Hampton Roads Crossing – Submerged Pipelines

5.5 miles of 24” diameter API 5L X60 steel pipe were installed across Hampton Roads Harbor and the Elizabeth River for the marine segment of the Virginia Natural Gas HRX Project.  Seven horizontal directional drills (HDDs), including one world record length drill of 7,357’ and three “water-to-water” drills over 3000’ each, and a  5100’ length of concrete weight coated pipe, bottom pulled across the harbor, defined the crossing.  Five flanged tie-in spools were fabricated, tested and installed to complete the line.  Over 200,000 cubic yards of dredging was required in total for the HDD entry/exit pits and the mile long trench for the weight coated pipe.  The pipe was protected at each tie-in location by 4.5” thick concrete mattresses and an additional 6’ of rock riprap placed over the pipe.  All work was completed per DOT requirements.