Boring Company's Second Tunnel Machine Ready to Dig in Nashville

LAS VEGAS — The Boring Company has commissioned its second Prufrock tunnel boring machine, effectively doubling its digging power beneath Nashville and pushing the Music City Loop from planning into full-scale construction. The company confirmed on June 17 that Prufrock MB2 had finished commissioning, and teased that a third machine, MB3, will ship in August.

MB2 arrives with meaningful upgrades. Lessons learned from launching and operating the first machine, MB1, have already been folded into its successor to improve efficiency before it breaks ground.

A Different Way to Tunnel

Conventional tunnel boring is slow because it is a stop-and-go process: dig about five feet, halt, install precast concrete liner segments, then resume. Prufrock is engineered to install the tunnel lining continuously while it mines, eliminating those interruptions. It also skips the excavated launch pit that traditional projects require — the machine arrives on a truck, tilts down, and launches into the ground within 24 hours.

When a tunnel is finished, Prufrock emerges and drives onto a trailer to its next site, avoiding expensive cranes and pit excavation. The machine is fully electric and, according to Teslarati, runs with zero people in the tunnel during normal operation, controlled remotely from a surface operations center.

Nashville Picks Up Speed

Nashville was chosen in part for its strong rock conditions, which suit the Prufrock machines, and for a comparatively streamlined permitting path. Progress has been steady: 37 of the 45 required permits and approvals are now in hand, including a fully executed state tunnel permit authorizing 25 miles of tunnel, unanimous airport authority approval for a Nashville International Airport station, and the city's first residential station agreement.

The Music City Loop is envisioned as an underground network that moves passengers in electric vehicles through tunnels at highway speeds, bypassing surface traffic entirely.

Building a Repeatable Playbook

With MB1 already tunneling, MB2 commissioned, and MB3 shipping in August, Nashville is becoming a live proving ground for tunneling at scale — a template the company has refined since its Las Vegas Loop build-out. The broader goal remains making underground transit a practical alternative to crowded surface roads in major metros. If MB2 and MB3 hit their stride alongside MB1, the pace of progress beneath Nashville could accelerate quickly through the back half of 2026.