Offshore windmills are a new technology in the U.S. — so new, in fact, that no commercial windmill power project has yet gotten off the ground. But the technology that will support Deepwater Wind’s windmill generators, planned for the waters of Rhode Island, comes from an old-school power industry: oil drilling.
“When it comes down to it, there’s not much difference between a foundation for an offshore oil platform and one for an offshore wind turbine,” the Providence Journal reports (see: “Louisiana builder is hard at work on R.I.'s offshore wind turbines,” by Alex Kuffner. “So in 2014, when Deepwater Wind set out to find a company to build the steel structures that would hold up the five huge wind turbines it plans to install off Block Island, it focused its search along the Gulf of Mexico, home to the nation’s offshore oil and gas industry.”
Deepwater turned to Gulf Island Fabrication, a Houma, Louisiana, steel fabricator specializing in oil-rig construction. “Very few companies can do what Gulf Island does,” the Journal reports. “It has worked on fixed rigs with foundations that are taller than the Eiffel Tower. It has built floating platforms tethered to the ocean floor in waters three-quarters of a mile deep. But until Deepwater came along it had never built a foundation for an offshore wind turbine.”
In a detailed report, the Providence Journal is following the construction of the first Rhode Island wind towers. “Each of the steel foundations for the Block Island Wind Farm is being assembled in two main sections: the jacket, which will be lowered onto the ocean floor and, at 110 feet tall, will be about two-thirds of the total structure; and the deck, which will sit on top of the jacket, hold the turbine in place, and measure 60 feet tall, a third of the total,” the paper reports.
Now, the first sections of tower are on a barge headed for Rhode Island (see: “First Deepwater Wind foundations on barge bound for R.I.,” by Alex Kuffner). “When it leaves Gulf Island’s facility sometime in the next few days, it will travel about 30 miles south to the Gulf, continue southeast, round Florida and turn north toward Block Island, a journey of about 1,800 miles that should take 15 days,” the paper reports. “While it’s en route, an installation barge with a crane operated by Weeks Marine, of New Jersey, will arrive at the project site, about three miles southeast of Block Island, to start preparations for the start of offshore construction. The cargo barge carrying the foundation sections should arrive in mid-July. Additional installation vessels, tug boats and crew vessels from Rhode Island, Massachusetts, New York and Louisiana will also make their way to the site of the wind farm as construction starts.”