Fugro Seacore (FSCL) has successfully installed three sets of foundations for Aquamarine Power’s full scale pre-commercial Oyster devices at the European Marine Energy Centre’s (EMEC) Billia Croo wave test site near the Orkney Islands near northern Scotland. The devices are wave-powered pumps that push high-pressure water to drive an onshore hydro-electric turbine.

“A paired foundation was used for the first 800 kW Oyster 800 now successfully installed at EMEC, and two monopiles are successfully in the seabed ready for two further Oyster devices to be installed to complete the 2.4 MW Oyster array,” explains Bob Jenkins, managing director of FSCL. ”We have many years’ experience in the renewables sector, and it has been good to continue our relationship with Aquamarine Power. We wish them every success with their array.”   

“Once again, Fugro completed the work to the highest standards” says Martin McAdam, CEO of Aquamarine Power. “Their knowledge and experience of foundation installation is invaluable, particularly in the testing conditions of Orkney waters. Their work on Oyster 1 led to us choosing them for the Oyster 800 contract, and we hope that we can continue building our relationship with Fugro Seacore in the future.”

  The $4.75 million contract for the foundations follows on from FSCL’s successful involvement in the installation and commissioning of the single full-scale 315 kW Oyster 1 at EMEC in 2009. At the time of signing the contract Martin McAdam remarked that: "This deal shows that a thriving marine energy sector has the potential to offered skilled jobs and economic opportunity the length of the UK.”

The installation of the foundations this year saw FSCL use in-house owned-and-operated equipment, including the jackup barge ‘Excalibur’ with the T40 reverse-circulation drill rig and grouting equipment. To achieve the required positional tolerances for the paired foundation, FSCL designed, built and commissioned a bespoke twin pile gate.

“Pile gates were used during drilling of the rock sockets for each pile, and to support each pile during installation,” explains Bob Jenkins. “These bespoke gates, which measure 112 feet long, 12.5 feet wide and 11.5 feet high, were able to move both vertically and horizontally using hydraulic pinning systems, enabling accurate positioning of the piles into position. The pile gates ensured the correct position of the piles, and held them securely in place after they had been grouted and during the grout-curing period.”

In total, nearly 1,650 cubic feet of sandstone was drilled and excavated, four 95-tonne large-diameter piles were installed, and 495 cubic feet of grout was mixed and pumped over the 34-day operational period.