Parallel Circuit Electric Transmission System Crosses York River by HDD

摘要

This paper describes the detailed, multi-disciplined approach necessary to design and construct arnthree mile river crossing project with multiple HDD segments for an electric transmissionrnsystem. The project was completed using the EPC method and involved a large group ofrnengineers and contractors to bring together the specialized technical resources required. Therngoal of the project was to extend the electric transmission system north across the York Riverrnwhich has a width of three miles at the crossing location. This included a total of six HDDrncrossings for the parallel system of 8” steel pipe requiring the construction of two platforms inrnthe river to allow HDD operations. This resulted in two shore crossings at each side of the riverrnand two water-to-water crossings between the platforms. The crossing lengths were 7,340’ (2),rn6,045’ (2), and 3,086’ (2) for a total of approximately 16,500’ for each circuit. After the HDDrnwork was completed, three electric cables were pulled through each pipe segment. The cablesrnwere then spliced on each shore and on each of the platforms. After the system was tested, thernpipelines were lifted and lowered into pre-excavated trenches within the York River andrnbackfilled. Final testing was completed successfully and the system was placed into service.