A marine vehicle manoeuvring model is concerned with the ability to simulate the status of a vehicle to various demanded controls on a digital computer. Such models have both shore based and sea going applications that are beneficial to the mariner, enhance safety of life at sea and aid in protecting the marine environment The mathematical representation of marine vehicles has generally been conducted by the measurement of the forces and moments that are experienced by a vehicle, in terms of a series of numbers collectively known as hydrodynamic coefficients. This has resulted in the non-linear force modular model which is considered to be the most accurate and versatile mathematical modelling technique. This thesis presents the results from research conducted into the construction of an accurate mathematical model of a patrol craft Picket Boat Nine. The non-linear force modular modelling technique was initially adopted. The required hydrodynamic coefficients were evaluated by the use of full scale sea trials, scale model testing techniques and by semi-empirical methodologies; by the installation of a towing tank, a data monitoring and acquisition system onboard Picket Boat Nine. An alternative new method for mathematically describing marine vehicles has also been developed based upon the drift angle theory. The existence and magnitude of the drift angle has been transformed into a set of hydrodynamic curves that mathematically represent a marine vehicle's manoeuvrability and into a method of determining the track history of a marine vehicle when underway. These two components have been developed into a new form of mathematical model This new approach to mathematical modelling has been tested by full scale sea trials in Picket Boat Nine and with comparison to a force modular model that demonstrates the stature and potential of this method. The results indicate that further research is required to include external disturbances and to prove its validity to other marine vehicles.

The increase in marine traffic has resulted in the need for traffic routing schemes in areas of high vessel density. In order to assess the viability of a scheme before it is brought into use a simulation study can be used. This thesis describes the construction of a computer model to simulate the behaviour of mariners using the concepts of domains and arenas to control their actions. The arena is an area around a ship where one navigator takes account of another ship's presence. The domain is the area around his ship which a navigator wishes to keep clear of other vessels and stationary objects. The model is validated against data gathered in the Dover Strait from the coastguard radar station at St. Margaret's Bay and from experiments conducted in a radar training simulator. The model is shown to produce realistic results for vessels overtaking one another and for vessels meeting with a collision risk 96 per cent of situations can be realistically simulated.

Fundamental to any business is the concept of performance. This can be compared by using the competition as a benchmark for achievement or by comparing performance with previously defined goals and objectives. Stakeholders constantly demand to know whether their investmerit in a company is obtaining an adequate return and whilst there are established accounting techniques to calculate return on investment or capital employed, calculating efficiency can be rather a grey area in some industries. Ports are no exception and it is only by comparison that performance can be evaluated. Ports are, however, a complex business with many different sources of inputs and outputs which make direct comparison among apparently homogeneous ports seem difficult. The subject is further complicated by the various types of port ownership and organisational structures that exist throughout the world. This thesis seeks to determine whether there is a particular type of ownership and organisational structure that leads to a more efficient port. This aim is achieved by examining the efficiency of differently owned container ports, comparing privately owned ports against those remaining in the public sector, and those that have elements of both public and private ownership patterns. In addition, the organisational structure of those ports examined is analysed and classified with the results placed into a singular conceptual model for a clear comparison. The conceptual model can be then applied to any type of business enabling the performance of ownership and organisational structures to be compared with ease. The results of this thesis show that there is a strong relationship between the relative efficiency of ports examined and organisational structure and a weaker relationship between port ownership patterns. These results should assist governments, port administrators and port owners in determining the different ways they can structure their ports.

Aeronautical and marine casualty statistics indicate that the human being, when under stress or at times of peak load, can be a poor co-ordinator of the information available to him, particularly when that information is from a number of different source:, as is often the case in modern ships. Integration and co-ordination of information and its useful application in a closed loop feedback system can reduce the probability of accident as has already been demonstrated in the case of automatic landing systems for aircraft. This thesis describes the development of a digital filter/estimator for use in conjunction with an optimal controller in the automatic guidance of large ships in the approaches to a port. A non-linear mathematical model of a ship is developed and validated by comparison with data from an actual ship. The model is then used in digital computer simulations of the passage of a twin screw car ferry into the Port of Plymouth. The simulations show that the control and guidance system is capable of safely navigating the vessel along the predetermined track through noisy measurements of position, course and speed, A reduced non-linear digital simulation model is then used in the design of a minimum variance filter suitable for installation in a physical model of the car ferry. Tests with this physical model confirm the earlier full scale digital computer simulations, showing that a minimum variance filter is capable of giving very good estimates of the measured states, even though the measurement subsystems are unable to give accurate information because of noise. In the event of a malfunction of one or more of these measurement systems it is shown that the filter continues to give good estimates of all the states.

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This thesis is concerned with the dynamics of low tension marine cables. These cables are widely used in the ocean environment for signal and power transmission applications. There are two main issues in the dynamic analysis of such cables. When the tension is zero, which is often the situation encountered at the seabed during cable laying, the cable geometric stiffness matrix becomes singular. The other issue is that the transformation from local co-ordinates to global co-ordinates made through Euler angles leads to a greater number of unknowns than the number of differential equations. The former problem can be overcome by taking into account the flexural rigidity of the cable. The latter problem can be overcome by assuming that one of the Euler angles is known. However, this procedure can introduce singularities on the formulation of the problem. A new three dimensional model for the dynamics of marine cables is presented in this thesis. The model takes into account the bending stiffness of the cable in order to overcome singularities in the geometric stiffness matrix. In order to overcome the problem owing to the use of Euler angles, a new displacement approach is introduced. This new displacement approach uses the differential geometry definition of curvature and torsion in order to establish the transformation from the local co-ordinates to the global co-ordinates. The general formulation of the dynamics of marine cables presented in this thesis is applicable to a wide range of cases such as towed cables, cable installation and cable recovery. In order to illustrate this new formulation the cases of towed cables and cable installation are investigated in the some detail. Solutions for the differential equations of motion are presented for two and three dimensions. The two dimensional solution is obtained through a finite element based technique which uses a weak Galerkin formulation for integration in space and the Newmark method for integration in time. The model's results are compared with full scale measurements. Simulations of the dynamic response of marine cables to vessel wave induced motions and vessel changes in speed are also presented. The three dimensional solution is obtained by expressing the equations of motion as functions of the Euler angles. The space integration is also performed by a finite element model but it uses a finite difference scheme for the time integration. This solution is then used to study the influence of sheared cross-currents in the cable's configuration. Finally, conclusions and suggestions for further research are presented.

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