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Multi-hull vessels have emerged as popular alternatives to conventional mono hull ships for high-speed crafts. However the bridging structures connecting the hulls are vulnerable to various wave actions and the wave impact to the bottom of these vessels is the most serious problem. In this study prediction of the relative wave elevations under bridging structures is investigated for multi-hull ships travelling with forward speed in waves. A computer code YNU-SEA of 3D Green function method with forward speed has been developed and used to analyse the hydrodynamic radiation and diffraction forces and motion responses for high-speed catamarans in waves. The results of present calculations are compared to those of the previous calculations as well as with the experimental ones. Numerical results reveal that the present computer code has the practicality to be a powerful tool for the accurate numerical computations of sea keeping problems of multi-hull ships advancing in waves. Numerical calculations of wave pattern are also carried out including wave interactions between the hulls to analyse the effects of hull form on the free-surface flow around catamarans advancing in waves. The analysis of the wave pattern allows the determination of relative wave height including radiation and diffraction waves. Finally discussion based on these numerical results is presented which may be helpful for the accurate prediction of relative wave height and wave breaking load on the deck associated with multi-hull ships.

Wave-impact related (slamming) loads can induce high stresses and cause deformation of local structural components. The accurate assessment of such loads is essential for the design of a ship's structure. Classification society rules contain formulas for slamming loads. Generally these formulae are adequate for conventional ships as they are based on operational experience. However for many modern ships it becomes necessary to resort to direct computations of slamming loads. A satisfactory theoretical treatment of slamming has been prevented so far by the complexity of the problem. Most theories and their numerical procedures were applied on 2D bodies; however slamming is a strongly 3D non-linear phenomenon that is sensitive to the relative motion between the ship and the water surface. Slamming is characterised by highly peaked local pressures of short duration. A numerical procedure to predict impact-related wave-induced (slamming) loads on ships is presented. The procedure was applied to predict slamming loads on two ships that feature a flared bow with a pronounced bulb hull shapes typical of modern offshore supply vessels. The procedure used a chain of sea-keeping codes. First a linear Green function panel code computed ship responses in unit amplitude regular waves. Wave frequency and wave heading were systematically varied to cover all possible combinations likely to cause slamming. Regular design waves were selected on the basis of maximum magnitudes of relative normal velocity between ship critical areas and wave averaged over the critical areas. Second a non-linear strip theory sea keeping code determined ship mot100094 Numerical prediction of model podded propeller-ice interaction loads

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Properly designed cargo access equipment is vital to the safety, efficiency and earning capacity of a merchant ship. This book covers all types of cargo access equipment for both vertically and horizontally loading ships, with particular emphasis on the latest developments in container ships, Roll on-Roll off systems and other specialised configurations. Detailed consideration is given to the relationship between access equipment and ship design, access equipment in operation and its effect on ship's performance, the historical background and likely future developments.

Fuel consumption measurement on ships has generally been an inaccurate process and the results are often viewed with distrust by shipowners. This paper reviews some of the recording methods used and gives details of a new monitoring system and how it was chosen. The system chosen was found to be significantly better than other systems and should encourage ships' officers to make better decisions about the operating of their ships so reducing main-engine fuel consumption. It is hoped to build up a data base for each vessel fitted with the system showing its fuel consumption characteristics. This can then be used for reference purposes to indicate ways of saving fuel.

Covering historic ships of the world, the author describes each vessel as she was in her prime, relates the ship historically to her time and to other ship designs, tells how she came to be preserved, and in what port she now has her final anchorage. The history of each ship, and how she looks today, is illustrated with more than 120 photographs throughout.

Modern integrated propulsion systems for naval and commercial ships are presented. Firstly historical propulsion systems are considered briefly. Then the determining factors in the choice of propulsors transmissions and prime movers are examined together with their applicability for modern naval ships and commercial ships. The choices between mechanical geared and electric drive are also considered. Finally a more detailed look is taken at some system configurations in both naval and commercial markets which offer alternatives to the current standard machinery system configurations. It is concluded that the power density requirement is key in the selection of any propulsion system.

The book is arranged into 2 parts. The first deals with Shipbuilding materials and strength of ships. The second part is more extensive and deals with Present day shipbuilding and maintenance. This includes the following chapters: Classification, Shipbuilding terms definitions and structural details of ships, Types of vessels (design of types, special types and vessels for carrying liquid cargoes), Principal features of structural design (including ballast arrangement), Shipyard practice, Ship modernisation and reconstruction (increased draught, length, tanker to bulk carrier or cargo-ship, removal and addition of decks) and Maintenance of ships.

This book presents the causes and means of prevention of corrosion in wood and iron ships. Contents include: Wood; Iron; Chronology of Iron Ships; Sheathing; Fouling; Corrosion; Improved construction;

The present work is a treatise on the work, design and construction of small sea-going ships and inland vessels which are generally built in small or medium-sized yards. It describes and illustrates cargo vessels navigating inland waterways; coasters of up to about 1000 tons deadweight and cargo ships intended for sea- and river-work combined; passenger ships and ferry boats on coastal and inland waterways; tugs, towboats, ice breakers and fishing craft regardless of size; and barges for the transport of dredging spoils. The description of each type if preceded by an outline of the conditions under which ship and engines have to perform their work. For inland craft this covers the main features of waterways with their depths, currents, navigability and dangers; for coasters and tankers the properties of cargoes and the demarcation of coastal waters; for passenger ships and ferry-ships the rules concerning number of passengers and amount of cargo, freeboard, safety-means and life-saving appliances, and in the case of ferries the different ways of crossing and accosting at landing stages; for tugs, ice breakers and fishing craft the various methods of towing, ice breaking and fishing. There is a special chapter devoted to some aspects of resistance and propulsion on waterways.

Review of 1990 developments in the world cruise industry including a discussion on corporate structure interrelation ships and groupings; Wartsila bankruptcy; Japanese built cruise ships; design features and characteristics of newbuildings and restructuring in particular layouts propulsion and safety features.

At the end of 1982 597 ships with diesel main engines and 90 ships with main steam turbine engines were given the MO machinery notations. This paper summarises the results of a statistical survey on the data of machinery failures and alarms collected from 272 diesel ships with MO notations.

A brief history examines the origins of Trinity House its work in training and licensing pilots the provision of pilotage services for London and other districts and as general lighthouse authority for England and Wales. Specialist vessels and equipment are described - pilot cutters; manned and unmanned lightvessels; lanterns; fog signal diaphones; lighthouse tenders; buoys and lighthouses.

Pump and pipe systems are described as follows Bilge and ballast for specialist ships including chemical and oil tankers liquid gas carriers and factory process ships; systems for ships using boil off or crude cargo as fuel; systems where waste gases are vented floored or incinerated; and manned space ventilation systems

Many issues impact the acoustic posture of a newly constructed vessel. The primary acoustic concern for oceanographic or survey type ships is to minimise the impact that ownship noise may have on installed sonar equipment. Ship acoustics are discussed together with how they evolved in the USNS PATHFINDER (T-AGS 60) class ship acquisition program. During the initial ship delivery process for this program it was determined that the acoustic posture of these ships was inadequate to support the mission requirement of deep-water bottom mapping. A comprehensive investigation was conducted and problem areas were identified. The findings of that investigation are summarised together with subsequent ones to fully document the acoustic issues that were present on this new class of ships. Additionally the modifications and improvements that were made to these hulls are addressed to stress the importance of vessel acoustic posture and how it relates to mission performance with respect to acoustics. The types of modifications that are addressed are: sonar fairing design; paint and hull conditions; propeller cavitation performance; hull appendages; bubble sweepdown and general acoustic requirements. Acoustic measurements and levels are provided as well as specific measures of system performance.

The USS Burke (DDG-51) Destroyer entered service in 1991. Since then over 50 ships of this design have been constructed. The production of these ships is to end in a few years with DDG-112 however these vessels will be serving in the US fleet for many years to come. They have received numerous upgrades over the years to keep pace with new and emerging threats yet the propulsion and electric power plant has remained largely unchanged. While this mechanical drive train has proved itself to be very reliable the design suffers from poor fuel economy when compared to other warships. Consequently there has been recent interest in exploring the addition of new technology such as hybrid electric drive or 'loiter motor' to improve the efficiency of these ships. The operational concept for adding a hybrid electric (COGLOG) drive system to the existing ships is explored a number of technologies for implementing such a system are examined and the potential for significant fuel savings is demonstrated if such as system were fielded. Both fuel savings and TOS (time on station) improvements for implementing a hybrid drive on the DDG-51 are noteworthy and will be reviewed.