Port Authority will use a tunnel boring machine (TBM) to construct two tunnels underneath the Allegheny River. It will take three years to complete construction on both tunnels. The TBM weighs roughly 350 tons and is approximately 200 feet in length. With five to eight people operating the TBM, 30 to 40 feet of boring will be achieved each day. The following video demonstrates the use of the TBM on another tunnel construction project.

Watch a Tunnel Boring Machine demonstration video (6.4 MB)