Block Island Wind Farm taking shape in the sea

Foundations are being driven into the seabed
Fri, 09/04/2015 - 9:15am
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The Deepwater Wind Block Island Wind Farm is beginning to take shape three miles off the southeast coast of the island. Although foundation number one, which was damaged during installation, was removed from the water for repairs in late July, two of the five steel foundation components have been installed and affixed to the seabed.

“Construction is progressing, with two jacket foundations in the water now,” said Meaghan Wims, spokesperson for the Block Island Wind Farm project. “Pile driving of these jackets and setting the third jacket are upcoming activities. The first jacket was removed for inspection and repair.” 

Foundations number two and three, of the five-turbine, 30-megawatt wind farm, are sitting in about 90-feet of water and visible from the bluffs of the Southeast Lighthouse. Protruding from the top of the four legs of the two yellow foundations are the brown pile sections that resemble rebar and will be driven down into the seabed.

“All four initial pile sections are inserted in the jacket,” said Wims. “One section has been driven into the seabed, the other three are waiting to be driven. The pile sections are driven into the seabed using a pile-driving hammer attached to the crane.”

The crane that Wims is describing is the 300-foot long Weeks 533 crane that is sitting atop a marine crane barge at the wind farm site. It is the largest revolving, floating crane on the east coast.

The 500-ton capacity crane is notorious for lifting and depositing large objects like the space shuttle Endeavor onto the flight deck of the retired aircraft carrier USS Intrepid in 2012. It was also responsible for plucking the downed US Airways Flight 1549 aircraft from the Hudson River in 2009. 

The crane, with its 210-foot boom, has been a presence ever since it arrived off the coast of Block Island on Saturday, July 18. The crane is utilizing a pneumatic hammer, a forging hammer, to drive the piles, like a large nail, down into the ocean floor.

Wims said that “each leg of the jacket will have either two or three pile sections inserted into it and driven into the seabed. The pile sections are welded together,” she said.

Once the pile sections have all been driven down into the seabed through the jacket legs, they will be severed flush at the top of each leg.

The next step in the process will require the crane to set the deck platforms atop the five bottom jacket foundations. The deck platforms will then be welded to the bottom component, forming one foundation that will serve as a base for the wind turbines.

The five wind turbines, including their 240-foot long Alstom blades, will be set atop the steel foundation in the summer of 2016. Deepwater Wind expects that the Block Island Wind Farm will be operational in the fall of 2016.