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Cavitation erosion on propellers and rudders during their operation at sea is destructive and may cause loss of performance of ships leading to costly maintenance. Determination of cavitation erosion characteristics on the different materials used for propellers and appendages will help the ship designer during the early design process in mitigating the problem through choice of materials their treatments and coatings. Also detection of erosion at an early stage through acoustic measurements can be valuable. This paper examines the development of the test method at Lloyd's Register's Laboratory. The approach taken characterises the propeller materials through cavitation erosion tests. Attempts have also been made to characterise materials based on mass loss and acoustic measurements.

This paper looks at the technology and manning of the future from the next class of Future Surface Combatant for the Royal Navy to the ships that might exist towards the end of the 21st century. The commercial and military trend is towards IEP with fully flexible power systems with a multitude of power sources. The paper discusses the benefits this adaptable architecture presents with possibilities of electromagnetic launch and novel sensor and weapon systems. The paper suggests that prime movers are drifting away from diesels towards gas turbines in the short term but towards the latter half of this century large fuel cells will be providing most of the power demands. After a brief introduction attention is given to technological developments. Next manpower is considered. Lastly the future is touched upon and conclusions are drawn.

Seven ship design studies carried out at University College London (UCL) are reviewed. The studies involved sizing the ships determining the dimensions and hull form and preliminary design of stability powering strength manoeuvring seakeeping performance and general arrangement. The studies have shown the versatility of the trimaran configuration but the need for more comprehensive testing of the concept was highlighted. The objectives scope and initial results of tests on a 6 m model trimaran frigate hull are described. The work is being carried out in the main Manoeuvring Tank at the Defence Research Agency (DRA) Haslar. Analytical predictions are being made at UCL in parallel to these tests and these are summarised. The advantages and disadvantages of adopting a trimaran form for future frigate design are discussed.

The United States Coast Guard is committed to the development of regulations that enhance maritime safety through partnerships with the marine industry. This paper discusses the development of two specific policy file memorandums (PFM l-98 and 2-98). PFM 1-98 provides guidance on fire test requirements for plastic piping as set forth in IMO Resolution A.753(18) Guidelines for the Application of Plastic Pipes on Ships and as required by 46 Code of Federal Regulations 56.60-25(a). The PFM also provides requirements for use in specific locations unique to offshore oil platforms. PFM 2-98 addresses FRP grating qualifications and tests to establish structural fire integrity characteristics based on location and service. This PFM also updates the requirements for flame spread smoke and toxicity testing for both FRP grating and cable trays.

A state-of-the-art report on the model experiment techniques and load prediction methodology for high speed craft is presented. A general review of theoretical load prediction methodology includes discussion of load components (hydrostatic loads wave and motion induced loads impact loads hydrodynamic and aero lifts and motion control forces) load prediction in irregular seaways linear theories (two dimensional strip theory and three dimensional theory) non-linear theories (2D quasi-linear theory two and a half dimensional high speed theory and 3D theories) slamming load prediction (Wagner's approach momentum theory 2D boundary element method) and prediction theories for surface effect ships and planing craft. Several model test techniques which are commonly used for high speed craft are discussed including: tank model tests (regular wave tests and irregular wave tests)

The complexity of today's ship systems exceeds capabilities of existing tools for 'total system engineering'. Complex systems can be simplified by applying advanced technology. The challenges of AES (all-electric ship) technology are analysed and some new ideas are described such as the 'relational' design process enabled by physics-based modelling and simulation. Physics=based analysis will enable statistics from all of industry to be gathered in support of engineering justification and reliability assurance. Power electronics is used to simplify complex systems. Also described are the marine industries sub-committee activities in the development of new IEEE standards based on collective industrial experience and consensus for power electronics and medium-voltage DC power systems on ships.

Second Int Conf held in 1972 Papers are Shallow draught towboats in the Canadian northland Towmaster tug progress Lighters and seagoing barges and the design of yaw controlling units Tractor tug family fitted with rudder propellers Marine equipment in the British Columbia logging industry Location of the towing hook on a Voith tractor Towage surveys Tow ropes Ropes and wire ropes for marine towage Dynamic properties of marine fibre ropes Replacements in a small tonnage fleet Crews grouses Considerations of the special problems of limitation of liability in the case of the tug Potential hazards of monster tankers Tug pneumatic fender An ocean going tug on heavy fuel Tug performance related to propulsion machinery Engine monitor systems for tugs Cable control systems Cathodic protection - how can it help tug owners? Tug communications Design and application of heavy duty towing winches The effect of a nozzle on steering characteristics Application of Kort nozzles - state of the art Economic advantages of sectional vessels and push towing A comparison study of tug barges and conventional ships "Murvicker" tugbarge system Economic assessement of tug and barge operations A tub/barge transportation system

UAIS (Universal Automatic Identification System) is presented. It is a shipboard broadcast transponder system combining satellite-based positioning systems electronic charting communication and network architecture. Its technology is specified and its principles products and services are examined. Its role in enhancing safety at sea is discussed. Firstly it is recommended as an enhancement to radar as it is not weather-condition-sensitive. Next its uses in enhancing search and rescue are considered. Then its role in various activities is examined: assisting in environmental activities and radar-relaying preventing piracy helping with navigation equipment passing safety-related messages and weather-related information. Finally the present situation of UAIS implementation and the future development of UAIS (including a link with SOLAS ships) are outlined.

Missile systems impose significant design requirements on their host platforms as did their gun-based precursors. This coupled with the increasing lifespan and flexible role requirements of new platforms can lead to an unsustainable spiral of size and cost. SVL (Soft Vertical Launch) is a technique that can break this cycle by allowing ship designers to integrate missile systems more seamlessly into new-build ships. Significant weight and volume savings are available by adopting this technique compared to only using general-purpose VL (Vertical Lift) silo systems. It is also economically feasible for the first time to retrofit new missile systems onto existing platforms as part of a through-life capability management plan. Adoption of SVL also benefits operational performance safety survivability and signature management compared to other options for installing ship borne missiles.

The search for the definitive passenger list of Titanic has consumed researchers for 90 years. Lists marketed under various names invariably prove to be compilations drawn from several sources, often perpetuating earlier inaccuracies and with no citations whatsoever. These documents are now scattered throughout archives in the UK, the USA and Canada, with most now being withdrawn from public access for safekeeping.Drawing upon her extensive research, Debbie Beavis is able to demonstrate the reliability or otherwise of these documents whose accuracy has never previously been fully examined.The information gleaned by comparing the US and British passenger records is astounding. In this book she demonstrates that any two entries for the same person were often far from identical and that any attempt to arrive at a complete list of passengers was futile. For many passengers not only was there contradictory evidence of their personal details and fate that night, but similar confusion as to whether they even sailed at all.

Navies have always evolved but the process is usually gradual and dictated by the longevity of the ships. (From the start of design to retirement of the last of class can easily be 50 years.) Occasionally there is a step change when a disruptive technology is introduced. HMS Warrior the Dreadnoughts aircraft carriers are examples of this. This paper considers what would happen if the whole RN surface fleet were to be renewed at once with an in-service date of 2015. Practical considerations of construction capacity and financial issues are put aside and historical ties are swept away. The analysis is based on the design requirements set for the MSc students at UCL in their ship design exercises for 2007. The paper will briefly describe the aircraft carrier and the impact on the design of having a fleet-wide policy that is temporally consistent and that does not have to accommodate any existing vessels or their operating practices. Surprisingly the apparent freedom of design is an illusion and there are so many external constraints that the resultant fleet is not that different from what we have today.

The many factors which affect the final consequences of ship hull damage are random in the nature and their influence is different for different ships. For this reason probability of collision survival is taken as a measure of ship safety in the damaged condition (e.g. a measure of merit of a ship's subdivision). A general framework of the probabilistic subdivision regulations is presented highlighting the fact that indices of subdivision are the same as the mean conditional probability of collision survival known as the 's' factor. Rules for averaging this factor are discussed. Finally a link between the indices of subdivision and the mean sea state the ship can survive is highlighted. This link may help with the selection of the required values of the indices.

Free-fall lifeboats are a newly developed evacuation system suitable for use in large merchant ships and offshore structures. Although the launching performance is efficient the motion of the boat after water entry can be dangerous if the launching conditions are not appropriate. Studies on boat motion and exerted acceleration on hull structure are described. The relationship between design parameters and the motion of the lifeboat after water entry is studied by a series of model experiments and a numerical simulation method. A new concept for launching free-fall lifeboats is described. A great improvement of the lifeboat motion after water entry is illustrated and performance validation of the concept is described. (Diagrams illustrating the research are shown on pages 6.2.7 - 6.2.11.)

The potential use of aluminium sandwich panels in the construction of weight-critical ships is considered with attention to theoretical and experimental determination of its mechanical properties (including tensile strength yield strength elongation compressive strength shear modulus and behaviour on bending and crushing) and to the way in which the material could be used in the structural design of a hypothetical fast catamaran ferry: the advantages of the sandwich material are discussed in terms of strength to weight ratio and fabrication costs: comparison with conventional single skin stiffened panels is made throughout.

Shaft generator systems feed power to ships' the electric apparatus using power produced by the main engine. However the drawback of this system is that there is a large amount of harmonics in the output voltage waveform. A new system is proposed with simple circuit configurations which prevents output voltage distortion. This system is equipped with a duplex reactor to cancel out the subtransient inductance of the synchronous compensator. The steady-state characteristics of the system are discussed and it is shown that when the duplex reactor is used the inverter dc input voltage and synchronous condenser terminal voltage increase for a larger system output to maintain constant terminal voltage output. A simple method of suppressing the increase in these voltages is also proposed. The effectiveness of the proposed system is confirmed with experimental investigations.

The manufacture of pressurised LPG tanks for installation on board ships at present requires PWHT (post-weld heat treatment) when the steel plate is over 40 mm in thickness. However there are few PWHT facilities in the world. A study is presented using fracture mechanism and experiments to produce LPG tanks made of welded steel plate with a thickness of more than 40 mm without PWHT. Results show that there is no difference in the strength and toughness between welded steel plate of 40 50 or 60 mm with PWHT or without PWHT at -10 oC.

A two-part paper which investigates the reasons for the loss of the OBO mv Derbyshire in 1980 for the purpose of examining the vulnerability of bulk carriers in general. The first part relates to theoretical studies which suggest that although field stresses in the hull of the Derbyshire complied with design rules that have not significantly changed they were dangerously large. The calculations suggest that cracking would likely occur just forward of the superstructure. The second part is based on re-interpreting available information for the Derbyshire and applying it to her sister ships to see what pattern of behaviour emerges. The conclusions of both parts are virtually the same and state that the vessels are susceptible to fatigue cracking.

A cavitating propeller is a major source of underwater noise produced by ships and submarines. If not addressed properly the noise can adversely affect the ocean environment passenger comfort and any stealth performance. Recent research in this area is presented. The research aims to develop computational techniques to allow a designer to predict propeller noise and to experiment with various propeller noise reduction measures in a virtual environment. The research covers the following areas: overall propeller noise prediction using ANPRO software and propeller noise prediction code; overall propeller noise prediction using 3D CFD simulation of propeller and propeller noise prediction code; overall propeller noise prediction with the effects of air injection control; CFD simulation of cavitating propeller blade section for the effects of skewed propeller and obstacle respectively. Some 14 pages of diagrams graphs and photographs conclude the paper.

The major influence on sound propagation and attenuation in surface ship wakes is the presence of bubbles. Air bubbles are created in copious quantities in wakes of surface ships. A better understanding of the propagation conditions for sound in surface ship wakes is sought in order to produce realistic sound propagation models for prediction acoustic qualities of wakes. A high resolution multi-beam sonar looking up at a wake produced by a passing surface ship provides data characterising the wake structure in the along-wake the cross-wake and the depth directions. A simple wake model is developed from historical data and is used with a 2D PE code to calculate the loss of acoustic energy in the wake. The models used and the results are discussed together with the plans for improvement.

Strong demand on efficient container tradce has accelerated the development of large containerships. the increased size which has never been experienced raises many challenges for designers such as initial design optimization hatch open ing deflection and strength. To achieve these challenges the authors developed and conducted initial design optimization system extensive structural analysis system named SPB-HULL and onboard measurement of ships in service. In this paper results of these activities and actual examples are described and it is shown that overall safety and economy can be simultaneously achieved even for ultra-large containership by effective combination of initial design optimization extensive structural analysis through SPB-HULL and feedback from onboard measurement. These achievements have been adopted to actual design