This thesis explores the use of Machine Learning (ML) techniques to model and predict transportation mode choice behavior, a critical component of urban mobility planning. Traditional mode choice modeling relies on Random Utility Maximization (RUM) theory, with models such as Multinomial Logit model and Mixed Logit model (MXL). While these offer interpretability, they often struggle with complex feature relationships and heterogeneity in large datasets. ML methods, by contrast, offer greater predictive power and flexibility, albeit with interpretability challenges. This study evaluates the performance of various ML models like Gradient Boosting and Random Forest Decision Tree on two datasets, with a primary focus on a detailed case study using Swiss travel data. The models are assessed under various configurations, including feature limitation, latent variable extraction, and SMOTE-based resampling. Comparative results demonstrate that ML models consistently outperform traditional Logistic Regression models in terms of F1 and Balanced Accuracy metrics. Additionally, tools like SHapely Additive exPlanation (SHAP) are employed to enhance the interpretability of ML outcomes. The findings highlight the potential of ML to improve Mode Choice modeling, particularly when combined with theory-informed structures and advanced data balancing techniques.

This study proposes an integrated mode choice and assignment model that combines the final steps in the classical four-step transport modelling approach. Using multi-objective optimisation, the model minimises service costs while simultaneously maximising the probability of mode selection. Compared to traditional sequential models, the integrated model prevents over-assignment to modes exceeding capacity. The model was then used to asses three key transport mode attributes—cost, capacity, and frequency—to evaluate their effect on the modal split, with a focus on increasing Inland Waterway Transport (IWT). Results showed that increasing road costs and IWT service frequency (with associated capacity growth) had the most impact on shifting modal share towards IWT. These findings demonstrate the potential of this integrated model to better evaluate policy impacts and inform transport planning.

This thesis presents a comprehensive Decision Support System (DSS) for selecting greenhouse gas (GHG) emission reduction technologies for heavy-lift vessels (HLV) owned by Jumbo Maritime. Given the increasing regulatory pressure from the EU and IMO, shipping companies must evaluate cost-effective solutions. Using the Best-Worst Method (BWM), the DSS prioritizes alternatives based on financial viability, operational flexibility, and technological readiness. The study examines eight sustainable retrofitting technologies and their selection methodology. Sensitivity analyses and verification tests confirm the robustness of the DSS rankings. The research highlights the limitations, implementation strategies, and the broader implications of sustainable decision-making in the maritime sector.

Green hydrogen has the potential to contribute in decarbonization efforts and achieving a net-zero emission economy by 2050. This report investigates the potential for production of green hydrogen offshore, using a Floating Production Storage and Offloading (FPSO) vessel. The aim is to determine a techno-economically feasible strategy for deploying this Green FPSO (GFPSO) and in turn its holistic hydrogen supply chain. State of the art literature is reviewed to define the knowledge gap to address and delineate the scope of the research. This is encapsulated by the main research question: "What strategy could be used to deploy a GFPSO supply chain and ensure techno-economically feasible outcomes?". To answer this question, a methodology is devised involving the breakdown of the strategy into key decisions, the outline of the criteria by which the strategy can be scored against, and the formulation of an MILP model. The model encapsulates the supply chain from energy generation, hydrogen production, storage, and transport to destination. Technical and economic parameters are implemented in a North Sea business case context, assuming 4 scenarios which represent how each implemnentation strategy varies. This comes down to the configuration of energy vector of gaseous hydrogen (GH2), liquid hydrogen (LH2), and ammonia (NH3), as well as the transport mode of either shipping vessels or a pipiline, used to deliver the medium from production to demand location. Based on the MILP model result, the optimal locations in the discretized region for energy generation within each scenario, as well as comparison across scenarios using the calculated levelised cost of hydrogen (LCOH) in [€/kg].

The results of the study reveal LCOH values of 4.05-6.52[€/kg] for the time period of 2020-2050. The lowest cost was observed in the GH2 pipeline configuration, followed by NH3 shipping. The pipeline configuration required implementation closer to shore, while the shipping configuration correlates with the location of highest energy availability in the weather data. The greatest portion of the overall costs in all scenarios originated from wind turbines used for energy generation. Conversion process costs formed another significant component of the total costs in the scenarios involving NH3 and LH2. Sufficient reduction of these conversion costs could enable a more competitive performance from the corresponding configurations. Based on the criteria framework, the strategy utilizing GH2 pipeline supply chain configuration performs best in terms of LCOH, CO2 emissions, and access, while NH3 shipping performs better in Commercial Readiness Index (CRI), Technological Readiness Index (TRL), Ease of Implementation (EoI), and in existing regulations. The significance of these strengths and weaknesses will vary depending on the weight attributed to the importance of the criterion by the decision making entity.

The consequences of climate change are becoming more and more visible. A significant cause of this is CO2 emissions; the shipping sector is responsible for 3% of global CO2 emissions. As a result, the Fourth IMO GHG Study 2020 presents pathways to reduce the GHG emission of the shipping industry by 50% by 2050. Recent IMO goals have overtaken this to reduce net emissions to zero by that year.

As a result, research in renewable energy sources has grown in significant interest, offering a wide range of potential solutions. Recently, (green) ammonia (NH3) has been added to these pools, as it is carbon-free and has a higher storage density than liquid or pressurized hydrogen. However, when comparing ammonia to the current conservative fuels, its energy density is still not at the same level, and more fuel volume would be required to deliver the same amount of energy. There are two ways to address this challenge. More frequent bunkering or larger volumes for the fuel tanks on board at the cost of cargo space and thus income. This is a difficult choice to make in the pre-design as it depends on the choices of other owners as well.

This report investigates the impact of a fuel switch to ammonia on the ship design and bunkering pattern based on the current operational profile of 1025 seagoing ships. A mixed integer linear programming model will establish the optimal fuel tank volume and bunkering strategy for each vessel. This model considers rerouting for trips that are not feasible and two approaches for the bunker strategy. Besides, a port model will establish the ammonia bunker pricing based on the resulting demand in each port. The estimated ammonia bunker prices are implemented in the bunker strategy model. This is repeated till a balance is found. The two models represent an Ammonia Powered Shipping Network considering a homogeneous shipping market. The report presents the results and key factors influencing the balance between the fuel tank volume and the sailing range. The simulated bunker strategies show different possibilities for finding this balance and reducing the operational impact caused by the transition to ammonia.

This thesis explores the conceptual design of a zero-emission, modular, and standardized Incident Response Vessel (IRV) for the Port of Rotterdam. The goal is to support the port's ambitious sustainability targets, which include reducing CO₂ emissions by 90% by 2030 and achieving a fully emission-free fleet by 2035. In response to the challenge of decarbonizing maritime operations, this research examines how alternative fuels, energy modules, and modular design principles can create a fleet that is resilient and adaptable to future energy technologies.

The study evaluates various ship design methods, focusing on modular design principles to assess how standardization and modularization can best apply to the new vessel design. Among several design approaches, Modular Function Deployment (MFD) was identified as the most suitable. A comprehensive analysis was conducted on all necessary inputs, tasks, functions, and requirements for an IRV, acknowledging that this vessel serves a specialized niche and cannot be treated as a standard vessel type. Due to this unique role, a detailed mapping of current systems onboard was necessary to identify which systems are no longer needed and which new systems are required. This structured analysis forms a foundation for the MFD model presented in the thesis.

Estimates for different alternative energy carriers were created based on scientific research and other data sources, identifying potential matches for the Port of Rotterdam. These estimates serve as a reference for assessing energy needs in the early design phases. By linking energy demands with specific energy carriers, the study enables the design of conceptual models. In addition to the developed model, visual sketches of systems and vessels provide concept designs that serve as visual aids for future decision-making, supporting the port's strategic planning.

This study employs MFD along with other ship design methods to identify strategies for flexible energy system integration, spatial layout efficiency, and operational effectiveness. MFD is applied to IRVs for the first time here, aiming to achieve a robust design that accommodates emission-free technologies such as electric propulsion and alternative fuels like methanol and hydrogen, while meeting functional and operational requirements.

The findings indicate that MFD provides a scalable and structured framework, enabling the Port of Rotterdam to maintain operational flexibility and comply with current and upcoming regulations. The research highlights that a swappable battery system is the most practical solution for immediate implementation, supporting both current tasks and future scalability. Additionally, modularity facilitates easier adaptation to technological advances, paving the way for long-term fleet evolution.

In conclusion, this thesis presents a viable strategy for the Port of Rotterdam to transition to a modular, emission-free IRV fleet that meets operational demands and adapts to emerging energy solutions, positioning the port as a leader in sustainable maritime innovation.

One of the greatest challenges of the 21st century is the reduction of greenhouse gas (GHG) emissions. The shipping industry accounts for 2.9% of global GHG emissions and faces increasing pressure to meet the climate goals set by the International Maritime Organization (IMO) and the European Union, as part of the broader global effort to limit temperature rise to 1.5°C under the Paris Agreement. Al- though the shift towards various forms of alternative fuels in the new-build market is clearly evident, 30% of the global fleet is expected to be non-compliant with the prevailing regulations within the next three years (2023-2026). Replacing all non-compliant vessels with new-builds within this timeframe is not feasible due to the limited capacity of the shipbuilding industry. This presents a critical challenge for the maritime sector, making retrofitting existing vessels a potential, and perhaps even necessary, solution.

Methanol, a cleaner alternative fuel, shows significant promise in reducing GHG emissions, especially when produced from renewable sources, such as Green-methanol or E-methanol. The initial signs of methanol adoption in new-building market appear to be successful, and the retrofitting of existing ships is seems to be feasible both in theory and practice. However, the conversion of an existing ship to methanol propulsion presents challenges, primarily due to the fuel’s lower energy density and its toxic- ity. These factors make the costs for methanol storage in the vessel and operational fuel consumption notably more dominant. Consequently, the potential cost savings from Energy-Saving Devices (ESDs), which can be installed during a vessel conversion, become more relevant.

The main objective of this thesis is to gain deeper insight into which retrofit strategies, in terms of methanol tank volume and the inclusion of ESDs, can provide a feasible option for retrofitting existing vessels to methanol, achieving the intermediate GHG reduction goals. A refit indicator model is devel- oped to evaluate various retrofit strategies, focusing on financial and regulatory performance, given a scenario of price trends and regulatory developments. The model incorporates key operational factors such as trip distance, sailing speed, and bunkering intervals. In a case study, a single base-case vessel was converted into several conversion cases, differing in methanol storage capacity and the inclusion of ESDs, and their performance was assessed under various potential future scenarios.

The results of this study suggest that significant reductions in GHG emissions can be achieved. Pro- vided that renewable methanol is used, it is possible for a methanol-converted vessel to meet the intermediate GHG reduction goals. The regulatory performance of many methanol vessel conversion strategies is also favorable, particularly when a methanol conversion is combined with one or more ESDs. The results showed that, in such cases, vessels can remain compliant for 15 to 20 years longer compared to their non-converted base-case. An important finding is that the shift from a tank-to-wake to a well-to-wake regulatory perspective is a key factor in the success of methanol retrofits. From a financial view, it can be concluded that the strategy of converting to a limited methanol tank volume, combined with a number of highly fuel-efficient ESDs, appears to be the most effective solution for the medium to long term.

Many recycled materials in different industries are traceable. The recycled content is often known in percentages. Steel is a material which gets recycled almost 100%. However it is not common practice to specify the recycled content for steel products. From a sustainability point of view this information can be very valuable. This thesis identifies the barriers and opportunities for a class notation that specifies the recycled content of a vessel or marine structure. Furthermore, the way certification of steel would influence trust, traceability and transparency of a circular economy in the shipbuilding industry has been investigated. This was done from the point of view of a classification society but to reach the conclusion, the entire shipbuilding value chain has been investigated. Semi structured interviews were held with different stakeholders from the ship building value chain. These interviewees were steel manufacturers, original equipment manufacturers, ship yards, recycling yards, classification societies, financial institutions, ship repair yards and shipping companies. Barriers that were found are, amongst others, technical feasibility, steel market, yard logistics, customer willingness to pay, green washing, ship recycling standards, demographic differences, etc. The first conclusion is that, although sustainability is high on the agenda for most companies, the efforts and goals on this matter are scattered and uncoordinated. All stakeholders, except for the steelmakers, see the benefit for certification of recycled steel in terms of increased sustainability. The steelmakers possess the ability to provide all necessary information and there are no technical barriers. This means that they are able to provide steel products with a specified percentage of recycled content. The main barrier for different stakeholders are the extra resources they need to spent to incorporate a new type of certification into their business processes. None of these stakeholders want to take the risk as a single player, but are willing to take part once collaboration amongst all stakeholders are guaranteed. This creates the business opportunity for classification societies to provide this opportunity and take the lead for this innovation. A review of current certification steps for steel products has been made and adapted to include extra steps to certify the recycled contents. The effect of this extra steps with regard to stakeholders downstream has been investigated and validated by means of the interviews. Another topic is the digitalisation. Because of the increased ability to process big data, there are opportunities to tackle certification of recycled products and the subsequent traceability by means of blockchain technology. These opportunities are identified and are proposed as optional further research topics.

This research examines the difference between two major component replacement strategies for the novel floating offshore wind turbines (FOWT), in terms of support vessel CO2eq emission and cost together with FOWT downtime. The first strategy is utilising a crane vessel to replace a component in offshore, this is called the heavy lift maintenance (HLM) strategy. The other strategy is the tow to port maintenance (TTPM) strategy, where the floating offshore wind turbine (FOWT) is towed to port to be serviced. Royal IHC is looking for a reliable and relatively quick method to determine the potential of both strategies and test new vessel and equipment concepts, which will allow a head start in this upcoming maintenance market.

To determine the three output parameters; CO2eq emission and cost originating from the support vessels and FOWT downtime, a calculation model has been developed, as this was not available. The calculation model compares seven different support fleet configurations for the two maintenance strategies. The configurations contain at least one heavy lift vessel (HLV), platform supply vessel or anchor handling supply vessel type, which are varied in this study on their empirical based parameterised designs. The calculation model also allows the possibility to include, amongst others, preventive maintenance, breakdown maintenance and utilization of different fuels. In total three FOWT farms, varying in size and distance from shore, were considered to determine the effect of those parameters on the different support fleet configurations.

The calculation model was verified and provides a reliable and relatively quick method to compare different support fleet configurations, concerning the two major component replacement strategies. With the use of this model it was found that the most sustainable support fleet configuration for both preventive and breakdown maintenance is a standalone HLV. However, this conclusion does not hold for full blade replacement campaigns. The cost of this HLM strategy is relatively high compared to the TTPM configurations, especially when considering preventive maintenance campaigns. Therefore, it is suggested that the TTPM strategy is preferred for preventive maintenance campaigns. It must be noted that this is also based on the assumption that the port of repair has unlimited facilities to replace the components as soon as the FOWT arrives. It should also be noted that the FOWT downtime is greater for the TTPM strategy, which could be a potentially important aspect of the repair. The calculation model also allows to test new innovative concepts, such as a quick mooring (dis)connection system and the climbing crane. Both show to have a beneficial effect on the replacement operation.

This research has shown that the developed calculation model is well suited, reliable and a relatively quick method determine the potential of both strategies. This research already provided Royal IHC insight into the new market, but can also be used to inform clients who request an advice. The flexibility of the model allows it to be used for different field, fleet and vessel parameters. Moreover, due to the modular programming method additional information can be added at a later stage. This also leads to some recommendations for further research. A suitable weather module has to be introduced in order to get a better estimation on the vessel downtime. After this is done the program should be optimised in terms of runtime efficiency, in such a way that a Monte Carlo method could be run. The added value of this method is that a more accurate support vessel downtime can be estimated. It is also recommended to include bunker time into the calculation as it is currently set to 0 h and potentially leads to an overoptimistic outcome. Lastly, two other floater types should be designed for a 15 MW turbine and included in the model. These floater types are the tension leg platform and barge floater.

This thesis provides a 'proof of concept' for a vanadium bromide redox flow battery-powered ship (E-Conoship) in the short sea shipping market of North West Europe. An elaborate analysis of historical voyage data has been carried out to determine operational feasibility. To determine economic feasibility, a cost-comparison model has been constructed, including the capital, operational and voyage related expenses of shipping. Case study method, including scenario analysis, has been used to determine under which circumstances E-Conoship is cost-competitive with diesel-powered ships. In conclusion, its operational feasible to operate an E-Conoship with a maximum range of 500 nautical miles. Two options are available: (1) direct replacement of vessels, and (2) acquiring voyages. It is economical feasible, provided that more than one of the following factors are addressed: battery system cost reduction, CO2-tax, lower electricity prices in comparison with marine gas oil, subsidies, increased amount of annual sailing days, and lastly financing at lower interest costs compared to diesel-powered ships.

The enlargement of the lock complex of Terneuzen in 2023 will allow Capesize vessels up to 300 meters in length, to access the Ghent-Terneuzen canal and reach the quay of ArcelorMittal Ghent (AMG). The goal of this thesis is to estimate to what extent these vessels can be used, the impact that these vessels will have on the supply chain and the cost impact of the implementation of Capesize vessels. The production of AMG is expected to be increased up to 5.5 million ton of steel for 2026. Therefore, it will require an estimated 12.9 million ton of raw materials (12% increase compared to 2019) which mainly consist of iron ore and coal. Up to 31% of this material can be shipped from source ports that are accessible by Capesize vessels. The draught restriction of 12.5 meters for the canal, limits the amount of bulk material that can be unloaded by the Capesize vessel to 105,000 DWT which is 60% of the maximum of 175,000 DWT. The remaining 70,000 tons of material can be unloaded externally and be transported to AMG by the use of inland barging vessels. The increased volume of Capesize vessels compared to the current Panamax vessels will lead to an increase in load size and a decrease in load frequency which will affect the downstream installations of AMG. Most of the current quay cranes will be unable to unload Capesize vessels due to the increased size of the ships. A proposed crane was introduced in the model to examine the ideal positioning to unload Capesize vessels and barges. 6 realistic scenarios for 2026 have been examined with varying levels of Capesize utilization. As a result of these scenarios vessel arrival lists for full year were simulated. Each of the vessel lists served as input data on a quay model with as results the downstream impact. The main output parameters were the waiting time for sea vessels, waiting time for barges and the amount of material that had to be stored on a temporary storage. In general, the implementation had a negative effect on all three of the output parameters resulting in additional quay costs. The net effect of Capesize vessels on the total costs was positive thanks to the lower shipping price per ton of material. This benefit was partly compensated by the increased costs for barging that was caused by Capesize transport. The shipping costs for Capesize vessels should at least be 2.53 dollar per ton cheaper, to break-even with Panamax vessels. Under current circumstances the full-scale use of Capesize vessels can be feasible. However due the high volatility of the dry bulk market and bunker prices, it is impossible to guarantee this will be the case for 2026.

Current challenges at Damen Technical Cooperation (DTC), regarding an imperfect procedure for documentation sharing, misalignment and quality issues in documentation flow, are the motivation for this master thesis. DTC is a company within the Damen Group that offers a unique service for shipyards; a variety of material and service packages to make local building possible. Project management is one of these services. Although their approach is unique, are the faced challenges not uncommon; similar issues are reported in shipbuilding literature. However, due to their method is documentation flow essential for good performances of DTC-projects. In shipbuilding projects project information is stored in project documents. Documentation is a term that includes both information storage and retrieval systems. Documentation quality concerns quality of the documents and the retrieval systems. The challenges faced at DTC can be described by documentation quality. This study aims to improve the documentation sharing strategy, and so project execution, of DTC-projects. In line with this aim, the central research question is: In what manner can project execution at DTC be improved, by providing insight into the effect of the quality of shared project documentation on project success? From the literature, it is found that project success requires process integration and process integration demands process understanding. Documentation flow modelling is seen as an attractive tool to obtain process understanding, that can lead in the direction of process integration. Out of four models, the Design Structure Matrix (DSM) is chosen to model documentation flow. Subsequently, a DSM-based discrete-event Monte Carlo simulation is used to analyse the documentation flow of a DTC-project. Documentation flow is studied by analysing the effects of flow interruptions. Rework is an example of a flow interruption. Based on the literature, multiple causes of document-flow related rework, document quality attributes, are simulated. Documentation quality attributes are ranked on 7 criteria: mean, median, 25th percentile, 75th percentile, standard deviation, the likelihood for the unacceptable outcome and schedule risk. These criteria rank the impact of the documentation quality attributes in the following order, where the highest impact is ranked highest: 1. Mistakes in documentation 2. Input changes in the documentation 3. Poor communication of the documentation 4. Delayed documentation - wait for documentation 5. Delayed documentation - use assumptions to start tasks early A detailed analysis is carried out to identify activities that have a large impact on total project outcome, when rework occurs. From the detailed analysis it is concluded that: 1. Rework on the below-listed activities has the most impact on project duration. - Detailed engineering tasks, specifically: a. Ship construction drawings b. Mechanical diagrams - Block outfitting, specifically a. Equipment b. Hot work - Zone outfitting, specifically: a. Equipment b. Hot work c. Remaining outfitting tasks 2. A balance exists for waiting on delayed documentation and using assumptions to start activities early. - Projects that have a forecasted overrun that exceeds 11% should use assumptions to start activities early. - Projects that have not a forecasted overrun that exceeds 11\% should force activities to wait on delayed documentation and prioritise activities that can continue. To end, this thesis underlines the importance of documentation quality in shipbuilding projects. Conclusions identify areas for improvement for DTC-projects. At the same time, the outcome serves as a guideline for project managers.

Liner shipping companies engage in strategic cooperation to deal with the market’s overcapacity, capital intensiveness and volatile freight rates. However, these partnerships do not reach their full potential and have lowered the level of service in the industry. To identify how carriers would be able to realise further synergies, this study has investigated the current performance of liner shipping companies and developed a model to identify and assess potential partnership opportunities. This model supports liner shipping companies in their decision of who to partner with and what kind of partnership to pursue. The study has been confined to a single transpacific route. On the basis is an overview of vessels that sail this route over a period of several years. This overview includes information on arrival dates, number of containers on board, capacity and operator for each vessel. This is used to examine local demand and deployed capacity, vessel utilisation and competition. The analysis confirms trends found in literature, such as the growing size of vessels that are enabled by strategic cooperation. Most importantly, it indicates flexibility on the side of vessel operators in their decision of which vessels they deploy per route during the year. A synergy model has been developed based on the findings in literature and the results of this analysis. This model uses the identified flexibility in vessel deployment and builds on the notion that liner shipping companies should pursue more integrated partnerships to realise further synergies. The model was also applied to the case of CMA CGM’s acquisition of APL in 2016. After calculating the costs for sailing each of the available vessels, potential partnerships were identified for the analysed route. This was done by optimising vessel deployment for the cargoes to be transported at minimum cost and with a limited number of partners. A strategic-level assessment was then performed to determine whether a partnership would be feasible among the identified companies and to what extent integration should take place. By including both the companies’ motivations (drivers) and factors that facilitate a positive environment (facilitators) for the partnership, this assessment brings multiple perspectives to the table. The conclusion is that carriers can adjust which vessels they deploy to match transport demand and that they can use this to realise further synergies. By using a model with both a quantitative and a qualitative component, it is possible to identify potential partnerships that result in cost reduction, maintain high vessel utilisation and allow for improvements in the level of service that companies offer to their customers. It is recommended to extend the coverage of the model to include more routes, ports and vessels for a more comprehensive analysis. Furthermore, using variable transit times in the model to determine when vessels are available would make the model more realistic and would also allow changes in vessel speed to be included in the analysis. It is also advised to explore opportunities for regulatory bodies to apply this model for monitoring and assessment of the effects partnerships have on competition per route.

This study was conducted to address the lack of insight port authorities have in port competitiveness. Within this thesis a data-driven model is presented that allows to assess port competition within a bounded scope. This model is developed from the ground up and programmed in the Python programming language as a stand-alone solution. The model doesn’t rely on extensive black-box models as often found in related literature. Due to its generic nature, the logistic chain choice model can also serve as a base model for different scenario analyses. Scenarios could include the change of ship-size, (oil) price or cost scenario’s and future throughput forecasts. The model can provide insights regarding effective port investments and policy making.

Nowadays the interest for environmental issues is steadily gaining ground. Inescapably, the shipping industry, is also called to contribute its fair share towards the reduction of air pollution. Harbour tugboats need to comply both with international but also with local exhaust air emission regulations, which are anticipated to become more stringent in the future. Kotug, is interested to proactively explore suitable powering solutions, which can be applied at its Rotortugs’ newbuilding scheme, to comply with upcoming regulations of the intended port of operation. The goal of this thesis is to develop a decision-support tool to facilitate the selection process between alternative prime mover combinations, based on what is needed in terms of operation while considering technical challenges, environmental performance and economic returns. The effect of a variety of promising alternative fuels matched with suitable prime movers was investigated for the period 2018-2033, which was set as the study’s time horizon. LNG, Methanol, Biodiesel and DME were assessed as feasible solutions. The first two were associated with gas-burning engines, whereas the rest were associated with conventional 4-stroke compression ignition engines, similar to the ones already installed in the existing Rotortugs running on MGO. The environmental performance differs substantially to a conventional prime mover running on MGO. However, to adhere to future stricter regulations in certain sea areas, additional after-treatment systems are necessary. Research indicated three post-treatment solutions are the most effective in limiting the majority of the combustion-related emissions; Selective catalytic reduction, diesel particulate filter and oxidation catalysts. The total environmental fingerprint of a vessel can be however assessed only under the context of its propulsion configuration layout. The operational profile of a tugboat is highly variable, allowing room for the exploitation of different drivetrains than the traditional diesel-direct layout, which could lead in benefits mainly in terms of fuel efficiency and maintenance savings. Three drivetrains were selected; a diesel-electric and two hybrid, based on AC and DC topology. Before deciding to invest on a future boat a ship-owner is expected to be eager to comprehend the cost-related issues between alternatives. Moreover, the already proven design of the diesel-direct Rotortug, complemented by the necessary after-treatment technologies, makes sense to be the first option to consider, provided it complies with the anticipated regulations. This option is considered the baseline case. It is reasonable to compare all other options against the baseline case. To this end, a decision framework based on a techno-economic evaluation is proposed for supporting ship-owners to take informative decisions on investment considerations; Three objectives were set; economic performance, environmental performance and cost-effectiveness. To quantify economic performance a comparative TCO analysis was implemented, while for environmental performance the emission output of alternatives is compared. Last, cost-effectiveness adds valuable insight into how good money are allocated towards emission reduction targets and provides a methodology to compete for funding from a regulatory authority. Two case studies are presented that demonstrate the utility of these methods and enhance the understanding of the impact of decisive factors in decision-making. It is concluded that the proposed decision-support tool enables decision-support at an early-stage; nonetheless can still be improved, by incorporating additional factors and expanding certain modules with more details.