Hanwha Philadelphia Shipyard, located in Philadelphia, announced on Wednesday that it has delivered the subsea rock installation vessel "Acadia" to Great Lakes Dredge & Dock Company, based in Houston, marking the first vessel of its kind in the U.S. fleet.
The Jones Act-compliant 461'x112' Acadia is designed to transport and install up to 20,000 metric tons of rock on the seabed, providing scour protection for submarine cables, oil and gas pipelines, telecommunications infrastructure, and offshore wind turbine foundations.
"Receiving the Acadia is a transformative moment for Great Lakes Dredge & Dock and underscores our commitment to installing and protecting offshore energy infrastructure both domestically and internationally," said Lasse Petterson, President and CEO of Great Lakes Dredge & Dock. "This highly specialized vessel positions us at the forefront of the U.S. and international subsea rock installation market and enables us to play a key role in major projects such as Empire Wind 1 and Sunrise Wind, which provide reliable, affordable, and clean energy solutions for New York State."
"The delivery of the Acadia means far more than the completion of a vessel. It reflects the strength of U.S. shipbuilding, the dedication of our employees, and the growing delivery capability of Hanwha Philadelphia Shipyard to provide highly specialized vessels for critical infrastructure," said David Kim, CEO of Hanwha Philadelphia Shipyard, in a press release. "On behalf of all shipbuilders in Philadelphia, I wish the crew of the Acadia fair winds and following seas on their future voyages."
In 2021, Great Lakes Dredge & Dock ordered the Acadia from Philadelphia Shipyard for $197 million, with the vessel originally scheduled for delivery in 2024.
The project faced significant delays, and by 2024, Great Lakes had filed a motion for a temporary restraining order and preliminary injunction with the U.S. District Court for the Eastern District of Pennsylvania, citing delays and disputes in constructing this first-of-its-kind vessel. Specific data on the cost impact of these delays has not yet been released.
The first offshore wind project for the Acadia will be Equinor's Empire Wind 1, followed by Orsted's Sunrise Wind, both located off the coast of New York.
Great Lakes ordered the subsea rock installation vessel during the Biden administration's push to expand the U.S. offshore wind industry. Now, under President Trump, the policy environment has shifted dramatically, with Trump taking steps to restrict offshore wind development.
The company stated that after completing the two U.S. wind projects, Great Lakes will move the Acadia to Europe for rock installation work in collaboration with "a major offshore wind developer," with the vessel expected to remain in service for most of 2027.
Ulstein Design and Solutions BV in Rotterdam, Netherlands, provided the basic design for the Acadia. The vessel is equipped with engines meeting U.S. Environmental Protection Agency (EPA) Tier 4 emission standards, shore power connections for port cargo handling, and battery packs for peak shaving. Additionally, the vessel can use biofuels to reduce CO2 emissions and is equipped with active emission control technology to minimize NOx emissions.
Following the delivery of the Acadia, Hanwha Philadelphia Shipyard (formerly Philadelphia Shipyard, acquired by Hanwha Systems and Hanwha Ocean in 2024 for $100 million) continues to build two National Security Multi-Mission Vessels for the Maritime Administration and three container ships for Matson in Honolulu.
Great Lakes Dredge & Dock, the largest dredging contractor in the U.S., has also changed ownership, becoming a wholly owned subsidiary of Seattle-based Saltchuk Resources Inc. The private family-owned company acquired the publicly traded firm for $1.5 billion, with the transaction closing on April 1.