Growing Volume of Work from the Offshore Renewables Sector

In part thanks to the huge volume of knowledge and experience acquired in the offshore oil and gas industry, Dutch offshore contractors and their suppliers have also succeeded in occupying a prominent position in the renewables sector. For example they are involved in the construction of almost all the offshore wind farms in Northwestern Europe. Well-known names among them are EPCI contractors like Royal Boskalis Westminster and subsidiary VBMS, Van Oord, Seaway Heavy Lifting and SPT Offshore.

Particularly remarkable is the wide variety of specialist activities for which Dutch contractors are called in. One excellent example is the transport and installation of the massive topsides for the DolWin gamma Offshore Converter Station in the German Bight. For the installation work for this 18,000-tonne topside module, Boskalis subsidiary Dockwise originated and implemented a special float-over method. Equally remarkable is the fact that together with Barge Master, Boskalis has developed a 3D motion compensated drill rig, capable of carrying out drilling work for soil surveys at locations

where offshore wind farms are due to be installed. The drill rig is installed on a Barge Master T700 motion compensated platform. Boskalis has also won the contract for the transport and installation of part of the foundations for the Hornsea Offshore Wind Farm Project One. The contractor will be deploying its new installation vessel Bokalift 1 for this project. For its part, the floating sheerlegs Asian Hercules III will be deployed installing the suction bucket foundations for the European Offshore Wind Deployment Centre. Each of these 77 metre-high steel jackets, weighing in at 1800 tonnes, will have to

be installed in Aberdeen Bay. Finally, using the fallpipe vessel Rockpiper, Boskalis has been responsible for rock installation work on the first of the two export cables from the Beatrice Offshore Wind Farm.

Cable layers Over the past few years Boskalis subsidiary VBMS has developed into a leading contractor for the laying of interarray and export cables for offshore wind farms. One example of this work was undertaken in 2017, involving the laying of 56 inter-array and export cables for the Galloper Offshore Wind Farm off the coast of the English county of Suffolk. This work was undertaken by the cable-lay vessels Stemat Spirit and Ndurance. A special plough was used for burying the cables in the seabed. New projects in which VBMS is due to play a leading role over the next few years include the construction of the Albatros, Hohe See, Triton Knoll, Moray, Horns Rev 3, Krieger Flak and Borssele 1 & 2 offshore wind farms. In collaboration with Tideway, VBMS will also be laying cables for the Hornsea Offshore Wind Farm Project One.

One of Boskalis’ best-known suppliers is SPT Offshore. For the Hornsea Project One, SPT Offshore will be installing the 174 suction pile foundations for the 58 suction bucket jackets. Boskalis has also contracted SPT Offshore for the detailed design and installation of 33 suction pile foundations for 11 suction bucket jackets for the Aberdeen Offshore Wind Farm. Finally, SPT Offshore was responsible for the design, fabrication and installation of the suction pile foundations for the transformer substation of the Dudgeon Offshore Wind Farm off the coast of Norfolk, UK.

Alterations Van Oord, with a reputation as leading EPCI contractor in the wind energy sector, in 2017 concluded a series of major projects and launched another series of new projects. In the Baltic to the northeast of the island of Rügen, Van Oord started construction of the Arkona Offshore Wind Farm. To carry out this project the heavylift installation vessel Svanen was deployed for driving the 81 metre-long monopile foundations. In total, 60 monopiles were driven into the seabed, to a depth of 40 metres. Van Oord was also responsible for the transport and installation of the transition pieces.

Another remarkable project successfully concluded in 2017 consisted of the transport and installation of the 87

foundations for the Walney Extension Offshore Wind Farm in the Irish Sea. This job involved both the Svanen and the Aeolus, while the Seajacks Scylla installed the turbines.

New projects in the books at Van Oord include the construction of the Norther Offshore Wind Farm off the coast of Belgium and the Deutsche Bucht Offshore Wind Farm, 95 kilometres northwest of the German island of Borkum. For both of these projects the heavylift installation vessels Svanen and Aeolus and the cable layer Nexus will be deployed. Because the components used in the wind energy sector are growing constantly larger and heavier, at the start of 2018 Van Oord altered the lifting capacity of the Aeolus. The Svanen is capable of lifting monopiles with weights of 8,000 tonnes and more. The crane on board the Aeolus, with a lifting capacity of 900 tonnes, has been replaced by a Huisman crane with a lifting capacity of 1,600 tonnes. For the East Anglia One Offshore Wind Farm Van Oord has signed a logistics contract for all jacket foundations and piles and transport to Flushing.

Pile installation frame With its own fleet of crane vessels Seaway Heavy Lifting was involved in the construction of a series of offshore wind farms in 2017. One year previously, together with Subsea 7, Seaway had been awarded the contract for the installation of the 84 jacket foundations and the transport and installation of the offshore transmission modules for the Beatrice Offshore Wind Farm. As part of this project, both the Stanislav Yudin and the Oleg Strashnov will continue to be deployed through 2017 and 2018. A specially built Pile Installation Frame

will be used for installing the jackets. The same Oleg Strashnov was also responsible for installing the four foundation piles for the transformer substation for the Arkona Offshore Wind Farm. At the end of 2017 Seaway Heavy Lifting was awarded an EPCI contract for the installation of the turbine foundations for the Trianel Wind Park Borkum II in the German Bight. This work is due to be carried out in 2018 by the crane vessel Stanislav Yudin.

Other Dutch companies active in the wind energy sector include the heavy cargo transporters Jumbo Shipping, BigLift Shipping and RollDock Shipping. In 2017 Jumbo’s Fairplayer, working in dp mode, took on the installation of 60 transition pieces during the construction of the Arkona Offshore Wind Farm. To undertake this project the vessel was equipped with a special SMST gangway.

For its part, in three trips between Bilbao in Spain and Stord in Norway, BigLift deployed its heavy-lift vessel the Traveller to transport all upper sections of the five wind turbines for the Hywind Scotland Pilot Park on behalf of Statoil. In total the transport involved

20 heavy sections weighing between 150 and 191 tonnes. As part of this project in Stord, Mammoet was responsible for the assembly of the wind turbines. Elsewhere, the Rolldock Sky operated by RollDock Shipping transported tower sections for wind turbines from Taicang in China to Egersund in Norway, while the Rolldock Sea transported transition pieces from Aviles in Spain to Eemshaven in the Netherlands.

ALE assembled the first ever floating wind turbine in Saint Nazaire in France. SIF, which operates an ultramodern production facility in the port of Rotterdam, produced the necessary monopiles for a series of offshore windfarms. For example, in 2017 a start was made on 44 monopiles for the Belgian Norther Offshore Wind Farm. Other projects involving this company were the fabrication of monopiles and transition pieces for the Trianel Wind Park Borkum II and monopiles for the Albatros Offshore Wind Park.

Finally, jack-up accommodation barges operated by Seafox and Jack-Up Barge regularly saw service during offshore windfarm construction projects n

In 2017 a more heavy-duty crane was installed on board Van Oord’s Aeolus. (Photograph: PAS Publicaties)

The brand new installation vessel Bokalift 1, owned by Boskalis, willbe deployed in the renewables sector. (Photograph: PAS Publicaties)

Seaway Heavy Lifting used a pile installation frame for installation work on the Beatrice Offshore Wind Farm. (Photograph: PAS Publicaties)