Mooring systems are critical for the success of all offshore floating renewable energy devices, which are constantly pushed to their extreme limits in their high energy environments. Importantly the use of moorings enhances depolyability, enabling deeper waters, closer to shore to be utilised with lower cost. In the past 10 years there has been significant research focused on ropes resulting in the production of lighter and stronger products. As a consequence weaknesses in the systems now occur in the rope in-line and end connectors with critical areas causing chaffing of the rope, resulting in its premature failure. The objective of this study is to design a new multi-material hybrid connector which will be lighter, easier to assemble and enhance the lifespan of the mooring system. The innovation arises from the use of the next generation of nylon/Al composite materials which when combined, exhibit higher strength, high corrosion resistance, low coefficient of friction, and are lightweight. For offshore renewables energy devices this will result in increased deployability, increased reliability and longer in-service times. This will yield an increase in energy output and improvement in safety.
The STORM connector is a multi-partner effort that offers a novel solution for this mooring challenge: The novel design in full compression offers the opportunity for the use of lighter materials hence offering a more deployable solution and an easier maintenance. The novel multi-material solution proposed not only offers a weight reduction but due to the anti-corrosion, anti-fouling and UV-resistant properties of both the core and the outer shell the life-span of the connector increases of 30%.
The Basaltium core, an innovative composite produced by Brunel University is a composite made of a recycled aluminium matrix reinforced with basalt fibres offering a sustainable and environmentally friendly solution, furthermore, the Nylacast proprietary low-friction nylon solution Oilon dramatically decreases the wear of the rope.
STORM project partners:
The STORM project was a feasibility study with the final scope to produce 5 connectors to be tested at 30 tonnes.
We successfully produced the prototypes and tested them in laboratory environment at 40 tonnes also including fatigue testing. The connectors designed for a 40 tonnes break-load weigh 13 kg, while its counterpart in stainless steel would have weighed 37 kg. The connector withstood the testing successfully proving the validity of the concept.
On the 25th of January the STORM connector was awarded the category Rushlight award 2018 for responsible product and on the 26th of January the connector was showcased to the industry during a mooring masterclass workshop organised by EMEC at Brunel University (www.emec.org.uk/ai1ec_event/storm-marine-moorings-masterclass)
The team will now focus on raising funds to upscale the connector to a 100 tonnes breaking loads that can be used for wave and also small scale offshore wind floating devices. We then aim to further upscale the connector to up to 800 to 1000 tonnes within the next 5 years in order to satisfy also full scale floating wind end users.
STORM connector being successfully tested at TTI’s facility in Wallingford, Oxfordshire:
Section of connector showing aluminium core fitted with strain gauges ready for testing. The black outer sheath is made from specialist low-friction nylon:
STORM consortium members receiving the Rushlight 2018 category award for responsible product or service: