Offshore Construction Start

Offshore construction for the London Array offshore wind farm effectively started with the installation of the first foundation in early March 2011. The project’s own history records that offshore construction began in March 2011 when the first of what would be 177 foundations was installed in the outer Thames Estuary, marking the transition from planning and onshore works into full offshore build-out. This followed earlier milestones including planning consent for the offshore wind farm in 2006, approval of onshore works in 2007, and the start of construction of the onshore substation at Cleve Hill in 2009, which provided the grid connection point for the power that the offshore assets would later deliver. More detailed contemporaneous reports from March 2011 by project partners DONG Energy, E.ON and Masdar confirm that the first monopile foundation, weighing 268 tonnes, was installed using A2SEA’s jack-up barge Sea Worker. The monopile was supplied and installed by the Per Arsleff Bilfinger Berger Ingeniurbeu joint venture, with a yellow transition piece then lifted into place to complete the first full foundation. London Array’s Offshore Construction overview reiterates that in March 2011 the first of 177 foundations was installed and that this kicked off a large-scale offshore programme involving up to 1,000 people and 60 vessels at peak. This milestone signalled the start of sustained offshore installation works, including the sequential installation of monopile foundations, transition pieces, turbines, array cables, export cables and offshore substations through 2012. It marked the point at which years of planning, environmental studies and onshore enabling works translated into visible offshore infrastructure, de-risking the project by demonstrating successful foundation installation at site. Subsequent offshore activities, managed from a temporary construction base at the Port of Ramsgate, would ultimately lead to turbine installation, first power in October 2012, and full build-out of the 630 MW phase one array.