One of the large reveals made by Tesla and SpaceX Chief Elon Musk at TED2017 was his plan to create a multi-layer high-speed tunnel infrastructure to support mobility by way of electric skates and Hyperloop tubes.
A key point that he drove home for the underground tunnel network was the integration of the system into cities.
“You have to be able to integrate the entrance and exit of the tunnel seamlessly into the fabric of the city. So, by having an elevator, sort of a car skate that is on an elevator, you can integrate the entrance and exits to the tunnel network just by using 2 parking spaces.”
Musk shared a video demonstrating how skate elevators would be integrated into city streets where they await vehicles looking to be transported through the underground labyrinth of tunnels. The serial tech entrepreneur envisions loading docks wherein vehicles would simply pull into the skate, get lowered into the tunnel network, and be sent along a slot car-like track at speeds of 200 km/h ( 124 mph). The Boring Company’s tunnel network won’t simply alleviate surface congestion, it will completely transform the way we move cars, people and freight, says Musk.
It is worth noting that The Boring Company and Tesla are under control of Musk, while the Hyperloop project has been open sourced, but with support from SpaceX.
Eliminating human drivers allows the skates to move at much faster speeds than human-controlled vehicles. Fixed routes within the tunnel network further improve safety beyond the dynamic nature of human-determined driving routes. The tunnel network is also infinitely scalable. “You can alleviate any arbitrary level of open congestion with a 3D tunnel network.” and that “There’s no real limit to how many levels of tunnels you can have.”, says Musk from TED2017.
The key barrier to creating tunnels today is the exorbitant cost. The recent 2.5 mile expansion to the Los Angeles subway system came at a cost of nearly $1 billion per mile. Musk and team at the Boring Company hope to cut the cost of tunneling by a significant amount by streamlining the tunneling process and reinventing the machines that help facilitate the digging.
Building Tunnels For Less
First, the team is looking to cut the diameter of the tunnels they dig, moving from the traditional tunnel diameter for passenger vehicles of 26 to 28-feet to a 12-foot standard diameter which would be sufficient for the Tesla skate. On the surface, this might not seem like a lot, but cutting the diameter by 50% cuts the cross sectional area by a factor of four. This is significant as the speed and cost of tunneling is largely driven by the amount of cross sectional area to dig. Being able to cut out 75% of the time associated with digging comes with enormous cost savings.
Second, the team plans to attack head-on the way tunneling machines currently dig. Traditional machines dig, slowly and incrementally, then stop to install reinforcements to support the newly exposed earthen walls. Musk and team are working to install the reinforcements continuously thus eliminating the need to pause operations. This integration is expected to increase the speed of the overall process by as much as 50%.
Finally, the team believes that current digging machines are nowhere near their power and thermal limits, and is looking to ‘jack up the power’ to the digging machines. Doing this, the team hopes to increase the speed by a factor of 4 or 5 on top of the other improvements being suggested by Musk.
Musk also revealed that The Boring Company has a pet snail named Gary who can currently travel at 14 times the speed of existing tunneling machines. While this is more a testament about how slow the boring process is than the amazing speed of Gary, it is a fun target for the team, to be able to build tunnels quicker than Gary can crawl, and continues the comedic spin on the new company.
These tunnels could be kept at or near a vacuum to reduce or eliminate air resistance for all the moving objects within it. Curiously, Musk shared that,
“To withstand the water table, you have to design a wall to be able to withstand 5 or 6 atmospheres. To go to vacuum, you only need to be able to withstand 1 atmosphere.”
It is clear that Musk is very excited about this new Boring Company. He indicated during his sit down at TED2017 that he spends 2-3% of his time on the project, noting that it’s essentially being run as not much more than an intern project with a used boring machine and a few people dedicating partial effort to it.