Seaway 7 Orders MENCK Hammer for Hollandse Kust Zuid

Seaway 7 has signed a contract with MENCK for the provision of a hammer for the installation of monopile foundations at the Hollandse Kust Zuid 1-4 offshore wind farms in the Netherlands.

MENCK, part of marine and subsea solutions group Acteon, will provide one of its MHU 3500S hydraulic hammers and spread for the project.

MENCK's MHU 3500S hydraulic hammer and adaptor in use

According to the company, the hammer will have the largest piling adaption to date and will be capable of installing monopiles with a 7.5-metre outer diameter. Vattenfall’s 1.5 GW Hollandse Kust Zuid offshore wind project will feature Siemens Gamesa’s 11 MW wind turbines installed on TP-less monopile foundations with an outer diameter of 7 metres.

“This contract follows a recent sequence of successful renewables projects using our largest hammers”, said Hans Frederic Gümmer, Project Manager, MENCK. “We are delighted to establish a relationship with Seaway 7 to provide product excellence and service expertise to help make the HKZ offshore wind farm project a success”.

Offshore construction will start this year, with the foundation installation to be split into two installation campaigns which are expected to take eight months.

The 140 monopile foundations for Hollandse Kust Zuid are being manufactured by Sif. With the TP-less monopiles, on which the work platforms and ladders will be attached directly, the developer aims to minimise the project costs.

In 2019, Vattenfall contracted Seaway 7, Subsea 7’s renewables business unit, for work on the Hollandse Kust Zuid 1 & 2 and chose the company as the preferred supplier for Hollandse Kust Zuid 3 & 4. In 2020, Subsea 7 signed a contract with Vattenfall to transport and install all the 140 foundations and 315 kilometres of 66 kV inner-array cables.

The 1.5 GW Hollandse Kust Zuid will become the largest offshore wind farm in the Netherlands once fully operational in 2023.