Prufrock

Prufrock is The Boring Company's own all-electric tunnel boring machine, built to dig tunnels fast enough and cheaply enough that underground transit finally makes sense to build across a whole city. A tunnel boring machine (TBM) is the giant cylinder-shaped drill that grinds out a tunnel and lines it with concrete as it moves forward. Prufrock is the company's from-scratch successor to its earlier machine, Godot, and it is the engine behind the car-carrying "Loop" tunnels The Boring Company is digging beneath Las Vegas and now other cities.

What is Prufrock

Prufrock is a family of in-house TBMs built to attack the two things that make tunneling slow and painfully expensive. The current production machine is Prufrock-4, the company's first designed to run with nobody in the tunnel, with Prufrock-5, -6, and -7 being built at The Boring Factory in Texas. Prufrock-2 set the company's record for the longest single drive in March 2026, finishing a 2.28-mile tunnel near Westgate Las Vegas after moving roughly 68,000 cubic yards of dirt. The Loop tunnels it leaves behind run 12 feet across and carry Tesla vehicles between stations at up to 70 mph.

Why Prufrock Exists

Elon founded The Boring Company in December 2016 around a simple mission, to "solve the problem of soul-destroying traffic." The problem he saw was plain: ordinary tunneling is so slow and so costly that almost no new transit miles ever get dug, with fewer than 20 miles of subway built across the whole United States in the prior 20 years. Two things are mostly to blame. The first is the weeks spent digging a launch pit before a single foot of tunnel even exists. The second is stop-and-go mining, where the machine halts every 5 feet to install its lining. Prufrock is a from-scratch design meant to erase both, aiming to move underground at roughly one-tenth of human walking speed.

How it Works

Three ideas set Prufrock apart. "Porpoising" lets the machine dive straight into the ground from the surface within about 24 hours, with no dug-out pit and no towering crane. "Continuous mining" installs the precast concrete lining at the same time the cutting head digs, instead of stopping every 5 feet. And "Zero-People-in-Tunnel" (ZPIT) means the machine is built to run with nobody underground during normal work, which the company calls the safest, fastest, and cheapest way to tunnel. The speed goals are bold: faster than 1 mile a week, six times quicker than Godot, with a longer-term target near 7 miles a day. The record drive fed dirt out along about 4.8 miles of conveyor belt, driven by six motors that together make 825 horsepower.

The Economics of Prufrock

Prufrock's economics are the entire bet. The Boring Company is trying to push all-in tunnel cost below 8 million dollars a mile while driving speed past 1 mile a week, and that combination is what would let it sell tunnels at a profit instead of building them as one-off public projects. To fund the effort, the company's April 2022 Series C raised 675 million dollars at a 5.675 billion dollar valuation, with the money aimed at speeding up Prufrock research and growing Loop projects. Every faster, cheaper version widens the profit on a product that, until recently, almost no one could afford to buy in bulk.

Current Status of Prufrock

The proof is in Las Vegas, where Prufrock machines dug a network that has now carried more than 4 million passengers across 11 stations. The LVCC Loop, the longest stretch running today, opened in 2021 and grew with a 2024 expansion that added two stations. Even so, the map that is open today is still a thin slice of what regulators have already approved, and that gap is the part worth watching.

What Comes Next

The model is now leaving Nevada. In February 2026, Nashville's Music City Loop got its construction permit, and tunneling is under way with two TBMs at the Lot 16 launch site near the Tennessee State Capitol, aiming for a roughly 8-minute trip from the airport to Lower Broadway. A Dubai Loop is under contract, planned at about 6.4 kilometers and four stations. The Boring Company calls Prufrock-4 its smartest, fastest and safest TBM, and it holds up continuous mining and ZPIT as the goal, while the next versions climb the ladder in Texas. Each one is meant to be smarter, faster, and cheaper than the last, and that is how the cost keeps coming down.

The Bottom Line

Prufrock is Elon's bet that tunneling can be made fast and cheap enough to turn dense, stacked transit networks from a fantasy into real infrastructure. Whether the cost falls far enough to make that pay off everywhere is still an open question. But Las Vegas already shows the machine can dig, and 4 million riders show people will use what it builds. Betting against Elon on a hard engineering problem has rarely paid off.

Related

Keep reading: Las Vegas Loop, Hawthorne Test Tunnel. Zoom out to the The Boring Company overview, or open the Ventures Map.