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The influence of the main factors on the impact toughness properties of low carbon steel welds
AuthorsT Wegrzyn
Date published1997
AbstractThe influence of the variable amounts of nitrogen and oxygen on impact properties of different welds are tested. Also on the basis of the results of the influence of the variable amounts of nitrogen oxygen and metallographical structure on impact properties mathematical equations regarding those relationships are given. First a look is taken at the welding procedure. Next weld metal testing is touched upon. After this the results are discussed.
AuthorsT Wegrzyn
Date published1997
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Third Report from the Select Committee on Science and Technology : Tracked Hovercraft Ltd : Session 1972-73
AuthorsSelect Committee on Science and Technology
Shelf Location237a
AbstractA report into the Tracked Hovercraft Ltd project, reporting on the project's history, the manner of its cancellation, the cancellation decision, comments on the evidence, proper evaluation of Tracked Hovercraft Ltd, the future of Tracked Hovercraft Ltd and the test site, and general conclusions.
AuthorsPublisherSelect Committee on Science and Technology
London : Her Majesty's Stationery Officer [HMSO]
Shelf LocationDate published237a
1972
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Vessel wakes and their impact on river banks: IMarE Sydney Branch Paper presented on 23-02-94 at a meeting of RINA (Australian Branch) and IMarE (Sydney Branch)
AuthorsB McRae
PublisherIMARE
AbstractA discussion of vessel wavemaking and its connection to river bank erosion. Reducing erosion from a combined hydrodynamic and geomorphologic standpoint is examined and topics include vessel modification and the Wigley hull model foil geometry foil position and foil angles levee bank simulation and a brief history of the problem.
AuthorsDate publishedB McRae
1994
PublisherIMARE
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Advanced applied research unravelling the fundamentals of 2-stroke engine cylinder lubrication - an innovative on-line measurement method based on the use of radioactive tracers
AuthorsV Doyen ; R K Drijfholt ; T Delvigne
Date published2007
AbstractDrain oils in 2-stoke marine engines are receiving a lot of attention as they are some of the most valuable tools for optimising cylinder unit operation and for defining predictive maintenance. Adapting lubricant feed rate burning bunker fuels of different sulphur content and of different quality or even adapting the lubricant to the fuel used are risky operations best associated with a control of wear and BN reserve by monitoring the drain oil for each cylinder. As the number of analysis results increase questions arise as to how representative such analysis is for the engine condition and also for the individual cylinders. Delta Services Industriels (DSi Belgium) and TOTAL France recently developed an innovative method for monitoring the flow of cylinder lubricant in a two-stroke marine engine. A key to this development is the use of new radiotracers compounds which are representative of the distillation interval of the base oil. The very high sensitivity of the new method allows the smallest remains of lubricant to be detected. These radioactive tracers are added to TOTAL Talusia LS40 cylinder lubricant and injected into a running full-size Sulzer RT-flex58T two-stroke test engine. The tracer was monitored using detectors to determine how long the cylinder lubricant remained on the liner wall and the flow of the cylinder lubricant through the engine.
AuthorsV Doyen ; R K Drijfholt ; T Delvigne
Date published2007
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Flow visualisation studies of exhaust smoke-superstructure interaction on naval ships
AuthorsP R Kulkarni ; S N Singh ; V Seshadri
Date published2006
AbstractThe problem of ship funnel exhaust is often studied through flow visualisation using smoke in a wind tunnel. It is a very useful tool for the naval architect to ensure that the funnel exhaust will not interfere during operation. Naval ships are particularly prone to smoke nuisance problems since they tend to favour short funnel heights because of competition for topside space. Flow visualisation studies are presented. These were carried out to understand the interaction between a bluff body air wake (of the funnel and superstructure or mast) and the ship's exhaust on naval ships. As a first step the analysis of the exhaust smoke-superstructure interaction was carried out in a wind tunnel for a generic frigate shape. Four variants of the superstructure configuration with progressive introduction of the structures on the topside (i.e. the superstructure or mast upstream and down stream of the funnel) were investigated in the wind tunnel at two velocity ratios through flow visualisation studies to understand their effect on the exhaust plume path. Apart from providing an insight into the process of plume dispersion in the vicinity of the funnel and other structures on topside of naval ships the results of the flow visualisation of the CFD (computational fluid dynamics) simulations (including particle tracing) of the exhaust smoke-superstructure interaction for cruise vessels ferries yachts as well as naval ships.
AuthorsP R Kulkarni ; S N Singh ; V Seshadri
Date published2006
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PACSCAT designs for operation on inland waterways
AuthorsJohn C Lewthwaite
Date published2006
AbstractA safe and environmentally friendly transport system is important for the entire European Community. Increasing levels of freight movements within the EU have led to major congestion on road systems with consequent increases in economic costs and environmental pollution. Demand for freight transportation is expected to increase by around 50% over the next ten years and it is difficult to see how road transport can absorb this. The PACSCAT (partial air cushion supported catamaran) high-speed river freighter project aims to develop and evaluate a novel vessel concept for fast waterborne freight transportation that will allow operation on inland waterways without the draught restrictions of conventional vessels. The vessels will operate at around 20 kt (37 m.p.h.) over twice that of a conventional barge thus competing directly with road transport. The payload capacity will be in the order of 2000 t which is equivalent to around 80 truckloads. The vessel's on-cushion draught is only 1.5 m in order to cope with shallow water conditions on the Rhine and Danube rivers. The PACSCAT river freighter design work was supported by a series of model tests in the UK and Germany. The manoeuvring and control characteristics have been represented in the real time simulator. A concept design for a smaller PACSCAT canal freighter has also been prepared.
AuthorsJohn C Lewthwaite
Date published2006
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Research on applicability of new materials to marine structures in tropical climates -durability assessment of new materials
AuthorsFuminori Tomosawa ; Shigeo Tsujikawa ; Tadashi Ono et al.
Date published2005
AbstractNew structural members that are light and durable are anticipated to reduce the running and maintenance costs of structures exposed to harsh marine environments such as offshore oil production facilities thereby reducing their lifecycle cost. This study investigates the applicability of new materials to marine structures focusing on their durability. To this end a 5-year exposure test has been carried out (beginning in 1999) on 3 types of specimens (for corrosion observation tension testing and joint strength testing) made of 21 selected materials (6 nonferrous metals 8 steels 4 composite materials and 3 rope materials). The specimens have been exposed at 3 sites: Okinotori-shima and Miyako-jima corrosive environments with high temperature and humidity and a thermo-hygrostatic room in a laboratory. Having completed the natural exposure tests in 2004 strength tests and observation was carried out afterwards until 2005. The results of such tests and observation carried out so far are summarised and a final assessment of each material is made. Within the range of the 5-year exposure test most of the selected new materials pose no problems with regard to durability. However marine structures are more vulnerable to alternate stresses than general structural members on land because of constant waves and pulsating gales on the sea. It is intended to investigate the durability of structural members under continued or cyclic stress as a subject in the future.
AuthorsFuminori Tomosawa ; Shigeo Tsujikawa ; Tadashi Ono et al.
Date published2005
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The effect of chord pre-load on the static strength of uni-planar tubular K-joints
AuthorsG J van der Vegte ; Y Makino ; J Wardenier
Date published2002
AbstractIn current design codes the equations accounting for the effects of CHS (chord stress in circular) and RHS (rectangular) hollow section joints are inconsistent. For CHS joints the chord stress function is based on the chord pre-stress while for RHS joints the maximum chord stress is used. To a designer it is confusing that different approaches should be used for different categories of joints which may lead to misinterpretations and errors. In the framework of a CIDECT programme it was decided to re-analyse the effects of chord stress of CHS joints in order to establish a chord stress function consistent for both circular and rectangular hollow section joints. A numerical parametric study has been carried out into the effects of chord pre-load on the static strength of axially loaded CHS K-joints where the main variables are the chord pre-stress the geometric parameters ß 2 ? and the brace angle ? which is directly related to the gap ratio ?. The effects of both tensile and compressive pre-load on the strength of the K-joints have been made clear. Furthermore the ultimate strength data have been compared with the recommended chord stress functions. It is concluded that a better understanding of the effects of chord pre-stress on the strength of K-joints is obtained by considering the maximum chord stress rather than the chord stress due to externally applied pre-loads as the governing variable.
AuthorsG J van der Vegte ; Y Makino ; J Wardenier
Date published2002
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The effect of wind waves on Langmuir circulations
AuthorsKen-ichi Uzaki ; Yukiko Uragami ; Nobuhiro Matsunaga
Date published2002
AbstractWhen the wind blows on lakes and seas wind-driven currents occur under the water surface and wind waves develop on it. The wind-driven currents often induce secondary circulations with the axes parallel to the wind direction. These are called Langmuir circulations. Since the circulations are relatively strong and comparable with the wind-driven currents their role is very important in the development of a mixed layer in the ocean gas transport processes through the water surface and sediment transport processes in a near-shore region etc. A study is presented to measure wind-driven currents in two cases where the wind waves are developed and suppressed and to estimate quantitatively the effect of wind waves on the Langmuir circulations. Two types of experiments are carried out to reveal the effect of wind waves on the Langmuir circulations which are the secondary circulations induced in wind-driven currents. One is the case where the wind waves are fully developed and the other is the case where the generation of wind waves is suppressed by adding surfactant to the working fluid. In both cases the formation of Langmuir circulations is confirmed and the reliability of the self-organisation mechanism was raised. It is suggested that the Langmuir circulations can be formed without the strong interaction between wind waves and currents. It was found however that the generation of wind waves makes the Langmuir circulations stronger and more stable.
AuthorsKen-ichi Uzaki ; Yukiko Uragami ; Nobuhiro Matsunaga
Date published2002
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Berlingieri on Arrest of Ships A Commentary on the 1952 and 1999 Arrest Conventions 3rd Edition
AuthorsF Berlingieri
PublisherLLP
AuthorsDate publishedF Berlingieri
2000
PublisherLLP
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Conf on - IMAS 94 Fire Safety on Ships Developments into the 21st Century London 26-27 May 1994
PublisherIMarE Conferences and Symposia
Date published1994
PublisherIMarE Conferences and Symposia
Date published1994
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A theoretical study on the effect of seaquakes on a three- dimensional floating body
AuthorsY Higo
PublisherInternational Society of Offshore and Polar Engineers
AbstractSeaquake forces acting on a three-dimensional floating body have been studied numerically. The green function which satisfies the Helmholtz equation and fulfils the free surface condition and the sea bottom boundary condition was introduced. The solutions of the seismic wave field and pressure distribution were obtained by making use of the boundary integral equation method. The seaquake forces were also obtained numerically.
AuthorsDate publishedY Higo
1998
PublisherInternational Society of Offshore and Polar Engineers
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Cost Effect of Ice Loads on Offshore Wind Generator Foundation
AuthorsM Maattanen
Date published2001
AbstractIn this paper a review on ice load scenarios and ice loads on a typical Northern Baltic offshore wind generator foundation are presented. The chosen ice conditions present a severe combination of level ice rafted ice and first year pressure ridge loads. A cost comparison is made on ice load effects on caisson and single pile foundations. Different water depth and ice load scenarios are compared to find out the cost effect and the potential of different foundation types.
AuthorsM Maattanen
Date published2001
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Ducted versus conventional propellers; a comparison based on economy
AuthorsL Sinclair ; O H Slaattelid
Date published1976
AbstractFull scale experience and model test data with computer analysis and prediction techniques are used to compare economic aspects and costs of ducted (fixed duct) and conventional propellers. These are specifically related to a system fitted on a bulk carrier and generally related to speed/power capital outlay on duct propeller and air injection equipment repair maintenance and operating costs with worked examples on the effect of ducts on tanker and OBO performance.
AuthorsL Sinclair ; O H Slaattelid
Date published1976
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Experimental investigation of the shipping of water on the bow of a containership
AuthorsNuno Fonseca ; Carlos Guedes Soares
Date published2003
AbstractThe paper presents the results of an experimental investigation of the shipping of water on the bow of a containership. Model tests were carried out in head regular and irregular waves of large amplitude. Measurements were taken of the absolute and relative motions the structural loads the height of water and the impact pressure on the deck and the horizontal impact pressure and total force on the first line of containers on the bow.
AuthorsNuno Fonseca ; Carlos Guedes Soares
Date published2003
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Feasibility of using free-fall lifeboats on passenger ships
AuthorsJ K Nelson ; R L Markle
PublisherInstitute of Marine Engineers
AbstractThe feasibility of using free-fall lifeboats on passenger ships is evaluated with discussion of: development of the concept from first patent to current implementation on cargo ships mobile drilling rigs and offshore structures; SOLAS carriage requirements for passenger ships placement implications and cost differential (comparison is made with conventional davit launched equipment); the need for crew and passenger training in the use of free-fall restraint systems; and the recent findings of an IMO panel of experts on RORO safety. Concluding remarks consider free-fall lifeboats to be inappropriate for general use on passenger ships but concede some specialist applications.
AuthorsDate publishedJ K Nelson ; R L Markle
1995
PublisherInstitute of Marine Engineers
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On ship manoeuvrability estimation based on IMO resolution No.A.751(18)
AuthorsE Nikolaev ; T Inutina ; M Lebedeva et al.
Shelf Location213c
AbstractThe ship dynamic stability criteria in the IMO Interim Standards for Ship Manoeuvrability - IMO Assembly resolution A.751(18) - are looked at. Course-keeping ability estimation for several ships is compared based on calculating both zig-zag and spiral manoeuvres. The spiral test gives a direct estimation of ship straight-line stability whereas the zig-zag test may give only an indirect assessment of this quality. The examples provided show the importance of including spiral tests in the procedure of ship manoevrability estimation.
AuthorsDate publishedE Nikolaev ; T Inutina ; M Lebedeva et al.
1996
Shelf Location213c
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On the modelling of foundations for jack-up units on sand
AuthorsM J Cassidy ; G T Houlsby
Date published1999
AbstractAn elasto-plastic model - Model C - appropriate for the modelling of foundations for jack-up units on sand is detailed. In addition the benefits of its application as the foundation model for a plane frame analysis programme (JAKUP) are demonstrated. The main characteristics of the structural foundation and wave loading models are looked at and example calculations are given. Lastly there is discussion of the applications of these models.
AuthorsM J Cassidy ; G T Houlsby
Date published1999
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Prediction method for hydrodynamic forces acting on a ship hull
AuthorsK Kijima ; Y Furukawa ; K Yukawa
Shelf Location213d
AbstractA prediction method for the hydrodynamic forces acting on a ship hull theoretically based on slender body theory is presented. This method needs only one parameter denoted by s which represents the initial position of vortex filaments shed from separation points on the ship hull. The results of numerical calculations show the prediction method to give good agreement between predicted and measured hydrodynamic forces acting on a ship hull.
AuthorsDate publishedK Kijima ; Y Furukawa ; K Yukawa
1998
Shelf Location213d
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The effects of scour on the design of offshore wind turbines
AuthorsJ van der Tempel ; M B Zaaijer ; H Subroto
Date published2004
AbstractThe effect of scour on the design of offshore wind turbines is explored. First some background information on scour is given covering development of scour types of scour effects of scour on offshore wind turbines and preventing scour. Next a look is taken at calculating scour including scour depth determination time scale of scour application of scour calculations in a random marine climate and standards/measurements. This is followed by consideration of effects of scour on the design of offshore wind turbines addressing pile designs natural frequency and fatigue.
AuthorsJ van der Tempel ; M B Zaaijer ; H Subroto
Date published2004