South Fork Wind is America’s first commerical scale offshore wind farm, designed to generate 132 MW of clean energy, that is powering 70,000 homes across Long Island. Grace Industries was contracted for the onshore underground duct bank system. This system involved the installation of a 4-mile, 138kV Alternating Current (AC) underground duct bank running from the Transition Joint Bay (TJB) on Beach Lane to the South Fork Wind (SFW) Interconnection Substation in East Hampton. In addition, 2-miles of this system were installed within the Town of East Hamptom roadways, while the remaing two miles were contructed along the LIRR right-of-way. The work along the LIRR required the installation of 2,700 linear feet of steel sheeting retaining wall and tiebacks to meet the Cooper E-80 loading standards mandated by the railroad. Additionally, the project included a 900-foot single-circuit 69kV AC duct bank to interconnect the SFW substation with the existing PSEG-LI East Hampton Substation. All duct banks were installed using open-cut trenching and were backfilled with thermal concrete and fluidized thermal backfill (FTB).
The Transition Joint Bay (TJB) Vault work involved furnishing and installing a first-of-its-kind vault, serving as the transition point between the marine and onshore cables. Due to challenging groundwater conditions, a cofferdam and tremie plug were used to control water intrusion and comply with dewatering permit requirements. The project also included the furnishing and installation of 9 splice vaults and 11 communication handholes. Restoration efforts featured curb-to-curb asphalt resurfacing of all impacted roadways and landscape restoration, including plantings along the LIRR right-of-way.
