Due to the growing demand for offshore wind energy and the increasing wind turbine sizes, a shortage of capable installation vessels is anticipated by 2024. Consequently, the utilisation of heavy-lift vessels, previously not employed for bottom-founded or floating offshore wind turbine installations, may become imperative to realise the offshore wind project pipeline. Therefore, this study analyses the technical and economic feasibility of installing floating wind turbines with the largest construction vessel in the world named the Pioneering Spirit. For this, the concept development stage of the systems engineering method was applied, consisting of three successive phases. Firstly, in the Needs Analysis phase, valuable insights regarding the operational environment were obtained, resulting in operational requirements for the concept design. Secondly, in the Concept Exploration phase, these requirements were used for generating multiple alternative concept options after which the most promising concepts were selected for further analysis through a trade-off analysis. Lastly, in the Concept Definition phase, the technical feasibility, workability and economic feasibility were evaluated for the selected concepts. The technical feasibility was assessed by creating storyboards for the different installation procedures, determining the stability of the barge named the Iron Lady for different load cases and providing technical descriptions of performed operations and required equipment. Furthermore, the workability was estimated by comparing statistical wave and wind data with the environmental limits for various operations obtained through literature, previous projects and a motion analysis model. Subsequently, with the storyboards and workability results, the economic feasibility was determined with a model that included estimations of the vessel and fuel costs for constructing a reference wind farm located at a variable distance to shore. Ultimately, it was found that Spar- and TLP-type floating wind turbines are of most interest for the concept design and that the Pioneering Spirit is in principle capable of installing the corresponding pre-assembled foundations and wind turbines relating to a capacity of 15 megawatt with a single-lift operation. Furthermore, this research gives valuable insights that extend beyond the initial scope of this paper. Since the performance implications of the selected concepts related to the workability assessment and economic feasibility study can directly be linked to specific design choices and limitations. This, in combination with the exploration of floating wind turbine installation with alternative lifting equipment, can be used to provide recommendations for future designs of purpose-built vessels in this sector. Finally, the methodology used in this study could be applied to evaluate the feasibility of other potential concepts for deployment in this area.

With the increasing water depths of the new offshore wind farms, the challenging soil conditions, the availability of assets, and other factors, jack-up installation vessels may no longer be suitable to complete the installation scope of work for the new wind farms. Therefore, installation methods and techniques using floating vessels must be further developed to allow safe and efficient installation of wind turbines. Due to the response of floating installation vessels, excessive motions can be transmitted to the lifted object, making the installation operation very weather sensitive. To increase workability, Heerema Marine Contractors (HMC) has developed the RNA method for wind turbine installation using a semi-submersible crane vessel. This method uses a temporary support structure on the vessel deck (installation tower) where the RNA is fully assembled with the assistance of the GREP (Guided Root End Positioning) tool to constrain the blade root to the top of the installation tower and consequently the hub. Finally, the RNA is installed in a single lift on the WTG permanent support structure. However, the GREP tool is compatible only with a specific range of wind turbine blade dimensions; therefore, for a different-size wind turbine blade a new GREP tool must be designed, fabricated, and mobilised. This project proposes an improvement to the HMC's RNA method to eliminate the necessity of the GREP tool. That is, a motion-compensated Stewart platform attached to the crane boom, where the blade is fixed to be installed in the hub on top of the installation tower. The project is developed by investigating the initial assumptions; those are crane boom stiffness, blade deflection, installation tower motions and their influence on the vessel's response, and aerodynamic loads acting on the blade during installation. The kinematics (inverse and forward) and dynamics of a Stewart platform are formulated, as well as the mechanical concept of the proposed system and the blade installation process using a Stewart platform attached to the crane boom. Furthermore, to eliminate the requirement of the GREP tool, a control system is developed to compensate for the blade root motions relative to the hub. The motion control system uses sensors to measure the hub's motions and generate the Stewart platform actuators' set points. Different possible sensor set-ups are evaluated, and a filter is designed to reduce the influence of the sensors' noise. The control system is developed on the basis of feedback PI (Proportional and Integral) and adaptive feedforward control to the actuators (hydraulic cylinders). It is concluded that it is technically feasible to use a motion- compensated Stewart platform for blade installation in the RNA method. However, the economic aspects of the proposed solution must be investigated.

The design of polar expedition cruise ship is not a trivial task to the naval architect due to the complex nature of the ship itself. Concept exploration are hereby required to improve the understanding of the design problem and identify its challenge as well as possible solutions. However, it is always difficult to generate the technically-feasible design solutions while still satisfying multiple and potentially conflicting performance criteria for the polar expedition cruise ship. There are currently two ways of optimizing the concept design: manual optimization and computer-optimization. The computer-based optimization, such as the Packing Approach developed by TU Delft, can semi-/automatically generate a set of design solutions. After the generation of these design solutions which are unknown in many performance behaviors, it is necessary to post-process them and increase the quality of those designs created from both optimization methods. Design rationale is an effective way to serve as qualitative metrics in post-processing the configuration layouts of the concept designs. However, the ambiguity and potential conflicting aspects within the design rationale are difficult to handle by the current post-processing method while fuzzy logic theory can be utilized to cope with the design problems involving subjective and ambiguity. Hence, it is proposed to develop a new methodology to better post-process the concept design of a polar expedition cruise ship.

The growth in the offshore wind industry sees an increased demand for offshore service vessels (OSVs). These vessels often operate in harsh conditions, and their performance is heavily dependent on their seakeeping characteristics. Conventional ship design processes fail to effectively consider seakeeping early in the design process, leading to sub-optimal vessel design. A design framework has been developed in the software 'NAPA' to efficiently design high-performing OSV concept designs. The developed framework is able to optimize a hull shape -specifically the main particulars and length of different hull sections- to maximize performance in certain objectives. These objectives are seakeeping, ship resistance, lightship weight, and station keeping power requirements. Regarding seakeeping, the attainable percentage operability is calculated for each iteration, although the Operability Robustness Index (ORI) is optimized. The ORI is a more robust seakeeping key performance indicator (KPI) than percentage operability, which is advantageous when facing concept design uncertainty. The framework maximizes ORI, thereby seakeeping performance, for a particular loading condition, motion sensitive criteria, and operational area. The ORI is evaluated based on the area of operation's scatter diagram and wave spectrum, governing motion limits, and iteration-specific RAOs. Designs are required to satisfy an initial stability constraint, to ensure feasibility. The framework's output is a Pareto-frontier showing the trade-offs between different KPIs, and the corresponding variable combinations. Thereby, the naval architect can evaluate what design offers the best overall performance. A 'feeder' OSV, designed to transport wind turbine components to wind installation vessels has been optimized to validate the framework. This OSV is currently being developed as a concept by C-Job naval architects. The ship has been optimized for maximum operability of an Ampelmann motion compensated platform. A single optimization run took three and a half hours to complete 300 iterations, thereby finding the Pareto-frontier. Comparing the Pareto-optimal solutions with the base vessel, the ORI can be increased up to 3.6%, the lightship weight decreased by 21.1% and the ship resistance decreased by 13.0%. The framework showed that smaller vessels can still attain good seakeeping performance, leading to a substantial reduction in lightship weight. The increase in seakeeping performance allows for the use of less expensive motion compensated equipment while maintaining high operability. The framework showed that there is a trade-off to be made with regard to seakeeping, and lightship weight, and ship resistance. The framework presents what variables and ship attributes cause these trade-offs. This information allows naval architects to determine the optimal design direction during concept design. Clients and naval architects can decide what trade-off in performance provides the ideal combination to achieve the ship's mission. Consequently, besides producing high-performance designs, the framework substantially increases early design knowledge. Thereby, the overall design process becomes more efficient. The framework showed to be a valuable tool for OSV concept design. By the extensive incorporation of seakeeping early in the design process, naval architects can design high-performance OSVs efficiently. The produced designs maximize performance in any of the KPIs, ensuring vessels have a high operability, but do not weigh more, or have higher fuel costs than is needed.

During the early stages of ship design exploration, design freedom is abundant but problem knowledge is scarce and most costs are already committed. This amounts to an incentive to look at the influences of the requirements on a design, to better understand how a concept is defined. This thesis investigates the operational architecture concerning how systems are used (often in a temporal fashion). A way to quantify the operational architecture is with operability, which describes the ability of a ship to perform its mission. This thesis identified the system performance consisting of availability and vulnerability part of operability as its main topic. Markov theory was selected to assess the availability of systems in order to maximize the operability of a naval vessel. Transition rates of systems are a key element of Markov theory but are hard to obtain during Early Stage Ship Design. A network-theory-based approach allocated nonquantifiable focus points to each system to determine their importance within a network. These were then linked to transition rates, which are required for a Markov chain to calculate the availability of a system. Four case studies were performed to test the model: several configurations were compared, two different focus points approaches were used, different ranges of rates were applied, and systems were added or subtracted. The model proved to behave according to educated guesses beforehand but also gave new insights in connections between nodes. The eigenvector centrality approach used to allocate focus points was found to be better than the combined connectivity approach. The scale of the ranges of rates should not result in very high values for system availability since they do not provide data which makes comparisons between network configurations possible. Very low values of system availability were deemed too far off from real-life values. This thesis paves the road towards a total assessment of operability. It has focused on the availability of systems, and delivered a method to make preliminary decisions for systems design in the early stages.

Traceability in complex ship design involves keeping track of the evolving relations between need, requirements and design. Such traceability is not fully developed in the current design process at DMO due to divisions in the design process and between design tools. This thesis proposes to use a single information model to facilitate traceability by connecting the need, requirements and design in a single database. Besides enabling traceability, such an information model can also be used to support modern modelling design tools. In the early design stage of naval vessels – the preliminary design phase – the capability, technical feasibility and affordability of a new ship are defined. Interactions between these three aspects are opaque and rely on the need for a new naval vessel and supporting requirements and preliminary design(s). Determining the need, requirements and design is in this thesis considered to be a ‘wicked problem’. In such problems, information gained by developing solutions helps define the problem itself. However, these solutions can only be determined with a certain interpretation of the initial problem. This results in many (evolving) interactions between the need, requirements and design in the ship design process as one is needed to define the other. With the help of Systems Engineering and Requirements Engineering information and relations in a ship design process can be determined and structured. These engineering fields are widely applied, and current technology enabled the development of computer aided approaches incorporating design theory, including computer aided traceability. One of the current developments in design approaches is the introduction of model-based approaches, which creates the possibility to actively manage more relations and interactions in the design process. Model based approaches such as the Design Structure Matrix are used to visualise relations between information, and Axiomatic Design enables the decomposition and creation of complex relations. A different approach to modelling in design processes is the use of Knowledge Based Engineering. Knowledge Based Engineering field aims to capture not only the relations and interactions between information in design processes, but also ‘knowledge’ about the ‘how’ and ‘why’ in these processes. Each of these model-based developments relies on, or enables, traceability of information. However, having a program capable of supporting an information storage to support these approaches remains difficult to achieve. For this purpose, Shipbuilder software was created to support transparent storage and management of information. In this thesis, theories for modelling approaches, Systems and Requirements Engineering and the DMO design process have been combined. This resulted in one information structure, applied in the Shipbuilder application, which enables traceability. To show that the proposed information model can model a ship and supports traceability, a case study has been performed. A small model of both an S- and L-frigate has been created to show how traceability can be performed in this information model.

The shipping industry contributes significantly to the global greenhouse gas emissions due to the use of cheap fossil fuels. The booming cruise ship industry is forced to reduce the emitted greenhouse gases and emission of carbon dioxide to be able to access remote areas with higher restrictions and to comply with upcoming regulations. Fuel cells are a promising alternative to conventional diesel-powered systems to reduce the emissions. Next to the physical implementation, fuel cells have additional operational limiting factors, which have to be matched with the power demand. Compared to conventional combustion engines, longer start-up times and a lower dynamic response ability can be expected. Typically, the energy demand is estimated for all electric power consumers with the load balance approach in the conceptual design phase. The actual power demand is calculated based on the absorbed power and additional predefined factors for specific conditions. This conflicts with the dynamic power demand of cruise ships in various operational conditions. This thesis discusses the used bottom-up approach for such an improved prediction of the total power and energy demand of an expedition cruise vessel for the early design stages. The focus is on identifying the peak loads and load changes under consideration of the passenger behaviour, environmental and operational conditions on the basis of predefined typical days of operations. The dynamic power demand is predicted for the different propulsion, auxiliary and hotel systems, as identified and grouped in the system breakdown. This is done by using separate prediction models for the defined groups of systems and electrical components. The required energy per day is calculated directly from a time-domain integration of the power prediction. The demand for a whole operational profile is obtained by adding different typical operational days. The highest power is required by the main propulsion in sailing mode. However, expedition cruise ships often operate at lower speeds below the design conditions resulting in a considerably lower load. The maximum load of the hotel systems always appears in the morning, when all passengers are on board and several components ramp up from the lower night mode. Comparing the total power demand shows that the load changes caused by the hotel systems gets smaller in relation to the changes within the propulsion system as soon as the speed varies. In port condition, the relatively constant auxiliary load, including the hotel systems, remains and describes the baseload throughout the day. Generally, the dynamic prediction clearly shows the potential to better estimate the required power and energy, if varying operational conditions are considered. The method supports a well-founded decision on the power supply configuration, if it comes to hybrid systems including different power supply components and their operational characteristics. A multi-criteria decision analysis on the power supply side can build up on the required energy and power demand of a certain part load. The required fuel cell size can be quantified based on the estimated maximal load and the fuel tanks by considering the predicted energy demand of the specific group of systems.

The urgent development of green energy has become a worldwide trend in the war against the threat of global warming and the impact of extreme weather. The offshore wind farm is one of the solutions that are able to harvest energy sustainably from the environment. To erect these offshore windfarms, the debate about whether a new fleet should be designed and built or make the existed offshore fleet go under retrofitting has been raised. The stakeholder group involved in this issue is formed by the ship designers, ship operators, and market analysts. The difference between the existed offshore support vessel fleet and the offshore wind farm support fleet is the former is built to perform a certain operation and will require another considerable investment to be retrofitted while the latter is looking for solutions to switch from different equipment thus to keep the flexibility between different operation. The main objective of this research is to propose a ship design methodology to enable the offshore wind farm's request in mission flexibility by improving the design process in the preliminary design phase. Modularity and Knowledge Based Engineering (KBE) are chosen to be the two main topics to support the research objective. To narrow down the research scope, the research object is limited to a small Offshore support Vessel fleet that is able to perform service throughout the lifecycle of an offshore windfarm. The application of the modularity concept is to break down the vessel system into smaller subsystem or function blocks then reassemble them to be self-sufficient modules. Modules are the basic elements for forming a modular platform to provide a basic model that is able to perform various operations by mounting different equipment. In the former research done in NTNU, a methodology for manipulating the modularity to assemble a product platform by processing previous configuration scripts has been developed. It has greatly reduced the repetitive and iterative works in the design of similar vessels, especially the design for OSVs. Though the configuration scenarios are flexible to change, the pre-designed modules' properties are limited by the based configuration. On the other hand, the configurations are closely tight to the hull shape thus limited the freedom from both the hull design and configuration design. In this research, an improved configuration generator is developed to separate the configuration design and the hull design. The proposed methodology will also keep the flexibility in importing new configurations and the latest hull shapes without conflicts. Knowledge based engineering is another topic included in this research. It has been proved and widely used in the aerospace industry. As for the ship design industry, the application is limited to local structure design. KBE is a bridge to bring the user and the designer together in the design project. It consists of a programming stage, Knowledge Based System (KBS), to process the selection of suitable design cases and a visualization stage, Computer-Aided Design (CAD) ,to give a direct review on the whole design project. The fundamental drivers for each KBE system are called "High Level Primitive" (HLP). They are the basic units for the knowledge stored in the database. KBS picks out suitable HLPs from the database and assigned them in a configuration script thus forming a design result stored in the digital world. CAD will take over the result and visualize it in the drawing window. This is the proposed methodology to fill the gap between the modularity re-configuration and the diversity of modules. A Multi-Model-Generator (MMG) will become the final output of this research. It is designed to be able to reproduce several vessels in the OSV market. A further demonstration of the ability to generate a modular OSV product family at the end of the research. Though the modeling output has been proved to meet the index set for the research object, the MMG has the potential to be improved in the future by importing a well-constructed database from the industry.

Solitaire is a DP positioned pipelay vessel capable of laying pipe up to 3000 meters. Currently, Solitaire is more than 40 years old. Although it has been upgraded multiple times, it has been identified that certain improvement can be achieved by retrofitting just the aft of the vessel. The purpose of the research is to evaluate the feasibility of improving Solitaire by retrofitting it with a new aftship, by exploring the different design possibilities, including the different stinger support configurations. To this end, an analysis of alternatives has been done and the preferred options have been implemented into a concept design. The use of Systems Engineering (SE) has been motivated by the need to establish a clear structure to guide the design due to the complexity of the problem. This methodology allows to keep a good overview of the requirements and constraints involved in the design. An operational analysis was carried out to identify the operational deficiencies of the design. This lead to four main areas of improvement. i.e, Longitudinal strength, Stinger and Stinger handling system (SHS), Resistance and Deck space. By addressing these operational deficiencies, the operational time of the vessel can be improved. Either by reducing the theoretical peak cycle time, decreasing the downtime or a combination of both. Based on the operational analysis a set of requirements has been compiled and a functional definition of the design has been made. With all the insight obtained through the operational analysis, the design requirements and the functional definition; an analysis of alternatives has been carried out. For each of the operational deficiencies, multiple alternatives are analysed. Local optima are found for each of the deficiencies although, if each of these local optima is implemented in the design, the global performance of the vessel is compromised. Therefore, a holistic design is proposed to integrate all the solutions into one preferred concept design. Overall, the findings of the research suggest that the retrofit of the aft is technically and economically feasible. Nevertheless, a design validation needs to be carried out to better quantify the total improvement of the new design.

The global temperature is rising as a consequence of the climate change. In order to stop the further increase of the global temperature, the international community has decided to aim at reducing global greenhouse gas (GHG) emissions in the near future. To achieve this ambition, various alternatives in shipping need to be explored including sailing on alternative fuels. This study investigates the consequences of sailing on alternative fuels. It is investigated which problems might occur when sailing on alternative fuels, which rules are mandatory when sailing on alternative fuels and as a consequence what the effects are on the cargo transport costs. The problems occurring when sailing on alternative fuels are caused by the lower energy densities of these fuels, the rules and requirements with regard to the storage of some of these fuels and the shape of the storage tanks for some specific fuels. The shape and requirements regarding the fuel storage tanks can make it necessary to replace cargo for storage tanks, which will result in increased transports costs. Furthermore, the lower energy density of alternative fuels result in more fuel weight, or volume as compared to conventional fuels. In order to transport the same amount of cargo, an extra bunker stop, or taking less fuel and reducing the sailing speed, can be an option. Another option to compensate for the increased weight, or volume of the alternative fuels, is to reduce the cargo taken on board. All options will result in higher transports costs as compared to sailing on conventional fuels. To investigate how these extra costs are composed a main question has been formulated: "In a situation where the transport costs are minimized, how do the transport costs compare when sailing on various fuels with different energy densities than conventional fuels?". To answer this main question, a model was developed. The model is suitable to calculate the transport costs in various situations. For this research, three vessel types on three operations, using seven fuel types have been analyzed. The analyzed vessels were a container vessel, an oil tanker and an ore carrier. The chosen voyages are common voyages. The analyzed fuels are fuels which are able to achieve the goal of reducing the CO2 emission with 70% per transport work in 2050 as compared to 2008. Heavy fuel oil was used as benchmark. Based on the simulations used in the developed model it was found that: the costs of alternative fuels are higher than those of conventional fuels. Batteries are too heavy, too large and too expensive to be considered as an option, for the researched vessels and operations. The capital costs of fuel cells make that the use of fuels in combination with a fuel cell is currently expensive at higher speeds. High fuel storage costs make hydrogen currently not competitive with conventional fuels. The transport using an oil tanker are the lowest for hydrotreated vegetable oil, second lowest for ammonia in combination with an internal combustion engine and the highest for battery electric.

From shallow to deep water, from the well to the ship, from the offshore field to shore or between countries, many kilometres of offshore pipelines for transportation of hydrocarbons (oil and gas) have been installed over the last decades. Allseas’ Tog Mor is a shallow water pipelay barge capable of laying pipes up to a water depth of 25 meters. Currently, Tog Mor is more than forty years old and is due for replacement. Therefore, Allseas has considered to replace Tog Mor with a new shallow water pipelay barge. However, it is unclear whether the current barge is optimised for pipelaying since it is designed for crane supported purposes. The aim of this research is to give insight into vessel properties which determine the pipelaying performances and to define a set of design requirements for the new shallow water pipelay barge, Tog Mor 2.0. To define the requirements of Tog Mor 2.0, the principles of Systems Engineering are followed. Based on the operational analysis, the performances of Tog Mor can be improved by a reduction of the theoretical peak cycle time, optimisations of the pipelaying process and a reduction of downtime. The output of the operational analysis in combination with the principles of pipelaying results in potential bottlenecks. Those performances and potential bottlenecks were the input of the functional definition of Systems Engineering. The aim of this functional definition is to allocate functions to systems and to prioritise the design focus point in terms of functions. Those functions were translated into hardware components and integrated in the total design. Due to the inversely proportional relationship of the number of production days and corresponding production costs, an increased number of stations and lay speed do not have an advantage in terms of costs. In order to reduce the theoretical peak cycle time, the specifications of the functional equipment are improved and the need of buoyancy modules is reduced. Less need of buoyancy modules is achieved by the increased capacity of the tensioner (two tensioners of 100 ton each) and an inner stinger. The pipelaying process is optimised by free deck space, a higher level of redundancy of the functional equipment and new technologies of equipment. The level of redundancy in combination with the improved workability results in a reduction of downtime. Those improvements results in a final concept design which proposes a barge with an off-centre firing-line of five stations (three welding stations, one testing & grit blasting station, one coating station). As a result of an improvement of each individual function and the interactions among those functions, an improvement of 30% in terms of theoretical minimum peak cycle is achieved by an optimisation of the pipelaying process and potential bottlenecks. A reduction of the peak cycle time, an optimised pipelaying process and a reduction of downtime percentages results in an improved overall performance of Tog Mor 2.0 compared to the current Tog Mor.

Recently the interest in hydrofoil vessels using a fully submerged hydrofoil increased. Hydrofoil vessels experience a resistance hump and possible instabilities during their takeoff of which both are influence by waves. In order to determine the required power during the takeoff to overcome the resistance hump and to investigate whether the hydrofoil vessel is stable during the takeoff numerical simulations or experiments have to be performed. Experiments covering the full takeoff require a long towing tank and high towing velocities and therefore these experiments are costly. The alternative, performing numerical simulations, is favorable but requires a suitable numerical code. As no validated code is available in which a takeoff can be performed in waves, in this research Panship, a potential flow code suitable for high speed craft and adapted for use with hydrofoil craft, is validated for the takeoff of a hydrofoil vessel. In this research the results of Panship are compared with results of experiments and other numerical codes in four different stage as little validation data is present for the takeoff of a hydrofoil vessel. The four different stages are: a foil without the influence of the free surface, a foil with the influence of the free surface, two foils with the influence of the free surface and the hull and foil system near during the takeoff. In these four stages the lift and drag determined in Panship is compared with available experimental results and numerical codes. As the simulations in Panship require a vast amount of input parameters, the influence of these parameters is studied first to ensure the reliability of the results. Comparing the results of Panship for a deeply submerged foil with another potential flow solver shows that the lift is predicted correctly, but that the induced drag is underpredicted. If viscous effects are required in the solution, the quality of the results of Panship is dependent on the type of hydrofoil used. As some foils have a large viscous effect on lift, the lack of viscosity on Panship, leads to a low quality of the results for lift and induced drag as they are overpredicted. The trends for interaction of a foil with the free surface are predicted correctly but the underprediction of induced drag influences the quality of the results. Panship is able to predict the effects of foil interaction for lift correctly, but the results for foil interaction for drag are poorer. During the takeoff Panship is able to predict the lift fairly correct but the total drag is underpredicted severely. Recommendations are given to improve the results of Panship and for future work.

Currently there is an energy transition from fossil fuels towards zero emission fuels within the marine sector. In addition to this, improvements are made in system design with regard to standardization of which allows for variation. The combination of these two improvements is found in the EU H2020 NAVAIS project which focuses on customer tailored vessels in combination with a standardized and modularized approach. The specific objective is to use modularity to help support the development of zero-emission propulsion methods for a ferry. The objective is fulfilled by answering the main question of this research: “How can the energy carrier and conversion system of a ferry be made environmentally friendly and modular and how does the inclusion of low emission and modularity objectives impact the power supply and total design of the ferry?” In the approach a Systems Engineering approach is used, including the V-cycle or the RFLP approach. In this approach the design is approached by the elaboration of the Requirements, Functionalities, Logical design and the Physical design. Based on the main vessel requirements, research requirements are defined as well which are the system’s ability to be: future proof, modular, fulfilling the energy and power requirements, the ability to be refitted and technical feasible. A platform approach is defined, which is called a platform approach, and for this research includes: The top-down approach, the common-core approach the design approaches combined in the platform approach are practically applied by using a design support tool which is the Design Structure Matrix. The DSM and specifically the clustering algorithm has the goal to find modules based on minimizing interactions between modules. This is done based on the logical or technical decomposition where only the sub-systems are included in the matrix. The interactions between the sub-systems are defined using a binary definition. The clustering algorithm is used where random groups of sub-systems, named clusters or potential modules, are formed which then are evaluated based on the interactions and parameters to control the size and interactions between the clusters. Simulated annealing is used to optimize the solutions in combination of multiple runs for the defined system configurations. In this way interchangeable modules can be defined which can be used for the diesel generator, dual fuel and fuel cell configuration. The multiple solutions are merged into combined potential modules after which the results are evaluated. The evaluation is done based on the number of interactions, the technical feasibility and physical evaluation of the modules and finally based on the ability to standardize the interactions of the module. These steps result in a suggestion of modules which are interchangeable and are based on a minimization of interactions between or outside the modules. While leaving the ability to extend the method to allow for new alternative fuel systems.

In this thesis a grey-box model is developed to predict the power increase over time due to marine biofouling. Biofouling is known as the undesired adverse effect of living organisms growing on submerged surfaces. Fouling creates roughness on the hull and propeller and thus additional frictional resistance and loss of propeller efficiency, also referred to as an additional sea margin for ships due to biofouling. The International Maritime Organization (IMO) identified marine biofouling as one of the primary problems from both economic and ecologic points of view. Biofouling threatens the ecological balance of world seas by transferring invasive aquatic species and it causes a reduction in hydrodynamic performance of ships, which in turn increases fuel costs and greenhouse gas (GHG) emissions. A white-box model is first developed to predict biofouling growth together with resulting roughness, and compute increase in frictional resistance, loss of propeller open water efficiency, and change in wave resistance. With this a physical modelled prediction can be made for increase in power. This increase is then used in a data-driven model together with all other used parameters, to improve the prediction and output of the model. With the developed model, relevant questions have been answered from both a research and industry perspective. For Feadship, the developed model was applied for their yachts to give insight in power increase, fuel increase, maintenance increase, speed loss, range loss and added cost due to biofouling. With implementation of the proposed grey box and white box models, predictions can be made for ships varying in all ranges of available data. With an indication of ship profile and parameters, biofouling and its resulting sea margin can be estimated with high accuracy in early stage ship design.

The research effort on autonomous ships has increased over the last years. The realisation of these ships will have as a consequence that the crew can be reduced significantly or even be removed entirely, resulting in unmanned ships. Although there is a strong belief that unmanned ships would lead to more economic efficiency, only limited research has been performed in order to demonstrate what the overall effect of the change to unmanned shipping would have on transport costs. Nonetheless, more reductions in cost or improvement of transport performance for unmanned ships would make them more attractive and economically viable. The design of a ship is subjected to regulations and requirements that limit the design freedom, but it increases safety. Removing the crew from the ship reduces the risk of shipping, under the assumption that the probability that an incident occurs does not change, since the lives of the crew are no longer at risk. If the risk is lower, the requirements to the design of unmanned ships might become less strict, while maintaining equivalent safety. In this way more design freedom can be realised for unmanned ships, as well as more economic efficiency. Within this report the required subdivision index will be evaluated, for it is expected that reducing this requirement can create more design freedom. Therefore, this research will focus on what reduction in the requirement concerning damage stability for unmanned ships can be allowed, if they are subjected to an equivalent level of risk as manned ships of the same size and type. It has been found that the required subdivision index can be lowered for unmanned ships, based on equivalent safety. The contribution of the risk of losing lives to the overall level of risk is larger for smaller ships. This is reasonable, since for larger ships, the size of the crew increases with a lower rate compared to the amount of cargo, installed power or capital costs. Therefore, the allowable reduction in the required subdivision index is largest for smaller ships. However, the size of the reduction depends strongly on missing accident statistics concerning the loss of life. The missing data results in the following uncertainties, for which further research is recommended. Firstly, for different ship types differences in the accident statistics are present. There are significantly less fatalities related to bulk carriers and container ships compared to general cargo ships. It is expected that these differences are related to the individual ship size and crew size, for which both the correlation with the probability of losing life is unknown. Secondly, there is a discrepancy between the theoretical probability of survival of a ship, namely the attained subdivision index, and the probability of survival that the accident data suggests. The attained subdivision index suggests that at least 30% of all accidents should lead to a total ship loss. The accident data reveals that for general cargo ships around 10% leads to a total ship loss.

To decrease Europe’s harmful emissions, the European Union aims to substantially increase its offshore wind energy capacity. To further develop offshore wind energy, investment in ever-larger construction vessels is necessary. Designing these vessels is difficult however, as this market is characterised by a large but seemingly unpredictable growth of market demand, turbine size and distance from shore. Currently no way of dealing with such market uncertainty within the ship design process was found to exist. This research aims to develop a method that is able to deal with market uncertainty in early ship design by increasing knowledge when design freedom is still high. The method uses uncertainty modelling prior to the requirement definition stage by performing global market research, and during the concept design stage by iteratively co-evolving the vessel design and business case in parallel. The method consists of three parts; simulating an expected market from data, modelling multiple vessel designs, and an uncertainty model that evaluates the performance of the vessels in the market. The case study into offshore wind foundation installation vessels showed that the method can provide valuable insight in the effect of ship design parameters like main dimensions, crane size and ship speed on the performance in an uncertain market. These results were used to create an initial design that is expected to perform well in the uncertain market. The developed method thus provides a way to deal with market uncertainty in the early ship design process.

Trim optimization is an approach considered by the industry to improve the energy efficiency of ships, having a potential in both reducing operational costs and to decrease the emissions of the ship. Potential fuel consumption reduction by trim optimization is 0.5 to 3 % and to up to 7% in extreme cases. Stolt Tankers, a shipping company active in the chemical tanker market, wants to increase the energy efficiency of their ships in operation by trim optimization. For a limited number of ships, trim tables from model scale towing tests are available, but these are not used and the accuracy of these tables are unknown. The objective of this research was to develop a method to decrease fuel consumption by trim optimization, by a dynamic fuel consumption estimation model based on available operational data, that can be integrated in the voyage management system of Stolt Tankers. A dynamic fuel consumption estimation model has been developed, using mainly the noon report data of the C-38 ship class, consisting of six sister vessels of 38 000 DWT chemical tankers. Quality of noon report data is an issue: human error in observing and recording data causes noise and a mismatch exists between the snapshot of conditions on one hand, and the 24 hr averaged sailing speed and recorded shaft power or fuel consumption on the other hand. A data pre-processing framework has been developed and applied to integrate and transform the data, clean and filter the data. The model is able to extract the effects of speed through water, mean draft, trim, sea water temperature, wind force, sea state and swell state and their relative direction to the ship and days since last hull cleaning and propeller polishing. The model has shown to perform optimal using the regression model of Lutzen and Kristensen (2013), combined with a multiple layer feed-forward neural network, consisting of 1 hidden layer with 15 neurons. The model is able to estimate the shaft power with an average accuracy of 6.58 % for a random test set of the noon report data. It is able to extract the effect of trim on shaft power and to consider the effect of weather and fouling conditions. Model results show that about 1 to 2% of shaft power per 0.50 m can be saved, with trim by bow being the optimal trim. Based on sea trial results, it is concluded that the model performs most accurate for conditions that are represented by a high quantity of historical data. The model can be applied for speeds between 12 and 14 knots and for mean draft conditions of 9.5 m and more. Within this range, the effect of trim and weather conditions are followed with reasonable accuracy. It is confirmed by the sea trial that trim by bow is the optimal trim, with a much stronger magnitude of the effect of trim on shaft power. A difference of 6 to 8% in shaft power was found for a change in trim of 0.50 m.

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.

The current global fleet is still dependent on conventional fuels as energy source to transport goods to various places in the world. These conventional fuels, such as MGO or HFO, emit large amounts of greenhouse gasses and other pollutant emissions. Regulation concerning these emissions becomes stricter every day, therefore institutions and governments have established reduction targets. To accomplish these reductions, net zero alternative fuels are serious candidates to investigate. As a result of these developments, Thecla Bodewes Shipyards is interested in solutions to reduce these emissions for their general cargo vessel series. Therefore, the objective of this research is to select the most suitable alternative fuel power- and energy system for a 7000 DWT general cargo vessel. In order to accomplish this objective, a literature review concerning potential alternative fuels is performed. After the selection of methanol as alternative fuel, the object of study is defined with specific boundaries and assumptions of the model. For the comparison of the current power- and energy system with future power- and energy systems, performance indicators are established and calculated. Subsequently, a case study is performed in which three concept designs for storage of methanol and two power plant configurations are proposed based on suitable energy converters on methanol and electrical load balance of the vessel. This research concludes that the fuel consumption of the vessel increased by a factor 2.1-2.4, range decreased by respectively 35% and 45% and payload decreased by 70 tonnes. Concerning the application of a methanol power- and energy system on board of a 7000 DWT general cargo vessel, a SI-ICE power plant with methanol as main fuel seemed most feasible.

This thesis research focusses on winning at sea. "Winning at sea" requires presence of relevant capability at the right time and for the required time. A winning fleet is a fleet that has the capability to achieve this. The goal of this research is to define a winning fleet and to create a method that can provide insight in how such a fleet can be obtained and maintained. One of the main challenges when operating a naval fleet is to match the fleet capabilities with the capabilities required from the missions that occur over time. The first part of this problem lies in the fact that it is never known what the future will bring. Especially when looking at a period of 30 years which is the general lifetime of a naval vessel. In practice this is partly countered by introducing a major update at the halfway point in the ship's life cycle. The other part of the problem is that the fleet capabilities need to be distributed over the different vessels and vessel types. Because having an infinite fleet size would be far too expensive, certain compromises need to be made. The main of which is that having a finite fleet will result in lower costs but also means that when a vessel is occupied all capabilities of that specific vessel are unavailable for other activities. For this reason it is important that the fleet composition is constructed in such a way that at all times, or at least within an acceptable error, the requirements set by the missions can be met. The method that is created during this research acts like a proof of concept of whether such a method could be useful in the future. This research should be able to help with the iterative process of balancing the operational need and design requirements with the feasibility and affordability that occurs within the early design stages of naval fleet design. The main stakeholders in this process are Commando Zeestrijdkrachten (CZSK), the department of planning (DPLAN), and the Defence Materiel Organisation (DMO). These three parties can respectively be categorized as the user, military planner, and the supplier. In order to reach the research goal a model has been created that simulates naval fleet behaviour. This Fleet Behaviour Model (FBM) describes a fleet as a collection of capabilities which are distributed over different vessel types. In order for this fleet to be operational it needs to comply with certain Life Support Activities (LSA) such as maintenance and the training of the crews. The operational need of this fleet is simulated by generating mission scenarios which require certain capabilities from this fleet for a specific time and at a specific location. Next to requiring mission specific capabilities from the fleet the missions also have the possibility of enemy presence. When this happens naval combat is simulated which introduces attrition into the model. The inclusion of attrition into a fleet behaviour model is what makes this research unique. Using this model the performance of multiple fleets can be tested against one or more scenarios. After the Fleet Behaviour Model was finished and tested a Genetic Algorithm (GA) has been constructed in order to systematically find an optimal solution. In this case an "optimal solution" is the fleet of which the capabilities and the distribution of these capabilities best fit a given mission scenario. It also takes into account the difference in design priorities that can change over time. One or more of three performance parameters: mission successfulness, attrition, and fleet size can be prioritized. Depending on factors like risk and budget these priorities can change which in turn can have a drastic impact on the resulting fleet compositions. In order to test the models' capability to provide insight into what makes an effective fleet, three test cases have been constructed. These test cases test the model on how well it can generate performance optimized fleet compositions as well as testing the performance of one fleet against a range of different scenarios. After these simulations the resulting data has been analysed in an attempt to find clues on what makes one fleet perform better than another. This insight was than translated to the broader spectrum of general early stage naval fleet design. In conclusion, the data gathered from the test cases has proven that the model is capable of providing insight into the early stage design requirements of naval fleet design. As a proof of concept this Fleet Behaviour Model seems promising as a useful tool for naval fleet design in the near future.