C1 Connections and Heerema Marine Contractors have successfully tested the C1 Wedge Connection offshore. This connection, developed by C1, is a high-capacity connection that can be installed faster and safer than conventional bolted flange connections. It can be used in off- and onshore wind turbines, both in turbine towers and foundations.

The installation of the tower on board Heerema’s semi-submersible crane vessel Thialf was performed as part of the preparations for the Arcadis Ost project, for which Heerema will install 27 wind turbines for the Belgian developer Parkwind. See a video of the testing of the connection as well as extra pictures below.

The C1 Wedge Connection can deliver the high capacity that is needed for the next generation wind turbines, which continue to grow in size and are installed on sites in increasingly harsh environmental conditions or on floating platforms. The C1 Wedge Connection will improve the levelised cost of energy (LCOE) by reducing capital expenditure (CAPEX) and operating expenses (OPEX) while allowing safer installation.

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Pre-installed fasteners and lightweight tools

Conventional bolted L-flange connections are reaching their capacity limits and are complex to design, install and maintain. This is where the C1 Wedge Connection will make a significant difference.

During the offshore test, C1 Connections and Heerema demonstrated that this new connection enables a safe disconnection of the tower from a grillage on a barge. The alignment and quick connection of the tower was successfully performed without any personnel below the suspended load. The C1 Wedge Connection features pre-installed fasteners, and only lightweight tools are needed to finalize the connection.

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The development of the C1 Wedge Connection started in early 2017 in close collaboration with Delft University of Technology (TU Delft). From the offset, this technology has received support from the Dutch government agency RVO, with several industry partners contributing to its further optimisation.

‘Prior research and testing have demonstrated that the C1 Wedge Connection delivers a very high fatigue and ultimate capacity,’ says Jasper Winkes, managing director of C1 Connections. ‘The collaboration with Heerema has allowed us to demonstrate offshore that we can make installation much safer and faster, which are key benefits the entire industry can benefit from.’

C1 Connecctions' C1 Wedge Connection
Heerema trials the C1 Wedge Connection on the Thialf.
Heerema trials the C1 Wedge Connection on the Thialf.
Heerema trials the C1 Wedge Connection on the Thialf.
Heerema trials the C1 Wedge Connection on the Thialf.

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