The Gateway Development Commission (GDC) has approved a change order to the Hudson River Ground Stabilisation (HRGS) Project contract to aid tunnel boring.
The change adds the removal of approximately 500 submerged wooden piles remaining from the demolition of Pier 68 to reduce the possibility of the TBMs meeting obstructions along the alignment.
The change order is valued at US$88m (€77m) and the HRGS contractor, Weeks Marine, is expected to start the work later this year.
The HRGS Project involves removing obstructions from the tunnel alignment then mixing lightweight concrete into the riverbed to ensure it is firm enough for the machines to dig through.
The project was originally scoped to prepare a 366m-long, 30.5m-wide section of the riverbed for tunnel boring. Work began in the middle of the Hudson River in 2024 and is progressing eastward toward Manhattan.
The change order extends the original work area approximately 81m toward Manhattan and adds additional activities to address piles remaining in the riverbed from the demolition of Pier 68.
Pier 68 was built in the late 1800s as a freight pier for the Delaware, Lackawanna and Western Railroad. It was damaged by a fire in 1964 and subsequently demolished, but many of the wooden piles remain in the riverbed.
Weeks Marine removed a small number of piles in 2025 to better understand the work required to prepare this section of the riverbed for tunnel boring. Lessons learned from this test project informed the change order.
In April, GDC awarded the Hudson River Tunnel construction package to Traylor/Walsh/Skanska JV. Two mixed-use TBMs will be used to build the stretch of the new tunnel tubes under the Hudson River. It requires tunnelling through mixed conditions, including rock, soft soil, and fill that was used to expand the Manhattan shoreline.
