Heerema Marine Contractors is committed to delivering solutions for clients worldwide. With Heerema Fabrication Group fabricating the required structures, the company is now modifying Thialf’s cranes capable of lifting 14,200 metric tons.  In 2022, Heerema will be installing 27 wind turbines for Parkwind’s Arcadis Ost I wind farm in the Baltic Sea using our novel Rotor Nacelle Assembly (RNA) installation method.

– We will execute this project with Thialf, the world’s second-largest semi-submersible crane vessel (only Sleipnir is bigger) – the company informed on the website.

Sounds straightforward, except between home base in the Port of Rotterdam and the Arcadis Ost project location sits Denmark’s Storebaelt Bridge, also known as the Swan. It connects the Danish islands of Zealand and Funen and has a clearance of 65 meters, while from Thialf’s floaters to the top of the vessel’s A-frames is a huge 105 mete

“We have a bold vision that we want to make the impossible possible offshore. But, this commitment also translates into all of Heerema’s activities and this mindset drove the decision to modify Thialf’s A-frames to access the Baltic Sea. This action ensures we can unlock the region without compromising the integrity of our 14,200 metric ton cranes”, the company explained.

At the moment, Thialf is moored in the Port of Rotterdam undergoing an A-frame modification. This action is possible as Thialf’s A-frames already have hingable corners that can accommodate the NOV custom-designed semi-permanent adjustment system.

Using this system, Heerema can lower Thialf’s cranes and fold the A-frames to create a sufficient air gap when combined with ballasting between the vessel and the Storebaelt Bridge.

The project has been greatly collaborative and was a Heerema Group effort as Heerema Fabrication Group’s Opole Yard completed most of the fabrication work. The team fabricated around 150 metric tons of structures required for the modification.

The Baltic Sea is a unique region for offshore operations with a heterogeneous seabed profile that includes sand, mud, hard clay, and bedrock. This variety of potential seabed materials can make installations challenging, but Thialf’s floating vessel capabilities mean that no matter what’s below the company can execute projects. With lots of offshore wind energy projects planned for the region, we are prepared to offer our unique solutions – Heerema explains.

Source: Heerema