SummaryIntroductionAdditive Manufacturing (AM) offers potential to add value in terms of storage, localised production, production rate, weight reduction, customization and offers complexity for free. Within the Maritime Construction Sector (MCS) business models for AM are difficult to obtain due to its relatively large objects and the corresponding low building cost. In recent years, AM processes have developed significantly in terms of machine dimensions, building speed, material properties and production costs. It is concluded there is sufficient reason for further research on AM production within the MCS. Large scale additive manufacturing, material extrusion, offers high deposit rates and thermoplastic composite material properties. Cheap thermoplastics in combination with fibre reinforcements provide the opportunity to reduce required mass, increase building time and cut building costs. Interest in composite cargo vessels is noticed mainly due to weight reduction and corrosion resistance. However, financial consequences due to mould making and expensive materials, and regulations obstruct widespread developments. To explore the possibilities resulting from additive manufacturing within the maritime construction sector a Class III inland waterway vessel is used as case study. For more in depth knowledge the bow section of the vessel is considered. To retrieve relevant information about the feasibility and requirements of a thermoplastic bow section the main question and resulting sub-questions are stated as follows:1: Can a thermoplastic composite Class III inland waterway vessel be produced competitively using Additive Manufacturing – Material Extrusion, compared to steel and what is the expected weight reduction?Following sub-questions are listed to help answering the main question.2: What are the vessel’s functional, market driven and regulatory requirements?3: How does AM-ME comply with stated market driven, functional and regulatory requirements?4: What AM-ME polymer and reinforcing material is best suited for inland waterway vessels?5: What is the expected weight reduction using AM-ME and accompanied thermoplastic composite?6: How is the required equipment within the vessel installed?7: What will be the final weight reduction and cost price of the inland waterway vessel and can it become Class approved?By answering the stated sub-questions, the main question is answered.Approach:Functional requirements describe what a bow section should do and how it should fulfil its purpose. Market driven requirements state maximum allowable costs, building time and weight in order to be competitive over traditional manufacturing. Regulatory requirements are derived from Lloyds Register Rules & Regulation on special service craft, in which composite vessels are treated. Rules prescribe material requirements, composite laminate requirements, design pressures, fire safety, maximum allowable stresses and deflection and more.AM ME offers advantages in terms of building dimensions, deposit rate and costs. Research on AM-ME results in a collection of technologies and developments required with respect to the production of large composite objects. Special attention is provided to multi-axis material deposition, material selection and cost price. Based on required mechanical material properties and material durability a selection of polymers, reinforcing fibres and additives is derived. Using composite theory for anisotropic composites, final material properties are calculated required for further bow section analyses. Besides direct composite characteristics some basic conclusions about creep and fatigue, and the use of recycled content, are derived.To estimate the final weight of the bow section, and complete inland waterway vessel, a global and local design space is derived. First, adjustments on the section due to installation of components is discussed. Manual calculations applicable on main components with composite material properties offer first weight estimations. Optimizing for laminate thickness and fibre orientation offers additional weight reduction. Insight is provided in the way the bow section is produced using AM, including installation of components and post-processing the outer surface.Besides being able to insert components and systems, these need to be connected to the bow section without causing extended assembly time, repair work, durability and leakage. Various methods of connection are proposed. To keep production costs low, weight reduction is a significant factor resulting from material costs and building time. Building time cannot exceed traditional building time especially during outfitting. In the final sub-question, final weight reduction, building time and costs are discussed. By answering the final sub-question, the main question can be answered.Conclusions:AM developments offer the possibility to comply with stated functional, market driven and regulatory requirements. Main challenge is keeping production costs low and offering cross-plied laminates. Uncertainties rising from AM production are material integrity, fatigue and classification. Keeping costs low is to be done by using cheap thermoplastic composites, increase deposit rates and reduce weight as much as possible, to keep machine time and material usage low.Based on the global design space and a reference local layout of the bow section a final weight reduction of 36% is estimated, in which various known and underestimated safety factors are taken into account. The outcome is validated by analyses of individual components and the complete bow section using software Hyperworks. By optimizing laminates on thickness and orientation an additional 9% weight reduction seems achievable, depending on initial selections for thickness and orientation. Since midship section are subjected to higher bending moments, less weight reduction is achievable for the entire vessel.It is concluded material costs can reach low values although it will be hard to prepare the required amount of materials for a cost price of in between 0.97 and 1.63 EUR/kg, to reach desired final production costs. Most favourable material compound is Polyethylene Terephthalate (40 wt%), Polycarbonate (5 wt%), E-glass direct roving (40 wt%) and E-glass short fibres (7 wt%) including a set of chosen additives (8 wt%). The selected material complies with stated regulations. The use of recycled polymers offers advantages since cost price is reduced. PET polymers show good recycling properties and allow for regeneration up to virgin quality. Although selected materials show promising fatigue properties, the effect resulting from AM deposition remains uncertain. Machine rate, building time, material costs and optimised weight of the object have resulted in a total cost price reduction of in between 15% and -22% of traditional building cost. Building time of 3 to 5 days is calculated feasible in which a 22 to 25 tonnes weighing bow section is deposited, offering 36% weight reduction over traditional manufacturing extrapolated to a complete vessel excluding extra margins for higher bending moments.Classification remains an issue although to direct rejections are expected. To comply with fire safety, fire resistant panels need to be installed. Most critical rules are respected but additional research is required on fire safety and process control during the manufacturing process, including standardization of machinery.