After years of delays, funding fights, and political back-and-forth, steel is finally chewing through rock. Officials gathered in North Bergen, New Jersey this week to celebrate the start of tunnel boring on the Hudson Tunnel Project, the first new rail tunnel to be dug beneath the Hudson River in more than a century. A massive tunnel boring machine, fitted with a roughly 28-foot cutterhead, is set to begin grinding through the Palisades within days, carving out the first mile of what will eventually become a brand new rail connection between New Jersey and New York. A second identical machine is expected to launch shortly after, with both working in tandem to bore parallel tubes toward the Hudson County Access Shaft near Weehawken.

This is the marquee piece of the $16 billion Gateway Program, a project designed to build two new tunnels that will finally ease the chokehold on one of the busiest rail corridors in the country, one relied on by more than 200,000 riders every single day. Just as important, the new tunnels will allow crews to fully rehabilitate the century-old North River Tunnel, the aging, Sandy-damaged tube that Amtrak and NJ Transit trains currently depend on and that has been a chronic source of delays and breakdowns for years. The initial hard-rock boring phase will grind forward at roughly 30 feet a day, a process expected to take about a year, before crews swap in different machines built specifically for the softer ground beneath the river itself. If everything stays on track, the new tunnels are targeted to be carrying passengers by around 2035.