Photo credit: Heerema Marine Contractors
Dutch offshore installation company Heerema Marine Contractors said Monday its semi-submersible crane vessel has crossed the Storebaelt Bridge, known as the “Gateway to the Baltic Sea“.
“This crossing is the first time a Heerema crane vessel has entered the region and is the result of innovative crane modifications to allow passage under the bridge. While the ballast was ballasted down to Thialf’s maximum draft, the total draft was just under 65m with the A-frame down,” the company said.
Photo credit: Heerema Marine Contractors
While the Thialf was anchored in the port of Rotterdam during the winter of 2021-2022, the onboard team successfully implemented modifications to the ship’s A-frames. This action is possible because Thialf’s A-frames already have hinged corners that can accommodate NOV’s specially developed semi-permanent adjustment system. Thialf’s deadweight tonnage is unchanged, with the ship capable of lifting 14,200 tonnes, the company said.
This system allows Heerema to lower Thialf’s cranes and fold the A-frames to create a sufficient air gap in combination with ballast between the ship and the Storebaelt bridge. 
Photo credit: Heerema Marine Contractors
“The project was a great collaboration and an achievement by Heerema Group as the Heerema Fabrication Group shipyard in Opole completed most of the fabrication work. The team fabricated around 150 tons of structures required for the modification,” the company added.
Heerema will install the 7,150 ton offshore substation Baltic Eagle (OSS) on behalf of its client Baltic Eagle GmbH before proceeding with the installation of 27 wind turbines for Parkwind’s Arcadis Ost I wind farm in the Baltic Sea using its novel nacelle assembly (RNA) installation method.
