U.S. Navy, Naval Sea Systems Command, Program Executive Office SHIPS, PMS 500 DD X Program

Fendering systems are widely used in offshore installations for attenuating the effects of the impact energy of ships and barges in berthing or moored conditions. This study focuses on investigating current design practices and, developing a rational and functional approach to address random loading effects exerted on fendering systems. These loadings are often a consequence of combined wind, wave and current excitation as well as more controlled vessel motions. Dimensional analysis is used to investigate the degree to which empirical design data can be collapsed and to provide an indication of the nonlinearity associated with the empirical data for fender sizing. In addition, model test data specifically measuring the normal fender force for a coupled mini-TLP/Tender Barge performed at the Offshore Technology Research Center (OTRC) model basin is used in this research investigation.. This data was characterized in terms of the typical statistical moments, which include the mean, standard deviation, skewness and kurtosis. The maxima and extreme values are extracted from the fender response data based upon a zero-crossing analysis and the results were studied in order to determine the underlying probability distribution function. Using selected parameter estimation techniques, coefficients of a best-fit two parameter model were determined. An illustrative example is presented and discussed that contrasts the deterministic and probabilistic models.

Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, June 2003. / Thesis advisor(s): Robert Ashton, Todd Weatherford. Includes bibliographical references (p. 93-96). Also available online.

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The point of this essay is to analyze, and compare the numerous articles of the local newspaper Tønsbergs Blad during the building of The Oseberg Viking ship. This ship is the most famous ship from this era, and was built in full scale in 2012. My focus is the use of history in regards to the construction of the ship, which was done by hand, using the Vikings methods, and tools. This essay represents a selection of 16 news articles during and after the launch the building. Focus is the use of history in a Norwegian context during the latest 100-150 years, with examples on how the past is used to describe Norway today, in contrast to the Viking age from the 800-900. To achieve the aim four questions are formulated:  Why did The New Oseberg Ship Foundation decide to build the ship just like the Vikings did, a thousand years ago?  What were the motives behind the project? Did the public show any interest for the Viking ship?  What were the challenges that faced the engineers and carpenters? The study indicates that the construction of the Oseberg Viking ship is built on extensive research in regards to history, archaeology and the vintage Viking ship still in existence. The Oseberg Viking ship is built by the use of original tools and methods. The aim was for The New Oseberg Ship Foundation to see if they could succeed in the planning of the project – and ultimately end up with a full scale, fully authentic functional Viking ship. The New Oseberg Ship Foundation today continues the building of other Viking ships. The interest from the public was, and continues to be great. The Oseberg Viking ship was found in Tønsberg. In modern times, images of Viking ships have been used in a mixture of ways, but especially as symbols of national and cultural identity. Viking imagery has been used to evoke a sense of past glory. The Oseberg Viking ship is the most spectacular ship from the Viking Age.

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Collisions and groundings at sea still occur, and can result in financial loss, loss of life, and damage to the environment. Due to the size and capacity of moden vessels, damage can be extensive. Statistics indicate that the primary cause of accidents at sea is human error, which is often attributed to misinterpretation of the information presented to the mariner. Until recently, data collected from sensors about the vessel were displayed on the bridge individually, leaving the mariner to assimilate the material, make decisions and alter the vessels controls as appropriate. With the advent of the microprocessor a small amount of integration has taken place, but not to the extent that it has in other industries, for example the aerospace industry. This thesis presents a practical method of integrating all the navigation sensors. Through the use of Kalman filtering, an estimate of the state of the vessel is obtained using all the data available. Previous research in this field has not been implemented due to the complexity of the ship modelling process required, this is overcome by incorporating a system identification proceedure into the filter. The system further reduces the demands on the mariner by applying optimal control theory to guide the vessel on a predetermined track. Hazards such as other vessels are not incorporated into this work but they are specified in further research. Further development work is also required to reduce computation time.

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This research concentrates on damage ship stability and means for assessing dynamic ship performance in this state. A consolidation of many approaches for tackling damage ship dynamics has been undertaken, culminating in the development of a numerical tool for simulating ship behaviour while accounting for progressive flooding and the ensuing effects of floodwater motion. General features that have been accounted for in a new purposely developed numerical program PROTEUS3 include the following: Linear concepts regarding intact ship hydrodynamics based on strip theory and Rankine source method (RSM). These are further utilised by convolution and spectral transformations in deriving relevant time domain force realisations. Non-linear excitation/restoring forces calculated from pressure integration up to the instantaneous undisturbed wave profile. Non-linearities in hydrodynamic properties arising from variation of mean underwater geometry due to occurrence of non-stationary asymm etries in mass distribution are taken into account by a database approach. Forward speed in arbitrary heading. Progressive flooding through a ship with any internal subdivision and floodwater motion simulations based on free-mass-on-potential-surface (FMPS) model. Non-linear treatment of the effects of cargo shift or floodwater motions on the overall ship dynamic behaviour. The underlying modelling has been explained by rigorous derivation of all the relevant equations from first principles. Validity of the model has been tested comprehensively through comparison with available physical model tests data. A thorough investigation on the new effects of modelling advancements concerning the accuracy of the developed model has been undertaken and the results are presented and discussed. Despite the introduction of simplifying assumptions concerning floodwater behaviour, the predictions show consistency with physical experimental data. It is believed that this pragmatic approach constitutes a very efficient tool for predictions of vessel performance in extremely adverse conditions. This effectiveness has been demonstrated by undertaking forensic analysis of two of the most controversial accidents of the last two decades, namely the loss of MV Derbyshire and the NW Estonia disaster.