Improving fuel efficiency is becoming an increasingly important objective for harbour tug operators seeking to reduce operating costs and environmental impacts. Through a combination of sea trials and analytical modelling, this research identifies optimal engine and propulsor operating conditions, providing practical guidance for enhancing fuel economy and supporting more efficient tug design and operation.

Understanding how ships respond to waves remains fundamental to safe and efficient vessel operation, particularly for Ro-Ro ships that can be sensitive to large motions. Experimental investigation of six-degree-of-freedom responses in irregular seas identified critical relationships between wave frequencies and vessel motions, providing insights that can help operators minimise excessive roll and improve seakeeping performance.

Understanding how water spreads through damaged compartments is essential for predicting survivability and improving damage-control strategies in naval vessels. Experimental flooding tests on a generic destroyer model revealed how damage extent, waves, and heel angle influence floodwater distribution and equilibrium levels, providing valuable data for validating flooding simulations and enhancing post-damage safety assessments.

Achieving reliable predictions of stiffened panel strength remains a key challenge in marine structural design, particularly when boundary conditions cannot be defined with complete certainty. This study evaluates a range of stiffener configurations and finite-element modelling approaches to identify more robust panel designs, improving confidence in ultimate-strength assessments and supporting more resilient ship structures.

Accurate prediction of extreme loads is fundamental to structural reliability assessment, yet traditional extreme value methods may not fully account for variations in the likelihood of occurrence. This study proposes an enhanced application of extreme value theory that incorporates exceedance probabilities, reducing uncertainty in predicted extremes and providing a more realistic basis for safety and design evaluations.

Underwater radiated noise from commercial shipping is becoming an increasingly important environmental issue, particularly because of its potential impact on marine species that rely on sound for communication, navigation, and feeding. This review highlights propeller cavitation as the dominant source of ship noise and identifies opportunities to reduce acoustic emissions through improved propeller and wake-field design. The findings suggest that targeting the relatively small number of vessels responsible for the majority of noise pollution could deliver substantial benefits, while emphasising the need for comprehensive full-scale measurements to support effective noise-reduction strategies alongside energy-efficiency improvements.

Offshore transhipment operations are often constrained by vessel motions and weather-related downtime, creating significant challenges for supply chains and port efficiency. This study evaluates an innovative Floating Harbour Transhipper concept and demonstrates that its sheltered well-dock arrangement can substantially reduce feeder-vessel motions compared with conventional side-by-side transfer methods, improving the reliability and operability of open-water transhipment.

Maintaining the structural integrity of submarine pressure hulls throughout their service life requires a clear understanding of how corrosion and geometric imperfections interact under external pressure loading. Experimental investigation of ring-stiffened cylinders shows that corrosion can significantly reduce collapse strength, particularly when combined with out-of-circularity defects, providing valuable insight for lifecycle assessment, maintenance planning, and submarine structural design.

Designing specialist vessels for uncertain and rapidly evolving markets requires balancing immediate operational needs with the flexibility to remain competitive over decades of service. This study applies Epoch-Era Analysis to the design of an Anchor Handling Tug Supply vessel, demonstrating how future market scenarios can be incorporated into early-stage design decisions to support more adaptable, resilient, and commercially sustainable vessel concepts.

Data-driven modelling techniques are creating new opportunities to predict vessel manoeuvring performance without relying solely on traditional mathematical representations. This study demonstrates the application of a recursive neural network trained using full-scale trial data to simulate catamaran manoeuvres, showing how artificial intelligence can support accurate prediction of ship handling characteristics and assist future vessel design and operational planning.

Bridging the gap between conventional ferries and high-speed craft is driving interest in a new generation of medium-speed catamarans that combine improved transport efficiency with lower environmental impact. This study identifies key hull-form characteristics for minimising resistance, providing design guidance for fuel-efficient twin-hull vessels capable of transporting larger payloads at economically attractive operating speeds.

Understanding the behaviour of high-speed vessels in severe sea conditions remains critical as operators seek to balance performance, passenger comfort, and safety. Full-scale trials of a large wave-piercing catamaran demonstrated the significant influence of vessel speed, heading, and ride-control systems on motion responses, while also providing valuable validation data for numerical seakeeping prediction methods used in vessel design and performance assessment.