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As part of the process of deploying new floating offshore wind turbines, scale model testing is carried out to de-risk and verify the design of novel foundation concepts. This paper describes the testing of a 1:43 Froude-scaled model of the TetraSpar Demo floating wind turbine prototype that shall be installed at the Metcentre test facility, Norway. The TetraSpar floating foundation concept consists of a floater tetrahedral structure comprising of braces connected together through pinned connections, and a triangular keel structure suspended below the floater by six suspension lines. A description of the experimental setup and program at the Alfond W2 Ocean Engineering Lab at University of Maine is given. The objective of the test campaign was to validate the initial design, and contribute to the development of the final demonstrator design and numerical models. The nonlinear hydrodynamic characteristics of the design are illustrated experimentally and the keel suspension system is shown to satisfy design criteria.

With the effects of global warming, the Arctic is presenting a new environment where numerous ice floes are floating on the open sea surface. Whilst this has unprecedentedly improved Arctic shipping navigability and brought about significant opportunities, the interaction of such floes with ships has yet to be understood, thus hindering appropriate assessment of corresponding ship performance. This paper presents work on developing empirical equations to estimate the effects of such floes on ship resistance. Based on extensive data from validated computational simulations, the ice-floe resistance has been shown to correlate with ship beam, ship speed, ice concentration, ice thickness and floe diameter, and the regression powers of each the parameter on resistance are ascertained for a container ship. This leads to an empirical equation that can immediately predict ice-floe resistance in a given condition. The proposed approach has the potential to facilitate propulsion power estimates for Arctic shipping, as well as providing valuable insights into ship design for these environmental conditions.

With the effects of global warming, the Arctic is presenting a new environment where numerous ice floes are floating on the open sea surface. Whilst this has unprecedentedly improved Arctic shipping navigability and brought about significant opportunities, the interaction of such floes with ships has yet to be understood, thus hindering appropriate assessment of corresponding ship performance. This paper presents work on developing empirical equations to estimate the effects of such floes on ship resistance. Based on extensive data from validated computational simulations, the ice-floe resistance has been shown to correlate with ship beam, ship speed, ice concentration, ice thickness and floe diameter, and the regression powers of each the parameter on resistance are ascertained for a container ship. This leads to an empirical equation that can immediately predict ice-floe resistance in a given condition. The proposed approach has the potential to facilitate propulsion power estimates for Arctic shipping, as well as providing valuable insights into ship design for these environmental conditions.

Indonesia is one of the top three countries in the world for fisher fatalities due to a lack of stability monitoring, poor vessel design, and the fishers’ poor safety culture. Improved safety through technology, in particular stability awareness, has been identified as a key aspect to prevent capsizing and sinking. Despite the low technology uptake by Indonesian fishers, they are known to make extensive use of smart mobile phones as a primary form of communication. These phones are equipped with various sensors, including motion sensors that can be used by different mobile applications. This paper proposes the use of a mobile application to aid Indonesian fishers in assessing the stability of their vessel by using results from a roll decay test or realtime roll motion data monitored when operating at sea. For the pre-departure test, the mobile application uses the onboard gyroscope to record the roll angle time series which can then be used to quantify the roll period. An offline calculation is then carried out to approximate the vessel’s metacentric height. This is then visually presented using a traffic light system to provide the fishermen with a simple indication of whether the vessel is stable or not. Should the boat be unstable, additional guidance is provided to improve the vessel’s stability. The realtime monitoring system alerts the fishers when the thresholds are exceeded, to ensure realtime awareness of increased risk to the stability of the vessel.