High fibre content composite laminate skins use marine grade orthophthalic polyester, POLYLITE® 440-M850 resin and chopped strand mat/woven E-glass for the thin outer face skins and DIVINYCELL® H100 closed-cell linear PVC foam as core. Marine grade hybrid sandwich panels are designed in accordance with BS EN ISO 12215-5:2008 for small craft hull construction, using a wet lay-up and cured under vacuum pressure. Impact damage testing followed ASTM D7766-11 and ASTM D6264-98 procedures A and B for rigidly supported and simply supported sandwich panels. A review of the current state of standard testing procedures of marine sandwich panels is described. Testing using the default hemisphere indentor also included other standard rock geometries – conical, square-based pyramid and flat-faced cylindrical. The damage incurred under each variation of indentation impact is described, in terms of force, absorbed energy and indentation displacement. New contact laws are suggested for the different rock geometries. Destructive sectioning of the panels provides the visual damage incurred through the thin face skins and core and the roles played by all members comprising the sandwich panels.

Marine grade hybrid sandwich panels are designed in accordance with BS EN ISO 12215-5:2008 using a wet lay-up and cured under vacuum pressure. The high fibre content composite laminate skins use marine grade orthophthalic polyester, POLYLITE® 440-M850, resin and chopped strand mat (CSM)/woven E-glass; the core is DIVINYCELL® H100 closed cell linear polyvinyl chloride (PVC) foam. Impact damage testing followed American Society for Testing and Materials (ASTM) D7766-11 procedure C and ASTM D7136/D7136M-05. Impact damage was sustained by the default hemispherical indentor and further ‘standard’ geometrical indentor rocks – conical, pyramid and cylindrical. The investigation reviews the current state of affairs in impact sandwich testing procedures. A 50–80% through thickness penetration criteria is proposed following noted shortcomings in the standard originally intended for laminates. It is shown that the panel overall flexural rigidity to thickness ratio better describes the transition between ‘thin’ to ‘thick’ impact response; force measurements indicate that strain rate effects need to be considered; dent indentation can only be assessed through data acquistion; destructive damage observation sectioned specimen observations describe the impact damage sustained under the various indentor conditions, as well as the roles played by both the face composite skins and the core material.

Research into the effects of hull roughness on ship resistance and propulsion is well established, however, the effect of heterogeneous hull roughness is not yet fully understood. In this study, Computational Fluid Dynamics (CFD) simulations were conducted to investigate the effect of heterogeneous hull roughness on ship resistance. The Wigley hull was modelled with various hull conditions, including homogeneous and heterogeneous hull conditions. The results were compared against existing experimental data and showed a good agreement, suggesting that the CFD approach is valid for predicting the effect of heterogeneous hull roughness on ship resistance. Furthermore, the local distributions of the wall shear stress and roughness Reynolds number on the hull surface were examined to assess the flow characteristics over the heterogeneous hull roughness.

Following the International Maritime Organization’s goal to reduce greenhouse gas emissions, the interest in the application of wind-assisted ship propulsion (WASP) in maritime transportation is on the rise. Although a variety of WASP systems exist, the application in maritime shipping is still limited, especially in the case of kite sails. This paper presents a numerical model to carry out a theoretical assessment of the influence of the kite planform area and wind speed on the aerodynamic performance of a kite sail providing propulsive assistance to a 75 m long ship having a Series 60 hull. A static kite sail is assumed, on which a tail wind generates a thrust force to pull the vessel via a tether. While the mass of the kite is neglected, that of the tether is accounted for. A model is implemented for the tensioned tether having a catenary profile. The results generally show a positive correlation between the aerodynamic forces and the kite parameters. As expected, the output parameter values corresponding to the optimal angle of attack for a range of vessel speeds are also found to increase with an increasing relative wind speed. It is concluded that a static 320 m² kite sail would be sufficient to meet the entire propulsion requirements of the vessel under consideration under appropriate wind conditions.

The hydrodynamic interaction between two or more ships in harbours or inland waterways is a classical maritime engineering research area. In ship manoeuvring practice, ship masters try to determine the speed and gap limit when a ship is passing or encountering others, particularly in confined water ways. This requires an accurate prediction of the interaction force acting on both ships. The pioneer experimental studies showed that the interaction could lead to a very large yaw moment and this moment is strongly time-dependent, which could make the ships veer from their original courses, leading to collisions. Based on the findings on experimental measurements, some empirical formulas are proposed in the literature to predict such interaction forces. However, these formulas could provide a satisfactory estimation only when the ship speed is quite high, and the water depth is shallow and constant. Numerical simulation overcomes this issue by simulating the ship-to-ship problem by considering the effect of the 3D ship hull, variable water depth and ship speed. Numerical simulation has now become the most widely adopted method to investigate the ship-to-ship problem. In the present study, the development of the methodologies of ship-to-ship problems will be reviewed, and the research gap and challenges will be summarized.