-
The effect on installation on the pullout capacity of ground anchor
AuthorsI Zakaria
Date published2000
AbstractThe objective of this investigation is to evaluate the effect of disturbance set up during installation on the pullout capacity of a ground anchor. Investigations show that the test results in homogeneous sands beds is consistent with previous theories. For an anchor embedded in a disturbed zone its breakout factor is also dependent on the ratio of depth/diameter of the anchor. The ultimate resistance of this anchor is significantly reduced when the ratio of depth/diameter exceeds 3. However the effect is not apparent when the width of the disturbed zone is equal to or more than three times the anchor diameter.
AuthorsI Zakaria
Date published2000
-
The influence of slamming and whipping on the fatigue life of a high-speed catamaran
AuthorsGiles Thomas ; Michael Davis ; Damien Holloway et al.
Date published2005
AbstractThis paper reports on an investigation into the influence of slamming and whipping on the fatigue life of a large high-speed catamaran. Full-scale measurements of slam events were conducted on a 98m Incat catamaran to investigate its slamming behaviour in a variety of sea conditions. The full scale results were then used to determine the influence of the presence of slam events on fatigue life. In addition the effects of significant wave height slam occurrence rates slam peak stresses and whipping behaviour on fatigue life were examined.
AuthorsGiles Thomas ; Michael Davis ; Damien Holloway et al.
Date published2005
-
Determination of wave bending loads on a 40 knot long slender open topped containership through model tests and hydrodynamic calculations with particular reference to the effects of hull flexibility on fatigue life
AuthorsE Dudson ; H J Rambech ; M K Wu
PublisherRINA Conference Proceedings
AbstractA project to determine the design loads on a high speed transatlantic pentamaran are outlined with two classification societies performing the design load predictions each calculating different loads. A comprehensive series of model tests were performed to increase confidence in the reliability of calculated loads. The model tests are described together with a discussion on the verification of predicted loads. The effects of non-linear movement and flexibility on the vessels fatigue life are also discussed.
AuthorsDate publishedE Dudson ; H J Rambech ; M K Wu
2001
PublisherRINA Conference Proceedings
-
On-line monitoring of continuous process plants
AuthorsD W Butcher (editor)
Shelf Location207b
AbstractIndividual chapters are based on papers presented at the International Conference on On-line Surveillance and Monitoring - organised by the Society of Chemical Industry in London during 1983. The subject matter has been systematically developed to include sections on physical and chemical condition monitoring, applications to components, processes, and complete systems. Topics that receive particular attention include: monitoring by acoustic emission and ultrasonics; on-line corrosion monitoring techniques; predictive monitoring of process equipment; plant monitoring by vibration and noise measurement; monitoring of conventional and gas turbine power plant.
AuthorsPublisherD W Butcher (editor)
Chichester ; Ellis Horwood Ltd, for the Society of Chemical Industry, London
Shelf LocationDate published207b
1983
-
On liquefaction countermeasure in the soil around a caisson- type quay wall on pile foundation
AuthorsT Takatani ; Y-h Maeno
Date published2000
AbstractThe seismic behaviour of a caisson-type quay wall resting on pile foundations against the 1995 Hyogo-ken Nanbu Earthquake is numerically evaluated using a liquefaction analysis based on an effective stress model. The effectiveness of applying pile foundations to a caisson-type quay wall is investigated by considering two liquefaction countermeasures for five different situations taking into account the pile length as well as the differences in pile arrangement beneath the caisson structure. The effect of pile length under the caisson on the deformation of the caisson and the soil around the caisson is numerically evaluated using liquefaction analysis. The feasibility of using non-liquefied material in the reclaimed land behind the caisson structure is investigated from the view of a liquefaction countermeasure.
AuthorsT Takatani ; Y-h Maeno
Date published2000
-
On the non-linear analysis of pipeline- soil interaction dynamics on the ocean bed
AuthorsVincent O S Olunloyo ; Charles A Osheku ; O Damisa
Date published2005
AbstractThe non-linear dynamic response interaction of a pipeline on a moving ocean-bed is investigated where the pipeline is idealised as a hollow beam vibrating on a non-linear elastic foundation with a fully developed fluid flowing inside and the assumptions made in respect of the material properties of the soil at the ocean bed are enumerated. Next the effect of the geology is examined by constructing a model for the geomechanical behaviour of the ocean bed. For this purpose the seabed is treated as a rigid porous body. After this the analysis of the results is considered using typical values for some of the soil and physical parameters experienced in practice. Finally results are discussed together with the implication for engineering works associated with the laying of the pipes on the ocean bed.
AuthorsVincent O S Olunloyo ; Charles A Osheku ; O Damisa
Date published2005
-
The Impact of Coiled Tubing Fatigue on Pressure and Tension Limits
AuthorsY S Yang
Date published2000
AbstractCoiled Tubing (CT) is subjected to mechanical fatigue damage as it is cycled on and off the reel and over the gooseneck. The impact of fatigue on CT material yield strength and the effects of reduced yield strength on CT pressure and tension limits were evaluated. Experiments on CT fatigue cycling and mechanical tests on cycled CT samples were conducted using both a standard CT fatigue fixture and a tensile testing machine. Based on the test data an empirical relationship between number of fatigue cycles and yield strength reduction was developed. This relationship was incorporated into CT collapse/burst and tension predictive criteria where the reduction in yield strength was not considered previously.
AuthorsY S Yang
Date published2000
-
What naval architects should be taught on marine engineering items and how - a view from Finland
AuthorsP Hakkinen
Date published2000
AbstractThe ship machinery topics that are lectured on to naval architecture students show an established content worldwide. There are some variations e.g. turbine propulsion plants receive more attention at US universities than in Europe. Respectively special courses on naval craft and fishing vessels are lectured on in some countries. The paper deals with the changing demands. The key question is ‘What should a naval architect know about ship machinery?’ The paper is based on 10-years of university teaching experience. The feedback of graduated naval architects and their employees is included. Also the students’ views on the courses various teaching methods and textbooks are looked at. Finally some remarks are made on the means of naval architects to maintain and upgrade their professional skills.
AuthorsP Hakkinen
Date published2000
-
Laboratory experiments on the hydrodynamics of waves on adverse currents
AuthorsL Cappietti
Date published2003
AbstractA series of laboratory experiments was conducted in a flume to study the effects of adverse currents on regular and irregular waves. The transformation of regular and irregular waves on a sloping bed was studied with and without currents. Effects of the currents on the waves transformations are reported. After some introductory information the experiments are described. Next the results are considered.
AuthorsL Cappietti
Date published2003
-
The consequences of environmental requirements on fuel oil specifications and on shipping operational costs
AuthorsP Melissen ; M van Mourik
PublisherIMarE Conferences and Symposia
AbstractThis paper describes the consequences of increased fuel costs on the operational costs of ships. Indicative calculations on shipping transport costs are made with references to the different types of shipping markets affected by increased fuel costs and to what extent these increases could be passed on to the users of shipping services. The impact of environmental legislation is examined regarding desulphurisation of crude oil and the additional of heavy metals to low quality bunkers. Bunker price fluctuations over the last two decades are also examined.
AuthorsDate publishedP Melissen ; M van Mourik
1993
PublisherIMarE Conferences and Symposia
-
On-line ground fault phenomena on an ungrounded electrical distribution system on vessels
AuthorsW Murai
Date published1982
AbstractDesign features of marine three-phase three-wire ungrounded electric distribution systems are discussed prior to a theoretical analysis with particular reference to ground fault phenomena - prediction of ground fault current and potential of each phase and distribution of zero phase current in system circuitry are compared with the results of field tests.
AuthorsW Murai
Date published1982
-
On the scale effect on thrust deduction
AuthorsG Dyne
Date published1973
AbstractAssessment of scale effects on thrust deduction critically reviewed with reference to - historical background; currently used formulae; components of thrust deduction - displacement friction and wave; and effects of scale.
AuthorsG Dyne
Date published1973
-
Endurance and stability of steel structures on the seabed
AuthorsR Haworth ; G T Houlsby ; P M Blair-Fish
Date published1998
AbstractOver time remnants of fixed offshore structures may corrode and split into smaller pieces from the repeated action of waves and currents. Efforts to predict what might happen to the remains of steel structures which may be left on the seabed following decommissioning are described. Of particular concern are remains left in waters deeper than 100 m of the northern North Sea from where complete fixed platforms have yet to be removed. If platform remains are to be left on the seabed the Regulatory Authorities will require evidence that they will remain substantially intact stable and not move across the seabed to become a hazard to fishermen and other sea users. All the factors are presented and considered. It is shown that hydrodynamic loads on debris may be assessed from the effect of waves and currents on the boundary layer close to the seabed. Expressions from lift drag and inertia forces are available from pipeline stability studies. New expressions are derived for stability and resistance of isolated tubulars and prisms on the seabed and compared with the results of model tests on sand and clay. The effect on stability of effective density size shape soil conditions environmental forces and height of fall to the seabed are discussed. It is found that tubulars tend to sink into soft clay but may roll on hard clay. Finally it is pointed out that data from wrecks shows the potential for self-burial due to sediment transport.
AuthorsR Haworth ; G T Houlsby ; P M Blair-Fish
Date published1998
-
Numerical study of flow-induced vibration in pipeline on offshore platform
AuthorsDezhong Li ; Ning Mei ; Defu Liu et al.
Date published2002
AbstractThe flow-induced vibration often occurs in the pipelines on offshore platforms when they are used to convey oil in high fluid pressure and there are many undesirable geometric shapes such as too many bends and large variation sections in pipelines on offshore platforms. There are few studies on the vibration of oil-conveying pipelines on offshore platforms. The mechanism of vibration induced by flow in the oil-conveying pipelines on offshore platforms is analysed. Based on the theory of oscillating fluid mechanics mathematical models of unsteady incompressible viscous vibrating flow are established. The expressions for differential coefficients of velocity and pressure in flow are derived according to the parametric polynomial method. The velocity and pressure distributions in flow in the different conditions are obtained. The results show that flow behaviours of flow-induced vibration are affected by pipe structure and properties of fluid. Comparison between numerical result and variational solution shows a good agreement. The method for studying flow-induced vibration in oil-conveying pipeline on offshore platform is shown to be effective.
AuthorsDezhong Li ; Ning Mei ; Defu Liu et al.
Date published2002
-
Second report on explosions in very large tankers
AuthorsInternational Chamber of Shipping
Shelf Location227f
AbstractFollowing explosions on three very large tankers in December, 1969, ICS set up a Tanker Safety sub-committee to co-ordinate and evaluate various investigations being conducted on a world-wide basis into the possible causes of these incidents. An interim report was issued on 1st December 1970. The suggestions on tank washing procedures under various tank atmosphere conditions made in the interim report still stand. As shown in the first report, research was initially concentrated on a number of possible sources of ignition in the 1969 explosions. The results of this research can now be said to justify, on a basis of very low probability, the discontinuance, as far as the December 1969 explosions are concerned, of further consideration of the following: impact sparking; compression ignition; auto-ignition by steam heating coils; pyrophoric ignition; R.F. induced current. In research of this nature, which is yet to be finalised, it is inevitable that certain statements are made which might well have to be amended in the light of further confirmatory work. Statements made in this report are therefore subject to this proviso and are based on the best information available at the present time.
AuthorsPublisherInternational Chamber of Shipping
International Chamber of Shipping
Shelf Location227f
-
Interim report on ballast water exchange - study on ballast water exchange methods in Japan
AuthorsH Yamamoto
Date published2001
AbstractThis interim report outlines the current movement of the ballast water control in IMO and regional areas in Part 1 and introduces the essential part from the latest study in Japan on ballast water exchange methods in Part 2.
AuthorsH Yamamoto
Date published2001
-
International symposium on fire safety of ships Vol 2
AuthorsIMO ; HMMM
Shelf Location223a
AbstractInt Symp held in Piraeus Greece on 9-11 May 1990 Papers are On fire! The need for new thinking Fire protection on large cruiser ships Fire safety on passenger vessels operating in the United States of America
AuthorsPublisherIMO ; HMMM
Hellenic Institute of Marine Technology
Shelf LocationDate published223a
1989
-
The effects of marine fouling on the performance of a single- point acoustic doppler current sensor mounted on a TABS-II spar buoy
AuthorsJ N Walpert
Date published2001
AbstractTABS (the Texas Automated Buoy System) has a network of buoys in the Gulf of Mexico along the Texas coastline which serve as an important tool to oil spill response oil-spill trajectory modelling and scientific research. The data are used by the TGLO to direct response activities in the event of an oil spill in Texas coastal waters. Near-surface current data are collected and processed within the buoy and then telemetered to GERG's facility where the data are quality controlled archived and displayed on GERG's Web page. Biofouling has been one of the limiting factors in data quality and deployment length. The TABS-II spar buoy is one of two types of spar buoys used by GERG (the Geochemical and Environmental Research Group) to monitor and report near real- time surface currents in support of oil spill response and trajectory modelling. An experiment was carried out to determine the effects of marine fouling on a single-point acoustic Doppler current sensor on a TABS-II spar buoy. An Aanderaa DCS3500R Doppler current sensor was mounted on a TABS-II spar buoy. A comparison was made of fouled and non- fouled sensors and conclusions were drawn regarding the effects of fouling on the sensor.
AuthorsJ N Walpert
Date published2001
-
2nd International Conference on Cavitation
AuthorsIMechEng
Shelf Location225d
AbstractSecond Int conf held in Edinburgh 5 - 8 September 1983 Papers are A study of cavitation bubble dynamics and resultant pressure on adjacent solid boundaries Cavity dynamics in a duct flow A study of the relationship between type of cavitation erosion and luminescence Bubble dynamics and cavitation Some recent aspects of bubble dynamics Classification of cavity mechanics and erosion Effects of magnetic field on cavitation damage A modelling study of the cavitation microjet Measurement of cavitation erosion in a centrifugal pump as a function of speed Cavitation in a binary mixture of polar liquids Studies on the cavitation characteristics of annular type jet pump Effect of inlet diameter of mixed flow impellers on suction performance On cavitation in stationary cascades of reversible hydraulic machines The calculation of three dimensional flows in impellers and its use in improving the cavitation performance of centrifugal pumps Cavitation signs in rotodynamic pump Recent and expected technological advancement towards the elimination of cavitation damage in control waves Vapour cavitation in dynamically loaded journal bearings Further studies of propeller cavitation erosion Effects of artificial roughness on sheet cavitation On application of nonlinear cavity flow theory to thick foil sections
AuthorsPublisherIMechEng
IMechEng
Shelf LocationDate published225d
1983
-
A research on characteristics of responses of a floating structure in tsunami
AuthorsKoichi Masuda ; Tomoki Ikoma ; Maki Uchida et al.
Date published2004
AbstractThe objective of this paper is to establish the practical numerical analysis system for responses of motions and mooring forces on a floating structure induced by Tsunami and to clarify the characteristics of responses on floating bodies in tsunami. In the present analysis system the initial tsunami profile is evaluated by Mansinha-Smylie's Method and propagating tsunami profiles are calculated by linear long wave theory and also the tsunami exciting forces on floating body are computed by the numerical wave tank based on VOF method. Then the motions and mooring tether forces due to Tsunami on floating body are predicted by the convolution integral method. The usefulness of the present system is confirmed by comparing with the experimental results on Tsunami exciting forces on floating bodies.
AuthorsKoichi Masuda ; Tomoki Ikoma ; Maki Uchida et al.
Date published2004