DONG Energy has awarded J. Murphy & Sons Limited (Murphy) the onshore cable installation contract for the 1.2GW Hornsea Project One offshore wind farm.
Hornsea Project One, located off the Yorkshire coast, will comprise 174 wind turbines installed across an area of 407sq km, and will be the first offshore wind farm in the world to exceed one gigawatt in capacity.
Murphy will lay over 350,000m of cable along a 38km route, onshore cabling of 220kV and 400kV, across three circuits. The work will encompass 25 joint bays and one transition joint bay, as well as one substation connection. Cable will be laid in trenches of 1,200mm width, with three direct buried cables and one 63mm diameter duct.
The cable route will cross agricultural farmland, roads, rail crossings, canal, river crossings and ditches, overhead and underground services. These will be crossed using either the open cut method or horizontal directional drilling (HDD). HDD will be used to cross approximately 50 assets along the route, minimising disruption to the local communities to keep the local infrastructure running as normal.
The onshore cable system being installed by Murphy will connect to the offshore cables at transition joint bays at Horseshoe Point, Lincolnshire. At the other end of the route, these three cable circuits, along with the fibre optic cables, will connect to the new onshore substation, next to the National Grid 400kV substation in Killingholme, northern Lincolnshire. Murphy will also connect two 400kV cables from the DONG substation to the National Grid substation.
Dan Rice, contracts manager for Murphy, said: “We are currently carefully planning all aspects of this project, taking into account all the specifics, including for example the narrow roads within this rural part of Lincolnshire. With this in-mind we are developing bespoke drum trailers, so we can ensure the project runs efficiently. We are also consulting local people who may be affected by the works and we are getting involved in community and charity events. We will be incorporating environmental best practice, as we want to benefit and protect the environment and agricultural land for the farmers.”
Hornsea Project One is expected to be fully commissioned by 2020. The work by Murphy on this project is due to commence in September 2016 with completion due in November 2018.
Duncan Clark, Programme Director for Hornsea Project One at DONG Energy, said: “Hornsea Project One is a huge infrastructure project that will be able to generate clean, green electricity for well over one million UK homes for decades to come. The onshore cable will run underground along its entire route and installation is a vital part of the construction process. We are very pleased to be working with Murphy on this. DONG Energy is committed to using UK suppliers whenever possible, and Murphy has an excellent track record of working with us to safely construct offshore wind farms.”
Murphy is currently constructing the Race Bank project which is almost complete and has commenced construction on the Walney Extension cable installation for DONG Energy.