American Roll-On Roll-Off Carrier (ARC) recently discharged a large Tunnel Boring Machine (TBM) at the Port of Norfolk’s NIT North Terminal in support of the Hampton Roads Bridge-Tunnel (HRBT) Expansion Project.
Hampton Roads Connector Partners (HRCP), the project’s joint construction venture, awarded a contract to Herrenknecht of Germany for construction of the TBM which took 14 months to build at their facility in Schwanau, Germany. The TBM was shipped through the port of Antwerp, Belgium to Norfolk on the ARC vessel M/V Freedom.
“It was a true team effort and a fantastic demonstration of ARC’s uniquely capable and flexible U.S.-flag fleet in support of the HRBT project”, said Chris Barber, ARC’s Sr Director Sales and project lead for the TBM.
Once reassembled, the TBM will be 46 feet tall, more than 430 feet long, and weigh more than 9 million pounds. Powered by 12 electric motors totaling 12,000 horsepower, the TBM was custom built for the HRBT Expansion Project and will be used to bore new twin tunnels next to the existing Hampton Roads Bridge Tunnel.
The TBM has been named “Mary the TBM” in honor of Mary Jackson of Hampton, VA, a pioneering mathematician and aerospace engineer noted for her crucial contributions to the NASA Space Program. Jackson’s story features prominently in the 2016 book Hidden Figures and the subsequent film adaption released the same year. In 2021, NASA’s Washington, DC headquarters was renamed in her honor.
The TBM will launch from the South Island (Norfolk side) and bore at a rate of about 50 feet per day until it reaches the layer of soil known as the Yorktown layer, approximately 50 feet below the current tunnels. Tunneling is expected to begin in 2022 and will take more than two years to complete.
Video Simulation of the Tunnel Boring Process: