National Grid to install new section of its cable
National Grid will be installing a brand new section of its sea2shore cable to address a depth issue at the Town Beach. National Grid has called the issue “complex,” and said that installation of the new section of cable will require drilling and splicing and occur some time after the summer season. Grid is currently conducting a survey of the seafloor from a lift-boat at the beach to inform its engineering.
National Grid and Ørsted’s cables became exposed due to dense sediment and shifting sands in the surf zone that prevents them from remaining buried beneath the seafloor. The cables, which were intended to be buried up to six feet deep in June of 2016, are part of the Block Island Wind Farm electrical transmission system. National Grid’s cable links the island to the mainland, while Ørsted’s export cable connects the wind farm to the island.
“National Grid is proposing to install a new segment of cable via horizontal directional drilling, which would run in parallel to the existing cable, and rejoin the existing cable at to-be-determined points offshore and on land,” said Michael Masseur, spokesman for National Grid. “We are still in the very early stages of engineering this plan, and will share more details as they become available.”
“National Grid is in the process of completing marine borings, which will help design the permanent solution for the sea2shore cable,” said Masseur. “Data collected along the cable route this winter shows that stretches of the seafloor contain dense sediment and boulders. Based on these findings, National Grid has proposed that it proceed with a horizontal directional drill along a path close to the existing cable. The engineering and design of this solution is complex and will extend beyond this summer. In the meantime, National Grid is working with all stakeholders to determine interim plans to address the cable during the upcoming summer season. We will provide more information as it becomes available.”
As for Ørsted, Meaghan Wims, a spokesperson for the company, said, “We’re working with National Grid and the Town of New Shoreham to evaluate options.” Both companies have conducted a variety of land- and sea-based surveys attempting to determine a solution to the issue.
“Ørsted jointly executed surveys with National Grid,” said Wims. “Surveys indicate that there is a greater presence of dense sediment and boulders beneath the National Grid cable compared to the Ørsted cable. Ørsted is currently working closely with National Grid to deliver the best solution for all stakeholders and to identify opportunities to collaborate.”
New Shoreham Town Manager Ed Roberge has said that the town is seeking a permanent solution regarding National Grid’s cable. As a temporary protective measure, Grid installed a protective plastic sleeve around its cable in April of 2017, but a larger section of the heavily armored cable has become exposed, making it visible 25 feet from shore at low tide.
Sam Bird, the town’s Facilities Manager, echoed Roberge’s sentiments of the need for a permanent cable solution. He told The Times that the town was not aware of National Grid’s plans to replace a section of its cable at the beach. “If that’s what they think is necessary, we’re going to have to explore what’s involved regarding timetable, etc. We want a permanent solution to this issue. Both cables are going to have to be addressed.”
Bird said that the issues with the two cables are “slightly different.” He said, the section of Ørsted’s cable that is exposed is shorter in length than National Grid’s exposed cable. “Whether or not Ørsted’s cable is capable of being buried, we don’t know.”