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Over the years there has been a number of reports of rogue or freak waves. In order to improve the design of ships and offshore structures enabling them to better cope with such severe weather conditions wave height and steepness as well as the shape of the wave profile have to be considered. The extreme New Year Wave as documented in numerous publications is varied with respect to wave height and period. These varied wave sequences are realised and measured in a model tank and applied to the investigation of motions and bending moments of an FPSO ship. The results are compared to the responses in the original wave train. Finally an investigation of the riskiness of extreme wave sequences in comparison with existing rules is presented.

The Code has been developed for application to small UK motor or sailing vessels of up to 24 metres load line length which are in commercial use at sea for sport or pleasure in favourable weather and daylight, and which do not carry cargo or more than 12 passengers. Chapters cover application and interpretation, construction and structural strength, weathertight integrity, water freeing arrangements, machinery, electrical installation, steering gear, bilge pumping, stability, freeboard, life-saving appliances, fire safety, fire appliances, radio equipment, navigation lights, shapes and sound signals, navigational equipment, miscellaneous equipment, anchors and cables, accommodation, protection of personnel, medical stores, requirements specific to use of vessel, tenders (dinghies), manning, compliance, clean seas and vessels operating under race rules.

The author (a Queen's Council) presents an update of a paper first given to the Institution twenty years ago in which he examines the place of expert testimony in the maritime courts of law and offers advice to those accepting the forensic challenge of propounding and defending a thesis in an adversarial context. Reference is made to Mr Justice Cresswell's summary of the duties and responsibilities of expert witnesses in civil cases and further discussion expands on: the role of the naval architect in the maritime courts of law; legal procedures; typical forensic problems for a naval architect; the advice of a naval architect; the expert witness; the preparation of the proof of evidence; relevant rules and procedure; and the art of giving evidence.

Reference is made to studies in which the feasibility of using gas turbine based power plant together with electric propulsion for future cruise ships - the COGES (Combined Gas Turbine And Steam Turbine Integrated Electric Drive System) is particularly discussed and the results of work in which it is evaluated for use in the Millennium Class cruise ships are presented - a comparative evaluation of conventional diesel-electric machinery was also carried out. Discussion includes - choice of gas turbine configuration (COGEN cogeneration vs COGES combined cycle); choice of machinery for a COGES application especially steam turbines and heat recovery steam generators; development of the COGES system; reliability analyses; and availability assessments in which compliance with the Rules is noted. The concept design COGES power plant and ancillary systems for the Millennium Class vessels is described with attention to the use of 3D and 4D modelling to co-ordinate technical basic design and architectural design. Significant further developments for the next generation cruise vessels are briefly considered especially the All Aft Concept with machinery comprising COGES power and pod propulsion.

The hydrodynamic behaviour of different aft body shapes are described with attention given to pressure distribution water flow direction buttock angle and shape effects. Some general information and thumb rules are given regarding aft hull lines design. The concept of a 'wave damping aftbody' is described. This has the advantage of not having a typical aft crest wave and much smaller wave troughs and transom waves than earlier forms. The design is illustrated with examples ranging from fast ferries to the world's largest Eagle-class cruise liner the Voyager of the Seas and its benefits are briefly outlined.

QinetiQ have been working on the design and analysis of trimaran warships for over 10 years. Details of work carried out to understand the wave-induced loading and consequent structural response of trimaran hulls is presented. The programme of work described has been based on hull forms varying from 12000 to 23000 tonnes displacement. Studies of local prediction finite element analyses and parametric studies to develop draft design rules for trimarans are presented. Load prediction methodologies have been developed based on static balance and 3D potential flow theory and validated against segmented model and full-scale operational trials. Finite element analyses have been carried out to derive an understanding of the load paths within trimaran structures in both the damaged and undamaged condition.

Recently IACS (International Association Classification Societies) adopted the CSR (Common Structural Rules) for Tankers and Bulk Carriers in which the requirement relating to the ultimate strength of the hull girder structure is described. The theoretical background and the results of verification study are neither released nor well summarised. Furthermore the requirement is not described as a form of deterministic formula but only a calculation program is provided whose source code is not disclosed. Here a formula for estimating the ultimate bending strength of the hull girder is proposed. The formula is compared to the results of rigorous non-linear finite element analysis and those of the program which was provided by DnV. For this study the reliability of the non-linear structural analysis procedure was verified by comparing its results with those of the test which was carried out for the large frigate model.

Fibre reinforced plastics have for a long time been used in boats and leisure crafts. In those applications the advantages such as low manufacturing cost and little need for maintenance are obvious and well known. The use of composites in larger vessels have been limited to some very special applications such as naval mine hunters. New production methods have been developed that have reduced the labour hours and the amount of materials needed. The materials have become cheaper and better due to increased volumes. As the knowledge among technicians and engineers has increased the composite technology has matured. Today many universities have education programs specialized in composites. This has helped to raise the acceptance among operators and the general public. Classification societies and governmental organisations have rules and regulations on the use of composites in ships that also include fire requirements. The future looks good for composites in commercial ships and the product range will be expanded from todays high speed ferries and smaller work boats to larger ships and superstructures.

In the practice of engineering design for ships and ocean structures and in many classification rules the Morrison equation approach and the strip method are used and defined to determine motions and loads encountered by floating structure in waves. Considering the complex structure and large-scale for the semi-submersible platform the panel method is used in this computation. For the global and fatigue structural strength analysis of a semi-submersible platform the wave loads of design conditions are calculated by using the 3D boundary element method. The maximum of vertical bending moment torsion moment and horizontal spilt force are determined from a series of design waves with limited period and positions of incident wave crest. The extreme wave loads under the combination of wave parameters and the transfer functions of wave loads are used as the input of hydrodynamic pressure in the 3D FEM analysis process.

High-speed vessels offer cost-effective options for short-haul surface transportation in regions with navigable waterways and heavily congested surface arterials. A concept is presented to use RCM (reliability centred maintenance) in conjunction with an existing ABS Guide to satisfy Special Continuous Survey of Machinery requirements. RCM combines design and maintenance requirements to control maintenance costs and realise enhanced operational reliability. It is shown how RCM concepts could be used with existing rules and regulations to help develop the maintenance plan intended to satisfy the maximum number of survey items and to provide data to support the extension of machinery overhauls beyond the five-year cycle and eliminate unnecessary maintenance tasks.

For mooring chains of offshore floating production units API (American Petroleum Institute) recommends the use of its TxN fatigue curve considering the MBL (Minimum Breaking Load) of an ORQ (Oil Rig Quality) chain even if the chain has a higher grade. This curve has been used in mooring system design of offshore floating production units since the draft edition of API Recommended Practice for Design Analysis and Maintenance of Catenary Mooring for Floating Production Systems in May 1989. Several fatigue tests have been done by petroleum industries chain manufacturers and research centres. Those fatigue tests show that the use of the MBL of an ORQ chain for higher grades is a conservative assumption. This paper presents an overview of the fatigue curves of materials for mooring lines: stud and studless chains steel wire ropes and polyester fiber ropes. This overview is based on recent tests rules and published papers.

A practical approach to determine the structural design loads of turret moored FPSO (Floating Production Storage and Offloading) tankers is suggested in this paper. The linearized restoring forces acting on the ship hull by the mooring system are calculated according to the catenary theory. The effect of the restoring forces is included in the equations of motions of the ship in the form of linear stiffness coefficients. The hydrodynamic coefficients are calculated by the three-dimensional potential flow theory. The equations of motions are solved in frequency domain and the motions and wave loads responses can be obtained. Then the short-term and long-term analyses are carried out for the wave loads of this kind of ship. With a 250m turret moored FPSO tanker as an example according to the given environmental sea states data headings exceeding probability for the FPSO tanker the structural design loads are calculated and compared with those obtained from rules for traditional tankers with the same dimensions. By this approach it is possible to perform a practical and efficient calculation of structural design loads of actual turret moored FPSO tankers.

'A handbook of rules, formulae tables etc. relative to material, scantlings, and pressures, safety valves, springs, fittings and mountings etc. for the use of engineers, surveyors, draughtsmen, boiler-makers and steam users'. It is stated in the Preface that it is hoped that the book will be of use in settling the scantlings for boilers in the process of construction and in determining the working pressures for those already made. Contents include sections on: properties of materials for boilers, iron boilers, steel boilers general aspects about boilers including testing and examinations of boilers. Presents numerous tables of data.

There has been a tendency over the last few years to develop ships capable of carrying several different types of cargo. This paper describes combination gas and chemical tankers. The liquids they can carry include oil products acids and edible liquids such as wine and vegetable oils. The SOLAS MARPOL and IMO safety rules applicable to such ships are outlined. The special arrangements for cargo containment cargo handling and safety are reported. Amongst factors considered are cargo tank design cargo tank insulation piping systems cargo transfer facilities cargo temperature control venting systems cargo monitoring instrumentation and fire-fighting installations. So far 10 such ships have been built with independant pressurized cargo tanks made of stainless steel and a further 5 are on order or under construction.

The LPA Watercraft is a 25-metre aluminium landing craft that has been designed to DNV's HSLC rules and the Commonwealths requirements to meet the requirement of Defence Project JP2048 Phase 1a. The Watercraft significantly improves the deployment capabilities of HMAS Manoora and Kanimbla reducing the time it takes the RAN's (Royal Australian Navy's) amphibious ships to unload a battalion-size group of soldiers equipment and stores by at least 30%. Equipped with 130 square metres of open vehicle deck sufficient to accommodate 5 ASLAVs (8 wheeled Light armoured vehicle) rather than the present limit of 2 onboard the current landing craft the LCM8s. It has full drive-through capability with bow and stern doors can carry 65 tonnes of vehicles and-or cargo and is able to undertake independent open water passages with full accommodation for crew. The vessel has been designed so that it is capable of being stowed on the HMAS Manoora and Kanimbla foredeck and handled by the ship's crane which has meant strict weight and size restrictions. Twin Detroit Diesel series 60 diesel engines coupled to two Doen DJ260 waterjets provide significantly improved manoeuvrability beach landing capability and a range of in excess of 700 nautical miles. The contract also includes the full suite of deliverables

Modern naval vessels have comprehensive platform management capabilities that allow them to achieve unprecedented levels of operational effectiveness and contribute to crew reduction. The design of advanced platform management systems requires an in-depth analysis of the consequences they will have on the vessel design and operation during the early project definition phase. The paper contends that analysis should be performed by a team with different expertise and shall include the system architecture and technology the level of functional integration the human-system integration the applicable standards and rules and the survivability of the system.

Decisions regarding the layout of a warship's compartments are taken at an early stage in the design process. DEGAs a software tool developed with a view to assisting the decision making process as well as providing input to the audit trail backing up the decision is presented. A graphical user interface enables the designer to interactively locate compartments and test the arrangement against a set of rules read from a database which dictates how the positions of different compartments should relate to each other. The use of The DEGAs tool is illustrated by application to generic monohull and trimaran configurations enabling the benefits of one to be compared to the other in a quantative way. Conclusions are made about the value of such tools to the overall design process.

Research into the problem of green water threatening and causing serious damage to vessels in rough weather dates back years. The purpose of flaring the bow or raising the freeboard was to help prevent green water from impinging onto the main deck as it could endanger equipment and lives. Breakwaters obviously need to fulfil their function (protecting sensitive structures or cargo) while at the same time remaining intact and imposing manageable loads onto supporting structure. Clearly such breakwaters should also be cost effective so that complex designs with extensive welding may not be preferable. Green water loading on breakwaters is discussed for trading vessels like container ships which have forward speed and for FPSOs which have zero speed. Different generic designs of V shape vane type double skin with and without holes and forward sloping forecastle (whaleback deck) breakwaters applied to trading vessels are discussed. Guidelines for modelling green water horizontal loading on breakwaters of FPSOs and trading vessels using CFD techniques is given. Also included is a review of breakwater design criteria in rules and regulations.

Pipelines are subjected to different combinations of loadings such as internal and external pressure bending and shear forces. The research programme that led to Dutch guidelines for limit state design of buried pipelines is summarised together with later programmes that focused on offshore pipelines. Limit state design differs from conventional design methods because it specifically addresses each failure mode eg burst collapse etc. The rules of the Dutch pipeline code NEN 3650 are considered and recent developments in international standards are discussed. Practical applications of the pipeline module available in the finite element program DIANA are given and its advantages particularly for evaluating fitness for purpose are highlighted.

A literature survey of high quality girth welds intended for pipeline risers was carried out and the results are compared with full scale resonance fatigue test data on 6" pipes. The samples were made from 168.3 x 9.9mm (OD x WT) seamless pipes each having two welds. Post failure examination of the welds was performed to determine the type and size of defects in the failure initiation area. Fracture mechanics calculations were carried out to determine the effect of defects on fatigue life. The main results from this project are summarized in this paper and the S-N data is compared with published data for pipes of similar sizes. The test results were compared with published data on 6" pipes with high quality welds. The scatter in the fatigue test data was reduced when comparisons were based on the local stress at the point of fracture initiation. The implications for design rules of the findings in this work are discussed.