Prufrock-MB ("Main Beam") is the hard-rock variant of Prufrock. It is designed for geologies where the natural rock itself is competent as the tunnel liner. Prufrock-MB1 and Prufrock-MB2 are currently mining the 10,000+ psi limestone in Nashville for Music City Loop.
Prufrock
See how Prufrock continuously mines — pushing and building at the same time. The machines are remotely controlled from our Bastrop Operations Center.
Prufrock is targeting a speed of 1 mile per week and an all-in cost of a Loop Transportation tunnel of less than $5M/mile. Five critical technologies/architectures to achieve this are listed below.
The Fastest, Smartest, Safest Tunnel Boring Machine in the World
Porpoising
To start the tunnel, Prufrock arrives on a truck, tilts down, and launches into the ground within 24 hours. To finish the tunnel, Prufrock emerges from the ground and mines onto a trailer (called "The Monster"), which then drives to its next launch site. This eliminates the need to excavate expensive pits or use enormous cranes.
Continuous Mining
All soft-soil TBMs mine ~5 feet, stop, erect the precast concrete tunnel liner, and then start over. Prufrock is designed to install the tunnel liner simultaneously with mining, eliminating the need to stop the TBM every 5 feet.
Zero-People-In-Tunnel (ZPIT)
Prufrock is designed to have zero people in the tunnel during normal operations. This is the safest, fastest, and least expensive method of tunneling. The ZPIT operation is controlled from the Operations Control Center, which supports the expanding fleet of Prufrock tunnel boring machines.
Vertical Integration
TBC designs and manufactures the TBMs and tunnel liners, designs the Loop transportation system, builds out Loop, and operates Loop. This promotes rapid iteration and large cost reductions.
Tunnel/TBM Size and Design Standardization
TBC maintains the same tunnel design for all projects to avoid "reinventing the wheel" for every tunnel. In order to accommodate different geologies with a standard design, TBC maintains conservatively large structural factors of safety.
Prufrock-MB
Boring Factory Tours
Tour the Boring Factory in Bastrop, TX — the first-ever recorded walk-through of TBC headquarters and the Prufrock production line, hosted by The Boring Company: Factory Tour Part 1 and Part 2 (Tesla Owners Silicon Valley, July 2026).
