Ex-Statkraft Engineer Develops New Foundation Installation Solution

Arild Bolsø, an engineer who worked for Statkraft in Norway and Forewind in the UK, has developed a new technical concept for offshore wind foundation installation. According to Bolsø, the concept would reduce installation time by 30-50%, compared to current methods.

After Statkraft decided to stop new investments in offshore wind, Bolsø set up a new company – Arild Bolsø Engineering – and worked fulltime to develop the Hydrostatic Structural Connection Technology (HSCT), with the early phase of development financially supported by Innovation Norway.

The HSCT involves a suction cap that connects two or more submerged structures. The technology can be used on submerged structures with a tower extending to the surface such as a wind turbine substructure, on completely submerged structures such as in oil & gas applications and tidal turbines, or as a quick connection on a mooring line.

Bolsø told Offshore WIND that he decided to introduce the technology to the industry after filing a patent application in December.

The concept

A substructure with sealing elements is installed on top of a foundation, creating watertight compartments between the two structures. The pressure inside these compartments is quickly reduced to atmospheric level allowing for the water pressure from outside to act on the structures and keep them connected. A secondary simple mechanical locking device takes the loads in the case of a sealing failure.

To some extent, the principle is similar to that of the suction bucket technology, but instead of pushing a bucket into the seabed, the HSCT is connecting two or more submerged structures.

The HSCT suction caps consist of peripheral sealing and rubber cushions (fenders) inside.

Because of the very instant attachment of the suction cap, floating vessels can be used and integrated installation becomes possible, Bolsø pointed out, adding that one floating vessel can carry six suction bucket foundations or four complete turbines and substructures per trip.

How it works?

A suction cap is mounted at the lower end of the substructure, which is very similar to a three-legged jacket and goes between a tower and a foundation already installed at the seabed. The upper part of a suction cap is attached to a flat surface on the foundation.

From the suction cap up, the foundation can feature either a jacket structure or a monopile-shaped structure.

“Below the suction cap one can imagine several types of foundations. As long as the foundation has a flat horizontal area that matches the suction cap on the substructure, it can be either pin-piled to the ground, have suction buckets or be a heavy concrete slab. Also, floating structures can be used as long as they have the same horizontally surface at c. 35-meter water depth,” Arild Bolsø explained.

Standardization and industrialization of substructures for bottom fixed and floating wind turbines can lead to significant cost reduction for both alternatives, according to Bolsø, since one installation vessel can be used for the standard “topside”, which may also install most of the foundation types.

Offshore WIND Staff; Images: HSCT

Share this article

Follow Offshore Wind

Events>

<< Jun 2017 >>
MTWTFSS
29 30 31 1 2 3 4
5 6 7 8 9 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30 1 2

FwP Atlantic Forum 2017

The event is being held during the tenth edition of Sea Tech Week, an international week devoted to marine science and technology, organised…

read more >

Cost Reductions for Offshore Wind Logistics 2017

Logistic challenges touch on all aspects of wind farm projects, with optimising transport and installation as a key challenge for offshore wind logistics…

read more >

Offshore Foundations 2017 Agenda

Offshore Foundations is a technical event for experts in the wind industry…

read more >

HUSUM Wind 2017

The new concept for HUSUM Wind 2015, with the focus specifically on the important German core market, has proven to be a complete success…

read more >

Jobs>

Commercial Manager - Liverpool based with some travel

As the Commercial Manager you can expect a variety of responsibilities. The principle focus will be the commercial management of the Bibby WaveMaster1 vessel...

apply

Network Support Engineer

As Network Support Engineer you will be responsible for the installation / configuration, operation and maintenance of the infrastructural network ...

apply

Offshore wind jobs at Shell Netherlands BV

Commercial Lead New Energies, Offshore Wind Operations Lead and Wind Turbine Engineer.

apply

Vessels>