Building Beatrice

offshore

One of the first offshore construction tasks was to install the 344 foundation piles, with four required at each of the 84 turbine locations  and the two offshore transformer module locations.

The specialist installation vessel, the Stanislav Yudin, owned and operated by Subsea 7, was contracted to undertake this work in water depths of up to 56m.

At each location, the piles were lowered to the seabed in to the reuseable 700 tonne pile installation frame which ensured each pile was in exactly the right place and straight.

Strong foundations

Each pile, 40m long and weighing around 50 tonnes, was then hammered into the seabed to a specific depth.

An industry-leading piling protocol was followed throughout this phase of work to minimise the risk of injury to marine mammals.

Dolphin, orca, seals and minke whales have been seen in and around Beatrice since construction was completed.

Jackets in

The next phase was the installation of the jacket substructures, undertaken by the Seaway Heavy Lifting operated vessel 'Oleg Strashnov', pictured.

The jackets, each weighing around 1,000 tonnes, were delivered in pairs on seagoing barges.  They were then lowered in to the sea with each leg being located in to the pre-installed piles.

Each jacket was then hydraulically levelled and then it, and the piles, were grouted in to place.

This image shows a jacket being lowered in to the sea and a number of jackets already in situ in the background.

The jackets were so tall, standing up to 81m high, the National Grid power lines over the River Tyne in Newcastle had to be raised to allow their passage underneath from the nearby Smulders fabrication facility.

 

Subsea cable installation

As well as the installation of the piles and jackets, a number of other vessels were also hard at work.

The Nexans owned and operated 'Skagerrak' cable laying vessel laid the two roughly 70km lengths of export cable from Beatrice to the Moray coastline.

Having extensively surveyed the seabed and cleared any obstructions, the cables were laid along the pre-determined route and buried below the seabed to prevent damage.

And a number of vessels owned and operated by Siem Offshore installed and buried around 140km of inter-array cable, connecting the 84 Beatrice turbines to the two Offshore Transformer Modules.

Offshore Transformer Modules (OTMs)

Beatrice has two OTMs which are located in the middle of the wind farm. The turbines are joined to the OTMs via the inter-array cables and their role is to transform the energy generated by the turbines up to 220,000 volts for onward transmission via subsea and underground cables to the substation at Blackhillock.

The OTMs were assembled at the Babcock facility at Rosyth and transported to the Beatrice site for installation and connection.

The image to the right shows the two OTM's installed and undergoing commissioning with two jack-up vessels operated by Seajacks in attendance. 

 

Wind turbine installation

The installation of the first Siemens Gamesa 7MW wind turbine was completed on 14 July 2018.

 

First power was exported on 19 July 2018 marking a significant project milestone.

The 84th (final) turbine was installed on 15 May 2019.

You can find out more about the installation process by clicking here.

© 2020  Beatrice Offshore Windfarm Ltd.