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Numerical modelling of snow-shedding effects on a 110 kV overhead power line in Slovenia
AuthorsJanez Jakse ; Mohamed Thabet Al Harash ; Ghyslaine McClure
Date published2001
AbstractThis paper presents a practical problem of reduced electrical clearances experienced in Slovenia on 110 kV overhead lines on double-circuit towers caused by the effects of heavy snow shedding. A numerical study of static and dynamic calculations has confirmed that deflected line configurations and large-amplitude oscillations resulting from load shedding are problematic. The situation was corrected by the utility on some line sections by installing phase-to-phase long insulating rod spacers similar to those used to mitigate galloping conductor oscillations.
AuthorsJanez Jakse ; Mohamed Thabet Al Harash ; Ghyslaine McClure
Date published2001
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On the behaviour of huge offshore structures in unprotected seas
AuthorsN Takarada
Date published1988
AbstractA summary of investigations into the technology assessment of huge offshore structures with special reference to the behaviour and stability of floating type airport structures is presented. Discussions are made first on the environmental conditions of the site and then the results of theoretical analyses and experimental studies are introduced on the motion of the floating model as well as on the feasible design of the mooring system for the structure.
AuthorsN Takarada
Date published1988
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Propagation of DC arc on ice surfaces
AuthorsJ Zhang ; M Farzaneh
PublisherInternational Society of Offshore and Polar Engineers
AbstractThe velocity of DC arc propagation on a triangular ice sample is described. Experiments were carried out in a temperature-controlled climate room using a thyristor- controlled DC system and a high-speed camera. It was found that the DC arcs may randomly propagate either inside or outside the ice sample in two stages - at a relatively low velocity and then at high speed when critical length is reached. The effects of voltage polarity on the propagation velocity of DC were studied. The mechanism of flashover arc on ice-covered insulators is discussed.
AuthorsDate publishedJ Zhang ; M Farzaneh
1998
PublisherInternational Society of Offshore and Polar Engineers
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Simulations of ice ridge forces on conical structures
AuthorsB Sand ; G Horrigmoe
Date published2001
AbstractThis paper is focused on nonlinear finite element simulations of multi-year ice ridge - structure interaction. A general finite element code (ANSYS Release 5.6) is used for numerical simulations. The ice is treated as an isotropic nonlinear material capable of cracking and crushing. An iterative procedure is used for automatic calculation of buoyancy forces on partially submerged ice features. In addition contact mechanics is applied for the precise tracking of contact and sliding between the ice ridge and the structure. Numerical results are compared with well established analytical procedures based on plastic limit analysis. The numerical results are in good agreement with analytical solutions obtained by plasticity theory.
AuthorsB Sand ; G Horrigmoe
Date published2001
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Spectral analysis of irregular wave impact on the structure in splash zone
AuthorsBing Ren ; Yongxue Wang
Date published2002
AbstractThe spectral analysis from experimental data of irregular wave impact on the structures with large dimension in the splash zone is presented. The experiments were conducted in the large wave-current tank in the State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology. The spectral analysis results of the irregular wave impact pressure on the subface of the structure under various case studies are presented. The distribution of spectral moment of the impact pressure on the structure along the subface is given.
AuthorsBing Ren ; Yongxue Wang
Date published2002
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Testing communications systems on diving installations
AuthorsV Flook
Date published1995
AbstractSafe practices efficient operations and effective response to an emergency depend on clear communications between diver and topside. Tests on commercial diving installations show that all parts of the system are important. The work which has been done on designing and testing helium unscramblers has resulted in several unscramblers which work well when tested under optimum conditions. Design of the complete system including microphones hard wiring and the acoustics of the space between the diver and the microphone needs to the addressed. The need for good pre-recorded tapes of helium speed remains.
AuthorsV Flook
Date published1995
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The impact of recent stability regulations on existing and new ships and the impact on the design of ro-ro passenger ships
AuthorsM Kanerva
PublisherElsevier
AbstractThe recent development of ro-ro passenger ferries is considered. Application of SOLAS 90 and the Stockholm Agreement is discussed for both newbuildings and existing ferries by describing typical two examples. Space below freeboard deck; centre or side casings; rational cargo handling; efficient arrangement for trailer ferry; damage stability; and upgrading existing ro-ro passenger ferries are all areas investigated.
AuthorsDate publishedM Kanerva
2000
PublisherElsevier
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The implications of an all electric ship approach on the configuration of a warship
AuthorsDavid Andrews ; Alistair Greig ; Richard Pawling
Date published2004
AbstractThis paper addresses the implication of the adoption of an All Electric machinery fit on the configuration of a modern warship. The paper presents a series of studies using the SURFCON graphically centred preliminary computer aided ship design tool based on the design Building Block approach which originated in the Ship Design Research team at UCL. Explorations are undertaken for a monohull frigate concept design on how an advanced electric machinery fit could be configured to provide a more effective and survivable overall ship design.
AuthorsDavid Andrews ; Alistair Greig ; Richard Pawling
Date published2004
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The influence of nickel and nitrogen on impact toughness properties of low alloy basic electrode steel deposits
AuthorsTomasz Wegrzyn
Date published2001
AbstractThe influence of the variable amounts of nickel and nitrogen on impact properties of different basic electrode deposits are tested. Furthermore on the basis of the results of the influence of the variable amounts of nitrogen and nickel on impact properties of low alloy basic electrode deposits mathematical equations regarding those relationships are assuming that oxygen content and acicular ferrite in basic electrode deposits are nearly constant and amount of each is respectively 350-450 ppm of oxygen and above 700 of acicular ferrite.
AuthorsTomasz Wegrzyn
Date published2001
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The ISPS Code as a component of onboard resources in Bayesian analysis
AuthorsV Loginovsky ; A Gorobtsov ; V Kuzmin
Shelf Location213c
AbstractThe already enormous regulatory workload on a ship's crew has been increased due to ISM Code requirements putting more stress on human and organisational factors and particularly on deck officers' attention and performance. Research to develop a model showing the impact of the ISPS Code on workload and crew performance is outlined. HUGIN is the Bayesian network tool used and shows overload on crew members and limited resources on onboard ship.
AuthorsPublisherV Loginovsky ; A Gorobtsov ; V Kuzmin
Southampton ; WIT Press
Shelf LocationDate published213c
2005
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Tidal effects on cross-shore sediment transport on a shingle beach
AuthorsL K Trim ; K She ; D J Pope
Date published2002
AbstractResults are presented from a laboratory model study of the sediment transport processes of a shingle beach under the combined action of waves and tides. Parallel experiments were conducted with a constant water depth corresponding to the high water level of the tidal experiments thus allowing a direct comparison between the two cases. A look is taken at the experimental procedure. This is followed by discussion of the results.
AuthorsL K Trim ; K She ; D J Pope
Date published2002
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Wastewater management on board - a burden or a necessity
AuthorsB Beler-Baykal ; M A Baykal ; A Kukner
Date published2000
AbstractShip-based pollution is the most significant source of marine pollution and accounts generally for around 20% of marine pollution. Factors affecting the pollution potential of sea-going vessels are considered. The impact of ship-based pollutants on the marine environment is examined. Wastewater management on board is discussed and it is concluded that it is environmentally friendly and essential (from the design stage and throughout a vessel's operational life) to prevent marine pollution and to maintain ecological balances in water.
AuthorsB Beler-Baykal ; M A Baykal ; A Kukner
Date published2000
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Wind tunnel investigation of the influence of propeller loading on ship rudder performance
AuthorsA F Molland ; S R Turnock
Date published1993
AbstractWind tunnel simulation experiments were used to study the interaction between a model propeller based on the Wageningen B-series and model rudders of different type (skeg fully movable) and taper/geometry. Model particulars are described together with details of the test rig data acquisition system and methodology. Results are presented as effect of propeller on rudder performance (load distributions and lift drag centre of pressure as functions of propeller thrust loading separation and geometry) and effect of rudder on propeller performance.
AuthorsA F Molland ; S R Turnock
Date published1993
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Analysis on the hull girder ultimate strength of a bulk carrier using simplified method based on an incremental - iterative approach
AuthorsO Ozguc ; P K Das ; N D P Barltrop
Date published2005
AbstractA ship hull's structure is composed of plating stiffened by girders and stiffeners. The hull is subject to loading generated by hull weight cargo equipment etc. and buoyancy force. The loading causes vertical and horizontal bending moments vertical and horizontal shear forces and torsional moment. In estimating hull strength it is essential to take into account the vertical bending moment which generates the largest stresses in the ship structures especially in the middle part of the ship hull. The ultimate strength of the hull girder of a typical bulk carrier is analysed using a simplified method based on an incremental - iterative approach. First the vertical bending moment is examined by seven different methods. The moment versus curvature curves and the values of the ultimate longitudinal moments at collapse states are determined for both hogging and sagging cases. Secondly the ultimate strength under coupled vertical and horizontal bending moment is described. An interaction curve is obtained corresponding to the results of series of calculation for the ship hull subject to bending conditions with different angles of curvature. It is found that the interaction curve is asymmetrical because the hull cross-section is not symmetrical with respect to horizontal axis and the structural response of the elements under compression is different from that under tension due to non-linearity caused by buckling. The angles of the resultant bending moment vector and that of the curvature vX27082
AuthorsO Ozguc ; P K Das ; N D P Barltrop
Date published2005
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Effect of anti-pitching fins on ship's motions by the methods of evaluation of passengers' comfort
AuthorsR Shigehiro ; T Kuroda
Date published2000
AbstractIn the past the reduction of the pitching motion of ships by means of the anti-pitching fins at the bow has been analysed. What seems to be lacking however is the analysis of the anti-pitching fins at the stern. This paper evaluates the effect of the anti-pitching fins at the stern from the viewpoint of passengers' comfort. The impulsive force on the stern fin is smaller than that on the bow fin in slamming conditions. Model experiments are conducted to evaluate the effect of our anti-pitching fins on ship motions. The anti- pitching fin at the stern reduced vertical acceleration by 0.05 g in head seas with a significant wave height of 2.0 m. The new method for evaluating passengers' comfort consists of exposure duration and amplitude and frequency of acceleration. These are based on questionnaires given to passengers and measured ship motions of the training ship Kagoshima-maru. The correlation coefficient between the method and the questionnaires is 0.71. The method is shown to be reliable for evaluation of passengers' comfort.
AuthorsR Shigehiro ; T Kuroda
Date published2000
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Investigation of cylinder liner lacquers in the North Sea and Norwegian Sea regions
AuthorsOyvind Buhaug
Date published2007
AbstractAccumulation of deposits in the honing grooves on a cylinder liner is problematic because it eventually leads to high oil consumption and some form of remedial action will be required. In most cases the cylinder liners are taken ashore and re-honed to ensure that the deposit is completely removed and oil consumption is returned to normal levels. These deposits are commonly referred to as cylinder liner lacquer since the groove filling is often associated with a glossy amber appearance of the liner although groove filling and high oil consumption can also occur on liners that appear to be completely clean. Here the focus is on the groove filling regardless of the appearance of the cylinder liner. Findings are presented from an independent study on cylinder liner deposits from the North Sea and Norwegian Sea region. The ships where the deposits were found were all operating extensively at low load. Based on the observations in this study it is proposed that groove filling is an accumulation of material that occurs naturally on the cylinder wall in small amounts. As such it is not only controlled by the rate and mechanisms by which this material is formed but also on the rate and mechanisms by which it can be removed from the cylinder liner.
AuthorsOyvind Buhaug
Date published2007
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The securing of ISO containers: theory and practice : an ICHCA survey
AuthorsAnthony R Cole
Shelf Location230c
AbstractThe purpose of this survey is to examine the securing of ISO series containers in a variety of circumstance and from a number of aspects. The circumstances include the securing of containers on the upper deck and hatch covers of cellular container ships and on the upper deck and in the holds of general cargo vessels, on the flatbeds of rail cars and road vehicles, and on barges. The aim is to investigate the various types of lashing systems available and their use. A particular aspect of the report is the minimisation of the cost, quantity and range of lashings required. The survey considers initial and maintenance requirements and costs for this equipment, its reliability, safety, strength and suitability for the purposes required. A further aim is to analyse the aspects of ease and speed of operation, and linked to these aspects are the quantity and skill of labour required and the influence on training needs of variations in the type of equipment employed. Differing approaches to determining motions and forces on containers at sea and on land are also considered. The most important aim of the survey is to examine the possibility of standardising lashing techniques and equipment.
AuthorsPublisherAnthony R Cole
London : International Cargo Handling Co-ordination Association, c1981
Catalogue number688.8
Shelf LocationDate published230c
1981
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Conf on - Effect on ship design and operation of the 1978 IMCO Tanker Safety and Pollution Prevention Conference 7 Dec 1978
PublisherIMarE Conferences and Symposia
Date published1978
PublisherIMarE Conferences and Symposia
Date published1978
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Log of the Centurion:Based on the Original Papers of Captain Philip Saumarez on Board HMS Centurion, Lord Anson's Flagship During his Circumnavigation, 1740-44
AuthorsLeo Heaps
Shelf Location36d
AuthorsPublisherLeo Heaps
London, Hart-Davis, MacGibbon [1973]
ISBN number24610581
Shelf LocationDate published36d
1973
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Maritime Heritage & Modern Ports - incorporates the 2nd Intl. Conference on Maritime Heritage and 4th Intl. Conference on Maritime Engineering Ports and Waterways
AuthorsR Marcet i Barbe ; C A Brebbia ; J Olivella
Shelf Location213e
AuthorsPublisherR Marcet i Barbe ; C A Brebbia ; J Olivella
WIT Press
ISBN number1845640101
Shelf LocationDate published213e
2005