Massive vessel heading to Long Island to begin work on Empire Wind project

An offshore vessel larger than two football fields is headed for the waters 14 miles off Long Beach this weekend, to begin the process of physically constructing the near 1,000-foot-tall components of the Empire Wind project.

The vessel, known as the Thialf, is under contract to Norway-based Equinor to begin offshore work for Empire Wind’s project. Its two main hoists are capable of lifting more than 14,000 tons, and will sit more than 300 feet above its expansive work deck, according to owner Heerema of the Netherlands.

The Empire Wind array, which is slated to consist of 54 monopiles and an offshore substation, will carry its more than 810 megawatts of power via undersea cable to a substation in Brooklyn to supply the New York City power grid and up to half a million customers, developers say. It's expected to be completed by 2027. 

The $7 billion-plus project was temporarily halted last month by U.S. Interior Secretary Doug Burgum, citing questions about its prior environmental review. But Burgum last week withdrew the stop-work order, partly at the urging of Gov. Kathy Hochul, who Burgum said in a social media post showed a "willingness" to work on increased natural gas pipeline capacity into New York.

The Thialf’s work will include lifting and positioning the 54 monopiles before they are driven into the seabed with a hydraulic hammer, Equinor spokeswoman Lauren Shane said in an email. 

Equinor is in the process of posting a notice to mariners about the vessel as it leaves its port in Rhode Island, but referred to one currently posted on the Coast Guard's website. 

That government notice said the Thialf will be present in the waters off Long Island from June 1 through Oct. 1, and that a 500-meter exclusion zone must be between the work site and vessels through June 4.

Equinor officials were not available to discuss the work. 

Equinor in a fact sheet provided to Newsday said the vessel will be used to install what it calls the "jacket foundation" for the offshore substation, which will "gather all the power from the turbines and be connected to shore via the export cable."

Shane wouldn’t say whether any New York workers would be employed on the vessel, which its owner Heerema says has a helicopter deck and living quarters "equipped to accommodate 736 men."

As a precursor to the work, Equinor in March began dropping rock piles in a 66-foot radius around each planned monopile location as a way to stabilize the structures, which will reach a height of nearly 1,000 feet to the tip of each turbine blade.

Equinor in 2021 abandoned its original plan to mount the turbines on massive concrete foundations dropped onto the seafloor, a method favored by environmental groups because it minimized impacts to wildlife from piledriving tower foundations.

By Mark Harrington

mark.harrington@newsday.comMHarringtonNews

Mark Harrington, a Newsday reporter since 1999, covers energy, wineries, Indian affairs and fisheries.