Buoys contract extended at Greater Gabbard

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 said. “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.”

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 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.”

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.