20,000 tonnes of rock precisely on the seabed

Around offshore wind foundations and on top of subsea cables and pipelines lies a layer of rock. It stops currents and waves from washing away the seabed, and keeps dragging anchors away from what lies underneath. Since the cable incidents in the Baltic Sea, that layer also counts as protection against sabotage of critical infrastructure.

In US offshore wind, placing that rock is the job of the ACADIA of Great Lakes Dredge & Dock Company, LLC. She carries up to 20,000 tonnes of it.

More information?

From hold to seabed

This is how the rock gets there:

  • Excavators and conveyors move it from the hold to the fall pipe.

  • The inclined fall pipe runs down over the side of the vessel.

  • Dynamic positioning keeps the vessel on station the whole time.

At the heart of it all is the Mission Automation System, which decides how the vessel places its rock. Batenburg Industrial Automation programmed it.

Keeping pace with changing requirements

Requirements changed during engineering and construction, and the automation had to change with them. Great Lakes brought the operational knowledge, and Batenburg turned it into control logic. "There will only ever be one first Jones Act-compliant rock installation vessel. We had automated vessels like this before, so we could support Great Lakes from the first concept all the way to delivery," says Kees van der Meijden, Sales Manager.

New York first, then Europe

Her first projects are off the coast of New York, at Empire Wind 1 and Sunrise Wind. After that, the ACADIA heads for Europe. Thank you, Great Lakes, for the trust and the collaboration.

More information about this project? Contact Kees van der Meijden, Sales Manager, at +31 (0)10 460 80 60 or kees.van.der.meijden@batenburg.nl. Read more about our work at sea on the Marine & Offshore page.

The ACADIA at a glance

  • Owner: Great Lakes Dredge & Dock Company, LLC

  • Type: rock installation vessel with an inclined fall pipe

  • Capacity: up to 20,000 tonnes of rock

  • Dimensions: 140.5 x 34.1 metres

  • Design: Ulstein Design & Solutions

  • Builder: Hanwha Philly Shipyard, delivered in June 2026

  • According to Great Lakes, the first US-flagged, Jones Act-compliant rock installation vessel