August 28, 2015

LEEDCo begins taking core samples of Lake Erie bottom

By John Funk, The Plain Dealer | August 27, 2015 |

A pilot project to determine whether wind turbines can be built in Lake Erie and survive its icy winter wrath takes a major step forward over the next ten days.

Before the Lake Erie Energy Development Corporation, or LEEDCo, can build anything, its engineers must have a detailed analysis of the Lake’s bottom.

The Farrell 256, a 200-foot crane barge owned and operated by the Donjon Marine Co. of Erie, Pa., will carry a crew out to the planned turbine site seven miles northwest of downtown Cleveland on Thursday.

Engineers will work around the clock in 12-hour shifts to pull core samples of earth to a depth of 75 feet below the lake bottom, said David Karpinski, an engineer and LEEDCo’s vice president of operations.

Core samples will be taken from the proposed sites of each of the six turbines, which LEEDCo plans to build in a straight line about 2,500 feet apart.

The Holiday, a 65-foot, Cleveland-based charter boat owned by Trident Marine Corp., will shuttle crews from the Port of Cleveland to the work site twice a day.

The work could take longer than 10 days, depending on the weather, Karpinski said. The core samples will be analyzed at Case Western Reserve University.

The core sample analysis and other tests are the same type of tests that are done for constructing buildings on land, Karpinski added.

LEEDCo has also contracted with Gardline Geosurvey, a UK company that recently completed similar work for a Maryland offshore wind project, and DOSECC Exploration Services, a Utah-based firm that conducted the geo-technical survey for the Block Island, Rhode Island, wind farm project in the Atlantic Ocean, three miles offshore.

The U.S. Department of Energy awarded a grant to LEEDCo in 2014 to pay for the work.

LEEDCo is planning to use a novel foundation that will not involve driving steel piles into the shale rock below the soil. Instead, LEEDCo is turning to a Danish company with a unique design.

Denmark-based Universal Foundation has for more than a decade been testing a wind turbine foundation design that eliminates underwater excavation or the need to drive steel piles deep into a Lake or sea bottom.

The company’s foundation system has been getting a lot of attention in Europe because its design saves money and time and is thought to be less environmentally disruptive.

Universal Foundation’s “Mono Bucket foundation” is an all-in-one steel structure – a monopile shaft attached to the bottom of a large-diameter bucket.

The bucket is sunk and placed open-side down on the sea or lake bottom with the pole extending toward the surface of the water.

And when engineers pump out the water trapped in the inverted bucket, the structure sinks itself into the sea or lake bottom, said Karpinski.

The all-steel mono bucket foundation could be built here.

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