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.

Currently, lower-body exoskeletons for paraplegics are investigated as an alternative to wheelchairs and as an exercise method with medical benefits. Literature provides little examples for users to influence the length or frequency of steps taken by the exoskeleton, complicating stability and practical usability. This study proposes a novel control paradigm that allows users to influence step parameters of the exoskeleton, through a bi-directional haptic interface that also provides feedback. The exoskeleton handles the cyclic walking pattern while the patient is enabled to correct for disturbances. I adapted an existing lower-body exoskeleton trajectory generator to allow real-time adaptation of step length and swing time. To demonstrate a proof-of-concept of the control paradigm, I implemented the controller for a virtual 2D exoskeleton, to be controlled by an existing bi-manual haptic control interface. A human-in-the-loop experiment was performed with the goal to compare the benefits of user control over either step length or swing time with a situation with no human control. In the experiment perturbations of increasing magnitude were applied to a 2D virtual exoskeleton, participants could increase or decrease either step length or swing time during swing to correct for these disturbances. The number of successful step taken before the perturbations resulted in a fall were measured. The swing time group succeeded in making the exoskeleton walk stably significantly longer then when there was no human input, proving that the proposed control paradigm is feasible and beneficial for stability.

The awareness of the impact of air pollution on global climate change is more and more growing in society. The urgency to make ships more eco-friendly captures the interest of shipowners and naval architects. Hull designs of a ship, with regard to minimum fuel consumption have been optimized in the last decades and it has been proven difficult to improve current hull forms. Another strategy is to reduce fuel consumption by using external wind power combined with engine power, so called 'wind-assisted propulsion' or 'motor-sailing'. The potential of an extraordinary high lifting device of a mechanical sail using aspiration power, known as a 'Turbosail' introduced by Jacques Cousteau [1], has been selected as wind propulsion for an existing cargo ship. This foil can generate about 3 times higher lift compared to conventional foils, which do not use active suction of the boundary layer. Similar to the concept of a velocity prediction program for sailing yachts, a fuel prediction program (FPP) is set up to visualize the fuel savings for all wind directions relative to the vessel. For a wind force 7 Beaufort, the fuel savings for optimal wind angle can reach up to 40%, which are enormous. The working mechanism of the Turbosail is further explored and examined with CFD using ReFRESCO [38], to see if the performance of the Turbosail is as high as reported by Cousteau. Steady and unsteady RANS simulations are conducted for infinite span Turbosail using the k-ω SST turbulence model of Menter [32]. As a verification study, an expansion of two other turbulence models are included, which are the  k-ω SST-LCTM model of Langtry et al [30] and the EARSM model for a more anisotropic flow accounting for Reynolds stresses. The difference between all turbulence models appeared to be small, and a fair agreement is found with the lift and drag coefficients found by experiments of Cousteau. A steady RANS simulation has been conducted at model scale for a finite Turbosail to calculate the lift, drag and aspiration power. The distribution of air suction along the span of the foil is visualized, which gives insight for the real experiments. During this study, a Turbosail at model scale 1:2 is built with a span height of 5.5 metres and a chord length of 1 metre. The comparison with CFD is therefore very useful for validation. As a final step, the lift and drag coefficients found from the numerical result are implemented in the FPP. The fuel savings from the FPP are analysed by placing four full scale Turbosails on an existing cargo ship. In this model, there has been accounted for aspiration power needed for the boundary layer suction. Hydrodynamic forces due to leeway of the hull and rudder, propeller efficiency and specific fuel oil consumption of the engine.

The FRISC is a high speed craft of the Netherlands Navy which came into use in 2012. Because these vessels sail with speeds up to 45 knots in inshore waters, a large amount of focus and accurate path following is needed for safe navigation, and due to large accelerations, there is a high level of physical strain. These two factors cause a high (prolonged) mental and physical workload which can heighten mental and physical fatigue, resulting in higher risks due to reduced alertness and mental performance. With this in mind, the focal point of this thesis is to increase the safety of the FRISC during high speed navigation by increasing the path following performance and reducing the level of fatigue through lowering the workload. With extensive literature research a possible solution was found to increase the safe navigation. Namely, haptic feedback which will decrease the workload and increase the path following performance. With this in mind, the following research question arises: To what extent can haptic feedback, implemented into the steering system of the FRISC, contribute to safe navigation during (nightly) high speed inshore navigation? A FRISC operates with high speeds in inshore waters, following a well prepared detailed planned route. During such an operation the FRISC is subject to performance shaping factors, factors “which influence the likelihood of an error occurring” [1]. With the use of the literature, a possible solution for almost all the factors, related to the FRISC, were found. This solution is a haptic feedback system which will lower the workload and increase the path following performance. An active guidance system is developed with two types of controllers (waypoint controller and XTE controller) to “advise” the operator with the correct rudder angle, to follow a preplanned route during high speed inshore navigation. The contribution of this thesis is tested by the implementation of a haptic shared control, and by investigating the cross track error and the workload. The results of the investigation of the XTE were unambiguous. The XTE controller lowers the mean and median XTE values by 20% and the absolute maximum value is lowered by 37% compared to manual control. The waypoint controller resulted in higher XTE values which means that manual control has the preference above the waypoint controller based on the XTE. Furthermore, the participants indicated that the perceived workload was 37% and 44% lower with the use of the waypoint controller and XTE controller respectively. The physical workload was compared between the experience of the participants and the measured physical demand. This comparison resulted in the fact that the experience of the participants was not in line with the actual physical effort. The physical effort was the highest with the use of both controllers whereas the experience of the physical workload was the lowest. This was assumed to be less important than the perceived workload and therefore it did not influence the conclusion of haptic feedback lowering the workload. Altogether, it is stated that the use of the correct haptic shared control system could increase the safety of navigating during (nightly) high speed inshore navigation.

Experience-based decision making by crew plays a key role in the safe and effective execution of maritime operations. For yachts and naval vessels, common operations can be identified as helicopter operations (take-off and landing), launch and recovery of small craft and (dis)embarkment to and from these small craft. All of these operations are limited by wave-induced ship motions. For these operations, experience-based decision making does however not always guarantee that the operations are carried out in the most safe and effective manner possible. Also, the level of comfort as experienced by a yacht-owner or guests can be directly affected by this type of decision making. With this in mind, Feadship aims to develop a Feadship Comfort System (FCS), which can contribute to the decision making process. One of the elements of this system is ought to be a waveradar. The aim of this thesis is to describe how the waveradar can be included effectively in the FCS, and how it can be used for the above mentioned operations. The waveradar is in basis a common navigation radar that can perform measurements of the surface elevation in the direct surrounding of a vessel. These measurements can be used to predict the ship's motions up to approximately two minutes ahead in time. With this, windows of opportunity can be distinguished when operations can be carried out best. These windows depend on the corresponding limiting criteria that are set on the ship's motions. A major issue is however that sea trials have shown that the roll prediction is inaccurate. Due to this problem, two methods are evaluated in this thesis to improve the accuracy of the roll prediction. These methods are set up such that they are practical in use and can be applied directly to the deterministic wave predictions from the waveradar. The first method is scaling the response based on the roll motion history, whereas the second method is based on scaling the roll damping. The latter is effectively linearising the viscous contribution to the roll damping. As no data from sea-trials is present to compare these methods, a benchmark calculation is carried out based on Cummins approach. In these time-domain calculations, a linear and non-linear roll damping coefficient are taken into account, which are based on a decay test that is available at De Voogt Naval Architects (DVNA). This follows from model tests performed by MARIN. Comparing both methods to this benchmark calculation showed that the method of scaled damping resulted in the best approximation, with a Pearson correlation coefficient of (only) 33 %. Also, in terms of the behaviour of the motion envelope, this method showed the closest approximation of the two methods. It is found that the way in which both methods influence the RAO of the roll motion has a great influence on the results found. More suitable methods that should provide a better approximation are suggested from this, such as a frequency dependent scaling of the roll damping. This is however not discussed further. With the method of scaled damping, the practical application of the waveradar within the FCS is evaluated. For the common operations of yachts and naval vessels, limiting criteria on ship motions are obtained from literature or stated by the author. The majority of these criteria are RMS values, for which a method is suggested to use them real-time. In this method, the most probable maxima are obtained from the RMS criteria, which are then applied as real-time criteria. This showed impractically large results, which showed that this method does not suffice. From this conclusion it follows that the analysis of the practical application of the waveradar is only carried out for the (dis)embarkment of small craft. From this, design considerations for the FCS are obtained, from which the main result is that heading suggestion is one of the most important tasks that the system needs to be capable of. Finally, a performance monitor has been evaluated for yachts at anchor. This performance monitor displays the predicted Comfort Rating (CR) real time, which can be used by the yachts crew to evaluate the current anchor location. This is a specific desire of Feadship and is developed next to the other operations. For this application, heading suggestion is also one of the most important tasks that the FCS needs to be capable of.

The need for advanced ship propulsion control systems is constantly increasing as the demand for high vessel performance is growing at the same time. Speed trials are considered as an operation during which the vessel has to achieve the highest performance by attaining the agreed maximum ship speed. However, sometimes vessels have to sail in waves during speed trials. In such case, resistance and wake field disturbances act on the vessel’s propulsion plant causing fluctuations of the engine’s operating point in the engine operating envelope. When these fluctuations are large enough to reach the engine’s operating envelope limits, the propeller pitch control is activated to effectively protect the engine by reducing the propeller pitch. This decrease results in reduced average delivered power, reduced average generated thrust and finally in a drop of maximum average ship speed. This work focuses on investigating the possibilities to refine the existing control system by means of gain scheduling the Diesel engine speed governor. The ultimate goal is the re-sizing and re-orientating of the engine’s operating point fluctuations in the engine’s operating envelope, keeping the propeller pitch control deactivated and thus, the maximum average speed retained. First of all a linearised model of the ship propulsion system is derived which is used for the analysis of the Diesel engine’s operating point dynamic response in terms of engine torque and engine speed fluctuations in case of regular waves. More specifically, this thesis investigates the impact of the direction of the ship with respect to the waves, the Sea State and the system operating point on the dynamic response of the engine’s operating point in the engine’s operating envelope. Based on the analysis of the dynamic response of the engine’s operating point with respect to the three above mentioned factors and by making use of the linearised model, the refinement of the Diesel engine’s dynamic behavior is achieved. In the first place, a static solution is given with the derivation of suitable plots. The derived plots provide the opportunity for manual governor gains scheduling, depending on the wave induced disturbance. In the second place, a gains scheduling algorithm is obtained by combining the linearised ship propulsion model with an optimization algorithm. The developed algorithm, after being integrated in the non-linear simulation model of the ship propulsion system, is capable of dynamically scheduling the governor gains in case of regular and irregular waves. Both obtained solutions achieve the ultimate objective of this work. The fluctuations of the Diesel engine’s operating in the engine operating envelope are effectively re-sized and re-orientated. As a result the activation of the propeller pitch control is prevented and the average ship speed is retained.

Currently there are three methods of calculating the Dynamic Positioning capability of a vessel namely: static calculations, real-time time domain simulations and fast-time time domain simulations, although the outcome of the last two should be identical. In each of these methods a set of input variables is required to perform the calculations. These inputs are not always exactly known and are therefore sometimes estimated or taken from databases. It is not always clear how big the uncertainty in these estimated inputs is, and on top of that: how big the effect on the predicted DP capability is. To be able to quantify how certain a DP capability calculation is and which input data contribute most to the output uncertainty, in this thesis the input uncertainties for both static and fast-time dynamic calculations are investigated. Each method is subdivided in three different design stages which are: conceptual design, preliminary design and as built design. For the static calculations all three design stages are evaluated but for the fast-time dynamic simulations only the as built stage is considered. The static calculation part of the analysis consists of determining the input uncertainties, the input sensitivities to the output and finally calculating the output uncertainty. The method used for this calculation assumes that either the relation between input and output is linear or can be linearised at the point of interest. The input uncertainties are calculated using historical data of the Bibby Wavemaster 1 which is the vessel used as case study throughout this thesis and is specifically designed for the purpose of servicing offshore wind farms. It is observed that the input uncertainties of the main dimensions of the vessel are clearly reducing when moving through the design stages. Furthermore it is concluded that the environmental coefficients of wind, waves and current are the most uncertain, even in the conceptual design stage where input parameters of the main dimensions of the vessel vary the most. When considering the sensitivity in the three design stages no big changes were observed, meaning that in all design stages the main dimensions of the vessel are most sensitive to the output. Finally the uncertainty in the output was evaluated were it was observed that for the as built stage still a standard deviation of 4% uncertainty of the output is present, resulting in a calculated 99.7% confidence interval of either 12% too high or too low. In the dynamic calculation part only the as built stage is considered. Again the uncertain parameters are defined but due to the PID controller in the dynamic model some new input parameters are now present. The gains of this PID controller are assumed to be uncertain and are therefore taken into account during the dynamic uncertainty analysis. Due to a limitation in the aNySIM licence bought by Damen it is impossible to change the wave coefficients which causes their uncertainty not to be taken into account. Since the dynamic simulations are considered to have strong non linearities and possibly even discontinuities due to thruster saturation, the calculation method used for the static part is not applicable anymore. Therefore it is decided to use Monte Carlo simulations to quantify the uncertainty in dynamic DP calculations. Due to the large computational time required to perform large amounts of Monte Carlo simulations with aNySIM, a machine learning method is used to capture the dynamic behaviour of the vessel. A small number of simulations performed by aNySIM is required to train the model which are selected using the Sobol design of experiments technique. This technique optimises the choice of the simulation points to make sure the complete space of possible inputs is covered. By using the machine learning model to obtain an output of a dynamic simulation only a fraction of a second is required instead of 17 minutes when using aNySIM. By running the Monte Carlo simulation on the created machine learning model it was observed that the 97.7% confidence interval for offset can either be calculated up to 8.7% too low or too high whereas the prediction for heading up to 23.1% too low or too high when compared to the base case. It is concluded that using DP for the purpose of people transferring by means of a "Walk To Work" bridge, uncertainties should be taken into account to reduce both safety and contractual requirements risks.

In recent years the awareness and the effort to reduce air pollution and global warming have increased. Many new ideas are being developed to reduce harmful emissions. Despite this, the shipping industry is still a large contributor to air pollution worldwide. To reduce the environmental impact of shipping, the use of sustainable energy sources such as wind energy on-board ships is being explored. Wind energy is widely available at sea, the challenge is to harness this energy. The relatively unknown wind propulsion device called the Turbosail is a vertical wing shaped device which uses wind energy to provide thrust. This propulsion technology was invented in the 1980’s by the Frenchman Jacques-Yves Cousteau. This report describes the investigation into the similar wind propulsion device called the VentiFoil. Two retractable VentiFoils are fitted inside a 40 foot container, this ship propulsion device is called the eConowind unit. Multiple eConowind units can be installed on the hatch covers of general cargo vessels. If successful, this wind propulsion device can be applied on many different ships. The VentiFoil concept will be investigated and improved using Computational Fluid Dynamics (CFD) research tools. These tools are used to simulate the flow around different VentiFoil geometries. The result of this project will be a better understanding of the working principles of the VentiFoil, sensitivity information for the variation of different characteristic design parameters and an evaluation of the generated forces and performance of VentiFoil propulsion.

Marine propulsion systems with diesel engines face continuous variations in propeller shaft speed and torque during operation, due to waves and changing rudder and water inflow angles. Traditional propulsion control systems do not take these variations into account, and attempt to maintain a constant shaft speed. These changing torques, in combination with inefficient control efforts, can increase mechanical wear and tear on the diesel engine, and reduce efficiency. More advanced control algorithms relying on the axial flow velocity of water through the propeller have shown great promise. Unfortunately, this velocity, also known as the advance velocity, is very difficult or impossible to measure. Therefore, it is possible to use state observers to estimate the advance velocity using available measurements of shaft speed and torque. However, the current state of the art regarding advance velocity estimation is very limited.In this paper, a complete model of a ship propulsion system is created. Several different observer structures are applied to the propulsion model to estimate the advance velocity. These include a Luenberger observer, a Shaft Kalman Filter (SKF), a Power Balance Estimator (PBE), a Measured Shaft Acceleration (MSA) observer with and without measurements of shaft acceleration, an Immersion & Invariance (I&I) observer and a Random Walk Kalman Filter (RWKF). The performance of these advance velocity observers using different observer gains is compared using several load cases. These load cases are used to assess time domain accuracy with and without measurement noise, and robustness to errors in a priori information regarding the propulsion system. The findings indicate a clear trade off between noiseless accuracy, and robustness to noise. If an observer has high observer gains, it is more accurate when no noise is present, but more sensitive to measurement noise, and vice versa. Furthermore, higher gains also lead to more robustness to errors in a priori information. The errors that lead to the most significant estimation errors were errors in the open water propeller diagrams, with errors in the shaft inertia proving to be much less significant. That being said, if accurate shaft acceleration is available, the MSA observer is most effective. If this data is unavailable or inaccurate, a choice must be made. If measurement noise robustness is paramount, the RWKF or an I&I observer with low gains is most effective. If absolute accuracy is most important, and the measured variables are virtually free of noise, an I&I observer with high gains is the best choice. The RWKF provided a very good compromise between noise robustness and noiseless accuracy, but requires a large amount of a priori information. Suggestions for future research include testing the observers in both cavitation tunnels and full scale propulsion systems, and implementing multivariable propulsion control using the estimated advance velocity.

Allseas Engineering B.V. is an offshore contractor, focussed on offshore pipeline installation. Since the late 80's, Allseas has been working on the design and construction of the Pioneering Spirit, a heavy lift vessel designed for the single-lift installation and removal of offshore topsides. From 2019, it is scheduled to be able to single-lift install or remove jackets with the jacket lift system. The jacket lift system is located at the aft of the vessel and consists of two 170 meter tilting lift beams, hinged around the stern. During a jacket removal, the jacket is cut-off at the bottom, hoisted from the tip of the beams, partially rotated, and then tilted inboard. In between the hoisting and tilting is the transition phase. At the interface between jacket and the tilting lift beams, jacket support structures are located. In this thesis, the behaviour of the free-hanging of the jacket and the loads on these support structures due to the mating with the jacket are researched. Jacket removal operations will take place in open sea and are thus subjected to environmental actions. The jacket, suspended from the tip of the beams, is excited due to fluid acceleration and velocity causing inertia forces and predominantly drag forces on the slender members of the jacket, as well as the excitation of the vessel through the suspension point. These motions are calculated with two different approaches. A direct-time domain model is developed of the jacket as submerged pendulum. To accelerate model simulations, the jacket is modelled as one single cylinder with different equivalent diameters to account for the total of drag and inertia. The second model is a full geometrical time-domain model simulation in AQWA. In the design sea state, simulations showed that the most probable maximum momentum of the jacket due to environmental excitation is 4.5 106 kg m/s, and the motions of the centre of gravity of the jacket are all within a range of 1 meter, for the single and double pendulum and the full model. The influence of the environmental actions on motions of the structure is concluded to be small. This suggest that the jacket mating loads are governed by the tilting velocity of the tilting lift beams and the motion of its tip. The jacket mating simulations are done in the full AQWA model approach. Fenders are modelled to absorb energy during the jacket mating. A sensitivity analysis showed that the parameters that have most influence on the mating phase characteristics are the tilting velocity and the stiffness of the fender. From still water conditions it seems that by increasing or decreasing the tilting velocity, this can affect the number of re-bounces and the maximum deflection. With increasing sea state, the duration and intensity of the mating phase increases. The fender deflection will increase for increasing significant wave height. The wave period does not have a significant influence on the maximum fender force. The amount of re-bounces reduces significantly for higher damping coefficients, while its influence on maximum deflection decreases. The maximum force on the jacket support structures caused by the static gravitational force by the jacket once it is fully tilted is approximately 10 times higher than the maximum occurring force exerted on one of the fenders. Therefore, this static gravitational force is critical for the design of the jacket support structure, not the force caused by the mating.

Offshore operations are increasingly executed by vessels operating on dynamic positioning (DP) due to advantages it has for short operations, such as maintenance and crew transfer but also for track keeping operations and projects in deeper water. Currently, DP capability plots are used to indicate whether an operation can be performed, but this is based on static calculations and it does not consider the offsets that are found due to motions of the vessel, while the offsets can be critical in case a structure is present or if a certain accuracy of a station keeping operation is necessary. Currently, to determine the offsets of a vessel on DP, the system is modelled using a time domain approach. Multiple simulation runs are carried out to calculate the expected extreme offsets in a given time interval, which is known as the most probable maximum offset (MPM offset). This is a complex and time consuming process and therefore it is not always done in practice before an operation starts. In this research, a method is developed to estimate the surge MPM offsets of a vessel on DP due to the wave drift forces using a frequency domain approach, as this can lead to faster estimates. But two problems are faced: The first is that there is no mathematical model available describing a vessel on DP which can be used to accurately calculate the offsets in the frequency domain. The second problem is that there is no known relation between the offsets and the extreme behaviour, which leads to the MPM offsets. To find the MPM offsets, first of all a one-dimensional time domain model of a vessel on DP is made, considering only the surge degree of freedom. Next, to determine the surge offset response using a frequency domain approach, the differential equations of the system are linearised, which gives the transfer functions from the environmental forces to the surge offsets. This is used to estimate the surge offset response in the frequency domain. The accuracy of this method is determined by comparing the root mean square value (RMS) and the zero up crossing period to that of the time domain results. Then, two alternative methods are developed to calculate the MPM offsets from the surge offset response characteristics directly. The methods use the RMS and zero up crossing period of the surge offsets calculated in the frequency domain, to determine the extreme behaviour statistically without the use of multiple simulation runs. Using the linearised model of the vessel on DP, it is found that the surge offset response can be calculated within an accuracy of 4% of the results generated by the time domain simulations, based on the root mean square value and the zero crossing period. Therefore, an accurate estimate of the surge offsets is found using a frequency domain approach. Both alternative MPM offset calculation methods, using the surge offset results of the linearised model, give MPM offset estimates within approximately 10% of the results of the time domain simulation approach. Taking into account the strong variability found in the MPM offsets calculated by the time domain approach, the estimates from the frequency domain approach are regarded as good estimates. It is concluded that the methods developed in this research can lead to faster and therefore timely MPM offset estimates to use for the safety and accuracy of operations. This can improve the way of working for many offshore operations where often no use is made of MPM offset estimates due to the disadvantages of the methods currently used in practice. It is recommended to extend the method developed in this research to three degrees of freedom, such that it can be implemented in practice.

The International Maritime Organization (IMO) issued on the 13th of April 2018 a press release titled: “UN body adopts climate change strategy for shipping”. [1] This document illustrates the commitment of the IMO to significantly reduce the emission of greenhouse gasses (GHG) from international shipping in coming decades. However, the question arises whether the ambitious goals, set out in this press release, are feasible to be met. This aim of this thesis is to investigate the economic and technological feasibility of powering a vessel while emitting minimal greenhouse gasses in 2050. The focus will be on power plant configuration consisting of an energy storage medium and energy converter. A case study, concerning a representative ROPAX ferry built in 2050, is performed to illustrate the feasibility of using such a power plant configuration. Energy storage media considered are hydrogen, ammonia and batteries. The use of internal combustion engines, fuel cells and an ammonia reformer are also investigated. The performance of power plant configurations with respect to their estimated greenhouse gas emission, overall weight, required volume, initial investment cost and cost of the required energy per day of operation is evaluated and based on the results of this study several conclusions are drawn. • First and foremost is the need to reduce the price difference of hydrogen and ammonia compared to LNG. Without this reduction, no single synthetic fuel can be considered economically feasible. Three options to reduce the price difference are identified: - a high LNG price including high emission tax; - a low commercial electric energy price; or - synthetic fuel production using excess renewable energy. Especially the last of these three is considered to be a feasible measure due to the expected presence of excess energy from solar and wind farms. • The second conclusion is that using fuel cells or batteries are the most environmentally friendly option due to the emission of N2O when using internal combustion engines. • Thirdly, all sustainable configurations require a considerable amount of space. • Furthermore, the combination of relative low electrical efficiencies and high hydrogen price result in high daily costs for hydrogen fueled internal combustion engines and PEMFCs. • The initial investment cost and system weight of batteries-based configurations are high. Following these conclusions, only three power plant configurations remain. Based on expected safety and logistical concerns and the expected potential for improvements, a single configuration was determined to be the most suitable to be used on a ROPAX ferry in 2050. This power plant configuration is composed of a SOFC directly fueled by ammonia. After assessing the safety concerns associated with handling ammonia and the implications the established power plant configuration has on the general arrangement of the ship, it is concluded that the use of such a power plant configuration is highly likely to be feasible in 2050. However, it is recommended to perform a more in-depth analysis of required safety measures and operating characteristics of fuel cells in future research.

During the energy transition, a wind-assisted ship propulsion system has the potential for increasing energy efficiency according to the ship’s EEDI (Energy Efficiency Design Index) in the short term. However, it would not only make the diesel engine run in off-design condition, but its dynamic behavior due to time-varying wind and waves is still unknown. Hence, for a selected case used in this thesis, a Flettner rotor is chosen to be further evaluated on the system’s dynamic behavior under its favorable wind angle at Beaufort scale 6 and 7. After modeling the wind-assisted ship propulsion system, it was linearized and normalized around its static operating point. This gives more insight into the system from a frequency-domain analysis via the Bode magnitude plots of engine speed, engine torque, and ship speed to the variation of true wind speed and wakefield induced by wave amplitude disturbance. In addition to the time-domain simulation for understanding the impact of the wind and wake disturbance on the system, the system response spectrum, which was proposed as an alternative approach for analyzing the system’s dynamic behavior, was derived by connecting wind and a derived wake spectrum to the Bode magnitude plots. Therefore, how the energy is conveyed from the marine environment to the system around its equilibrium can be tracked clearly. Consequently, according to the selected case with a given controller, the results show that the fluctuation of true wind speed directly influences the ship speed, which in turn makes the engine torque be more sensitive to the variation of true wind speed in low-frequency regions. Besides, the engine speed resists to the variation of true wind speed very well due to the controller’s introduction. Although the Flettner rotor generates approximately 44% of thrust at Beaufort scale 7, the true wind speed disturbance does not result in a significant engine loading disturbance compared with the fluctuation of wakefield, which significantly influences the engine speed and torque. It was found that it is related to the frequency region where the wake spectrum overlaps with the system sensitivity function. Within this region, the controller has a relatively poor performance, and thus an engine operating cloud can be noticed in time-domain simulation. However, the ship speed is not influenced significantly by the wakefield disturbance because the frequency region of wake spectrum does not overlap with that of the transfer function where the ship speed is more sensitive to the variation of wakefield. Finally, the sensitivity study implies that a further increase of ship total mass and moment of inertia enlarge the engine speed and torque in the frequency region where the controller does not perform well. In conclusion, based on the selected case under its favorable wind condition, the potential of the wind-assisted ship propulsion system is still promising. Furthermore, the linearised model is a useful additional tool, and the system response spectrum gives more insight into the system.

At the Lion Foundation a hunting simulator is used to stimulate the hunting instincts and skills of lions and tigers, in order to improve their health and increase chances of relocation into the wild. The hunting simulator is an animal enclosure wherein a piece of meat, used as prey, is moved by means of a joystick-controlled cable-driven system. The animal caretakers find it difficult to operate the hunting simulator effectively: the position of the prey relative to the hunting cat and enclosure is hard to judge. Evading the fast unpredictable cats requires high prey velocities without crashing into obstacles or enclosure walls. In this study it is hypothesized that providing the operators with haptic assistance through the joystick will help them to improve their performance, i.e. it will allow them to navigate the prey through the enclosure at higher velocities while having fewer collisions. Haptic assistance was designed as a force-stiffness feedback algorithm based on the inverse Time-to-Collision. It was implemented on a purposefully designed virtual hunting simulator operated through a force-feedback gaming joystick. Naive subjects (n=10) participated in an experiment in which they were asked to navigate the virtual prey through a series of waypoints, without hitting the boundaries of the virtual enclosure or the obstacles within it, both with and without the designed haptic assistance. Results show that haptic assistance leads to significant benefits for the operators, as they moved significantly faster while having significantly fewer collisions. In conclusion, the designed haptic assistance is beneficial when used in the virtual hunting simulator, and therefore constitutes a promising method that warrants implementation and evaluation in the real- world hunting simulator.