In this thesis, it was examined how high-frequency operational data collected from an automated recording system, can be used to develop a vessel’s performance model. Both the traditional and the Machine Learning (ML) approach were examined. In the traditional approach, every component of the propulsion plant was examined separately, while empirical or semi-empirical methods were used for the added resistance due to waves, wind and shallow water. Historical data were used for verification and tuning (where needed) during the development of the model. In the Machine Learning approach, the method of Support Vector Machines was used. Also, it was examined whether a vessel’s performance model can be developed by combining the methods mentioned above. Thus, in total four models were developed. The data regarding the last year of operation of the vessel Schippersgracht were used (45000 data points) to test the models. It was found that with all the four models, 80 % of the examined dataset was calculated with an error of less than 10 %. The daily fuel consumption was calculated for the same dataset and for 90% of the days examined, the daily fuel consumption was calculated with an error of less than 10 %. The main conclusions about the developed performance models is that all the models resulted in more less the same accuracy. The model based on the traditional approach has the advantage that it offers more information and more outputs can be taken, compared to the ML approach which only provides the output of the fuel consumption. On the other hand, the model based on the ML approach is significantly faster and allows many iterations to be performed in a short time. Regarding the models which were developed by combining the approaches mentioned above, they did not result in additional advantages. Finally, two case studies were performed. In the first case study, it was presented how the model, developed following the traditional approach, can be used to examine how modifications in the propulsion system will influence the vessel’s fuel consumption. The case of switching from fixed rpm (that is currently used) to a variable rpm system was examined, which is a real scenario that the company is considering. It was calculated that installing the variable rpm system and a frequency converter will result in annual savings of around 250,000 € while the investment’s payback time is estimated to be around two years. In the second case study, a future voyage simulation algorithm was developed. This algorithm receives as inputs the voyage plan(route and speed) and performs a calculation for the voyage’s fuel consumption by taking into account the weather predictions. The voyage simulation algorithm is making use of the ML model. A few cases were examined in order to examine how many days in advance the calculation is reliable (due to the uncertainty of the weather predictions) and about the time interval that should be used in the algorithm. However, clear conclusions were not derived, and further examination is suggested(by examining more voyages).

Over the past years tugs are evolving to more compact designs equipped with large power installations. This inherently increases the risk of accidents, demanding a more reliable prediction of the tug’s dynamical behaviour in critical situations. To capture the dynamic behaviour of a tug, a time domain simulation tool has been developed and used to evaluate the tug’s safety in those critical situations. Multiple methods derived from recent studies are combined and used to establish a reliable description of the involved hydrodynamic forces and moments. Besides a sensitivity study is performed to investigate the impact of inaccurate approximations of those forces and moments. Furthermore, the sensitivity to a change in more design and operation related parameters has been investigated. Finally, the research includes a step by step validation and an evaluation of the current regulations.

Maritime piracy has been a problem for the last decades and peaked in 2010. This resulted in large investments in anti-piracy measures, but as piracy waned over the following years, so did the investments in anti-piracy measures. This could be an indication that the stage for maritime piracy has been reset. This report suggests a more efficient and cheaper approach to counteract maritime piracy on merchant vessels indefinitely. SeaState5, the company at which this research is done, came up with the idea to combat pirate attacks on merchant vessels using a Fast Rescue Craft (FRC). Merchant vessels are obligated by law to carry an FRC; used for instance for man over board missions. SeaState5 focuses on developing an add-on plug and play system compatible with existing FRC. It turns these sole-purpose rescue craft into a multi-purpose craft, in this research referred to as the Beagle. This Beagle will serve both rescue and anti-piracy purposes. In this report the concept development of this add-on system is established. This is done by developing a simulation in MATLAB and Simulink that mimics a pirate attack on a merchant vessel. During the pirate attack the Beagle uses a defense strategy to repel the pirates. A Beagle defense strategy is a combination of a non-lethal weapon and a set of parameters that define the trajectory of the Beagle. Different Beagle defense strategies are subjected to different pirate attack scenarios to find the most effective one. The simulations resulted in a list of requirements for the Beagle. A check has been done to prove the feasibility of equipping an existing FRC with the add-on system meeting these requirements.

Subsea rock installation is widely applied in the offshore industry and utilized for a wide range of purposes including but not limited to: pipeline protection, scour protection, insulation of pipelines, upheaval buckling prevention and seabed preparation. Tideway Offshore Solutions is specialized in subsea rock installation and currently operates three state-of-the-art fallpipe vessels. Their vessel 'Flintstone' makes use of an innovative closed fallpipe system to provide high accuracy subsea rock installation. The presence of rocks in the water column of the fallpipe increase the density of the mixture in the fallpipe. The density difference between the mixture in the fallpipe and the density of the surrounding sea-water results in a water level drop in the fallpipe. To keep this water level drop within acceptable limits extra water is added to the fallpipe system which accelerates the fallpipe flow. The accelerated fallpipe flow can result in high outflow velocities of the rock mixture at the fallpipe exit. High outflow velocities of the rock mixture can eventually result in increased impact velocities of the rock particles on the seabed. Increased impact velocities of the rock particles on the seabed can lead to unsatisfactory rock berm shapes resulting in the need for remedials. To have their fallpipe system perform as efficient as possible Tideway Offshore Solutions was interested in possible measures to reduce the outflow velocity of the fallpipe which resulted in this thesis. In the first part of this thesis different concepts, that could potentially reduce the outflow velocity of the fallpipe, are generated and conceptually analyzed. The information acquired from this analysis is used as input for a multi criteria analysis that resulted in the selection of the most promising concept, the use of a deflector. The deflector will act as a flow deflector at the fallpipe exit thereby decreasing the impact velocity of rock particles on the seabed. In the second part of this thesis a complete three-dimensional computational fluid dynamics (CFD) analysis is performed on the fallpipe outflow with and without deflector. The CFD program used to simulate these situations is ANSYS Fluent. The simulations for both cases are performed for two different turbulence models, the k – ε and k – ω SST turbulence models, the distance from the fallpipe exit to the seabed is varied as well and a range of deflector angles and dimensions are simulated. The fluid flow velocities obtained from the CFD analysis are used as input in a MATLAB model to compute the rock particle trajectories in a two-dimensional plane. Combining the rock particle trajectories and their velocity components it is possible to compute the impact velocities of the rock particles on the seabed. The results of the trajectory model set up in MATLAB showed that a substantial decrease in impact velocity of the rock particles on the seabed can be achieved by using a deflector at the fallpipe exit.

Harsh market conditions make optimising the performance in shipping more and more important. Shipping companies are becoming more and more data driven due to developments in data systems and these harsh market conditions. The goal of this research is to determine how and how much added value can be realised through shipping performance management with the help of a ship performance monitoring system within Spliethoff Group. This research continues after the development of the performance monitoring system. The demand or this research arrived from the fact that simply putting a performance monitoring system in place does not realise added value. Applying the knowledge creation from the performance monitoring system through well structured performance management is what realises the added value. Determining the methods and quantifying the potential results is what is done to realise the goal of this research. During the research it is found that high data quality is of the utmost importance in order to accurately asses the performance of a vessel. A structured method for assessing the data collected by the performance monitoring is found and applied to the performance monitoring system as a verification. Data quality deficits such as the speed of the ETL processes, incorrect data blending and calculations are identified and corrected. This led to a near live, high quality data stream which can be used to asses and optimise the performance. Continual assessment and improvement of the data quality is recommended. Suitable methods to analyse this data to create knowledge are determined. A form of hybrid modelling where simple theoretical models are fitted to the filtered data using regression is used to create baselines and give a clear overview of the effects of certain operational parameters on the performance of a vessel. These models can then also be used to increase the accuracy of tools such as the weather routing and voyage planning tool. Benchmarking between sister vessels or the baselines is seen as a good means to identify performance deficits. Visualising and analysing the data with the help of a BI tools is a good way to share the knowledge throughout the company. The performance management in place at Spliethoff is assessed to form a baseline to improve upon. It became apparent that Spliethoff overall has a good idea how to optimise performance but it does not have the information or data needed to do so. Since there is no information about the gain in performance of certain tools they are not used correctly. Being able to show the performance gain from using these tools is an important benefit of the performance monitoring system. The communication and knowledge sharing throughout the company can also be improved with the use of the performance monitoring system. Poor follow up from upper management when performance deficits on top of this indicate that a lot of value can be created with an improved performance management plan which incorporates the performance monitoring system. A new performance management plan based on ISO 50001 is proposed to realise this value. Due to the available data the management plan focuses on reducing fuel costs and optimising voyage planning.This is done by awareness creation through performance dashboards which also increase the information sharing between shore and vessel. A change in company culture to a more data based decision making and communicative culture is promoted and implemented through this plan. To determine how much added value can be realised, the costs and value realisation potentials of the performance management system are specified. These are then used to determine the net present value of the performance management project for several scenarios. A large fleet and a small fleet implementation are researched. The total capital investment is either €543,000 when only the large consumers of the fleet are included (small fleet) or €1,310,000 when almost the entire fleet is included (large fleet). Only the direct monetary value is used to determine the net present value but indirect and non monetary values are also mentioned. The direct monetary value potentials are derived from operational cases where performance deficits have been identified. The resulting total added value (NPV) of the small fleet implementation ranges from €2,165,970 in a pessimistic scenario to €8,711,272 in an optimistic scenario after 11 years. €6,000,146 is the expected total added value realisation for the small fleet implementation after 11 years. For the large fleet the results are: €4,966,756 for the pessimistic scenario, €18,103,704 for the optimistic scenario and and expected added value of €12,805,994 after 12 years. Most scenarios have a pay back period of less than 2 years with the exception of the pessimistic scenario of the large fleet which has less than 3 years. All indirect and non monetary value is seen as a bonus on top of this meaning that there certainly is a lot of added value to be realised by implementing performance management which is supported by a performance monitoring system.

In recent years, ships are expected to improve energy efficiency and reduce carbon emissions. For naval vessels, it is important to be able to maintain their mission profile. It is therefore required to provide real-time advice to the ship’s crew on the optimal speed and propulsion mode settings that include the actual environmental conditions. This paper proposes a novel machine learning approach to establish the ship’s fuel consumption per mile for the actual environmental conditions and develop fuel consumption curves for the various propulsion configurations. The proposed approach uses a multi-layer perceptron (MLP) model to establish the ocean parameters based on the own ship data, with an accuracy of 4.150 %. Using these ocean parameters combined with the own ship data, the fuel per mile is predicted and fuel consumption curves are established using an MLP-model, with an accuracy of 1.551 %. This thesis shows that the proposed approach makes it possible to help a ship’s crew make well informed decisions to reduce their CO2 emissions in real time while still meeting their mission profile. The proposed approach is especially useful for military operators since there is no need for external data sources. Further research is identified to optimize the proposed approach using a dataset containing a higher variety and number of environmental conditions and propulsion modes to improve and validate the fuel consumption curves for the entire spectrum of speeds, environmental conditions and propulsion modes.

Due to the increased social importance and regulations on shipping emissions, effort must be made by shipowners, operators and naval architects to reduce the amount of air emissions from ships. A large set of emission control methods exists, but compatibility and interaction issues complicate their implementation. This thesis contains a decision-making method tailor-made to the case of Seatrade. The decision-making method makes a cost comparison of different emission compliance methods for an arbitrarily ship, making use of the NPV. Case studies are performed to get an indication of the promising emission compliance methods for the Seatrade fleet.

In dredging there are a lot of opportunities to improve the production processes and to make the production cycle more efficient, especially the excavation process of the draghead. The aim of this research is to determine the trailing forces and to estimate the production of the draghead. Besides that, the goal is to get more insight into how the draghead behaves, depending on the trailing velocities. The variations in the trailing velocities, soil characteristics, control settings and draghead and suction pipe geometries that can occur do not make it easy to determine the trailing forces on the draghead and suction pipe. Because of this complexity, it is also hard to define how to estimate the production. Therefore, the scope of this research is limited to just one sand type with specific soil characteristics. An analysis of the draghead and the suction pipe, with a freely suspended visor, showed the physical processes in and around the whole suction pipe system. Because the draghead is fixed to the suction pipe, the influence of suction pipe on the draghead is analysed first. After that, the draghead is divided into two parts, the visor and the visor house. With the use of force and moment balances the trailing forces are determined for every trailing velocity. In addition, the production and its production limits are defined. The calculations show that the increase of the trailing velocity results in higher trailing forces on the suction pipe and draghead. For a velocity of around 2 m/s the draghead, for a Damen SLK600 used in the case study, will lift of from the bed. It should be notified that, among other variables, the dredging depth has an effect on this ‘floating’ point. Moreover, the results showed that the drag forces at common trailing velocities of 1-2 m/s are relatively low compared to the soil excavation forces and therefore have a small share in the total trailing forces. When the suction pipe system is trailed against the current the dragforce becomes more significant. The interaction of the draghead with the bed causes several processes to take place. The resulting relevant trailing forces are mapped and determined. The settlement of the draghead causes a hump of sand to be pushed forwards which result in a sled force and a friction force. Besides that, the flow through the pipes will cause impulse forces in the bends and at the end of the jet pipe out of the nozzle. The jets fluidize the sand which results in the largest production contribution. Furthermore, it can be seen that the penetration depth and cavity width of the jets depend on the trailing velocity and determine the amount of sand that is loosened. The cavities can overlap at low trailing velocities, resulting in a jet production limit. The jets have a significant influence on the behaviour of the visor. The freely suspended visor will drop until a solid bed layer is reached. The cutting force and vacuum force are the dominant forces working on the visor. Application of the equilibrium-moment method showed that the visor is slowly moving upwards when the trailing velocity is increased. However, the cutting layer thickness remains almost constant for an increasing trailing velocity which results in a linear increase of the cutting production. The cutting production contributes, 20-25%, to the total situ production. The total jet and cutting production lead, together with the jet water inserted and ambient water flow, to the total production and mixture density. When the capacity of the dredging pump is insufficient, spillage will occur. This research shows the best possible estimate of the draghead production and corresponding trailing forces. It should be kept in mind that the calculations are based on a simplification of the suction pipe system and the geometries of the suction pipe system of Damen. Nevertheless, a lot of research can be performed into the processes that occur, to improve the results of the calculations. Suggestions for further research would be to determine the magnitude of the vacuum force, the erosion production which is not considered in this research or the on velocity depending cavity width. Validations of the results is another point of consideration. Thus, to determine trailing forces and production, the new approach used in this study contributes to a better understanding of the draghead.

New offshore wind farms are moving farther away from the shore; to locations characterised by adverse weather conditions. This challenges current maintenance strategies because, besides being further from shore, far-offshore wind turbines need more frequent maintenance and must be accessed in rougher weather conditions. Service Operation Vessels provide high accessibility to far-offshore wind turbines, but they lack multitasking capabilities. Its daughter craft is a valuable asset for unplanned maintenance in the summer when it can operate safely, but it is often not deployable during the winter due to the rougher weather conditions. The main research question is: What are the deficiencies of current DCs, and how can these access vessels be modified to operate year-round at far-offshore wind farms? The results show that the current DC’s deficiencies lie in its current operational requirements. Also, performance in oblique waves is currently riskiest since that is when there are higher vertical accelerations or a combination of vertical and lateral accelerations. Furthermore, wave steepness has significantly more effect on accelerations that wave height. Lastly, future DC designs should be focussed on stable seakeeping performance during transfers rather than high-speed transit. An analysis into the seakeeping performance of four prototypes showed that it is feasible to increase the transfer requirement from Hs ≤ 1.5 m to 2.0 m ≤ Hs ≤ 2.5 m. The catamaran type DCs have a high potential to realise year-round accessibility to far-offshore wind farms due to their resulting performance in oblique waves.

During specific operations, offshore marine contractor Heerema Marine Contractors reduces the draft of their Semi-Submersible Crane Vessel (SSCV) such that the floaters are submerged in close proximity to the free surface. This draft is also known as inconvenient draft. At this draft the motions of the vessel do not fully comply anymore with the computed prediction using linear diffraction theory. A proper motion prediction is required to ensure a safe execution of the offshore operation. The key issue is the submerged part of the floater, since discrepancies occur as soon as there is only a small water column on top of the floaters. Motion RAOs are computed via the hydrodynamic coefficients and wave loads. The reason why this leads to discrepancies in the motion RAO is not yet known. In addition, qualitative hydrodynamic data should be gathered for an object submerged in close proximity of the free surface. Therefore, in this study the cause of the discrepancies in motion RAO is studied on an experimental basis for an object submerged in close proximity to the free surface. The scope is narrowed down to a two-dimensional cross-section of a SSCV-floater. Numerical simulations using linear diffraction theory are performed in WAMIT. The results are compared to experimental data obtained via model tests performed at the towing tank facilities at the faculty 3mE at Delft University of Technology. Based on experimental data is concluded that linear diffraction theory does not predict physical phenomena that satisfy the boundary conditions and that underlie principles of the theory. Despite the fact that the experimental data does satisfy the boundary conditions of the numerical simulation, discrepancies occur at the hydrodynamic coefficients and wave load. As a result, it can be concluded that linear diffraction theory malfunctions at the inconvenient draft region, and therefore is not the correct theory to determine RAOs for an object on inconvenient draft. Discrepancies in motion RAO are found to be dominated by the discrepancies the wave load, except for the frequency at which the added mass equals negative inertia of the body. Discrepancies for added mass are less significant than for the damping coefficient and wave load. At higher frequencies inertia becomes dominant over damping and damping deviations affect the RAO less. The pitch motion about the center of the cross-section does not represent a rotational motion about same the degree of freedom for an SSCV. However, it allowed to experimentally investigate the global numerical extremes. In addition, it led to the finding that it seems that the rotational data is more affected than the heave data. There is a strong suspicion that poles in the complex plane are the cause of the discrepancies in the hydrodynamic data, which result of the used Green's function by Wehausen and Laitone. This suspicion is based on characteristics of the numerical data in combination with findings in literature and the experimental data, accumulate. Currently, an approach that makes use of free surface damping is applied to predict the motion of an SSCV at inconvenient draft. Based on experimental data can be concluded that the use of free surface damping without further modifications does not result in an accurate motion prediction. Lastly, the effect of nonlinearities when increasing the oscillation or wave amplitude. The wave load is found to be more prone to nonlinear effects than the hydrodynamic coefficients.The force signal remained dominantly harmonic, but higher harmonic forces did show up. Furthermore, with the exception of most tests at the largest tested submergence, higher harmonic waves were measured and visually observed during the tests. These higher harmonic waves arose at the transition from the shallow to deep water regime and vice versa. These forces were found to have hardly any effect on the force signal.

The Defence Materiel Organisation found that using a design margin to estimate required space for logistic systems (e.g. staircases, hallways) during the concept exploration design phase is insufficient and impractical. A more educated estimation of required space for logistic systems is hard, because the configuration of systems is varied significantly. Indeed, the size and location of logistic systems are dependent on the location of functional systems, amongst others, which could be driven by logistic systems in turn. To solve this iterative problem, a novel Logistic Model was created and integrated in the TU Delft Packing approach. Based on a network representation of the ship's structural subdivision, a novel path finding and selection approach, initial positions of functional systems and upfront defined logistic relations between these functional systems, the size and location of logistic systems has been determined for and integrated in each concept design created by the TU Delft Packing approach. The logistic performance of the low detail designs was calculated by a novel Logistic Performance Measure and used to find logistically promising designs during concept exploration. Test cases indicated that the new method meets the research objectives.

The shipping industry has a notable share in global greenhouse gas emissions and other pollutants such as sulphur and nitrogen oxides. Fuel cells and batteries are identified as relatively new technologies for shipping with high potential and hydrogen is also considered as one of the most promising sustainable fuels, especially for smaller vessels. This research contributes to three identified knowledge gaps: (1) the potential of hydrogen propulsion for high-speed craft, (2) the hybridisation of fuel cells and batteries for marine applications and (3) the characteristics of the response of a hybrid fuel cell/battery propulsion system under transient loads. The objective of this research is to analyse these aspects based on a series of time domain simulations of various operational conditions. A mathematical model of a fuel cell/battery propulsion system is developed in Matlab/Simulink. The developed model is used to analyse the energy consumption for various operational conditions of a test vessel. Based on this analysis, two configurations of fuel cell power and battery energy are selected. If the vessel sails at top speed, the fuel cell power stacks operate at maximum power and the battery operates as power booster. A strong correlation was found between the endurance at top speed and the battery size which is selected. A larger battery has a positive effect on endurance, but it also increases the displacement of the vessel significantly and, hence, required power. Fuel cells are least responsive and these should be protected against high fluctuations in a short time. A fuel cell can only follow low-frequency transient loads. The battery is required to support in high-frequency load changes. Contrary to the fuel cell, both the battery and PMSM were found to have very favourable characteristics in transient conditions. Finally, it is concluded that it is feasible to implement fuel cell/battery propulsion on high-speed craft. It is proposed that the fuel cell and hydrogen deliver the majority of the energy and use the battery as power booster and for transient support. Novel energy management strategies can deliver high system efficiencies in both full and part load and this is one of the main advantages of hybridisation. The implementation of a fuel cell/battery system does, however, come at significant costs in terms of endurance and top speed due to the low volumetric energy density of hydrogen. It should be acknowledged that the functionality of the vessel is reduced. In addition to this, the storage of hydrogen requires some deck space, so the cargo capacity in terms of crew and material is also reduced. Therefore, it is recommended to redefine the user profile of the vessel.

The crises of global warming, air pollution, acid rain and the running out of oil make the investigation into alternative fuel technologies crucial. New technologies are being investigated on a global scale in an attempt to address these problems. This thesis investigates the use of hydrogen-diesel dual-fuel engines and fuel cells. The economic feasibility includes the comparison of these energy converters with more conventional alternatives. The storage of alternative fuels, the reforming of hydrogen carriers or the inclusion of carbon capture systems are some of the aspects considered in the analysis.

This work is focusing on the 2020 IMO sulphur regulation and its impact on the shipping industry and more particularly Fednav’s activity. The thesis report presents a holistic approach starting with IMO emission regulations including current and future. The thesis is then moving on to Fednav business characteristic followed by the possible solutions to successfully implement the 2020 IMO sulphur regulation and stay competitive. These solutions are shortlisted to LNG and scrubber as they are the only mature technologies already implemented in the industry. They are then analyzed using both a private and welfare cost & benefit analysis to evaluate LNF and scrubber systems economic feasibility from a business and society perspective. LNG is discarded based on low bunker availability worldwide in combination with Fednav’s fleet tramping sailing patterns. For the scrubber, the opened loop solution is selected as the one offering the best return on invest- ment. After the welfare cost & benefit analysis, all scrubber solutions are also discarded because of the low pH washwater dump in the ocean. The strategy for Fednav is to make sure Canada is strict on sulphur regulation, mitigate bunker sensibility risk as well as bunker quality risk.

The Autonomous Low Energy Replenishment Dredger (ALERD) strives to revolutionize the dredging world. The ALERD operates autonomously underwater, which saves energy during the dredging process and transit. Autonomous underwater operation drives the need of alternative energy facilities. However, due to the energy savings of dredging, alternative energy supplies are possible. A wish of C-Job is that the ALERD operates with zero emissions, and therefore the system should comply with it as well. This introduces the research goal: Devising a sustainable electrical energy supply for ALERD. An additional challenge to the research goal is that the dimensions are not yet established and are still an open question in the research. The simulation model uses the calculated electric load balance of the Autonomous Underwater Maintenance Dredger (AUMD) and scaling to determine the power balance of the ALERD over various hopper volumes. Furthermore, the operational area has been studied to determine charging/bunker locations and distances. The project requires an annual sedimentation of 12 million m³, including foreshore and coastal replenishment. To determine the best system, a literature review was done towards the systems. Two key systems came out as the best systems for autonomous and sustainable operation: The Li-ion battery and the Proton Exchange Membrane Fuel Cell (PEMFC). The systems have very different characteristics. Typically, batteries have high costs for the energy storage and fuel cells costs are determined by the nominal power output. The abovementioned systems were both used in a simulated operational profile of the ALERD. Results from the simulation, suggests that the battery has the optimal performance at 2-3 times dredging per energy cycle, where 4-9 times are the optima for the Hybrid solution. When both systems have charging/bunker stations near the operational area, a dredging cost of €*** per m³ can be achieved for both systems. However, when the ship is charging/bunkering in the port, the costs per m³ increase with €*** for the hybrid and €*** for the battery powered ALERD. This results in a maximal investment of €** million for a local charging/bunker station, to be economically feasible. By making these stations accessible for other purposes, profit can be taken to recoup the investment. It is however expected, that these local stations will not be feasible for the first generation of ALERDs. When cost development is taken into account, the Total Cost of Ownership (TCO) prefers the hybrid system. Which is a result from the sharply decreasing hydrogen and fuel cell costs. The system also achieves a lower TCO than a conventional dredger, in a manageable time. A (near) future orientated system has also been considered, the direct-fed ammonia Solid Oxide Fuel Cell (SOFC). It has comparable costs per cubic metre for port bunkering as the other systems, when they are locally charging/bunkering. Furthermore, there are a lot of practical advantages by the use of ammonia instead of hydrogen as fuel. This consists of better fuel handling and easier storage. Together with the benefits of taking more energy inside the ALERD, it is believed that the hybrid types of ALERD have the best characteristics for coastal maintenance. It depends on the developments of the ammonia SOFC, if it is ready to supply energy to the ALERD, or that the hydrogen PEMFC is the best solution in a hybrid design. Furthermore, the decision depends on the results of the weight and stability study, which is still ongoing. The results could eliminate a systems by its volume or weight. Due to the reserved space and freedom in the ship design, this is however not expected.

The IMO has proposed Just-In-Time arrivals and services as one of the short-term solutions to reduce greenhouse gas emissions in maritime shipping. The Just-In-Time concept allows vessels to optimize their speed during the voyage. If a vessel earlier knows at which time it is requested to arrive at the pilot boarding place, the vessel can adapt its speed to arrive when the berth, nautical services and the fairway are available. Besides environmental reasons, shipping companies as MSC consider the Just-In-Time initiative as a major port call process optimization. It has obvious advantages for MSC since this concept aims to minimise unnecessary ad hoc waiting times and reduces fuel consumption per mile steamed. In the past, it has become clear it is extremely complicated to implement this initiative. Research is required in order to find out what needs to be improved to enable Just-In-Time arrivals and services. The current port call processes must be analysed. As start point, a case study is conducted on the port call processes of the world’s second largest shipping company in the biggest port of Europe. In this study, the current port call processes of MSC container shipping in the Port of Rotterdam are identified and improved in order to enable Just-In-Time arrivals and services. First, an actor-stakeholder analysis is conducted to understand the incentives and relations between actors involved in a port call. Subsequently, this information is used in the process analysis. In this study, the port call processes are analysed by both qualitative and quantitative research. The research has emphasized the complexity of the port call business processes. Actors primarily act on the basis of their own incentives. In order to enable Just-In-Time arrivals and services, collaboration is required among the involved actors. Today, most actors see the benefits of this concept. However, some actors are not willing to share data about their processes since this is considered as sensitive information. In case actors are willing to share data, it can be concluded that the information is not exchanged frequently enough or does often not meet any data standards. As last, this study shows that adaptations are required to the current business process of a port call in the Port of Rotterdam in order to enable Just-In-Time arrivals and services.

The suitability of the MoorMasterTM system by Cavotec MSL in inland shipping is researched. It is an innovative mooring system using vacuum pads with active motion control, utilising a PID controller. A case study of a 110m Large Rhine vessel moored directly beside the Amsterdam-Rijnkanaal (ARK) is performed. In order for the system to be suitable, the ship motions have to remain within certain mooring criteria, while passing vessels should not have to reduce speed. The forces on the moored vessel caused by the passing vessels are simulated using ROPES, a numerical method based on a 3D flow model, using the panel method. Three different passing vessels at three different passing distances are simulated. All passing vessels are simulated to sail at the maximum allowed speed in the ARK. Next, the manoeuvring model is used to set up the equations of motion of the moored vessel. The external force consists of the forces calculated in the Ropes simulations and the modelled forces of the MoorMasterTM units. Solving these equations results in the ship motions.

In this thesis I present a novel discretization procedure which combines two relatively new technologies for solving partial di_erential equations (PDE's): IsoGeometric Analysis (IGA) is a new paradigm which provides an exact geometry description and tight integration of Computer Aided Design (CAD) and Finite Element Analysis (FEA) by using the same basis for representation of the unknown _eld variables as is used for describing the geometry in CAD. Mimetic Discretization Methods on the other hand combine concepts from the Finite Element Method (FEM) and the Finite Volume Method (FVM) and provide a uni_ed and straightforward approach to model any physical _eld problem. Mimetic Methods aim at preserving as much as possible the structure of a PDE by 'mimicking' at the discrete level, important properties of the continuous realm, such that symmetries and conserved quantities are preserved. Central in this framework is the relation between physics and geometry. The Mimetic Discretization approach developed in this thesis is based upon B-splines1 for representing the unknown _eld variables. Besides inheriting all advantages from the IsoGeometric Analysis framework, B-splines appear as a natural basis for Mimetic Discretization Methods. They can be seen as higher order Whitney forms and provide vector spaces which are discretely conservative by construction. The resulting discretization approach resembles a Finite Volume Method on a staggered grid for the representation of the conservation laws and a Finite Element Method for the representation of the constitutive equations. In short, the scheme features the following advantages, - exact geometry description and tight integration with CAD; - fundamentally a higher order approach, featuring spectral like convergence. In practice though, IGA is con_ned to low or medium order due to bad conditioning of inner product mass matrices as a function of the polynomial order; - increased continuity resulting in continuous representations of _eld variables and derivatives; - a strong indication exists that these methods automatically meet the inf-sup conditions, leading to naturally stable discretizations of any physical problem; - local conservation of primal variables (strong) and secondary variables (weak); - in contrast to FVM and FEM which describe variables only locally, the Mimetic discretization is induced with a global topology which makes it possible to make useful decompositions of _eld variables.

The bulbous bow is a common feature for large displacement vessels. The purpose of the bulbous bow is to reduce the bow wave, hereby making use of wave cancellation theory. The main drawback of these type of bows is that the drag reduction effect is only present for a limited range of sailing speeds. If the transit velocity is altered, the effect of the bulbous bow can even result in an increase of wave making drag. Due to this sensitivity to the sailing speed it is important to be able to predict the location of the waves generated by the protruding bulb. Computational fluid dynamics is gaining interest in commercial marine industries. The size and transit velocity at which the previously mentioned vessels that employ the protruding bulb operate, results in the common use of Reynolds averaged Navier Stokes (RANS) models. To investigate the accuracy of these RANS models, a 2D model is presented in this thesis. The bulbous bow is modeled as a shallowly submerged 2D naca0012 hydrofoil. The justification for this simplification is that the geometry and flow over a bulbous bow is too complex for the duration of this project. A submerged 2D hydrofoil can still capture the important flow dynamics for free-surface waves. In this thesis we focused on evaluating the accuracy of RANS models for simulating the wave dynamics that arise when a shallowly submerged 2D naca0012 hydrofoil moves through water. The main objective is to find which geometrical and fluid dynamic properties have an effect on the free surface wave profile. Apart from questioning if these properties have an influence on the wave profile, we also want to know how the wave profile changes by altering these properties. The interFoam package from OpenFoam was used for simulating the flow. InterFoam adopts the volume of fluid (VOF) approach proposed by Weller (Weller, 2008) for simulating multiphase flows. Turbulence modeling was done using the k-ωSST two equationmodel from Menter et al. (Menter, 1992). In 1983 Duncan and his colleagues published a paper on the free surface wave dynamics generated by a towed naca0012 hydrofoil (Duncan, 1983). The results from their experiments are used as a benchmark for the present study. From a single phase test we found that the experiments from Duncan where performed in the regime where transition of the boundary layer from laminar to turbulent is present. The presence of this transition is expected to be one of the reasons for the disagreement in literature on wave elevation, wavelength zero point crossings and lift and drag coefficients. It is shown that the relatively small gap between the basin floor and the hydrofoil of 0.86 chord lengths has a significant impact on the wave profile and the flow at the hydrofoil. Reynolds independence is found to be at Re ¸ 2•105 for a towed hydrofoil submerged at h/c = 0.955 with the basin floor located 10 chord lengths below the hydrofoil. Below this value a reduction in Reynolds number results in an decrease of the wave amplitude and an increase in the wavelength. The assumption to neglect the resistance from the hydrofoil wake made by Duncan is shown to be false. The dominating dimensionless parameters for these types of flows are: Froude based on submergence Frh, Froude based on basin to foil height FrD and the Reynolds number based on the chord length and the bottom fluid parameters Rec . Note that in this thesis the angle of attack (α) has been kept constant at 5° which does effect the flow but this has not been investigated during this research. A attempt is made to simulation breaking waves in the present model. The Breaker type in the present study differs from the one found by Duncan et al. (Duncan, 1983). Even if the same breaker type was found the elevation and wavelength differ a lot. It is therefore concluded that The present model is not suited for predicting breaking waves.

A two-dimensional (2D) panel method is developed to find the first and second order wave forces acting on a semi-submerged cylinder in regular waves. The panel method is based on potential flow and the waves are modeled for both finite and infinite water depth. The motion is limited to heave, but allows for extensions to other modes as well. It uses boundary conditions for floating body dynamics with Neumann and mixed type boundaries on the surfaces. The waves are generated and the reflection of the waves is suppressed by generating absorbing boundary conditions (GABC) on the radiation surfaces. The model is used to investigate the hydrodynamics of an oscillating buoy wave energy converter (point energy converter). For this, an analytical solution of the optimal damping is used. The method uses panels along all boundaries to solve the boundary conditions. The model can be used for any time-harmonic free surface flow problem. A second order wave running through the domain is successfully modeled, without the interference of a body. Challenges of a second order model with body are explained. The boundary element method has innate challenges finding the correct solution to tangential flows on the panels and spatial derivatives of the velocity, which are required for the second order solutions.