Top position in offshore wind energy sector

The Dutch offshore contractors and their suppliers are forever expanding their position in the offshore wind energy sector. They are closely involved in the construction and development of practically every offshore wind farm and wind project, not only in Western European waters but also in other parts of the world, including America and Asia. Their extensive knowledge and experience acquired in Europe is currently being deployed globally. Frontrunners are Royal Van Oord, Royal Boskalis Westminster and DEME Offshore.

In 2018, just as in previous years, Van Oord launched a series of new projects. In mid-April, in the German sector of the North Sea, the company deployed its cable-laying vessel Nexus in the construction of the Borkum Riffgrund 1 Offshore Wind Farm. In total, the job entailed the laying of 110 kilometres of cable. Van Oord was also responsible for the laying of the interlink cables between Borkum Riffgrund 1 and Borkum Riffgrund 2. The new Dig-It trencher was deployed for the very first time to entrench the cables. The project was successfully concluded, later in the year. Another project in the German sector that involved Van

Oord was the construction of the Deutsche Bucht Offshore Wind Farm. The first monopile foundations for this project, each weighing 1,100 tonnes, were installed in September by the jack-up vessel Seajacks Scylla. The monopiles and the transition pieces were supplied from the German port of Cuxhaven. As part of the same project, Van Oord was called upon to install two special monobucket foundations. Within this pilot project, two wind turbines each generating 8.4 MW were installed on these foundations. Off the coast of Belgium, Van Oord was involved in the installation of the foundations, inter-array cables and export cables for the

The crane vessel Aeolus is equipped with a 1,600-tonne Huisman crane. (Photograph: PAS Publicaties)

Norther Offshore Wind Farm. This work was carried out by the jack-up vessel Aeolus, which had just been equipped with a 1,600-tonne Huisman crane, and the cable-laying vessel Nexus. Sif and Smulders supplied the foundations and transition pieces for this project, while Engie Fabricom was responsible for the offshore high voltage station. DEME Offshore (formerly Tideway) undertook the scour protection work. In June 2018, Van Oord made a start on the installation of foundations and pin piles for the East Anglia One Offshore Wind Farm, in British waters. The initial work was undertaken by the new dp2 crane vessel Bokalift 1 operated by Boskalis, which was subsequently joined by the Seajacks Scylla. The foundations consisted of 102 three-legged steel jackets, 60 of which were carried to Flushing from Jebel Ali in the United Arab Emirates, by heavy transport vessels also operated by Boskalis.

New contracts were signed for projects in Taiwan, the Baltic and the Netherlands. Van Oord has been appointed preferred contractor for a huge 640 MW wind farm in Taiwan. The contract includes the design, fabrication and installation of 80 foundations, some eight kilometres off the coast of Yulin County. In the Baltic Sea, Van Oord will be installing 72 monopiles and transition pieces for the Kriegers Flak Offshore Wind Farm. The crane vessel Svanen will be deployed for this work. In the Netherlands, a new contract was signed for the installation of 94 inter-array cables for the Borssele I and Borssele II wind farms, by the cable-laying vessel Nexus. For the Borssele III and IV wind farms, too, a contract has been signed for the installation of the foundations and the laying of inter-array cables. For the Borssele V innovation site, a further two 9.5 MW turbines will have

The Bokalift 1 was deployed by Van Oord in the East Anglia OneOffshore Wind Farm. (Photograph: PAS Publicaties/maritimephoto.com)

At the start of 2018, Van Oord took delivery of the brand-new flexible fallpipe vessel Bravenes, with her eyecatching X-bow. This innovative vessel, built according to a design from Ulstein Design & Solutions, is equipped to perform three different types of rock installation work, namely fallpipe delivery through the moonpool, fallpipe delivery over the side, and tremie pipe over the side. Immediately following her handover, the Bravenes was deployed in the Merkur Offshore Wind Farm to install rock at eight cable crossings, at a depth of 30 metres, to protect the wind farm’s export cable. The inter-array cables at this wind farm had previously been laid by the Nexus. The takeover of the head offices of MPI Offshore in Stokesley led to further expansion of the Van Oord fleet with the two jack-up vessels MPI Adventure and MPI Resolution, and their crews.

Finally, in collaboration with Ace Aquatec, Van Oord established a strategic partnership, according to which the FaunaGuard, an acoustic device to protect marine fauna near marine construction activities, was made available to all marine contractors and other interested parties.

Royal Boskalis Westminster In 2018, Boskalis was involved in the construction of the European Offshore Wind Deployment Centre close to Aberdeen in Scotland. As part of this project, among others, the sheerlegs Asian Hercules III was deployed. For the same project, Smulders fabricated the jackets with suction buckets. Each jacket weighed 1,800 tonnes. In total, eleven of these large jackets were installed. As already mentioned, the new dp2 crane vessel Bokalift 1, equipped with a 3,000-tonne crane, was deployed for the installation of foundations for the East Anglia One Offshore Wind Farm. The numerous activities carried out by Boskalis in the field of cable laying attracted particular attention. For example, off the North Sea coast of Germany, the inter-array cables were laid for the Albatros and Hohe See wind farms operated by EnBW, and the interconnection was laid between these two farms. The heavy transport barge Giant 7 was deployed as a cablelaying vessel for the export cables of the Borssele I and II project. New contracts were signed for the Triton Knoll, Ostwind 2, Moray and Inch Cape wind farms, all four of

which are due to be built in Western European waters. The final signature was added to a five-year subsea cable repair framework agreement with Transmission Capital Partners. This market leader in offshore electricity transmission operates and maintains the transmission links between the UK onshore grid and the offshore wind farms Barrow, Gunfleet Sands, Ormonde, Robin Rigg, Lincs and Westermost. Elsewhere, together with NKT, Boskalis won a turnkey order to replace the high-voltage AC interconnector system between Denmark and Sweden. As well as the Giant 7, the vessels Ndurance, Ndeavor and Stemat Spirit will be deployed for the cable-laying operations. Finally, Boskalis strengthened its position in the offshore installation of cables, in 2018, with the acquisition of the German company Bohlen & Doyen, based in Wilhelmshaven.

DEME Offshore (formerly Tideway) In mid-2018, DEME Offshore took delivery of the brandnew cable-laying and multipurpose vessel Living Stone. The first project for which this innovative vessel was deployed involved the laying of 467 kilometres of export cable for the Hornsea One Offshore Wind Farm. As part of this same project, three landfall cable sections were installed by the Ndurance operated by Boskalis. Elsewhere, DEME Offshore was responsible for laying 73 inter-array cables for the Merkur Offshore Wind Farm, while off the coast of Belgium, the flexible fallpipe vessels Flintstone and Rollingstone provided scour protection for the Norther Offshore Wind Farm. Rock placement services were also undertaken in the Arabian Gulf, the Mediterranean, the Baltic and the Gulf of Mexico. Together with Boskalis, another five-year contract was signed with Equinor, to provide subsea rock installation work across all of its operating assets on the Norwegian shelf, in the North Sea.

Immediately following her handover, DEME Offshore’s Living Stonewas deployed to lay export cables. (Photograph: PAS Publicaties)

Platform fabricators The Dutch platform fabricators, who had already established a solid reputation in the offshore oil and gas industry, have now acquired a firm foothold in the offshore wind energy sector. One of these fabricators is HSM Offshore, which on 28 May 2018 was responsible for the loadout of the 2,500-tonne topside of the Borkum Riffgrund 2 offshore high-voltage substation at its yard in Schiedam, assisted by SPMTs operated by Mammoet. The sail away took place on 26 May. In addition, in 2018, HSM worked hard on the fabrication of the jacket and topside for the Borssele Alpha high-voltage station. Following another loadout, also carried out by Mammoet,

the 2,900-tonne jacket headed out to sea, on 5 August. The handover of the 3,700-tonne topside will take place later this year. At the yards operated by the Heerema Fabrication Group (HFG), a series of projects for the wind energy sector was completed in 2018. In Flushing, for example, the loadout of the 3,100-tonne jacket for the BorWin 3 substation took place, on the barge H-542. The sail away followed shortly afterwards. The same yard also delivered the 1,500-tonne jacket for Elia’s Offshore Switch Yard (OSY) platform that was due to be installed in the sea, off the coast of Belgium, in November. The topside of this transformer platform, currently under construction at the Heerema yard in Zwijndrecht and weighing 2,100 tonnes, will be completed in March 2019.

Loadout of the Borkum Riffgrund 2 topside at HSM Offshore.(Photograph: PAS Publicaties)

The sail away of the Hohe See substation jacket from the Smulders yard in Flushing took place on 29 May. At the

end of June, ENGIE Fabricom delivered the topside for this substation, that was built at the yard in Hoboken. In August, the same Hoboken yard was the backdrop to the loadout of the 1,300-tonne topside for the Norther substation. Smulders and Sif joined forces to produce the foundations and transition pieces for the Hohe See Offshore Wind Farm, and in the large construction hall at Damen Shiprepair Flushing, Smulders fabricated the topside for the Deutsche Bucht offshore substation. This topside will be installed in the German sector of the North Sea, on a jacket previously fabricated by Smulders, in the first half of this year.

In April 2018, Sif was awarded the contract by Van Oord for the production of 77 monopiles for the Borssele III and IV wind farms. Sif was also contracted to supply 47 monopiles for the Borssele I and II wind farms. A further 58 monopiles will have to be supplied for the SeaMade Offshore Wind Farm. For this same project, together with Smulders, Sif will also be supplying the transition pieces. In March 2018, SPT Offshore completed the design of the three-legged jackets, including the suction pile foundations, for an offshore wind farm project off the east coast of Scotland. SPT Offshore was also engaged in a project to perform research and consultancy work on the wind turbine suction foundation design for two offshore wind projects in China.

Installation contractors During the course of last year, the two monohull crane vessels operated by Seaway Heavy Lifting (SHL) were responsible for a huge amount of installation work for the offshore wind energy sector. In April, the Seaway

Sail away of the jacket for Elia’s OSY platform at Heerema Flushing.(Photograph: PAS Publicaties/maritimephoto.com)

Strashnov installed the 1,000-tonne jacket and 4,000- tonne topside for the Arkona substation in the Baltic. Earlier in the year, this same crane vessel had already installed 45 jackets in the Beatrice Offshore Wind Farm. This work was subsequently completed by the crane vessel Seaway Yudin. As part of the same wind farm, the Seaway Yudin also installed a second offshore transformer module.

At the end of June the vessel then made a start on the installation of 32 monopiles, each weighing 900 tonnes, in Trianel’s Borkum II Wind Farm. In August, the Seaway Strashnov installed the jacket on Tennet’s Borssele Alpha offshore transformer station. This jacket alone weighed 2,900 tonnes. In the same month, the crane vessel also installed the 2,750-tonne jacket and the 4,200-tonne topside for the East Anglia One Offshore Wind Farm. At the end of October, the Seaway Strashnov returned to the Belgian coast to install the 1,500-tonne jacket for Elia’s OSY platform, while in July SHL was awarded a contract for the installation of 90 wind turbine foundations and two offshore substations for the Triton Knoll Offshore Wind Farm. This work will be carried out by the Seaway Yudin.

The crane vessels operated by Heerema Marine Contractors (HMC) were also active in the offshore wind energy sector. The Aegir completed the installation of suction bucket foundations for the European Offshore Wind Deployment Centre, while the Thialf was responsible for installing the jacket and the 4,500-tonne topside for the Hohe See project. A short time later, the Thialf went back into action to install the 2,500-tonne topside for the Borkum Riffgrund 2 station.

For her part, the Aegir was deployed by Van Oord to install jacket foundations in the East Anglia One Offshore Wind Farm, and to install the Delft Offshore Turbine (DOT) at the Princess Amalia Offshore Wind Farm off the coast of the Netherlands. Finally, a series of jack-up platforms operated by various Dutch companies, including the Seafox 5, JB-115 and JB-117, were deployed for hookup work at several high-voltage substations.

Although not yet mentioned, several Dutch companies are heavily involved in seabed survey work, the disposal of unexploded ordnance and the supply of accommodation vessels, fast crew supply vessels and service operation vessels. All in all, Dutch companies are able to deliver a full range of services for the fast growing offshore wind energy sector n