Deepwater Wind connects its cable
On the afternoon of Saturday, May 14, Deepwater Wind floated its eight-mile long export cable ashore via airbags from the cable-laying-barge CLB Big Max, which was parked off Town Beach. The barge contains the entire submarine cable for the Block Island Wind Farm project. The cable was then connected to the land-based transmission system after it passed over the cofferdam wall at the beach and was threaded through a piece of equipment called a jet plow into a pipe running under the dunes to a manhole located in the north parking lot.
It was a meaningful moment for Deepwater Wind, as the accomplishment indicated that the wind energy developer had reached another milestone and was one step closer to linking its 30-megawatt wind farm to Block Island’s infrastructure.
Deepwater Wind spokesperson Meaghan Wims told The Block Island Times that “cable lay operations remain on-schedule. The cable lay vessel is currently installing the export cable from Crescent Beach to the northern-most turbine foundation. When the cable is pulled into the first foundation successfully, the current plan is for the vessel to sail to Scarborough Beach and begin the installation of the transmission cable to the island.”
Deepwater Wind began installing its export cable on May 11, and noted that the installation process would take approximately 10 days to complete. Deepwater Wind has employed two lift boats to aid with the installation process at the wind farm site: the Lift Boat Michael Eymard and the Lift Boat Lacie Eymard.
With the export cable now tied into the land-based cable system at the Town Beach, Deepwater Wind has removed its cofferdam from the beach. The CLB Big Max is now in the process of installing the export cable under the water and out to the wind farm site. During installation the CLB Big Max will be towing the jet plow along the seafloor as it clears a trench for installing the export cable six-feet beneath the seabed.
The jet plow that is being used for the cable portion of the wind farm project is called the Sea Venture II Jet Sled that is produced by Engineering Technology Applications (ETA) based in the United Kingdom. Per its website, ETA has “developed a highly successful range of jetting sleds for the burial of cables and pipelines. Extensive research and trials conducted by ETA have led to a design that optimizes jetting efficiency resulting in minimum water pump requirements for a given burial depth and soil type.”
The Sea Venture II Jet Sled is approximately 31-feet in length, 15-feet in width and 15-feet in height. The jet plow is towed along the seafloor where it uses its water jets to unearth a trench to install the submarine cable in the seabed. For information regarding the jet plow go to: http://www.eta-ltd.com/jettingsleds
Once Deepwater Wind completes its export cable installation from Block Island to the wind farm site the CLB Big Max will begin installing National Grid’s sea2shore cable from the mainland to the island.