Дисертації з теми "Ship Collision"

The serious consequence of ship collisions necessitates the development of regulations and requirements for the subdivision and structural design of ships to reduce damage and environmental pollution from collision, and improve safety. The on-going revision of IMO regulations on oil outflow performance and damage stability in grounding and collision is focused on a transition to probabilistic performance-based standards. This thesis addresses one aspect of this problem, a simplified collision model sufficient to predict collision damage, and fast enough to be used in probabilistic analysis requiring thousands of collision simulations. The simplified collision model (SIMCOL) developed and evaluated in this thesis is based on a time domain simultaneous solution of external dynamics and internal deformation mechanics. The external sub-model uses a three-degree of freedom system for ship dynamics. The internal sub-model determines reacting forces from side and bulkhead structures using mechanisms adapted from Rosenblatt and McDermott, and absorbed energy by decks, bottoms and stringers calculated using the Minorsky correlation as modified by Reardon and Sprung. SIMCOL is applied to a series of collision scenarios. Results are compared with MIT's DAMAGE, a Danish Technical University (DTU) model and ALPS/SCOL. SIMCOL provides a fast, consistent and reasonable result for ship collision analysis. An actual collision case is used in an initial attempt to validate the model. This research is sponsored by the Society of Naval Architects and Marine Engineers (SNAME) and the Ship Structure Committee (SSC).
Master of Science

This present thesis investigates the accidental load of ship collision and grounding performances. To achieve this objective the thesis is composed of several main tasks. The main tasks comprise the rupture prediction, validation of material failure, ship grounding analysis and ship collision analysis. To predict material rupture, FLD material failure was used and validated with available experimental and FEA data. The FLD was extended to established material failure scaling laws which consider onset failure at plane strain in relation to mesh sizes. This was accomplished by running mesh convergence studies at different mesh sizes and at different FLD0. The linear material damage evolution is adopted in this case until the convergence results were satisfied. The material damage was used for all of further analysis in ship collision and grounding and employed mild steel and high tensile steel material properties. The ship grounding structure damage was investigated by deploying conical rocks at different locations of the ship's double bottom structure. The analysis focused on vertical penetration and horizontal penetration which contributed to significant damage to the structure. The ship collision analysis was investigated in various types of structures arrangement and diverse ship striking scenarios to penetrate struck ship and collide rigid wall. Furthermore, the prediction of ship collision and grounding were extended by using simplified approaches that were capable to predict ship collision to rigid wall, rigid body striking ship collided with deformable struck ship and deformable collision of striking and struck ship. Finally, this substantial amount of research work achieved the objectives of the study when the results of accidental load were validated and correlate well with experimental, empirical and FEA simulations at more than a satisfactory level.

The Canadian government has committed substantial research funds towards improving guidelines for the structural design of commercial ships operating in northern waterways. Of particular concern is the threat to survivability presented by head-on collision with multi-year ice or fragments of icebergs. The task of developing effective numerical models for studying the collision process has been hampered by the complexity of the physical interaction mechanisms. The present research considers the nonlinear and dynamic character of this problem. A method for time-domain simulation of hullgirder stresses in icebreaking ships during collisions with multi-year ice is described. The model, ITHACA$\sb{-}$SHIP, considers the transient ship-ice interaction and fluid-structure phenomena as strongly coupled through ship dynamics. Emphasis has therefore been placed on the development of hydrodynamic and ice force models. Rigorous kinematic constraints at the interaction interface were identified as a critical factor in replicating the dynamic characteristics of prototype collision response. This led to the development of techniques for the three-dimensional mapping of this instantaneous ice boundary relative to the moving hull surface. The transient hydrodynamic force is also calculated directly, using boundary integral equation methods and a two-dimensional strip approach. The wave radiation problem for defining the free surface boundary of the fluid is based on a mixed Euler-Lagrange formulation. The prediction of hullgirder stresses is carried out in two steps. Ice and fluid interaction forces are first determined from a rigid body motions simulation, and then subsequently applied as generalized forces in an analysis of flexural response. The hullgirder bending moments and stresses are extracted from the response. The modeling methodology has been verified by predicting simulated stress results for the MV Arctic, a multi-purpose bulk carrier. Good correlation was observed between the numerical predictions and corresponding results from physical model tests and full scale ramming trials. Further discussion is given concerning whipping indicated at higher impact speeds. Nonlinearity of the ship-ice and fluid-structure interaction phenomena has been assessed by introducing progressively more complex representations of the physical mechanisms into the ITHACA$\sb{-}$SHIP model. These studies found a high degree of coupling between the two effects. The transient hydrodynamic term was shown to be a significant factor, and the importance of the kinematic criteria confirmed. The indirect representation of collision interaction forces using conventional added mass and damping coefficients in the equations of motion was shown to be conceptually incorrect. The present research has largely been limited to the development of the modeling methodology and examination of a number of suppositions concerning the collision process. But, interactive design software is available in the ITHACA$\sb{-}$SHIP model which gives it a capacity for representing realistic ship forms. It may therefore be applied more generally as an engineering tool for conceptual design and parametric analysis; either to investigate collisions with ice, or other types of obstacles, such as mud banks and reefs.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2000.
Includes bibliographical references (leaves 108-110).
Collision of ships with oil tankers poses, next to grounding, one of the most serious environmental threats at sea. In many previous analyses of the collision problem, the bow of the impacting ship was considered rigid. The objective of the present research is to include the finite strength of the bow in the overall collision simulation. The emphasis will be placed on typical raked shapes because some work already has been reported in the past on bulbous bows. The main structural members will include side shell and the deck. Transverse and longitudinal stiffeners will be taken into account by means of a smearing technique. A structural model is developed by identifying localized zones of plastic deformations from photographs of damaged ships. Then, the contributions of the membrane and bending resistance is assessed and a simple computational model is developed. The solution includes determination of the force-indentation relationship, a number of folds and a total amount of damage for a given speed of a ship. Five scale model tests were run and the force-deflection characteristics were recorded. A good correlation was obtained between the analytical solution and experimental results.
by Ji Young Kim.
S.M.

The serious consequence of ship collisions necessitates the development of regulations and requirements for the subdivision and structural design of ships so that damage and environmental pollution is reduced, and safety is improved. A simplified collision model (SIMCOL) is currently being developed at Virginia Tech to conduct probabilistic analysis of damage in ship collisions and ultimately optimize ship structural designs to improve crashworthiness. Collision data for validation of SIMCOL is very difficult to obtain, and model testing is very costly. Finite Element Analysis (FEA) provides an alternative to physical validation that can be used to increase confidence and insight in simplified model results. This thesis develops a complete methodology for ship-to-ship collision simulations using the explicit non-linear FE code LS-DYNA3D. Various modeling alternatives are considered. The ability to model a complete ship-to-ship collision is developed incrementally starting with bow collisions with a rigid wall. A super-element (intersection model) approach is considered to increase the calculation speed of bow models. A conventional fine mesh finite element bow model is also developed. Results from both models are compared with each other, and with a closed-form calculation from Pedersen. A fine mesh model is developed for a struck tanker cargo section and integrated in a total ship framework modeling external dynamics and ship-to-ship contact. A series of collision scenarios is simulated using the conventional bow model and a rigid bow model striking a double hull tanker. Results are compared with SIMCOL, DAMAGE, DTU and ALPS/SCOL models. LS-DYNA provides detailed and reasonable results for ship collision analysis and comparison to increase confidence in simplified models.
Master of Science

The serious consequences of ship collisions necessitate the development of regulations and requirements for the subdivision and structural design of ships to reduce damage and environmental pollution, and improve safety. Differences in striking ship bow stiffness, draft, bow height and shape have an important influence on the allocation of absorbed energy between striking and struck ships. The energy absorbed by the striking ship may be significant. The assumption of a â rigidâ striking bow may no longer hold good and typical simplifying assumptions may not be sufficient. The bow collision process is simulated by developing a striking ship bow model that uses Pedersen's super-element approach and the explicit non-linear FE code LS-DYNA. This model is applied to a series of collision scenarios. Results are compared with conventional FE model results, closed-form calculations, DAMAGE, DTU, ALPS/SCOL and SIMCOL. The results demonstrate that the universal assumption of a rigid striking ship bow is not valid. Bow deformation should be included in future versions of SIMCOL. A simplified bow model is proposed which approximates the results predicted by the three collision models, closed-form, conventional and intersection elements, to a reasonable degree of accuracy. This simplified bow model can be used in further calculations and damage predictions. A single stiffness can be defined for all striking ships in collision, irrespective of size.
Master of Science

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.

The overall objective of this thesis is to develop, validate and assess a probabilistic collision damage model to support ongoing work by the Society of Naval Architecture and Marine Engineering (SNAME) Ad Hoc Panel #6 and IMO working groups. It is generally agreed that structural design has a major influence on tanker oil outflow and damaged stability in grounding and collision, but crashworthiness is not considered in present regulations. The proposed methodology provides a practical means of considering structural design in a regulatory framework, and when implemented would improve the safety and environmental performance of ships. This thesis continues the development and applies a Simplified Collision Model (SIMCOL) to calculate damage extent (transverse, vertical and longitudinal) and oil outflow in ship collisions. The primary contribution of this thesis is the development and validation of a theory for the determination of energy absorbed in longitudinal extent of damage, and the implementation of the theory within SIMCOL. SIMCOL is sufficiently fast to be applied to thousands of collision cases as is required for a probabilistic analysis. The following specific tasks were completed using SIMCOL in support of this project: · Completed the development of SIMCOL Version 3.0 including: 1) Deformable Bow sub model 2) Implementation and validation of theory for the determination of energy absorbed in longitudinal extent of damage. · Developed the capability to model collision events using LSDYNA. · Validated Virginia Tech LSDYNA ship collision modeling procedure. · Validated SIMCOL using real collision data, and probabilistic collision data for penetrating collisions.
Ph. D.

Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 135-137).
The OFNP research group in the Nuclear Science and Engineering Department at MIT is developing a power plant that combines two well-established technologies -- light water reactors and offshore platforms -- into a new design called the Offshore Floating Nuclear Plant (OFNP). Deploying a nuclear reactor aboard a floating platform up to 12 nautical miles into the ocean raises unique security questions and considerations. This investigation presents a framework for analyzing the threat of intentional ship collision, modeling damage and characterizing the effectiveness of potential solutions, as well as integrating or adapting the recommended security strategies into existing regulatory and legal environments. First, a collision risk assessment is completed and a postulated design-basis collision threat (DBT) is determined to be a 150,000 DWT ship. Next, using the DBT characteristics and the finite element modeling software ABAQUS, estimations for damage are provided for a reference case and for cases with variations in collision characteristics. Results indicate increased ship penetration from faster and larger ships, wedge-shaped ship hulls, fixed OFNP moorings, direct broadside collisions, and OFNP designs with less internal structural support. Additionally, in order to minimize risk of unacceptable damage, the results indicate that vessels larger than 70,000 DWT should be restricted from entering within an eight-nautical mile exclusion zone. The results from the previous assessments are then used to present technical, operational, and regulatory recommendations for damage mitigation. The analysis concludes with an assessment of the existing regulatory and legal environments in which the regulatory solutions would have to be implemented, provides an analysis of the degree to which the ideal regulations comply with existing laws, and then culminates with the presentation of further recommendations and a regulatory strategy framework for meeting security goals while achieving legal compliance. In summary, this investigation considers the threat of intentional collision with an Offshore Floating Nuclear Plant and utilizes risk assessment techniques, numerical modeling, and legal research to contextualize the threat, model possible damage, and present technical, operational, and regulatory solutions for avoiding or mitigating damage.
by Grant Norman Genzman.
S.M.

During ice voyages, level ice and iceberg with huge inertia force can cause large deformation and even damage on the ship hull structure. Hence the hull structure for ice voyage requires higher strength than it for open water voyages. A container ship will be re-designed for ice voyages in the thesis. Generally, the ice strength is evaluated in ice class rules. IACS polar class and FSICR are adopted in this thesis. Ice class rules are based on experience and experiment data, but there has been no exact formula or parameters to described the ice properties so far. In other words, the results from ice class rules include uncertainties. In order to improve physical understanding, non-linear FE simulations will be processed after the re-design. In the simulations, the ship has a collision with different ice scenarios. The simulations are carried on ANSYS Workbench Explicit Dynamic using the solver of Auto-dyna. Afterwards, the results from the two designs schemes are compared and analysed.

Syftet med denna studie är att granska hur man som nautiker skall framföra sitt fartyg med hänsyn tagen till säkerheten och sjövägsreglerna i en korsande situation där ett väjningsskyldigt fartyg inte väjer. Vi genomförde en fallstudie bestående av en simulatorövning för ovetande styrmän och semistrukturerade intervjuer med nautiker från Stena Line, Scandlines och Wallenius. Genom att testa intervjurespondenternas lösningar i fartygssimulatorn på Sjöbefälsskolan i Kalmar kom vi fram till för- och nackdelar med olika sätt att agera. Vi har fått en ökad förståelse för hur sjövägsreglerna bör tillämpas i korsande situationer som vi vill att läsaren ska kunna tillgodogöra sig genom att läsa vårt arbete. Styrmännen som intervjuades berättade att de upplever att det är vanligt med fartyg som inte följer sjövägsreglerna.
The purpose of this study is to examine how a Navigating Officer should pilot his vessel safely while taking the Collision Regulations (COLREGs) into account whilst in a crossing situation in which a give-way vessel does not give way. We have examined how these situations can be solved by obtaining qualitative data from semi-structured interviews with Navigating Officers from Stena Line, Scandlines and Wallenius. All the officers whom we have interviewed told us that, in their experience, it is common to meet a ship that does not follow the COLREGs. By putting our respondents’ solutions to the test in the ship simulator at Kalmar Maritime Academy we were able to conclude the pros and cons of different approaches to the problem arising in a crossing situation when a give-way vessel coming from port does not give way. Through this process we (the writers) have gained a better understanding as to how the COLREGS should be applied in crossing situations and we hope that all readers can assimilate this knowledge by reading our thesis.

In this day and age of europeanisation and internationalisation of all aspects of society, including law, the topic of medieval maritime law has attracted increasing interest.  Regulating sea shipping, which is characterised by the connection between different ‘nations’, sea law is intrinsically international.  Or is it?  The existence of a common medieval maritime law has often been presumed, but is researched thoroughly for the first time in this study. By analysing the developing and spread of the written sea laws across Northern Europe and by comparing the contents of the different maritime regulations, as well as the legal practice in five Northern European towns (Lübeck in Northern Germany, Reval (Tallinn) in Estonia, Danzig (Gdansk) in Poland, Kampen in the Netherlands and Aberdeen in Scotland) by using the examples of shipwreck, jettison and ship collision, the author has aimed to determine whether it is accurate to speak of a common law of the sea in medieval Northern Europe on the level of the books of law, their contents and the practice of the law at the town courts. Research has proven that there was no uniformity on any of these levels, despite occasional similarities between the laws and the judgements passed by the courts.  There was no single law compilation available throughout Northern Europe at any time during the Middle Ages, there were no common regulations in the written laws and there was  no uniform legal practice in the towns of Northern Europe. The divergence between the five towns handled in this study could largely be explained by the different role each of the towns played on the European stage.

Cette thèse traite du développementde méthodes analytiques pour l’analyse de laréponse aux collisions de navires d’éoliennesoffshores tubulaires telles que les monopieux etles flotteurs de type Spar, en considérant lesdéformations non seulement plastiques maisaussi élastiques, ceci afin de traiter des impactsà faible et à haute énergies.Le travail de recherche s’articule en deuxparties. La première concerne la réponse àl’impact d’éoliennes classiques tubulaires endéformation élastoplastique quasi-statique. Unalgorithme « pas à pas » est développé sur labase de formulations théoriques puisimplémenté dans un solveur permettant deprédire le processus de déformation complet del'éolienne.Dans la seconde partie, la réponse dynamiqueélastique d’un monopieu impacté par un navireest étudiée. Une méthode basée sur desmatrices de transfert est développée pourquantifier la réponse de l'éolienne à une chargeimpulsionnelle donnée et en particulierl'accélération vue par la nacelle.Ce travail de thèse s’inscrit dans le cadre duprojet de recherche ColFOWT, qui vise àdévelopper un outil complet et rapide d'analysede collisions navire-éolienne offshore. L'outilpermettra à terme de modéliser le processusde transfert d'énergie multi-mécanismes qui alieu lors d'une collision de navire, y compris lesmodes de déformation locaux et globaux ainsique l’effet des chargements hydrodynamiqueset des lignes d’ancrage
This thesis focuses on thedevelopment of simplified methodologies toassess the ship collision response of offshorewind turbines (OWT) supported by standalonetubular members such as monopiles and sparfloaters, with the inclusion of elasticcontributions, and the capability to address bothlow and high-energy impactsThe research is divided into two parts. The firstpart concerns the quasi-static elasto-plasticimpact response of typical OWTs. A timesteppingalgorithm was developed based ontheoretical formulations and implemented in astructural solver that is capable of predicting theOWT’s complete deformation process.The second part examines the dynamic elasticresponse of a monopile to a ship impact. Asimplified two-step framework based ontransfer matrices was developed to assess theresponse of the OWT to a given collision load,in particular the RNA acceleration.This thesis was conducted in the framework ofthe ColFOWT project, which aims to develop acomprehensive and rapid assessment tool forship-OWT collisions. The tool will be capable ofmodelling the multi-mechanism energy transferprocess that takes place during a collisionevent, including local and global deformationmechanisms, hydrodynamic effects, andmooring response

This thesis considers the relationship between collision regulations and an automatic collision avoidance system (ACAS). Automation of ship operations is increasingly common. The automation of the collision avoidance task may have merit on grounds of reduced manual workload and the elimination of human error. Work to date by engineers and computer programmers has focused on modelling the requirements of the current collision regulations. This thesis takes a new approach and indicates that legislative change is a necessary precursor to the implementation of a fully automatic collision avoidance system. A descriptive analysis has been used to consider the nature of the collision avoidance problem and the nature of rules as a solution. The importance of coordination between vessels is noted and three requirements for coordination are established. These are a mutual perception of: risk, the strategy to be applied, and the point of manoeuvre. The use of rules to achieve coordination are considered. The analysis indicates that the current collision regulations do not provide the means to coordinate vessels. A review of current and future technology that may be applied to the collision avoidance problem has been made. Several ACAS scenarios are contrived. The compatibility of the scenarios and the current collision regulations is considered. It is noted that both machine sensors and processors affect the ability to comply with the rules. The case is made for judicial recognition of a discrete rule-base for the sake of an ACAS. This leads to the prospect of quantified collision regulations for application by mariners. A novel rule-base to match a pm1icular ACAS scenario has been devised. The rules are simple and brief. They avoid inputs dependent on vision and visibility, and meet all the aforementioned coordination requirements. Their application by mariners to two-vessel open sea, encounters was tested on a navigation simulator. The experimental testing of such a rule-base is unique. Mariners were given experience of applying the rule-base in certain circumstances and asked by questionnaire what their agreeable action would be. This was compared with their usual action. While the number of experiments was small, an indication was given of the impm1ant issues in applying a quantified rule-base. Aspects identified for fm1her study include the testing of rule base elements in isolation, and the use of quantified rules in multi-ship and confined water encounters.

Ship collision accidents are rare events but pose huge threat to human lives, assets, and the environment. Collision resistance of ships is usually assessed in terms of ship structural response such as member displacement, energy dissipation and the extent of damage. Many researchers have sought for effective models that compute ship stochastic response during collisions by considering the variability of collision scenario parameters. However, the models were limited by the capability of the collision computational models and did not completely capture collision scenario, and material and geometric uncertainties. In addition, the simplified models capturing the input-response relationships of the ship structural impact mechanics are in implicit forms which makes them unsuitable for assessing the performance of structural design specifications in collisions. Furthermore, with increasing ship passages in the Arctic region, the probabilities of ship-iceberg interactions are increasing, highlighting the need to focus on risk based ship designs. In this research, a conceptual stochastic modelling framework is developed for performance characterisation and quantitative risk assessment of ship-ship and ship-iceberg collisions. In this direction, an interface for automated stochastic finite element computations was developed to model ship structural resistance in reference collision scenarios. The stochastic structural response was characterised based on the onset of the ship structural failure. The focus was initially on ship-ship collisions to quantify the uncertainties experimentally and to characterise the performance for a variety of striking ships. The framework was then extended to consider probabilistic performance measures in ship-iceberg collisions. The computationally intensive collision response models were captured with efficient surrogate representations so that the performance measures can be obtained with gradient based reliability approaches. The most probable input design sets for the response distribution were sampled with Latin Hypercube models. The probabilistic performance measures were also combined with available collision frequency models from literature for risk computations and to demonstrate the risk tolerance measures. The framework underlines the significance of different risk components, providing valuable guidance for improving risk-based ship designs. Although, a double-hull crude oil carrier is presented as the struck ship, the approach can be readily extended to characterise the performance and risk of other ship structures in collisions.

This thesis presents a new set of methods to assist the process of ship design for safety with particular reference to collision damage. The study has two principal objectives: " investigations into subdivision aspects of passenger ships to improve their overall survival index " investigations into the subdivision of oil tankers in order to improve the effectiveness against spillage in the event of collision damage. In order to investigate the ship subdivision aspect a damage stability model was needed. A pre-requisite for developing the damage stability software was a robust but flexible method to define the hull and the compartments of subdivision. B-splines have been a popular representationatl ool in computer aided design over the past three decades.T his method, though more complex than other spline techniques such as cubic splines, was adopted with a fourth order basis function in this work. A complete set of spline manipulation libraries and associated numerical solvers were developed for this purpose. In addition to this, a method to define the intersection between the hull and the waterplane in the form of a closed B-spline curve for any given orientation of the vessel in terms of -heel, trim and draught was developed to aid the damage stability calculations. Though the earlier regulations stipulate fixed trim assessments to ease the computational process, it is clearly unsatisfactory and research has confirmed this to be a flawed approach. Free trim calculations on the other hand require an iterative and time consuming process to arrive at the equilibrium trim position for each heel angle. Pawlowski proposed a new method for the stability calculations of a freely floating rig when the unit is arbitrarily orientated to the wind direction. It uses the Euler theorem on the properties of equivolume waterplanes to arrive non-iteratively at the new inclined position. This theory was adapted for use in damage stability calculations and was numerically tested and proved to be sound. Damage stability calculations, though combinatorially large, are also inherently parallel. Parallel Virtual Machines (PVM) is a Message Passing Interface (MPI) developed jointly by ORNL, University of Tennessee, Carnegie Mellon University and the Pittsburgh Supercomputing centre. PVM enables a "virtual configuration" so that a collection of serial, parallel and vector processing machines appear as one large distributed memory computer. PVM was compared with another MPI called Network Linda where the advantage of PVM's user controlled message passing was demonstratedP. VM was used to implement the MJMD Distributed Memory paradigm to exploit this inherent parallelism in damage stability calculations and to obtain speedups. A systematic exploration of the search space for this design problem involves the generation of a large number of internal subdivision configurations. This, coupled with the fact that the design space was multimodal in nature made it suitable to the application of a class of heuristic search algorithms called Genetic Algorithms (GA). A brief description of the mechanisms behind GA is presented along with their mathematical basis in the form of two theorems: the schema theorem and the building block hypothesis. Various techniques for solving constrained optimisation problems with GA was explored. The penalty function method was found to be the most suitable and was finally adopted. The above techniques were applied to the optimisation. of the internal subdivision of passenger ships and cargo ships, oil tankers in particular. For passenger ships, the nature of the 's'-factor formulation on the local index was shown. The multimodal nature of the subdivision problem was highlighted and a GA was used to investigate the optimal subdivision characteristics of the vessel. The 's' factor formulation for cargo ship rules is different to that described by the A. 265 set of regulations for passenger vessels. In addition, the cargo ship rules describe a factor V which accounts for the probabilities of vertical extents of damages. However this formulation does not assign any credit for horizontal subdivision below the waterline. Data on vertical extents and vertical location of damages for cargo ships was collected and analysed in earlier studies done at Newcastle University. This data was used to develop a probability function akin to that developed for the longitudinal extent and longitudinal location so as to give credit for any horizontal subdivisions. The principal objective of this part of the study was to explore the search space for subdivision configurations that would minimize net oil outflow.

The scope of the present Ph.D. thesis was to investigate the mechanics of collisions between icebergs and ship structures. Large reservoirs of oil and gas and new sailing routes in the Arctic area are two large motivations for the present research. Human activity in the Arctic demands well-designed naval architectures for facing different kinds of ice loads. According to modern design codes, ship and offshore structures are usually designed under the ultimate limit state (ULS) methods and checked with the accidental limit state (ALS) methods. The methods and assumptions presented in this thesis are only valid for ALS design. This thesis considers three topics related to the iceberg collisions with ship structures: external mechanics, internal mechanics and residual strength assessments. Collisions between icebergs and ship structures are quite complicated processes. For simplicity, this problem was split into its external and internal mechanics. External mechanics talks about the translational and rotational momentum balance. It is believed that the impact mechanics of iceberg collisions with ship structures should be presented in three dimensions. Thus, a new formulation of impact mechanics was proposed that describes the impact in three dimensions. All forces except for impact force are neglected. This new three-dimensional method degrades to existing two dimension (2D) method. It was successfully applied to the calculation of the demanded dissipated energy for iceberg and ship collisions. Internal mechanics deal with both deformations of icebergs and ship structures. Nonlinear finite-element analysis (NLFEA) was used in this research. The commercial code LS-DYNA 971 was used to assess the internal mechanics of both icebergs and ship structures. Deformations of both icebergs and ship structures should be well captured by numerical simulations. However, due to the difficulties of simulating ice, NLFEA is not straightforward. To facilitate such simulations, a plasticity-based material model for icebergs was developed in this thesis. Iceberg crack propagation was simulated by element erosion. An empirical failure criterion for detecting those failed ice elements is proposed. Numerical examples showed that the new iceberg model gives good results. The model was successfully implemented in LS-DYNA 971 through a user-defined subroutine. Subsequently, the integrated numerical analysis of iceberg-ship collisions was then successfully performed. Efforts were made to investigate the internal mechanics of both icebergs and ship structures during collision, such as local structural behaviours and ice failure. Two scenarios of iceberg-ship collisions were investigated: iceberg collisions with foreship and side-ship structures. In the first scenario, efforts focused on the investigation of the detailed internal mechanics of the icebergs and ship structures. The strength of ship structures was varied by adjusting the parameters of the steel material model, thereby varying the relative strength of icebergs and ship structures. A comprehensive discussion is based on the simulation results. The discussion addresses contact pressure, iceberg shapes and collision locations. In the second scenario, investigations focused on the influences of the iceberg shapes. Simple iceberg shapes representing “sharp” and “blunt” icebergs were used. The results show that “blunt” icebergs may behave as rigid bodies. Finally, the residual strengths of the ship structures after impact, which may be caused by the icebergs, was assessed. A simple plasticity method and a single stiffener model were developed to quantify the residual strengths of the damaged ship structures. In the simple plasticity method, elastic and rigid-plastic methods were combined to derive the end-shortening curve for damaged stiffeners. In the single stiffener model, proper boundary conditions were proposed. Both methods were verified against numerical simulations. Generally, good results were obtained. From this work, a rapid method to assess the residual strength of damaged ship structures is suggested.

Offshore wind farming is an industry under development and involves challenges. The farms might be located close to ship trading routes. This increases the risk of ship-wind farm impact, causing economic losses, environmental pollution and human fatalities. The first part of this report describes various bottom supported wind farm technologies and presents a discussion of the risk picture considering oil spill due to this collision event. A review of relevant standards is enclosed. The main part of this thesis considers finite element modelling and simulations of impact between a jacket supported wind turbine and a large oil tanker. The goal with these analyses is to study the possibility of achieving the Bundesamt für Seeschifffahrt und Hydrographie standard "Design of Offshore Wind Turbines", requiring minor oil spill due to ship-wind turbine collision involving ship kinetic energy larger than 500 MJ. The standard requires that a risk analysis is performed to demonstrate that either the collision energy is absorbed by the structures or that it results in collapse of the wind turbine without damage of the ship hull. The wind turbine model is received from the company Virtual Prototyping. Geometric and load modifications are performed in order to obtain realistic results representative for the North Sea. The global response of the jacket is studied using the computer program USFOS. The ship is modelled drifting towards the corner of the jacket, hitting one leg. The ship is assumed to be rigid, not contributing to dissipate the collision energy. The contact between the structures is represented by a nonlinear spring. Different impact locations on the jacket are considered. Both collapse due to overall deformation of the installation and local damage of the tower is studied. In addition, failure of the nacelle bolts is investigated in order to verify the possibility of the nacelle dropping on the deck, penetrating the cargo tanks.

As the worlds demand for energy is increasing mostly due to the increase in population, and coal, oil and gas deposits are limited, it is desirable to gather energy from renewable energy sources. Wind energy is a form of renewable energy. Wind turbines have been common on land and near shores for some time, but now one wants to take advantage of the wind resources further away from the coast. As the length from the coast increases, so does the water depth making it necessary to use other foundations than the well-known monopile. In this thesis the “Federal Maritime and Hydrographic Agency” in Germany, also known as Bundesamt für Schifffarth und Hydrographie requires in the standard “Design of Offshore Wind Turbines” that an offshore wind turbine needs to be risk evaluated against a ship tanker of more than 500 MJ in collision energy in order to be classified as collision energy. This is to prevent environmental pollution in form of oil spill. Whether the offshore wind turbine models used in this thesis are collision friendly or not relies on different factors. When the given soil properties are used the analyses show in all cases except one that the offshore wind turbine models can be called collision friendly. The case were it could not be called collision friendly was a case with the small jacket at a water depth of 27 m getting hit by a loaded ship at a column of the jacket, but installing a horizontal brace on this jacket would make it also collision friendly. The effects of soil, water depth and a horizontal x-brace are looked further into in this thesis. If the soil had been stronger it is not certain that the outcome would be the same. When the jackets were fixed to the sea bed, several of the models could collapse in the dangerous direction over the ship. A horizontal brace was seen to have a positive effect when installed on the different jacket models. It seems also that it is more favorable to use jackets at deeper water.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, (M.S.)--Joint Program in Marine Environmental Systems, Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1998.
Includes bibliographic references (p. 79).
by Charles E. Rawson.
M.S.

This thesis is a framework for risk influence modelling of supply vessel-platform collisions, with the inclusion of central concepts from the Risk OMT model. The framework is a improvement from existing QRA frameworks in the sense that it has taken recent collisions into consideration, and enabled the opportunity to do risk influence modelling for the calculation of site specific risk. It can also be used as a tool for risk management, when the risk influences have been quantified. This model provides no quantifications, but it makes a good foundation for future work.The thesis incorporates knowledge from recent, representative collisions on the Norwegian Continental Shelf (NCS), and considered the guidelines and official safety procedures. This has been used to make three generic collision scenarios are general enough to take all probable collisions into account and at the same time be specific enough to account for the chains of events in previous accidents.These generic collision scenarios has been analysed with event tree analysis (ETA) and fault tree analysis (FTA) to identify and break down the operational barrier functions available to prevent collisions. A large set of risk influencing factors (RIFs) have been identified to be used to express the failure rate probabilities of the basic events found the FTA. These have been included from many different sources, to ensure that all significant RIFs are presented.

Kollisioner, grundstötningar och andra haverier till sjöss har förekommit lika länge som det funnits fartyg. Dessa olyckor är vanligt förekommande och utgör fara för människor, fartyg, miljö, last och ekonomi. Med dagens utvecklade teknologi finns det bra metoder och utrustning för att undkomma grundstötningar och kollisioner, dock är det fortfarande vanligt förekommande händelser. För att kunna minska denna typ av sjöolyckor är det viktigt att undersöka orsaken till varför de inträffar. Syftet med studien är att undersöka och få en djupare förståelse om varför passagerarfartyg går på grund eller kolliderar i svenska havsområden. För att få fram vilka bidragande faktorer som orsakar dessa typer av sjöolyckor granskas och analyseras 29 haverirapporter från Statens haverikommission (SHK) och Transportstyrelsen. Resultat visar att majoriteten av olyckorna sker i farleder runt om i Sverige. Faktorer som bidrar till olyckorna är bland annat brist på rutiner, accepterat möten i för liten marginal, utkik används på fel sätt och brist på framförhållning. Därmed är det betydelsefullt att fartygen ser över sina rutiner och bryggbemanning.
Collisions, groundings and other accidents have been occuring for as long as ships have existed. These accidents are common and pose a danger to people, ships, the environment, cargo and the economy. With today's developed technology there are good methods and equipment to avoid groundings and collisions, although they are still common. To be able to reduce these types of accidents it is important to investigate the reasons behind them. The purpose of this study is to investigate and develop a deeper understanding as to why passenger ships ground or collide within Swedish waters. To obtain the contributing factors behind these types of sea accidents 29 accident reports from The Swedish Accident Investigation Authority (Statens haverikommission - SHK) and the Swedish Transport Agency (Transportstyrelsen) have been reviewed and analyzed. The results show that the majority of accidents happen in fairways around Sweden. Contributing factors to the accidents include a lack of routines, two ships passing with too small of a margin, lookout used incorrectly and a lack of forward planning. It is therefore of importance that ships review their routines and bridge manning.

From the inception of the Reformation, Protestants have championed the doctrine of justification as the foundational core of their creed. In fact, it has often been said, then and now, that the doctrine of justification is articulus stantis et cadentis ecclesiae—the article upon which the church stands or falls. Yet, at the start of the twenty-first century there is strong dissent over this core doctrine. In recent years, this topic has attracted vast attention and stirred immense conflict within evangelical circles. Scholars are increasingly at odds as to how to define the doctrine, while questions abound concerning the role it plays in the soteriological, eschatological, and ecclesiological framework of the evangelical faith. At the center of the dispute are two opposing and well-respected evangelical leaders, John Piper and N.T. Wright.

The purpose of my project is to capture this contemporary debate on justification between John Piper and N.T. Wright—to aid in understanding the details of their debate in better measure. The primary question I will address is, Are John Piper and N.T. Wright on a collision course, or are they two ships passing in the dark of night? A secondary question will guide us towards an answer, “How do two Protestant, evangelical, sola scriptura theologians arrive at such different places in relation to this essential doctrine?”

I will first address how the doctrine of justification has been understood throughout the history of the church, starting with the apostolic fathers, then tracing the doctrine through the medieval church and culminating in the Reformation, as well as the Counter Reformation at the Council of Trent. Thus, this journey will highlight the soteriological views of the patristics, Augustine, Anselm, Aquinas, Ockham and the nominalists, Luther, Melanchthon, and Calvin. Putting the Piper and Wright debate into historical context is imperative to understanding their dispute. We will also look briefly at what has been termed the new perspective on Paul, a label which has been ascribed to Wright. Finally, we will look at the intricacies of John Piper’s and N.T. Wright’s doctrines of justification before answering the central question.

碩士
國立臺灣海洋大學
通訊與導航工程學系
103
Maritime transportation and trade has expanded rapidly over the past few decades, while the transported cargos may contain dangerous or harmful ones.. Even a single accident could cause serious environmental disaster and the loss of human’s life. This makes vessel traffic analysis and maritime spatial planning more important than ever, to prevent accidents and facilitate maritime development and management. This thesis uses huge amount of AIS data collected from the west coast of the Taiwan to assess the risk of ship collision, in case the development of offshore wind farms has to constrain vessel navigation into designated traffic routes. In this study, programs are developed to extract parameters from AIS data and put into mathematical model approved by IALA in the IALA Waterway Risk Assessment Programme, to calculate the ship collisions frequency in each waterway. Ship-to-ship collision risk in each encounters situation, Namely overtaking, head-on, and crossing, are estimated for the case of free navigation and that with traffic separation scheme. The effect of route separation distance on head-on collision risk and that of route intersection angle on the collisions risk while crossing are estimated and analyzed to assist in the design of ship's routing measures to lower the collision risk while allowing for harmonized use of the maritime space.

碩士
玄奘大學
法律學系碩士班
99
ABSTRACT As international trades become much frequent, marine transportation system is getting more and more important. For long-distance transport’s need, ships are made huge on size and advanced complex on equipment day by day. However, that will cause huge damage between ships if they have the collision. Obviously speaking, there has the importance on ship collision. In this study, on chapter two, we start from the description of the definition of ship, especially what kind of ship meant on Maritime law. To distinguish the benefit between ships, it must depend on the ships which stipulated for Maritime law in be able to be suitable for Maritime law. Looking from the angle internationally, new concept of ship collision is no longer direct collision but indirect one. Speaking of its legal nature, ship collision is a kind of torts with foreign elements. So, it belongs to foreign right infringement case. On chapter three, we interpret that ship collision is whether there is neglect duty and whether should take the liability of compensation, and it has to the person compensation and to the thing compensation. For a foreign-related civil case, there is three points. First, this case shall be govern by which country’s court. Second, after the determination of the jurisdiction of the court, this court shall depend on which country’s law to be the trial standard, which called the law as Criterion law. Third, whether this judgment is recognized or acceptable and enforced by other foreign courts after making a judgment by this court, to ensure and protect the litigant rights and interests. So, on chapter four, we explain the conflicts and differences of jurisdiction on ship collision among various countries’ courts. Besides, we discuss how to solve and then focus on interpretation of ship collision’s jurisdiction of our country. On chapter five, we explain the basis on each theory of Criterion law and then ship collision among various countries on Criterion law is also explained. Finally, international convention on certain related rules of ship collision is explained on chapter six and our conclusion points out the probably insufficiency of our law and take it as the reference of repairing the law in the future.

博士
國立臺灣海洋大學
系統工程暨造船學系
107
In recent years, global trade has continued to grow, and the demand for marine transportation has increased. Although the navigation aids have developed rapidly, the increase in the size of ships, the number of ships and the speed of navigation have caused collisions and grounding in busy waters area frequently. Most of these collisions are classified as human error. Traditional maritime transport is dominated and operated by pilots. Maritime data shows that 75-96\% of marine accidents and casualties are classified as human error, of which 56\% of collision cases are in violation of the International Regulations for Preventing Collisions at Sea (COLREGs) by International Maritime Organization (IMO) or regional navigation regulations. Casualties and environmental disasters accompany shipwrecks accident caused by human error. Therefore, in order to improve navigation safety, it is important to develop an intelligent navigation system to assist the pilots in performing decision-making and operation of collision avoidance . When ships are sailing in narrow and busy waters or port areas, multi-ship collision avoidance and safe path planning are key technologies for developing intelligent navigation systems. Due to the limitations of ship maneuverability, sea meteorological environment and geographical environment, Developing the intelligent navigation systems has become a more complicated and difficult subject. However, the growth of Information Technology (IT) has led to the rapid development of Intelligent Systems, such as Big Data, machine/deep learning, Artificial Intelligence (AI), Internet of Things (IoT), virtual/augmented reality, etc. The technologies make intelligent navigation systems a viable development trend. The intelligent ship collision avoidance system is different from the car collision avoidance system in that it is not only to obtain a safe target path but also to comply with COLREGs and local navigation rules. In addition to the international collision avoidance rules, the development of intelligent ship collision avoidance systems must also incorporate practical navigation experience. Therefore, further quantitative analysis of collision avoidance rules and navigation experience is “intelligence” to giving collision system "wisdom". However, the international collision avoidance rules do not provide specific collision avoidance measures. How to automatically make collision avoidance decisions under the COLREGs to complete the collision avoidance operation requires further research, especially in the case of multi-ship encounters. The ship's collision avoidance system must operate with high reliability, fault tolerance and safety for detecting the surrounding environment of the ship in real time to avoid collision and grounding with other ships or obstacles. Based on the artificial potential field method, this study develops a decentralized collision avoidance model suitable for complex waters and multi-ship encounters based on ship maneuvering and COLREGs. Moreover, carry out quantitative analysis of the decision-making problems of multi-ship ship collision avoidance by the COLREGs. And discuss that in the case of multi-ship encounters, each ship gives way to certain target ships while stands on to other target ships. When to use a proper action of the engine orders and rudder orders to carry out collision avoidance of the ship. The main contents of this thesis include: (1) ship encounter situation identification, (2) intelligent ship collision avoidance algorithm, (3) ship maneuvering and navigation simulation system, (4) collision risk assessment model, and (5) cases analysis of ship encounter. The description is as follows: \noindent {\bf Identification of ship encounter situation:} According to the COLREGs, ships encounter during navigation in the waters are classified as give-way ship and stand-on ship. And it is mentioned that the stand-on ship should maintain its speed and course to pass the area as soon as possible. At the same time, the give-way ship should change its speed and course to clear the area. There are three situations mentioned in the collision avoidance rules, that are head-on, crossing, and overtake encounter situations. Rule 14 states head-on situation; when two power-driven vessels are meeting on reciprocal or nearly reciprocal courses so as to involve risk of collision each shall alter her course to starboard so that each shall pass on the port side of the other. Rule 15 states crossing situation; when two power-driven vessels are crossing so as to involve risk of collision, the vessel which has the other on her own starboard side shall keep out of the way and shall if the circumstances of the case admit avoiding, crossing ahead of the other vessel. This situation would frequently arise and it is always better to avoid a close quarter situation and go right around the stern of the other vessel rather than cross ahead of the other vessel. Rules 13 and 17 describe the overtake situation as follows: any vessel overtaking any other shall keep out of the way of the vessel being overtaken. Meaning: It does not make a difference whether any ship ahead of the own vessel has permitted by signalling that overtaking may take place. As long as the give-way vessel takes action well in time there is no problem and the stand-on vessel follows the above Rule, and the stand on the vessel is required not to take action, but it does not mean that she would not be alert and monitor the situation. From this study, a three-dimensional ship maneuvering simulation system can be used to obtain real-time dynamic results of the ship and the target ship. The distance between the ships, the bearing angle, and the speeds are used to calculate real-time data, such as the distance to the closest point of approach ($DCPA$) and time to the closest point of approach ($TCPA$), and quantitatively combined with the COLREGs to create an identification system of ship encounter situation. When ships encounter, the system determines whether the own ship is a give-way ship or a stand-on ship, and determines the encounter situation between the ship and the target ships. \noindent {\bf Intelligent collosion avoidance algorithm:} The artificial potential fields method was proposed by Khatib in 1986. The concept is to form a virtual artificial potential field by the interaction between the repulsive field of the obstacle and the attractive field of the target position. Also, then search for the direction of the potential function to find a collision-free optimal path, which was mainly applied to robot motion guidance in the early stage, and belongs to the reactive robot obstacle avoidance algorithm. The artificial potential fields can create a deterministic solution because it does not involve random variables in the calculation, and the output is completely predictable. The decentralized structure with immediate processing capability is an important key to the development of intelligent ship collision avoidance systems for the real-time changes of local environmental conditions and comply the COLREGs. Based on the deterministic structure of the artificial potential fields, this study introduces the velocity potential field of the ideal flow theory to develop the ship collision avoidance algorithm. The algorithm developed in this study consists of a course-changing mode constructed by vortex potential and a track-keeping mode of dipole potential. The course-changing mode sets a virtual vortex velocity field in the ship's navigational waters, and guides the give-way ship to avoid obstacles or target ships according to the COLREGs rules. Track-keeping mode produces a virtual velocity field of dipole flow that allows the give-way ship to return to the originally set route after performing the collision avoidance operation and to keep the stand-on ship sailing along the original set route. According to the navigation status of the ship and the target ships, the distance between the two ships, the position two ships (the bearing angle), the $DCPA$ and the $TCPA$, the two modes of operation and the transformation criteria are established, which is in line with the experience of navigation practice. \noindent {\bf Ship Maneuvering and Navigation Simulation System:} Assuming that the ship acts as a rigid body in the horizontal plane, ignoring the pitch, heave and roll motions, the mathematical model is reduced to the sway, sway and yaw of three degrees of freedom. In this study, using the mathematical model of ship motion developed by Maneuvering Mathematical Modeling Group (MMG) in Japan to separate the ship's hydrodynamic force and moment into the parts of hulls, propeller and rudder and to be constructed separately. The inertia and the damping effects are computed and corrected by considering the mutual interference among hull, propeller and rudder to obtain the total forces and moments acting on the ship. Then the Runge-Kutta method is used to calculate the ship motion parameters for each time step. In this study, the fuzzy control module of the ship speed is established. The speed and speed change rate of the ship obtained by the ship dynamic simulation is used as the input of the control module. The membership functions of the ship speed and speed change rate are converted into the fuzzy value. The fuzzy value of the rotating speed of propeller is obtained by fuzzy inference, and then the corresponding rotating speed membership function is used to defuzzify to obtain the command to control the rotating speed of the main engine. At the same time, the proportional-integral-derivative (PID) control algorithm is used to establish the course controller. The rudder angle is calculated by the dynamic course deviation, cumulative deviation and deviation rate of the ship. Combined with MMG ship motion mathematics mode, ship speed fuzzy control mode and PID control algorithm, a platform for implementing multi-ship encounter collision avoidance operation simulation is established. \noindent {\bf Collision risk assessment model:} This study uses two methods, fuzzy inference and fuzzy comprehensive evaluation methods, to establish a collision risk assessment model. Among them, the fuzzy inference method uses the fuzzy IF-THEN rule to infer the fuzzy value of the collision risk through the parameters such as the rate of change of the bearing angle, the $DCPA$ and the $TCPA$ obtained by the dynamic simulation. Through a defuzzification procedure, the system evaluated the collision risk index. The fuzzy evaluation method obtains the risk index by input the distance between the two ships, the ship position (bearing angle), the $DCPA$ and the $TCPA$. The corresponding membership function fuzzifies the input parameters and then a weighted evaluation or fuzzy comprehensive evaluation were used to obtain the collision risk index. The collision risk assessment model established in this study is used as a criterial to switch on or off the ship collision avoidance operation procedure when the ship in encounter situations, and also used to assess the relative risk index of target ships when multi-ships encounter to adopt appropriate avoidance priority order. The results show that the fuzzy inference method based on the parameters such as the rate of change of the bearing angle, $DCPA$ and $TCPA$ can fully demonstrate the risk characteristics including head-on, crossing and overtake encounter of ships. \noindent {\bf Cases analysis of ship encounter: } In order to verify and confirm the decentralized collision avoidance algorithm and the intelligent ship collision avoidance system developed in this paper, we design a variety of ship encounter situations, such as cases of fixed single/multiple obstacles, cases of two ship encounter situation(including head-on, crossing and overtake) and cases of multi-ships encounter situation(four ships symmetry, sequence and staggered) will be studied. The results of the static obstacle test show that the ship can avoid obstacles by autonomous navigation. Moreover, the sensitivity test of the starting distance and the criterial of switching the course-changing and track-keeping mode was performed, and the results show stability performance of the collision avoidance algorithm. The results of the cases of the two ships encounter show that all the collision avoidance operations are in line with the COLREGs, and the course-changing and track-keeping mode are acting exactly according to the situations of the ship and the target ship. It also verifies the applicability of the collision risk assessment model established by the present study. The results of the four-ship symmetry case show the symmetry and stability of the collision avoidance algorithm. In the case of the four-ship sequence, the ship was tested to avoid multiple ships at the same time. The result shows that the collision avoidance algorithm can stably perform the collision avoidance operation. The results of the four-ship staggered case show that the ship is synchronous execution give-way and stand-on operations to target ships, and the head-on, crossing and overtake encounters situations simultaneously occured. The simulation results of the cases of two ships and multi-ships show that the intelligent ship collision avoidance system combined with the ship encounter situation identification, intelligent ship collision avoidance algorithm, ship maneuver simulation system and collision risk assessment can be effectively and safely perform avoidance decisions and operations. In each case, the ship passes the obstacle or the encounter ship at a preset safe distance. \noindent {\bf Epilogue:} This study addresses the design and preliminary application of intelligent collision avoidance and path planning algorithms for multi-ship encounters, that must find a safe route and decide on the control actions required to ensure compliance with COLREGs rules and minimize hazard to an acceptable level. Through the cases studies, the velocity potential fields model is consistent with the navigation practice and the concept of ship maneuvering. It is suitable for collision avoidance evaluation under multi-ship encounter conditions and for real-time environmental variations in accordance with the COLREGs rules. The system is decentralized and can be installed to each ship and onshore office of watch. At the same time, the collision risk assessment model is used to evaluate the relative risk value of each target ship when multi-ships encounter, and adopt appropriate action priority order to provide learning knowledge for intelligent collision avoidance system to improve the widom of the system. The relevant research results in this paper also can be provided as a reference for practical workers.

碩士
國立臺灣大學
工程科學及海洋工程學研究所
94
Collision and grounding may cause serious injury of ship structure and oil pollutions on the sea. In order to prevent this kind of disaster and reduce the loss, the US Coast Guard introduced the design of double-hull tankers to avoid the leakage of oil from the struck ship fifteen years ago. The mechanics of ship collision and grounding are very complex topics because the complexity of ship structure, and multiple failure modes may occurred for damaged parts. In the past decades, the damage modes have been categorized into different fundamental modes, and the approximated methods have also been developed based on the combinations of suitable fundamental modes. The structures of double-hull tanker includes side plate, inner plate, stiffeners, web frame, decks and girder, it is necessary to understand the failure mechanism of each component and the interaction of each part. In this paper the formulae to approximate the energy dissipation and the impact resistance of a stuck double-hull structure based on Stretching mode and folding mode have been derived. The denting mode of girder and crushing mode of the crossing girder also been discussed. In this paper FEM analysis were compared with the simplified estimate formulae. The double-hull models from Wang(2000) was selected as care study. The damage process of double-hull structures was analyzed by FEM, the result of experiment, FEM analysis and simplified estimate formulae are compared. The results show that the proposed approximate method have acceptable accuracies.

碩士
國立成功大學
造船及船舶機械工程學系
90
This research is bulding virtual environment which using for ship collision avoid training system. We use the high speed and powerful computer system and 3D painting card . Build the port of KaohShiung and other 3D model on AutoCad、3D Studio .And import of VR software OmegaSpace and creat whole world. We also use Virtual C++ to build the main program of ship motion which product basic action of real ship ,and added to the ship which use Winstoke network translate. According to International Regulations for Preventing Collisions at Sea , we decide six condition for the boat .And take the move path of ships which in simulate loop . According to Japan Ship and Ocean juridical person statistics and use the software Fortran and MatLab to paint the path and graded.

碩士
國立臺灣大學
工程科學及海洋工程學研究所
101
Ship collision and stranding usually causes the damages on hull structures, series injuries of crews and loss of cargoes on ships may occur. Furthermore, collision may result in the consequently oceanic catastrophes, etc. In order to protect and to maintain the ocean environment and to promote the crew’s safety, as well as to minimize the losses and damage after accident, special designs for anti-collision and navigational safety has been taken into consideration in the last two decades. In the engine room the propulsion unit, power unit, and key equipment, and kernel of control system of ships are installed. If the engine room section of ship is struck, the serious consequence and escape of fuel oil may be caused with very high probability. In this paper, the engine room section of an 8,236TEU container was selected case study. The conditions of structural damages and impact characteristic of engine room section were examined. The structural damage of both colliding ships, the motion of ships were analyzed. The results of different cases were compared. The effects of change of local structures in engineering room on the crashworthiness were also investigated. At last, investigates the effect on collision, causing from partial filled fluid in side tank of a double hull container ship on the impact resistance for facilities in engine room the consequent crashworthiness hull structures in ship collision will be investigated. The LS-DYNA nonlinear finite element analysis program was used to analyze the ship collision in this paper. Using high deformable bow and also high ductile material for hull structure has the best results to improve crashworthiness of structure in ship collision, nevertheless, the design of ship structures may have changed significantly; using partial filled fluid in side tank can also improve the crashworthiness of ship structures, and it needs only small change of structural design.

碩士
國立臺灣大學
工程科學及海洋工程學研究所
107
An autonomous collision avoidance system was built and validated by the ship model collision experiments in this study. The autonomous collision avoidance system consists of three subsystems which are detection system, collision avoidance decision-making system(CADMS) and control system. The detection system consists of the various sensors and detects the dynamic information of the target ship by the laser scanner. The dynamic information of the target ship was smoothed by the Kalman one-dimensional model and was transmitted to the CADMS. The CADMS makes the collision avoidance decision by the Convention on the International Regulations for Preventing Collisions at Sea with the dynamic information and fuzzy logic theory. The decisions were then transmitted to the control system. The control system has two control logics which are fixed heading and variable heading. The fixed heading logic uses the fuzzy control steering system to calculate rudder angle to keep the ship sailing in a straight line. The variable heading logic adopts the first-order Nomoto equation of motion model with the coefficients calculated from the ship model turning cycle test. The rudder angle which makes the ship to reach the yaw rate was then determined by the CADMS. The scenario of the autonomous collision avoidance experiments is to make a target ship driving to an own ship which is sailed along a course and cause a collision crisis. Then, the own ship will turn to the collision avoidance course at the design speed until the collision crisis is averted. After the collision crisis, the own ship will return to its direction of original course. The distance at closest point of approach was about 2.4 ship length in the head-on situation experiment, and the distance at closest point of approach was about 2.0 ship length in the crossing situation(left) experiment. The own ship can pass the target ship safely and return to original course from a collision crisis. The autonomous collision avoidance system built in this study is successful.

碩士
國立海洋大學
航運技術研究所
85
When a ship is exposed to risk of collision, the navigator has to take avoiding actions complying with the international regulations for preventing collisions under the circumstances to prevent a marine casualty. The judgment of the risk completely depends on the navigator''s subjective recognition to navigational safety. In other words, if his collision-avoidance actions can not keep a safe distance to other ships, consequently the accident may still happen. Ship domain which is a basic theory for analysis of ship-handling behavior can display the characteristics of the requirement for ship movements. There are some factors, such as ship-handling and marine environment, affecting the difference of the requirement. Therefore, this study is focused on the actions and behaviors of mariners by questionnaire and ship handling simulator experiment. The former surveys the navigator''s comprehension and desire to collision avoidance with experience and knowledge. The latter analyzes actual expressions within navigable sea rooms with different encounter situations and visibility. The study shows that the safe distance between ships under collision risk is compressed and less than navigator''s desire, and the effect of poor visibility significantly causes navigators to take safe and early actions. The results can provide navigators correct aspects assessing the requirement of safe distance when facing collision risks, and are helpful for auto collision avoidance system as reference to design collision warning signals.

We consider a ship subject to kinematic, dynamic, and moment equations and steered via the rudder under the assumptions that the rudder angle and rudder angle time rate are subject to upper and lower bounds. We formulate and solve four Mayer problems of optimal control, the optimization criterion being the minimum time. Also, we formulate and solve four Chebyshev problems of optimal control, the optimization criterion being the maximization with respect to the control history of the minimum value with respect to time of the distance between two identical ships, one maneuvering and one moving in a predetermined way. Problems P1 and P2 deal with course change maneuvers. In Problem P1, a ship initially in quasi-steady state must reach the final point with a given yaw angle and zero yaw angle time rate. Problem P2 differs from Problem P1 in that quasi-steady state is required at the final point. Problems P3 and P4 deal with sidestep maneuvers. In Problem P3, a ship initially in quasi-steady state must reach the final point with a given lateral distance, zero yaw angle, and zero yaw angle time rate. Problem P4 differs from Problem P3 in that quasi-steady state is required at the final point. Problems P5 and P6 deal with collision avoidance maneuvers without cooperation, while Problems P7 and P8 deal with collision avoidance maneuvers with cooperation. In Problems P5 and P7, the maneuvering ship must reach the final point with a given lateral distance, zero yaw angle, and zero yaw angle time rate. Problems P6 and P8 differ from Problems P5 and P7 in that quasi-steady state is required at the final point. The above Mayer problems and Chebyshev problems, transformed into Lagrange problems via suitable transformations, are solved via the sequential gradient-restoration algorithm in conjunction with a new singularity avoiding transformation which accounts for the bounds on rudder angle and rudder angle time rate. The optimal control histories involve multiple subarcs along which either the rudder angle is kept at one of the extreme positions or the rudder angle time rate is held at one of the two extreme values. If quasi-steady state is not required at the final point, the total number of subarcs ranges from 4 to 8, depending on the particular problem. If quasi-steady state is required at the final point, the total number of subarcs ranges from 6 to 10, depending on the particular problem: the higher number of subarcs, is due to the additional requirements that the lateral velocity and rudder angle vanish at the final point.

碩士
國立臺灣海洋大學
商船學系
102
When a ship collision occurred, it might be involve in Civil, Criminal, Administrative liability. The issue of this study is to clarify the evidence collection of each liability which may be required, up to the jurisdiction and law application which derived from the accident. This study is limited to discuss the ship collisions which happened on sea area of ROC’s jurisdiction, whether Taiwan has the right to judge for the accidents isn’t the scope of this study. Due to the unpredictable risks of the sea activities, lots of international conventions and regulations are instituted in order to solve the disputes of property damage and reimbursement which caused by ship collisions. In judicial practice, however, the property disputes of ship collisions still happen constantly. Thus, clarification of ship collisions and the burden of proof are emphasized issues.When the ship accident occurred at sea, for the reasons and process of the accident, in addition to a statement of the crew, the other as evidence migration, vessel data records, etc. they can be appear the fact after the accident, but on the perpetuation and inspection of evidence, which is important to note and which is necessary to collect, there is a considerable degree of difficulty issues on execution. In Taiwan, major traffic safety agency on sea is Maritime and Port Bureau, Ministry of Transportation and Communications (MOTC) and Coast Guard Administration, Executive Yuan. The Group for Investigation of Marine Casualties is focused on the reason of collisions. And the collection of relevant evidence is conducted by Coast Guard. In this paper, literature review, cases-study comparative analysis, and inductive method will be conducted to clarify the liability of ship collision, analyzing the rules of evidence collection in other countries, in order to build a model for Guard’s current situation, procedures, investigation report of accident, and how to collect evidence when the collision occur. Furthermore, through this model, we can advise Maritime and Port Bureau, MOTC to accelerate the formulation of Maritime traffic safety law to seek proper law and way on evidence collection and procedure to establish the sources of maritime law when officials are on their duties.; through this model, we can have the sample to follow and know how to reserve the evidence in time and on judicial practice, to offer the useful evidence. Besides, we can establish a data base for collisions and combine it with the vessel monitoring system. It can not only secure the human lives and properties and clarify the subsequent liabilities, but also can prevent and minimize the time handling the maritime disputes and reduces the disputes.

碩士
國立高雄海洋科技大學
海事資訊科技研究所
103
Since the 18th century, the Industrial Revolution, labors have been replaced by the machines and ships have also evolved into steam boats (mechanism) from sailing boats (natural wind power), thus ship industry has been developing rapidly. Ships today have become larger, faster and more professional than before. Frequent maritime traffic increases the chances of accident in the sea. When shipwreck happens, it can be the loss of the property and the lives or even caused the damage of marine ecosystem. During Japanese occupied period, ships had been bombed into the Kaohsiung harbor due to the war strategy. After R.O.C. government came to Taiwan, it set up Kaohsiung Harbor Bureau in order to manage the maritime affairs, salvage the wrecks, clean the ship canals and make a long term plan for harbor development. Kaohsiung harbor became the top three business harbor in the world in 2009. It is the biggest harbor in Taiwan, thirteen in the world (Containerisation International, 2015) and Ⅲit is the distribution center for ships, thus the safety of the harbor is extremely important. This research focuses on analyzing the root causes of ship colliding accidents. According to all the information from the sea protest, organizing all the parameters from the accidents and using Neural Network to calculate in order to find out the relations between each parameters. The result can be useful for ship companies, port state control units and pilots ,etc. It can service the reference for the maritime risk assessment in order to avoid ship colliding in the harbor and reduce the risk of damaging harbor and ships.

碩士
國立臺灣大學
工程科學及海洋工程學研究所
99
Collision and grounding may cause serious injury of ship structure and human beam, the oil may spill on the sea, nowadays in view of saving of the maritime environment and for crews security reasons. In order to prevent this kind of catastrophe and reduce the oil pollution, the double hull and mid-deck structures for tanker were requested, later 1990s the soft bow concept was also proposed to reduce the stiffness of bow structures and improve the capacity of total energy dissipation of ship collision. This study investigated the deformation and damage process of four different types of bow structures and bulk carrier of double hull structures in bow-side collision, and evaluated their crashworthiness, the effects of ship motion doing collision on the collision damaged was also taken into consideration. The phenomena of rupture and penetration of bow and bulk carrier during ship collision were analyzed using LS-DYNA code. For outside shell and inside web plates, web frame and deck of bow structures, the damage mode and damage status were observed. In addition, their impact force and energy dissipation were compared.

碩士
國立臺灣科技大學
電機工程系
106
This thesis proposes antennas for the applications of the ship automatic identification system and the anti-collision radar system for the blind spot detection and the lane change assistant. For the ship automatic identification system, a symmetrical meander-line design for a monopole antenna is introduced. This design effectively improve the radiation efficiency of the meander-line antennas, particularly for a small antenna size in wavelengths. For the anti-collision radar system, serial-fed patch antenna arrays are designed. To integrate with a radar module, we also have to design some RF front end circuits to achieve system’s requirements, such as baluns, filters, DC blocks, and RF chokes. Three types of the serial-fed patch antenna arrays are proposed, which include a new approach to feed the patch elements by coupling from both sides of the feeding line to further improve the antenna performance.

碩士
國立臺灣大學
造船及海洋工程學研究所
88
The purpose of this paper is to present a basis for the estimation of collision forces between aluminium-constructed high-speed ships and other structures, like offshore structures, vessels, and ground by theoretical and numerical methods. In respect of numerical investigation, the ship cross-section is considered as assemblage of basic elements, and crushing behavior of basic elements is analyzed by using finite element software LS-DYNA. In addition, composite structure, simplified bow structure, and real bow structure are also modeled to verify the validity of theoretical prediction. In respect of theoretical investigation, a rigid-plastic material is assumed. Progressive buckling model of bow structural elements due to axially impact load was studied and compared with numerical calculation results. And the validity of the formulas of L shape, T shape, and ┼ shape is proved. By changing the material property of theoretical model, the difference between aluminum alloy and mild steel in impact collapse mode was compared. Effects of strain-rate on the crushing of structure are also included. The Yang & Caldwell''s technique as well as Ohtsubo''s technique of deriving the simplified equation of mean crushing force is used and applied to the composite structures. The composite structure is divided into simple elements of L shape, T shape, and ┼ shape. In the same way, simplified bow structure and Hagiwara''s real bow structure models are established numerically and theoretically. The theoretical prediction and the numerical results are also compared. On the basis of crushing behavior of bow structure, furthermore, the high-energy collision between bow and side structures is modeled with the assumption of energy conservation and then the force-indention relation is established. The paper concludes with the crashworthiness of collision between two ships.