Vesterhav offshore wind farms

Rock installation

Rohde Nielsen was contracted to install the protective layer of armour rock on the 41 foundations for the Vesterhav North and Vesterhav South offshore wind farms.

The rock was produced at a quarry in Norway. The total amount of rocks produced was approximately 69,000 tonnes. All produced rocks were shipped from Norway to Thyborøn Port, Denmark. All shipping took place in the period from December 2022 to May 2023; in total, 17 shiploads of rocks were shipped. All 69,244 tonnes of rocks needed for the project were stockpiled in Thyborøn and ready for installation, all before the armour layer installation campaign started.

Before loading the rocks, a stevedoring company in the port made a pile of approximately 4,000 tonnes of rocks along the quayside, within reach of the Grane R crane. This was continued throughout the project; every time Grane R left Thyborøn port, a new stockpile of 4,000 tonnes was prepared.

Grane R then loaded herself with her crane and transited to the offshore installation site to install the rock according to the given positions and design. Before installation commenced, an in-survey was done. The installation was done with a fall pipe and wire crane; during the installation, frequent surveys were conducted to monitor the status of the installation. When the final design was achieved, an out-survey was done. All out-surveys were immediately forwarded to the client for final approval.

  • Location: Vesterhav (DEN)
  • Scope: 69,000 ton of rocks
  • Client: Asso Subsea Limited
  • Year: 2023

The fleet that made it possible

  • Grane R
Hopper capacity
Length overall
Draught loaded
Draught unloaded
Dredging/Installation depth
up to 100.00m

Talk to us about your next project

Would you like to know more about us and our services? Rohde Nielsen operates globally as a general contractor as
well as a subcontractor.

Get in touch