Fluor – the principal contractor for the Greater Gabbard Offshore Wind Farm project – originally approached Hydrosphere in 2009 for the supply of temporary navigation lights to mark the site in its construction phase. This involved the installation of 140 3.6MW wind turbines located around two sand banks known as the ‘Inner Gabbard’ and ‘The Galloper’ in the North Sea off the Suffolk Coast.
Hydrosphere delivered a total of 174 Carmanah 601 and M650 solar powered marine navigation lights in the construction phase – these were used to mark the monopile foundations to ensure the site would be seen by shipping, making the site as safe as possible for marine traffic.
The Carmanah M650, an advanced, self contained, high-performance and low maintenance solar LED marine lantern, has proved to be highly reliable and extremely robust and is one of the most popular lights Hydrosphere supplies to wind farms.
Previously lights powered using solar panels needed a separate battery box, however, as both lights and solar panels have become more efficient it is now possible to incorporate the solar system within the light.
“Integrated lights are increasingly being used for wind farms,” Andy Reid, Director for Hydrosphere, explained. “Their small size and lightweight construction makes them ideally suited for this sort of application as they can be put on smaller platforms. We’ve supplied many of these lights to wind farms across the UK.”
Impressed with Hydosphere’s track record, Fluor employed the company for the supply of six cardinal navigation buoys needed to mark the Greater Gabbard wind turbines. After undertaking a full site and design study to ensure that the buoys and mooring systems would be suitable for the stringent 100 year Ramboll weather study, Hydrosphere recommended six JET 9000 buoys, which were installed in February 2009.
Reid explained the reason behind the choice: “The JET 9000 buoys are manufactured by world-leading buoy manufacturer Mobilis and provide a really robust and cost-effective solution for offshore and deepwater applications, especially where high visibility is a must. As with all Mobilis buoys in the JET range, because they are constructed from UV stabilised polyethylene components these buoys really do withstand the elements and will retain their colour within IALA guidelines for more than 15 years.”
Throughout the buoy rental period Hydrosphere has carried out two scheduled maintenance visits – one in 2010 and one in 2011 – and the buoys are reported to be in good condition. In addition, each of the buoys is fitted with an automatic satellite monitoring system designed by Vega Industries Ltd, which has greatly reduced the number of expensive onsite inspections required throughout the buoy rental.
As well as monitoring parameters such as solar energy in, power used, current in and out, lamp condition and the buoys’ geographical location 24 hours per day, all of which is transmitted via regular status reports, the units also transmit emergency alerts in the event of a vessel colliding with the buoy or if the buoy drifts or is dragged out of position.
Should the buoys require any replacements Hydrosphere has spare parts stored in Harwich, where a Trinity House vessel commissioned to undertake any necessary repairs is also based. This has proved to be an efficient arrangement that has helped Fluor to comply with the 97% operating availability cycle as required by the General Lighthouse Authorities.
A Trinity House vessel will also be used to remove the buoys and moorings at the end of the contract. As the Lighthouse Authority for England and Wales, Trinity House was commissioned by Hydrosphere as the most experienced organisation to carry out the installation, maintenance and lifting of large navigation buoys.
Hydrosphere has supplied navigation lights and buoys for wind farms across the whole of the UK during both construction phase and through to the completed turbines. The projects they’ve worked on include Sheringham Shoal, Walney, North Hoyle, Scroby Sands, Kentish Flats, Burbo Bank, Robin Rigg, Lincs, and Strangford Lough.