Search our collections

A turret-moored FPSO under harsh conditions is supposed to align with wind-driven waves due to its weathervane capability. However the ship can find herself beam on to the seas in mild environments as a result of a combination of wind-driven waves and swell condition. This means that a misalignment between ship's heading and waves can happen leading to large amplitudes of roll motion for a reasonably long time. This really gets worse in the case the FPSO is at low draft and the roll natural period is in the vicinity of the peak period associated with the swell condition. It is well known that one of the most effective devices to reduce the roll motion of ships is the bilge keel. The importance of the bilge keel increasing the roll damping moment stands out for resonant conditions. The results of free decay tests for various bilge keel arrangements are presented regarding roll damping coefficients. Tree representative drafts were considered for the FPSO and the bilge keel configuration varied from bare hull (no bilge keel) to bilge keel. Finally a tailor-sized bilge keel is defined for a typical F(P)SO operating at Campos Basin.

Shipbuilding facilities and ship repair facilities produce wastewater that requires treatment and is discharged into surface waters. Many wastewater contaminants exert oxygen demand which is measured in terms of BOD (biochemical oxygen demand) and COD (chemical oxygen demand). Since there exists the potential to damage the water quality of the receiving stream pollutants discharged by shipyards require proper management. The CWA (clean water act) of the US uses a variety of tools to restore and maintain the nation's surface waters. The CWA have authorised the US EPA (environmental protection agency) to use the NPDES (national pollutant discharge elimination system) permit program to control the water pollution by regulating point sources that discharge pollutants into surface waterbodies. Under this program each shipyard that discharges pollutants into the surface waters is required to obtain an NPDES permit. These permits have numerical limits for each pollutant discharged from each outfall. Shipyards are required to monitor each outfall for each permitted pollutant as well as the quantity of wastewater discharged and to report the results in a standardised fashion in a DMR (discharge monitoring report). These reports can be tedious and time-consuming. To address this problem an automated DMR has been developed. This is a knowledge-based intelligent system. Its various components user-friendly features and the benefits of the system are presented and it is described how the system can be adopted not only in the United Stat102617 An automated Futura Shipping World & Shipbuilder

The aim of high-resolution marine seismic exploration is to obtain an image of the sea bottom lithography from reflected acoustic waves emitted by various seismic sources. The seismic source which produces the seismic wavelet is tracked by a ship which records the reflected acoustic signals. The received signals can be modelled by the convolution of a source wavelet and a reflectivity sequence which describes the most important interfaces met by the emitted wave. The source wavelet cannot be considered as a stationary signal for three main reasons. The problem can be modelled as the filtering of the reflectivity sequence through a low-pass filter whose impulse response is the wavelet source. So blind deconvolution must be applied to recover the reflectivity sequence from the recorded trace because the wavelet is unknown. A blind deconvolution algorithm involving a parameter estimation by SEM and a Monte Carlo method for the maximisation of the marginal distribution is applied to the data of the ESSR4 campaign. Many practical problems have been solved by an experimental procedure such as the wavelet shift problem and the MA model order. The deconvolved image shows a better resolution which implies an easier use by geologists.

Contents: Peter Clowes, 'The Windjammer Wives', p.9 R D Southan, 'Bunkers', p.13 Hilary Ferguson, 'A Story of Two Brothers' p.20 Captain Nick Roman, 'My travels on the Magellan Straits' p.23 Daphne Pochin Mould, 'First in Steam' p.27 James Ritchie Grant, 'Escape!' p.32 D G A Williams, 'McCreary's Mattress' p.35 Peter Yates, 'Defiant to the End' p.37 Len Jones, 'Single-Handed Around the World' p.42 Alec Gill, 'Suicide Mission to War Torn Norway' p.45 Colin Waters, 'The Loss of the City of Gloucester' p.49 Michael J Thorp, 'Crossing to Shetland' p.52 E M Shipsey, 'RMS Carmania Versus the Cap Trafalgar' p.56 J C Goble, 'Selling a Ship' p.62 F T Grover, 'The Loss of the SS Automedon' p.67 Captain W Ayres, 'Voyage Report of the SS Kayeson' p.70 Peter Colbeck, 'Great Excitement Here' p.78 Brian Leathem, 'A Voyage in the Llandovery Castle in 1937' p.85 Ken Kent, 'Boy on the Warspite' p.94 Captain R J K Taylor, 'The SS Lovat and the Emden' p.97 Ronald Bayly, 'H M Customs at Sea' p.104 Charles Dawson, 'The Hornet' p.113 Captain Wilfred Scott-Shawe, 'Looking Astern' p.120

No other areas of shipping are so affected by rules regulations and trade requirements for high quality as the bulk chemical and petroleum sectors. The degree of regulation and limitation has increased significantly over the years. There is also bound to be further regulation in the future. Access to a large amount of information is needed to ensure compliance with regulatory and trade requirements and the immediate availability of emergency requirements in the event of a casualty. The problem is exactly how does the shipowner or operator or master handle all of this information in a timely manner? Ship operators need a tool that makes it easier for them to meet the demand for sage cargo operations. With the development of high capacity personal computers during recent years a tailor-made computerised information system is a logical solution to this problem. Such a system should contain all the relevant information required in one place. The time has come to emphasise the provision of tools to assist the shipboard staff in the task of ensuring correct safe and quality handling and transportation of the cargo. The concept of an effective computer-based information system capable of storing and processing the large amount of data necessary to operate in today's regulatory environment is presented.

Stiffened plating is one of the most fundamental structures in ship and offshore structures as well as in many other civil engineering structures. It is therefore very important to assess the strength of stiffened plating; and one of the most important strengths is against buckling-plastic collapse. To investigate such collapse behaviour and strength a lot of research has been carried out both experimentally and theoretically. In theoretical analysis; stiffeners are modelled in two ways: by plates and by beam-columns. It has not been clear when stiffeners should be modelled by beam-column and when they should be modelled by plate. Here; this problem is discussed on the basis of analytical and numerical calculations. Firstly local buckling strength of a stiffened plate is both analytically and numerically calculated with beam-column modelling. Then after confirming that analytical and numerical results showed good correlation an application limit of beam-column modelling is discussed by comparing the results of analyses by beam-column modelling and shell modelling. Next the difference in collapse behaviour is discussed when stiffeners were modelled by beam-column and plate respectively. Further for the analysis of ultimate strength an applicability of the beam-column modelling is discussed.

The installation design of small structures using an AHTS (anchor handling and towing ship) is addressed through the coupled motion analysis of the two structures connected by an installation cable in the frequency domain using the WAMIT program. This problem is sometimes analysed by imposing the AHTS stern motions on the top of the installation cable an uncoupled analysis. It is shown that in some situations the presence of the small structure will influence the AHTS motions mainly the pitch motion and should be taken into account. The influence of some parameters on the solution is addressed - for example the depth of the submerged small box structure and the cable stiffness. The converged results are post-processed in order to get short-term statistical responses of the line tensions as a function of the sea-states using a Jonswap spectrum to represent the sea environment. Varying the significant wave height and peak period we will be able to define a window in this domain where the marine operation will be safe with regard to the line tensions. The suspended structures weight around lOOtf while the installation cables have an operational maximum tension around 300tf. The most critical design condition will occur when the dynamic maximum tension in the installation line gets close to the structure self weight as the cable will not be allowed to get slack.

It is anticipated that Russia will be one of the major suppliers of LNG to meet energy demand in Europe and in the US in the future. As a result large quantities of gas will be transported from Russia by sea in LNG ships. Due to the geographical location of large gas fields in Russia these LNG ships will need to be designed specifically to operate in severe weather conditions. Meeting the transportation challenge demands an analytical and a more comprehensive and systematic approach to the management of the risks. More detailed analysis has been made possible through developments in computing and modelling technology. That technology plays an essential role in addressing the key safety issues associated with emerging LNG transportation needs in Arctic trade. In addition the application of risk assessment methodology in the evaluation of novel concepts allows a better understanding of the risks associated with LNG shipping in arctic waters and its integration into design technical standards survey requirements and operational practices. Various aspects of the ship design and operational requirements are discussed from a Classification perspective. Particular consideration will be given to issues such as the strength of the hull structure to endure ice loads on deck ice-breaking capabilities and the design of the containment system to withstand the dynamic loads envisaged under harsh weather conditions in particular sloshing loads. In addition requirements for safety equipment and systems under freezing condition are addressed together with the propulsion systems for ships in this Design assessment of engineering systems with particular reference to shaft alignment

Wave-induced hull girder loads such as vertical bending moment amidships are very important for design. The effect of heavy weather avoidance on the long-term wave-induced loads on ships is evaluated. Two hydrodynamic codes VERES based on a 2D strip theory and WASIM based on a 3D Rankine panel method are used to calculate the wave-induced loads and motions on various vessels. Two models for heavy weather avoidance are proposed. The first is based on the assumption that operational criteria relevant to vertical acceleration green water and bottom slamming are fulfilled. The second is based on the assumption that the sea state forecasts are available to the shipmaster and that rerouting is made. Based on the first model considering avoidance of heavy weather and the hydrodynamics results calculated from two codes wave-induced hull girder loads are obtained. The results are discussed - in particular the effect of different hydrodynamic codes and various scatter diagrams. The long-term prediction of wave-induced hull girder loads considering the effect of avoidance of heavy weather will give a relatively more realistic evaluation of the extreme hull girder loads. Finally the results from ship rules are also re-evaluated compared with the long-term prediction with and without heavy weather avoidance.

The Royal Swedish Navy (RSwN) is looking to procure a new set of amphibious crafts Combat Boat 2010 (CB 2010) their main purpose being to provide indirect fire supporting ground troups in archipelago-like areas. Prior to procuring the crafts a feasibility study has been carried out by the Swedish Defence Materiel Administration (FMV). The study indicates that the CB 2010 will have a displacement of approximately 56t carrying a grenade launcher with an electrically manoeuvred gun carriage. Pwered by two diesel engines of about 1.5 MW each the CB 2010 is designed for a top speed of almost 40kts using two water jets. In recent years there has been a lot of development in Electric Weapons and Armour Systems (EWAS) and it is not unlikely that these will be reality in the near future. In addition the advent of the All Electric Ship (AES) future naval copmbatants tend to revolve around large ships e.g. destroyers. But does not the introduction of EWAS affect all kinds of military platforms not only large ships? It ought to be of relevance to also look at how smaller platforms can adapt to these sorts of systems. this paper focuses on small amphibious crafts and investigates if it is possible to install EWAS onboard. As a reference the CB 2010 is used.

Navigational charts have always been and continue to be one of the most important navigational aids on the ship's bridge. The demands of modern navigation are such that it is hard to imagine navigating waters with dense traffic without electronic aids for navigation or an integrated bridge system. One of the basic components for the modern navigation equipment is ENC (electronic navigational chart) which helps mariners steer their ship safely precisely on time and with more efficiency. The basic standards of the IHO (International Hydrographic Organization) are analysed together with different types of electronic charts and systems and how users see this new navigational tool. The analysis shows the difference between electronic charts systems different types of electronic charts and the benefits of using them for navigation at sea. As a result of this research suggestions are made about what can be used under SOLAS convention and how navigators shipping companies and safety of navigation can benefit from this. This first systematic analysis of electronic charts in Slovenia shows how the shipping companies can use their ships with more efficiency how the workload for navigator is reduced and how a navigator's situational awareness is increased. This can help reduce accidents at sea loss of ships cargo human lives and protect the environment.

The ocean environment is described using wave current and wind statistics in deep and shallow water with the aim of creating a basis for determining environmental loads for structural design. Also included is the statistical description of temperatures which are relevant to the design of ship and offshore structures. The main areas of focus are environmental data; fidelity of environmental measurements; ocean currents; description of sea states; and design environmental conditions. First the various sources of environmental data are examined together with theoretical models to complement environmental data. Next 'fidelity' is defined and the main measuring systems and parameters involved are discussed. The data from the various sources is compared and metadata is explained. Then ocean currents in deep water are investigated. Current profiles and decomposition of currents are covered. Following this sea states are explained including wave spectra and the probabilistic description of stationary sea states and a description of long-term climate freak waves and the laboratory generation of sea states. Finally design environmental conditions are explored. The challenge is explained together with the parameter definition of design wave environments and the time domain representation of design wave environments. It is concluded that despite extensive development in the amount and type of recent environmental measurements there remains a significant lack of data and basic knowledge for some met-ocean parameters which are important for design purposes and reliability assessment. The areX43533

A study of the peak global loads measured aboard a Canadian HMCS (Halifax Class naval frigate) during a two-week sea trial in the North Atlantic is outlined. A comparison of the peak hog and sag BMs (bending moments) is undertaken to determine the extent of possible asymmetry in the VBM (vertical bending moments). It is common for ships with slender hull-forms such as frigates to experience asymmetric wave-induced VBMs. The requirement for a slender hull-form to obtain relatively high speeds combined with the need for adequate deck area generally results in a hull-form with higher topside flare minimal or no region of parallel sides and a finer underwater geometry than higher block-coefficient ships. The sag VBM can be significantly higher than the hog VBM. This may be attributed to the occurrence of the wave crests at the bow and stern areas in the sag condition corresponding to maximum immersion of the nonlinear hull geometry. A structural sea loads trial with full-scale strain measurements is briefly described followed by a description of the procedure for the calculation of the global BMs from the measured strains. The vertical and lateral BMs were also calculated using the 2D frequency domain panel code PRECAL. The PRECAL predictions are compared with the BMs derived from the strain measurements. Peak hog and sag VBMs are determined for each trial run and their relative magnitudes investigated with respect to heading angle wave height ship speed and the number of encountered wave cyc96702 Global loads derivation of large high-speed vessels

During violent weather conditions offshore structures are subject to different types of wave impact. The impacting waves are complex mixtures of water and air the properties of the mixture having a serious effect on velocity fields around and pressure levels on offshore structures. The numerical simulation of hydrodynamic wave loading on different types of offshore structures is important to predict forces on and water motion around these structures. A numerical study of two-phase flow over a sloping bottom with the presence of breaking waves is presented. The details of the numerical model an iVOF (improved volume of fluid) method are presented. The program has been developed initially to study the sloshing of liquid fuel in satellites. This micro-gravity environment requires a very accurate and robust description of the free surface. Later the numerical model has been used for calculations of green water loading and the analysis of anti-roll and sloshing tanks including the coupling with ship motions. The model has been extended recently to take two-phase flow effects into account. Two-phase flow effects are particularly important near the free surface where loads on offshore structures strongly depend on the interaction between different phases like air and water. Entrapment of air pockets and entrainment of bubble clouds have a cushioning effect on breaking wave impacts. The velocity field around the interface of air and water being continuous across the free surface requires special attention. By using a newly developed gravity-consistent discretisation spurious velocities at theX40537 Hydrodynamic strength and fatigue foil design

Naval vessels are increasingly using IEPs (integrated electric power) systems to supply main propulsion and ship services and these are applied to most substantial benefit on vessels with highly variable mission cycles. Currently there is a drive towards the adoption of compact propulsion motors where for surface vessels the provision of a lower shaft-line height and thus lower rake angle results in higher propulsion efficiency whilst overall mass and volume savings translate to increased payload or fuel. These enhanced propulsion capabilities could offer opportunities to radically change the types and number of ships comprising the future fleet to reduce total ownership cost. This paper discusses the design and analysis of a 7.5 MW magnetically geared propulsion motor or PDD (pseudo direct-drive) for a naval main propulsion application. The drive-train comprises two motors mounted in tandem to produce 15 MW at less than 100 rpm within a specified maximum volume envelope of 3.5 m x 3.5 m x 6 m and with a maximum weight of 100 mt. It was found through the course of the design study that the resulting PDD could be realised in a 3.5 m x 3.5 m x 2.1 m volume with a mass of 53 mt with no trade-off in efficiency.

Nowadays the success of the missions of naval ships depends highly on the use of sensor weapon and command systems. the availability and capability of these systems depend on support delivered by support systems such as chilled water systems and electrical power systems. It may be argued that the main task of the automation of these support systems is to quickly restore the system capability in the event of unavailability due to battle damage. Traditional platform management systems are not up to the task due to their centralised design. Next generation platform management systems will therefore be based on a decentralised design. Decentralised platform management systems use distributed intelligence which has two important benefits compared to the traditional platform management systems: it lowers the vulnerability and increases the availability of the support systems. These benefits imporve the survivability of the ship as a whole. The Royal Netherlands Navy and TNO Defence Security and Safety have conducted a project on this subject called Robust Automation. This paper describes this project. In order to prove the technical feasibility a demonstrator has been built and tested. the results are very promising. The project Robust Automation finished last year but will be continued by the Distributed intelligent Networked Control Systems (DINCS) projects a new European research and technology project focussing on a further de-risking of the technology. DINCS will ensure a sufficiently de-risked technology ready to be s99384 Robust broadband adaptive beamforming via polynomial eigenvalues

Aircraft carriers generate large amounts of paper cardboard and textile wastes. Each aircraft carrier needs an incinerator to supplement other solid waste processing equipment which includes pulpers and plastics wastes processors. The COTS (commercial off-the-shelf) TeamTec Golar Model GSA500CSW incinerator was chosen to replace obsolete MIL-SPEC incinerators which have significant safety problems and high repair costs. The Golar incinerators however have also had some reliability and safety problems. The most critical problems were the rapid deterioration of exhaust stacks and catastrophic flue gas fan failures. Therefore NAVSEA and the type commanders developed a ship alteration package that calls for the installation of a new exhaust stack and an upgraded MK2 version of the incinerator. The new stack will be routed to minimise direct impingement by the hot exhaust gases and have materials that are more resistant to high temperatures. The MK2 incinerator design is the product of an extensive design and testing effort by TeamTec and NAVSEA and has many improvements. The most significant change was the addition of a shredder-conveyor-stoker system that automatically loads the shipboard waste into the incinerator smoothing the flow of waste and minimises temperature spikes. The final prototype unit was tested successfully in September 2004.

Deterioration in propellers performance occurs in a variety of ways including corrosion cavitation impingement and marine fouling and these can have a considerable negative effect on propulsion efficiency. Appropriate coatings can mitigate the effects of certain types of deterioration but historically coating of propellers has not generally been used for this purpose. In recent years coatings based on a new technology for prevention of fouling have been developed. Known as 'Foul Release' these now have a proven track record on the outer hulls of fast and active ships. These ultra-smooth coatings rely on low-surface energy and water movement over the surface to keep fouling from attaching thus they are ideal for use on propellers where the water velocity around the blades is very high. Trials on propellers of ships using the Foul Release coating 'Intersleek' have shown that prevention of fouling can be achieved over long in-service periods. There is usually detachment on the blade edges due to the high cavitation forces but since fouling never occurs in these locations coating detachment in these areas does not have a deleterious effect overall. Some ship owners have reported reduced cavitation-induced noise and increased speed after coating their propellers with Intersleek. In order to quantify these more accurately sea trials were carried out over a measured mile using Newcastle University's dedicated research vessel Bernicia

Marine exhaust gas economiser systems (thermal energy recovery equipment provided in downstream flues for exhaust gases of marine diesel main engines) are widely employed to use the thermal energy from exhaust gases of marine diesel main engines effectively and to reduce ship's operating fuels. At present low-speed two-cycle single-acting crosshead-type long-stroke diesel engines are the mainstream of main engines of general merchant ships in Japan. The current state of MEGE (marine exhaust gas economizer) systems and a view on system reliability are discussed. MEGEs are directly joined with diesel main engines by an exhaust gas piping. So when there is trouble with MEGEs onboard immediate action must be taken (particularly for systems that have no redundancy) otherwise the total reliability of the ship is lost. Improvements in reliability of MEGE systems are an important factor in the maintainance of a ship's reliability. The main troubles with MEGEs onboard are with deformation and meltdown of heat-exchanger tubes due to soot fire or leakage from pitting of heat-exchanger tubes due to dew-point corrosion of sulphuric acid. Measures are suggested directed towards improvements in reliability based on prediction of soot fire and pitting of heat-exchanger tubes due to dew-point corrosion of sulphuric acid prevention of soot fire and dew-point corrosion of sulphuric acid from design.

A 'state of art' in the development of the time domain dynamic simulation of 3D bending hysteresis behaviour of a flexible riser under offshore environment loading is presented. The main technical challenge is to understand and model the riser tensile armour behaviour under continuous changes in both the magnitude and direction of bending and its subsequent impact on the riser's bending hysteresis characteristics. Because of this technical obstacle the current industry practice is to model the riser as a linear structure with certain conservatism enforced and then to extract the global dynamic loads to a detailed local model for stress and life assessment. Two 3D flexible riser bending hysteresis models are introduced that were developed by Wellstream and Orcina respectively. Also presented are their calibrations against the bending hysteresis loops measured in full-scale tests. Both models are implemented using the analysis program OrcaFlex; the Wellstream model is a detailed model that calculates both the total bending moment and the stresses in the tensile armour; the Orcina model is a simpler model that only calculates the total bending moment. A study is presented to illustrate the difference in the riser dynamic responses with and without consideration of the bending hysteresis behaviour and to assess the difference in the dynamic responses between the Wellstream and Orcina 3D bending hysteresis models. This development permits more realistic riser structural properties to be modelled in the dynamic simulation and reports detailed time history stress or strain resultX39366 Time Domain Simulation of Vertical Ship Motions and Loads in Regular Head Seas