Autonomous sailboats (ASBs) have been researched since the early 2000s. Despite their theoretical advantages in autonomous data gathering, especially in the form of swarms, successful real-world deployment remains rare. Many ASBs still fail during deployments in the harsh marine environment, often as a result of structural failures due to their small size and prototype-nature. This thesis began with the observation that small vessels are hard to get right and fail over time. The aim was to explore how to design ASBs with minimal environmental impact, without compromising basic functionality, when embracing the inevitable failure of small ASBs.

Two research questions were addressed: (1) Which low-impact solutions are suitable for use in an autonomous sailboat? (2) How would the design of a low environmental impact autonomous sailboat look?

The methodology involved two complementary tracks. First, a theoretical exploration examined how environmental impact could be reduced by optimizing the swarm system and better material selection. Through a dimensional analysis of naval parameters it was concluded that small ASBs travel more slowly, but collectively in a swarm, achieve higher data collection for the same total material cost as a single large vessel. For a similar material cost, a swarm of smaller ASBs could thus outperform larger vessels in data gathering and less ASBs would be needed to curb environmental impact, so long as the smaller size does not compromise operational reliability.

Material selection was evaluated both from a production and end-of-life perspective. For durable, scalable production, glass fibre composites and steel were identified as relatively low-impact options when balanced against performance needs. A more radical approach explored biodegradable structural materials, particularly flax fibre-reinforced bioplastics. Two resin options, polyglycerol citrate and polyvinyl alcohol, were identified for their environmental degradability and non-toxicity, although practical fabrication challenges limited their evaluation. The total life cycle cost of both approaches cannot yet be known, as the environmental cost of marine litter is not yet quantifiable.

In parallel, a practical design study led to the SDC25 prototype: a small ASB which naval parameters were set using a statistical design approach. These statistics were based on a comprehensive overview of existing ASB designs, compiled during this research and stated for future work. The swarm optimisation analysis provided a good argument to design a small ASB with an overall length of 1.36m. The resulting boat includes a self-trimming wingsail that uses no energy except during manoeuvres, to curb the use of electronic components and energy. Initial testing suggested the vessel was very stable, even though testing quality was limited by calm weather conditions.

A custom-built CNC foam cutter machine played a key role in fabricating the complex curvature of the wingsail and hull. The setup consists of two XY gantries holding a tensioned, heated nichrome wire, which cuts through foam by melting it along a programmed path. The machine, and the generation of the G-code, toolpaths directly from Rhino using Grasshopper, are described.

By being a conceptual design, several uncertainties remain: the relative environmental impact of marine litter compared to production impacts, the exact influence of certain design interventions, the minimum feasible vessel size, whether investing in fleet management is worth the added complexity, and the vessels actual working lifetime all remain uncertain. In light of those uncertainties, few definite conclusions could be drawn, and two production pathways were outlined: a durable, low-impact approach and a fully biodegradable concept.

Technological advancements are increasing system complexities, posing challenges for modern warship design. Early-Stage Ship Design (ESSD) is a vital stage, involving critical decision-making with limited information. The early-stage design of warships entails intricate decision-making considering temporal influences, interdependencies, external factors, trade-offs, high costs, evolving requirements, and other challenges. Developing well-defined system architectures is essential for managing these complexities. Model-Based Systems Engineering (MBSE) is pivotal for overcoming precision issues, inconsistencies, and difficulties in maintaining and reusing information associated with conventional document-centric approaches in systems engineering (SE).
Despite the growing popularity of MBSE, the maritime industry continues to rely on traditional document-centric approaches, lagging behind other sectors in adopting MBSE. These challenges stem from a lack of empirical evidence demonstrating MBSE's full benefits and confusion regarding its implementation practices. Moreover, there is a lack of comparative studies that assess how well MBSE tools are tailored for naval warship design. Thus, this research explores the value of MBSE in the early design stage of naval vessels. Specifically, the research aims to validate and demonstrate MBSE's benefits in developing systems architecture for warships, focusing on operational, functional, logical, and physical perspectives within the context of ESSD. By analyzing industry approaches and utilizing two representative modeling tools, this thesis provides practical insights, clarifies MBSE practices, and promotes its effective implementation in future naval design projects.
A structured research process is formulated to achieve the thesis objective. It begins by defining the mission, capabilities, and requirements. For illustration purposes, a hypothetical Landing Platform Dock vessel mission is chosen, necessitating the creation of fictitious capabilities and requirements. MBSE tools Capella and CDP4-COMET are then selected for this analysis. Next, a metamodel is established for a unified understanding among stakeholders, guiding decision-making throughout the design process. Once the baseline models are constructed, the validation and verification capabilities of the tools are evaluated. The baseline models are modified to simulate the dynamic nature of warship design. Finally, the tools are systematically assessed based on selected key MBSE factors: consistency, traceability, flexibility, and trade-offs.
Transitioning to conclusions, the analysis reveals that both tools effectively validate anticipated benefits. By synthesizing the knowledge gained, it is concluded that MBSE can enhance and accelerate the design process during the early design phase of warships. Capella demonstrates superior performance in the early design stages, whereas CDP4-COMET excels in the latter design stages. This emphasizes the critical role of integrating MBSE tools to enhance design outcomes, leveraging their strengths across diverse phases effectively. Thus, integrating MBSE tools and establishing a unified source of truth is one crucial aspect of advancing MBSE in ship design. Further recommendations are detailed in the thesis.