NORTH KINGSTOWN, R.I. — This is going to take a long time.
At an excruciatingly slow rate of 15 feet per minute, the cable that will connect the Block Island Wind Farm to the mainland power grid is being moved from a transport ship to the special vessel that will bury it under the seabed.
The cable is 20 miles long, so the transfer, which started on Sunday, won’t wrap up until Thursday — four days in all. Like almost all the other parts of building the first offshore wind farm in the nation, it’s not a simple process.
The cable, which was fabricated in South Korea and arrived at the Port of Davisville in the Quonset Business Park on March 28, has to be unwound from a giant spool in the hold of the cargo ship BBC Ruby, fed over to the installation vessel Big Max, pulled up a multistory iron gantry, dropped onto the deck, and coiled around another big spool.
It has to be done just so, without the cable kinking or getting twisted in any way. The operation is running around the clock, with crews from North Kingstown-based Specialty Diving Services and Durocher Marine, of Cheboygan, Mich., working in 12-hour shifts to get the job done.
“The first wrap was the hardest,” said Specialty Diving CEO Nick Tanionos. “The next ones just fall into place.”
The Big Max came up from Florida weeks ago so Specialty Diving could retrofit it for the cable-laying work. The spools and the gantry had to be assembled on the ship’s deck. Six thrusters to power the ship — three on each side — were also installed.
There are actually two cables — a shorter one that will connect the wind farm to Block Island and a longer one that will run from Block Island to Narragansett. The former is in place on the Big Max while the latter is still being moved.
Deepwater Wind, the Providence company building the five-turbine project, will start laying the cable from Block Island to the wind farm in a couple of weeks. And then utility National Grid will follow up with the cable from Narragansett to Block Island. National Grid is going second because work to drill underneath Scarborough State Beach is taking longer than originally thought.
“There’s a lot more granite than any of us initially expected,” said David Campilii, consulting engineer, underground transmission engineering for National Grid.
A pilot hole has been drilled underneath the beach, but crews are still in the midst of enlarging it to make room for the cable. They’ve gone 960 feet, but still have 1,290 feet to go, said Campilii.
The cable project should wrap up by the end of June.