R&D highlights edition 2019

PROJECTS Delta infrastructure 44 S hips moored at a berth need to be as stable as possible to allow efficient loading and offloading. However, in challengingwind andwave conditions at berths, traditional mooring techniques can generate unacceptably high forces in the mooring lines. The ShoreTension (ST) system is already widely used in existing ports as a solution to this problem. The aim of this project was to verify whether the ST system can also be useful in more open port layouts. If so, the system may provide a mooring solution where breakwaters would otherwise be required, potentially reducing the impact of infrastructure on the coastal system and providing significant cost reductions for port developers. Tests are required to explore the limits and possibilities of this innovative mooring technique in terms of minimising wave- generated vessel motion. However, field-scale testing of the ST system in relatively high wave conditions involves practical problems, cost and risks. Furthermore, the test conditions cannot be controlled adequately in the field. Physical-scale model tests were therefore set up using a scaled-down version of the ST system. These tests were performed at Deltares in the Delta Basin, a physical-scale model facility where multidirectional waves can be generated. A scaled (1/40) Capesize dry bulk carrier (LOA = 252 m) was moored in the basin using four different mooring configurations and subjected to three series of different types of wave conditions with increasing complexity. These conditions were chosen such that they corresponded to the most challenging wave conditions for the ST system. During the tests, the waves in the basin, the line forces, the vessel motions and the characteristics of the ST systemweremeasured and stored in a systematicmeasurement database. The project showed that the ST system can effectively reduce low-frequency horizontal wave-generated vessel motions which are generally normative for loading/offloading operations in sheltered port layouts. During the development of new port concepts in which innovative mooring techniques are used in more exposed conditions, it should be kept in mind that other aspects may become normative (such as the vertical roll of the vessels). Well-validated numerical tools are necessary to assess these situations. The systematically generated measurement database, together with the project report by Deltares, provides a sound basis for the validation of numerical representations of the ST system. The scale model results provide sound verification of the functionality and performance of the innovative mooring system. The results will help to increase the acceptance of innovative mooring solutions such as the ST system throughout the waterborne transport community and for use in the Port of the Future. In addition, the exploration of the implementation constraints on a systemsuch as the ST could diversify and extend the fields of application of systems like this. This was a collaborative project involving ShoreTension, Royal HaskoningDHV, Shell, Vopak, Marin and Deltares and it was partly subsidised by the ‘Delta Technology’ TKI. Contact: Bas Reijmerink, Bas.Reijmerink@deltares.nl, t +31 (0) 6 4691 1152 Niek Bruinsma, Niek.Bruinsma@deltares.nl t +31 (0) 6 5129 5588 Further reading : https://publicwiki.deltares.nl/display/TKIP/DEL083+-+Innovatief+afmeren +van+schepen+in+de+haven+van+de+toekomst SCALE MODEL TESTING: INNOVATIVE MOORING IN THE PORT OF THE FUTURE In the Port of the Future, which will be built in open water in order to reduce the impact on the coastal system, the wave conditions at the berth may be much more challenging than in traditional enclosed port basins. To continue to operate a port safely and efficiently in these conditions, innovative mooring techniques like the ShoreTension systemcan be used tominimise vessel motions andmooring forces. Detail of scale model representation of ShoreTensionmodule Scale model test with vessel moored in a realistic configuration, including mooring fenders ShoreTensionmodule in the port of Sines, Portugal