Half time at sea

Construction of foundations on schedule


Aachen. Three months after construction started, half time is reached at the site 45 km off the coast of Borkum. “20 of the 40 foundation structures have been anchored to the seabed”, explains Klaus Horstick, Managing Director of Trianel Windparks Borkum (TWB). 

The calm sea in recent weeks made it possible for the construction ship Goliath to continue working at sea without interruption. This made it possible to erect one foundation per day. Each foundation is anchored by three piles which have to be driven into the seabed. “The challenge is to drive the piles to their exact position, to the nearest millimetre”, says Horstick, “so that next year the wind turbine holding devices, the tripods, can be placed on the piles.” In order to achieve this a template is anchored on the seabed before driving starts.

The tripods, which could be called the “underwater cellars” of the actual wind turbines, have three cylindrical openings. The piles fit into these openings. The tripods are manufactured by Weserwind in Bremerhaven, they weigh 700 tonnes and will be installed next spring. The other components of the wind turbines such as the towers, nacelles, hubs and rotor blades will then be installed in the summer of 2012.

While the Goliath construction rig remains at sea, the supply ship Maersk Finder continues to bring the necessary supply of piles from Bremerhaven to the construction site at sea. The piles are between 35 and 40 metres long and weigh more than 100 tonnes.

“Our decision to start by inserting the piles seems to have been exactly right”, assures Horstick. The target is to complete all foundation structures by Easter 2012, so that the tripods and wind turbines can be installed thereafter. The first 40 foundation structures are part of the first construction stage at the Trianel’s Borkum wind farm. The second construction stage, with a further 40 wind turbines, has been scheduled to follow on straight after the first construction stage. “We want to tackle the contracts for the second construction stage as early as next year”, explains Sven Becker, Chairman of the TWB partner meeting and speaker for the Trianel GmbH management.

Trianel GmbH contact: Elmar Thyen, Head of Communications Tel +49 (0)241 41 32 04 13 | Mobile +49 (0)151 12 64 17 87 | Email e.thyen@trianel.com


  • Windkraftwerk Borkum Englisch