The trend towards fully autonomous navigation or reduced manning concepts, coupled with increased integration and interdependence of onboard systems due to the shift towards sustainable fuels and ever-increasing electrification and automation, has stressed the significance of ship systems’ reliability. These developments reinforce the demand for a clear assessment of the robustness of main and auxiliary systems in early-stage ship design. Network theory offers a promising approach to address this demand. However, current graph measures do not align with industry-specific requirements for improving system robustness. This study aims to augment robustness evaluation components, such as modularity (independent subsys-tems), redundancy and reconfigurability, with additional considerations specific to Dynamic Positioning (DP) applications in the maritime industry. The enhanced robustness evaluation components are translated into graph measures. By employing these graph measures, different systems can be compared with respect to robustness, enabling informed decision-making in the trade-offs typical to early stages of the design pro-cess (e.g., cost versus redundancy). The proposed methodology combines the principles of network theory and industry-specific DP requirements to provide a comprehensive framework for evaluating the robustness of ship systems. System reliability can be assessed by integrating the identified robustness components and incorporating them into the graph measures. The early findings of this study show the potential to improve ship design processes by providing a systematic and quantifiable approach to enhance robustness.@en

Every now and then, every marine engineer dreams of a compact, lightweight and inexhaustible energy source to power large ships across the seven seas. Nuclear fusion of deuterium and tritium promises to be a safe, compact, carbon-free, and inexhaustible energy source. Even though it will take decades before conventional power plants may be replaced with nuclear fusion, the concept of nuclear fusion for marine propulsion has already been put on the table by commercial parties. This research investigates the potential of nuclear fusion onboard ships. The design investigates putting the smallest imaginable magnetic confinement reactor, ARC, on a ship. The only commercial ship requiring significant amounts of power is the Queen Mary 2. The large power output of ARC (200 MWe) is one of the major issues of putting a fusion reactor on a ship. Other issues may include intact stability, structural design and influences of vibrations on the fusion reactor. All in all, we found that a fusion reactor onboard a ship is unlikely to be feasible in the near future.@en

It is essential to use alternative fuels if we are to reach the emission reduction targets set by the IMO. Hydrogen carriers are classified as zero-emission, while having a higher energy density (including packing factor) than pure hydrogen. They are often considered as safe alternative fuels. The exact definition of what safety entails is often lacking, both for hydrogen carriers as well as for ship safety. The aim of this study is to review the safety of hydrogen carriers from two perspectives, investigating potential connections between the chemical and maritime approaches to safety. This enables a reasoned consideration between safety aspects and other design drivers in ship design and operation. The hydrogen carriers AB, NaBH4, KBH4 and two LOHCs (NEC and DBT) are taken into consideration, together with a couple reference fuels (ammonia, methanol and MDO). After the evaluation of chemical properties related to safety and the scope of the current IMO safety framework, it can be concluded that safety remains a vague and non-explicit concept from both perspectives. Therefore, further research is required to prove the safe application of hydrogen carriers onboard ships.@en

Reliability and survivability play a key role in the ship operation and ship design process of navy ships, but increasingly also of complex commercial vessels. These requirements prove relevant for different elements within the ship design scope, including the distribution system design of data, energy and fluid (water, fuel, oil, etc.). In early-stage ship design, distribution system robustness estimation is crucial in performing a substantiated trade-off between system availability and system investment costs. Van Mieghem et al. have developed a framework for computing topological network robustness; a generally applicable robustness approach using a graph representation as network system model. This framework has been applied on on-land power grids and more abstract networks such as the internet. However, due to the general nature of the framework, the applicability of the framework to on-board distribution systems is not self-evident. In this study, the required assumptions and adjustments to applyt his mathematical approach to on-board distribution systems are described. Moreover, the usefulness of this method for system robustness estimation in early-stage ship design is considered and demonstrated. In conclusion, an improved robustness estimation of distribution systems makes for an overall more reliable ship; a property to be pursued for increasingly complex ships.@en