. The cylinders are forced to oscillate in otherwise calm water in a water tank. To validate as well as to compare the experiment results a smooth cylinder is included in the test matrix. Digital signal filtering is found to influence the results obtained. Thus sine-fitted signals are used to obtain the coefficients. For cylinders with strakes it is also found that the coefficients vary little with Reynolds number. It is further concluded that the pitch ratio has a significant impact on the hydrodynamic coefficients.

Nelly Bay Harbour on Magnetic Island Queensland is located in both the GBR (Great Barrier Reef) Marine Park and in the GBR World Heritage Area. It is composed of breakwaters marina ferry terminal residential development and commercial enterprises and has had a very long and controversial history. Started in the late 1980s the original proponent abandoned construction in the face of pressure from environmental groups and some difficult engineering problems. Recently the state government resurrected the project with additional funding. The proposed construction process requires dewatering during construction and dredging of the marina basin. This dewatering will be a continuous process since the breakwaters and substrate of the marina cannot be completely sealed. The effluent has the potential to damage coral reefs that lie along both sides of the marina as well as along much of the nearby island coastline. It was proposed that the extracted water be discharged approximately 100 m seaward from the HWM (high water mark). It is investigated whether an outfall situated 400 m from the HWM would reduce the concentration of sediment over coral colonies. Methodology is presented followed by simulation details and results.

The primary aim of this research is to locate the source of the vortex-induced vibrations (VIV) for long flexible cylinders at high-mode number and to help determine the source region for future predictions. The two Gulf Stream tests were conducted to collect data on a scale-model pipe that was excited at high-mode numbers. Two methodologies are presented to locate the area of the region that is the source of the vibration. In VIV the current causing the vibrations is important. Therefore one important question is which section of the pipe will be the source of the vibrations for a known current profile. This source region is known as the power-in region. Four different factors are presented that effect the locations of the power-in region: the angle of the pipe with respect to the vertical the gradient of the current direction the current profile and the end effects at high mode number. A dimensionless parameter is presented which helps in the prediction of VIV given a current profile. The power-in factor predicts the region where the source of the vibration occurs using a combination of the current velocity and the source region length.

Hydrocarbons have recently been discovered in the shallow waters of the Northern Caspian Sea. There is now a need for intensive drilling to be carried out shortly to explore this potential. Until now the only experience of operating mobile drilling units in seasonally ice-infested waters has been in on the Sunkar drilling barge at Kashagan and Kalamkas. However with increased drilling activity imminent innovative drilling concepts are required to maintain drilling operations during the ice period with conventional non-ice-resistant drilling platforms. External SIBs (shoulder ice barriers) are proposed to protect conventional jack-up drilling rigs from the hazards of drifting ice in shallow water. The design of SIBs design should increase ice rubble generation at the ice-facing slope and thereby provide sufficient protection from drifting ice impact. The modular concept of the SIB makes it possible to deploy each module in a floating mode to site where they are ballasted and connected to each other forming a sheltered position for the jack-up. Just before the end of the drilling campaign the SIB modules may be retrieved by de-ballasting and towing out without significantly impacting the environment.

Naval operations can be seriously disrupted by the presence of sea mines in operating areas. Tow innovative conceptual designs for mine countermeasures ships are offered together with an operational concept for their timely and efficient employment in conducting mine warfare. The first design concept is for a small SWATH (small water plane area twin hull) vessel for mine hunting in near shore waters. These small craft (Drones) are crewless and remotely controlled from a mother ship (Host). They are also stealthy to enhance clandestine operations in the hostile littoral prior to arrival of an expeditionary assault force. The Host vessel solves the problem of transporting small craft to remote locations and supporting mine countermeasure operations with minimal dependence on deployed naval combatants. The Host has space and services for maintaining several Drones as well as unique capabilities for launch and retrieval in rough seas. Cruise speed of the Host is adequate to accompany an amphibious task force in all sea states. Endurance is sufficient to reach most remote locations via ports of call. These new SWATH designs and the HAD (Host and Drone) concept of employing them with amphibious forces in advance of assault are considered to be fundamental to the success of future marine expeditionary campaigns.

The architecture of an inspection AUV (autonomous underwater vehicle) is much more complex than that of a survey type AUV since it requires high manoeuvrability and hovering capacity. It needs a specific AMS (autonomy management system) and navigation software as well as dedicated sensors to allow it to navigate relative to the structure to be inspected instead of the type of 'absolute' navigation usually used for survey AUVs where the only purpose is to give an accurate location of the vehicle. The relationship between different autonomy-related issues due to this complexity is shown using the findings from the development and testing of the ALISTAR 3000 AUV. This AUV is designed to answer the complex requirements to enable the inspection of underwater structures such as pipes wellheads mooring lines through embarked intelligence. The focus is on the functional description of the AMS in displaying different dual concepts that help to structure general functions linked to autonomy: supervisor and vehicle perception and decision symbolical and numerical descriptions mission and environment description external and internal worlds etc. This dualist approach leads to an AMS whose structure comprises one main supervisor

Stirred tanks have wide applications in the chemical and process industries. Crystallisation operations liquid-liquid extractions biological fermentations and heterogeneous catalytic reactions are just a few examples of industrial operations usually carried out in mixing tanks. Traditionally solid-liquid mixing has always been regarded as an empirical technology with many aspects of mixing dispersing and contacting where related to power draw. One important application of solid-liquid mixing is the preparation of brine from sodium formate. This material has been widely used as a drilling and completion fluid in challenging environments such as in the Barents Sea. Large-eddy simulations of a turbulent flow in a solid-liquid baffled cylindrical mixing vessel with a large number of solid particles are carried out to obtain insight into the fundamental aspects of a mixing tank. The impeller-induced flow at the blade tip radius is modelled using the dynamic-mesh Lagrangian method. The simulations are four-way coupled which implies that both solid-liquid and solid-solid interactions are taken into account. By using a soft particle approach the normal and tangential forces are calculated acting on a particle due to viscoelastic contacts with other neighbouring particles. The results show that the granulated form of sodium formate may provide a mixture that allows faster and easier preparation of formate brine in a mixing tank. In addition it is found that exceeding a critical size for grains phenomena such as caking can be prevented. The numerical results obtained suggest that