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Experimental study on vertical ice loads acting on multi- leg structures
AuthorsT Terashima
Date published2000
AbstractIf an ice sheet adfreezes to a structure with a circular cross-section such as the pile of a pier or a mooring pile set in the water of a cold region vertical ice loads act on the structure and can cause the uprooting of a pile if there is fluctuation in the water level due to the tide or other factors. Therefore vertical ice loads must be considered when designing structures that will be subjected to ice loads. The vertical ice load acting on a single pile structure can be estimated using the theoretical calculation method proposed by the authors. In this study field experiments are carried out for the first time on ice loads acting on multi-leg structures to try to establish a theoretical method for calculating ice loads acting on such structures.
AuthorsT Terashima
Date published2000
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On the effect of water on deck on ship motion
AuthorsDimitris Spanos ; Apostolos Papanikolaou ; George Tzabiras
Date published2002
AbstractThe effect of trapped water on deck or the interior compartments of ships on ship motions is closely investigated by use of a non-linear numerical simulation method. The employed method enables the efficient simulation of the wave excited coupled ship - trapped water motions and proves to be a very valuable tool for the assessment of the survivability of flooded ships in waves. A detailed study has been carried out to more carefully investigate the coupling effects between the ship and the floodwater mass that can be expressed through a resultant interaction force. This interaction force has been approximated both by a simplified model employed by the present simulation method and also by a more accurate CFD code and satisfactory agreement between the results of both approaches has been obtained.
AuthorsDimitris Spanos ; Apostolos Papanikolaou ; George Tzabiras
Date published2002
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On the reliability and risk analysis of subsea blowouts preventers with focused attention on DP rigs
AuthorsNilo de Moura Jorge
Date published2005
AbstractThis paper provides a selection of findings on the reliability and risk analysis of submarine blowout preventers (BOPs) achieved in recent studies in which the author has participated among technicians in Petrobras and Rio de Janeiro Federal University - UFRJ. Special attention is given to the deepwater and ultra deepwater scenarios. The riser safety margin tends to be unavailable as the water depth becomes deeper and so in an emergency disconnection the safety isolation of the well tends to be relied on the BOP mechanical barriers only. In this context risks on different configurations of the BOP are compared and their results discussed with focused attention on main factors of risk. Finally there has been visible progress on BOP reliability within recent years and a number of good operational practices in place are also mentioned in the paper.
AuthorsNilo de Moura Jorge
Date published2005
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Uncertainties in the estimation of fluid loading on offshore structures with special emphasis on wind forces
AuthorsS Singh
Date published1989
AbstractSome of the major uncertainties in the estimation of mean drag forces on offshore structures especially those generated by wind are presented and discussed. Standard techniques as suggested by published criteria and guidelines are used to illustrate some of these uncertainties for three cases. These are loads on the legs of a jack-up unit loads on a group of conductors and finally wind forces on a semi-submersible unit. Potential problems in the use of wind tunnel modelling are also discussed and recommendations made for a unified and consistent approach to estimating mean drag forces on offshore structures.
AuthorsS Singh
Date published1989
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Wind forces on modern ship forms effect on performance
AuthorsW B Van Berlekom
Date published1980
AbstractA systematic series of wind tunnel tests examine direct wind forces and moments on ships of different above-water structures particularly size and position of deckhouse (tanker containership RORO small craft) and induced forces and moments on underwater hull. Results include - wind coefficient curves added resistance due to drift and rudder angles effect of added resistance on propeller efficiency wind effects on manoeuvring.
AuthorsW B Van Berlekom
Date published1980
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BSRA Technical Memorandum No. 125 Reports on foreign observers' course on the nuclear ship 'Savannah'. Report on Visits
AuthorsJ A Dodd ; S Macdonald
Shelf Locationin storage
AuthorsPublisherJ A Dodd ; S Macdonald
British Ship Research Association
Shelf LocationDate publishedin storage
1960
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Report on the investigation of the grounding of the class VI passenger vessel Pride of the Dart on Mew Stone rocks near the entrance to the River Dart on 28 June 2002
AuthorsMarine Accident Investigation Branch
Shelf Location40d
AuthorsCatalogue numberMarine Accident Investigation Branch
UNK
Shelf Location40d
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Environmental Forces on Offshore Structures and Their Prediction Volume 26 of Advances in Underwater Technology, Ocean Science and Offshore Engineering
AuthorsSociety for Underwater Technology (SUT)
Shelf Location213a
AbstractConf held by SUT in London 28-29 November 1990 Papers are The use of joint probability in deriving environmental design criteria The effect of frequency spreading on a two component sea state Wave kinematics within the crest to trough region Review of recent analytical and approximate solutions of wave-current interaction Wave current interaction In-line forces on fixed cylinders in regular and random waves Marine roughness and fluid loading On the effects of wake re-encounter for wave forces on cylinders Wave and current forces on conductor pipe groups Coupled experimental and analytical investigation of hydrodynamic forces on a jacket in waves Slender well conductor design Applicability of 3-D wave loads in offshore design A critical assessment of Turkstra's Rule related to the reliability of offshore structures A new stress range distribution model for fatigue analysis under wave loading Environmental loading on fixed offshore platforms Prediction of loads on floating production systems Wind loading and dynamic response of a floating production platform in waves Wave-drift damping of a TLP Effects of joint probability and short crestedness in designing a compliant structure
AuthorsPublisherSociety for Underwater Technology (SUT)
Kluwer Academic
Shelf LocationDate published213a
1990
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Developments on exhaust emission modelling for large two-stroke diesel engines - some comparisons with measured data and an update on the latest emission reduction techniques
AuthorsNiels Kjemtrup ; Kjeld Aabo ; Thomas Knudsen
Date published2007
AbstractThe continuous development of the MAN B&W Diesel two-stroke engines within the field of exhaust gas emission reduction methods is presented. A variety of approaches used towards a better description of emission formation inside the combustion chamber are discussed. The modelling tools described cover a range from simple 0D and 1D formulations to complex state of the art 3D CFD models with advanced sub-models for spray combustion and pollutant formation. And on the experimental side details are given on extensive parametric studies with the in-house two-stroke test engine. Further a novel study on large engine fuel injection is presented using latest technology high-speed imaging techniques. In addition to the in-house tests all major engine test results from production sites since year 2000 have been recorded in a database allowing the statistical analysis of engine test data across engine type engine configuration and of course engine operating conditions. Major results from an extensive ongoing data-mining activity on the basis of this database are given. In particular the results confirm the full potential of the electronic-controlled engine with variable injection-rate profiling. Finally status on development issues such as SAM (Scavenging Air Moistening) TES (Thermo Efficiency System) and use of turbochargers with VTA (Variable Turbine Area) are outlined.
AuthorsNiels Kjemtrup ; Kjeld Aabo ; Thomas Knudsen
Date published2007
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A finite-element model for in-situ behaviour of offshore pipelines on uneven seabed and its application to on-bottom stability
AuthorsB A Ose ; R Nystrom ; A Damsleth et al.
Date published1999
AbstractA Finite Element (FE) model for simulation of the in-situ behaviour of offshore pipelines laid on a 3-D seabed with focus on on-bottom stability is presented. 3-D FE simulations are provided as design examples. After some introductory information a look is taken at the area of application and model details. Next validation of the FE model is addressed followed by acceptance criteria and design examples.
AuthorsB A Ose ; R Nystrom ; A Damsleth et al.
Date published1999
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Discussion on high-speed boat run-up on rocks and its impact force
AuthorsGuoyu Chen
Date published2006
Abstract'Boat run up on rocks' means boat and rock collision. This also refers to boat collision with things fixed under the water such as piers. There is much interest and there has been much research in this area. A formula on the calculation of the impact of force of 'boat run up on the rocks' is presented. The formula includes parameters such as angle speed rigidity and qualities of the 'impact pair' and may provide help with the designing of bows for high-speed boats.
AuthorsGuoyu Chen
Date published2006
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Marine Accident Investigation Branch Report No 37/2000 Report on the Investigation of a Rupture of the Port Economiser on board Island Princess resulting in two deaths on 7 December 1997
AuthorsMAIB
PublisherDETR
AuthorsDate publishedMAIB
2000
PublisherDETR
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Observations on the Effects of Lightning on Floating Bodies with an account of a new method of applying fixed and continuos conductors of electricity to the masts of ships in a letter addressed to Vice-Admiral Sir Thomas Byam Martin. Harris on Lightning
AuthorsWilliam Snow Harris
Shelf LocationRR11
AuthorsWilliam Snow Harris
Shelf LocationRR11
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Influence of cavitation on the force acting on a single blade
AuthorsV Vujanic ; B Velensek
Date published1995
AbstractForces acting on a single blade placed in a water tunnel were experimentally investigated with the main focus being on the lift to drag ratio in different flow conditions. The intention was to locate the influence of cavitation and blade inclination on the lift to drag ratio and to discover optimum flow regimes even in cavitation conditions. The experimental apparatus is described. The results are presented and analysed.
AuthorsV Vujanic ; B Velensek
Date published1995
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Vortex shedding induced oscillations on pipelines resting on very uneven seabeds - predictions and countermeasures
AuthorsR Bruschi ; P Simantiras ; L Vitali et al.
Date published1994
AbstractIt is important to establish a recognised approach regarding pipe lengths in suspension under vortex shedding induced vibrations (VIV). Several projects have been carried out to improve knowledge of VIV on submarine pipelines. Many aspects have been examined in the laboratory and in the field. Some aspects of the hydroelastic excitation and response are examined. The focus is placed on prediction tools. Countermeasures are discussed particularly hydrodynamic devices to tackle VIV. Experimental laboratory data on slender tubulars is discussed.
AuthorsR Bruschi ; P Simantiras ; L Vitali et al.
Date published1994
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Biofilm Effects on Drag - Measurements on Ships
AuthorsG S Bohlander
PublisherIMarE Conferences and Symposia
AbstractThis paper describes the results of two full-scale power trials on a US Navy frigate to determine the effect of biofilms on ship power and fuel consumption. A significant change in power consumption ranging from 8-18% was measured by trials before and after underwater cleaning.
AuthorsDate publishedG S Bohlander
1991
PublisherIMarE Conferences and Symposia
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A general scheme for substructuring on-line hybrid test on planar moment frames (the neural network model)
AuthorsC Zavala ; K Ohi ; K Takanashi et al.
Date published1995
AbstractA general scheme for on-line hybrid substructuring simulation is presented aiming to achieve the deformed position of testing specimen. An artificial neural network is used as predictor of the incremental forces on the specimen to achieve the displacements of the system. Firstly a look is taken at the substructuring on-line hybrid test. Next the artificial neural network predictor is described. Lastly the prototype test is discussed.
AuthorsC Zavala ; K Ohi ; K Takanashi et al.
Date published1995
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Guidelines on the impact of aggregate extraction on European marine sites
AuthorsPosford Duvivier Environment
Date published2003
AbstractThe EC Habitats Directive aims to promote the conservation of habitats and species within the European Union by designating sites known as SACs (special areas of conservation). The UK Marine SACs Project aims to promote the implementation of the Habitats Directive in marine areas through trialling the establishment of management schemes on 12 sites in the UK and by providing proven good practice and guidance to practitioners in the UK and Europe. To support the establishment of these management schemes the Project is undertaking a series of tasks to collate and develop the understanding and knowledge needed. One of the areas for providing guidance to those developing the schemes concerns the interaction between human activities and marine features. Human activities have an important role in the management of marine features and may have both beneficial and damaging impacts. This report has been prepared to provide information and guidance on aggregate extraction activities. There are a number of objectives for the series of guidance documents forming part of the UK Marine SACs Project. The overall aim of this task is to provide information on the potential impacts of aggregate extraction on marine and coastal habitats and species listed in Annexes 1 and 2 of the Habitats Directive and to provide guidance on the assessment of potential impacts. Among the habitats and species specified in Annexes 1 and 2 several are marine features and SACs have already been selected for many of these in the UK. One initiative now underway to help implement the Habitats Directive is the88712 Guidelines on the use of high-modulus synthetic fibre ropes as mooring lines on large tankers OCIMF
AuthorsPosford Duvivier Environment
Date published2003
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Tenth International Towing Tank Conference Volume 2
AuthorsNat Phys Lab
Shelf Location213c
AbstractTenth Int Conf held in Teddington in Sept 1963 Papers are The resistance tests on the ITTC Standard Model Results of resistance tests of standard model Resistance tests of standard model Resistance tests of standard laminated fibre glass model An analysis of some Mitsubishi standard model tests Further model tests with a 760 tdw motor coaster A study of the turbulence stimulation device in the model experiment on ship form Actual ship thrust measurement as a means of breaking down the correlation allowance into its components (abstract) Some experiments of yawing effect on ahead resistance of ships (abstract) Further experiments of yawing effect on ahead resistance of ships (abstract) Frictional resistance in towing tanks Variation of viscous drag with froude number The influence of form and scale on model and ship resistance Formal contribution On the flat plate experiments of Kyushu University (abstract) Some remarks on the logical approach of model ship correlation Considerations on the experimental determination of the form effect from results about transition line Form effects on viscous resistance and their estimation for full ships Testing of standard model - Kryloff Shipbuilding Research Institute The effect of loading on wake and thrust deduction Some remarks on the logical approach to ship model correlation The influence of scale or size on ship model tests involving propeller generated vibration Propulsion trial code Recent studies by the British Towing Tank Panel of ship model correlation Calculation of the hydrodynamic exciting damping coupling and inertial forces of ship propellers based on wake distribution and90767 Terminal compatibility MER
AuthorsPublisherNat Phys Lab
Min of Tech
Shelf LocationDate published213c
1963
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The Elbe river - a life line for Northen Germany: the sense of maintenance dredging on the Elbe and the future requirements for its navigational fairway
AuthorsN Marusic ; C Iwens
Date published2007
AbstractThe future deepening of the Elbe will be a groundbreaking innovation of environmental and marine engineering. This is described. First there is an historic review addressing historical development on the deepening and maintenance dredging works on the ELBE trading position of the harbour of Hamburg. Next a look is taken at the current maintenance dredging concept on the Elbe dealing with longer sailing distances and correlation to the TSHD types along with pilot tests with water injection dredgers in order to optimize hopper planning. After this consideration is given to the future for maintenance dredging on the Elbe including new relocation areas under investigation on the Elbe research programme of the Federal Institute of Hydrology (BfG) for new relocation areas and its impact on the habitat of fauna and flora. Lastly attention is given to the future deepening of the Elbe covering the licensing process and the time frame (planning) economic benefits and socio-economic impact on the Hamburg metropolitan area hydraulic engineering concepts and dredging techniques.
AuthorsN Marusic ; C Iwens
Date published2007