700,000 German homes receiving clean power from the HelWin Beta platform

HelWin installation Thialf TenneT
HelWin installation Thialf TenneT
Offshore Wind

HelWin Beta platform installation

Installing the HelWin Beta jacket and topside over two campaigns with Thialf

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At a glance

  • Transport and installation of the HelWin Beta platform for client Heerema Fabrication Group, and end client TenneT
  • 4,500 metric ton jacket
  • 10,300 metric ton topside
  • Installation over two campaigns
  • 23.3 meter water depth
  • 3m keel clearance for topside installation

The Heerema promise


As a carbon-neutral contractor you can trust Heerema to create sustainable value on your project.

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We have the highest standards of safety and believe in an incident and injury-free workplace. To achieve this goal we follow our Dare to Care program.

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With over fifty years of experience in transporting, installing, and removing offshore infrastructure you can rely on Heerema.

HelWin installation Thialf TenneT
HelWin installation Thialf TenneT 2
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Thialf approaching HelWin Beta

Thialf carrying the 10,300 metric ton topside

Thialf installing topside
Thialf installing topside

Thialf lifting the topside from the barge

Thialf carrying HelWin Beta topside
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Heerema Fabrication Group EPCI Contractor
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HelWin Beta Platform installation

Heerema Marine Contractors was contracted to transport and install the Siemens operated HelWin Beta platform. The platform consisted of a six-legged 4,600 metric ton jacket, 10,300 metric ton topside, and bridge constructed by EPCI contractor Heerema Fabrication Group.

The installation was split over two campaigns with the jacket and piles installed in May 2014, followed by the topside and bridge in July 2014. The HelWin Beta platform connects wind farms in the North Sea to the German electricity grid.

HelWin Beta platform

The offshore converter platform HelWin beta is a subsidiary platform of HelWin alpha, and both provide power to the HelWin2 high-voltage direct current (HVDC) transmission system that has a capacity of 690 MW, t.

The HelWin beta platform is equipped with Siemens’ High Voltage Direct Current (HVDC) technology, which provides a low-loss transmission of generated wind power. The offshore converter station’s 690 MW transmission capacity started supplying power to over 700,000 homes in Germany from 2015.

Offshore operations

Heerema transported the HelWin Beta 4,500 metric ton jacket from Heerema Fabrication Group’s yard in the Netherlands to the offshore location in the German sector of the North Sea and started offshore operations on April 16, 2014. The jacket and six piles were successfully installed on April 20, 2014.

After that, Thialf returned to the location on June 30, 2014 to install the topside and bridge that were transported to the site from the HFG yard in the Netherlands. The topside measuring 100 meters in length, 45 meters in width, and 28 meters in height, was installed in 23.3 meter water depth.

The platform was safely installed around 20 meters away from the existing HelWin Alpha platform, with zero recordable HSE cases.

Key information


Offshore start date: April 16, 2014
Offshore end date: April 20, 2014

Topside and bridge:
Offshore start date: June 30, 2014
Offshore end date: July 10, 2014

Main spread


Main technical data

Jacket weight: 4,500 metric tons
Topside weight: 10,300 metric tons

Have a specific question? Let us help.

Pieter Thomasson
Pieter Thomasson

Commercial Manager Wind

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