Big tunnel projects usually give you one groundbreaking photo and then go dark for a couple of years while the machines grind away out of sight. The Boring Company has decided to run its Nashville dig more like a sports season, posting drone footage and performance numbers while the borers are still underground. And the September updates were actually worth the follow.<\/p>\n
We covered the setup back in July<\/a>: two 400-ton Prufrock machines, each about the length of a football field, assigned to the Music City Loop, the two-tube route the company is cutting between the Tennessee State Capitol and Nashville International Airport. Nashville Scene<\/a> puts the route at 19 miles across its two one-way tunnels, and The Boring Company has said it’ll pay for all of it, somewhere between $240 million and $300 million of its own money. Since July, the dig has gone from one machine in the ground to two machines racing each other through the rock.<\/p>\n On September 7, the company posted drone footage of Prufrock-MB1 and Prufrock-MB2 tunneling at the same time, the first clear look at the twin dig in action. The clip shows broken limestone riding a conveyor out of each bore, then climbing two side belts stacked one above the other to a shared rock pit. Hauling rock out is half the job. If the spoil can’t leave as fast as the cutterhead makes it, a machine that’s built to never stop cutting ends up stopped anyway.<\/p>\n MB2 launched from the Lot 16 worksite in August once commissioning wrapped up, per the company’s August project update<\/a>, and spent its first weeks in testing while MB1 kept grinding ahead. The company set up the race itself, by the way, asking publicly whether MB2 would catch the head start MB1 has held since February. I don’t know many construction firms that trash-talk their own equipment, and it’s a pretty effective way to keep people watching.<\/p>\n On September 11, a Friday night post put numbers on MB2’s progress: more than 1,000,000 pounds of axial thrust and more than 4,000,000 pounds of lateral gripping force to get through the Music City limestone, as The Tennessee Star<\/a> reported from the company’s update.<\/p>\n A borer can’t just floor it like a truck, because there’s nothing solid to push off down there except the tunnel itself. So Prufrock clamps grippers outward against the walls with four million pounds of squeeze, then uses that hold to drive the cutterhead into the rock face with a million pounds of shove. It’s basically doing a leg press against the inside of the hole it just dug.<\/p>\n So how hard is this rock, anyway?<\/p>\n Hard, and conveniently consistent. Core samples keep coming back at around 14,000 psi compressive strength, the company says, which is the kind of ground this machine was built for, since it lines the tunnel while it cuts and doesn’t stop for segment work. MB2 also swings 17-inch disc cutters, up from 15.5 inches on MB1, so the newer machine has more bite for the same rock.<\/p>\n The August update said Prufrock-MB3 was on track to arrive in September, fresh out of the company’s factory in Bastrop, Texas, and promised it would be “significantly more efficient from day one.” As of this writing, I can’t find a post confirming MB3 has actually rolled into Nashville. This is a company that celebrated being 2.5 feet into the ground, so my guess is you’ll know within an hour of the truck showing up.<\/p>\n Mileage is the other number missing from the feed. The company’s stated target is more than a mile of tunnel per week per machine, but it hasn’t published a running total for Nashville, so you and I are watching a race with no scoreboard. When that total does land, it’ll say more about this project than any station announcement.<\/p>\n The August update also added the JW Marriott Nashville to the station list, joining the airport station the airport authority approved 8-0, the Music City Center easement, and a private station serving the Prime, Alcove, and Paramount towers downtown. The cars doing the driving are Teslas, Model Ys and Model Xs with human drivers to start, and the headline promise hasn’t changed: roughly 10 minutes from BNA to downtown.<\/p>\n The schedule has moved, though. When we covered this in July, the company was pointing at a first operational segment in late 2026. The current line, per The Tennessee Star, is spring 2027 for the first phase. Frankly, 2027 was always the likelier date, and I’d have bet on it in July too. Nobody bores 19 miles of tube in a year, even with three machines, and for a sense of what American tunnel timelines usually look like, the 1,680-ton machine starting the new Hudson rail tunnel<\/a> just made its first cutterhead spin on a project New York’s been arguing about for decades.<\/p>\n Not everyone in town is cheering, either. Metro Council voted to formally oppose the project in March over safety and environmental concerns, and the state approvals let the digging continue anyway. That fight hasn’t gone anywhere, and so far the company’s answer has been more footage of machines making progress.<\/p>\n If MB3 does show up this month, you can bet there’ll be a video before the local news has it. The Boring Company’s last concrete update is the September 11 post of MB2 shoving through the limestone, and the company says the first riders should be making the downtown-to-airport run in spring 2027.<\/p>\n","protected":false},"excerpt":{"rendered":" Big tunnel projects usually give you one groundbreaking photo and then go dark for a couple of years while the … <\/p>\nBoth machines are in the rock now<\/h2>\n
The second machine is through the limestone<\/h2>\n
So where’s machine number three?<\/h2>\n
The first rides are now penciled in for spring 2027<\/h2>\n