Elon Musk Shows Off The Boring Company's LA Tunnel (theverge.com)

Elon Musk is keeping to his promise of opening the Boring Company's proof-of-concept tunnel to the public on December 10th. The two-mile-long Los Angeles tunnel takes 30 seconds to get through via a sped-up video. The Verge reports: Construction on the tunnel began over a year ago, and extends from SpaceX's Hawthorne, California headquarters, to an LA suburb. Since then, the Boring Company has been selected to build tunnels for Chicago and Washington DC, and has sketched out plans to build a larger network of tunnels under LA, with the aim of reducing congestion. The tunnels will theoretically use autonomous, electric skates to move anywhere from 8 to 16 people along the system's rails at speeds anywhere from 124 mph to 155mph.

Comments

200 to 250 km/h

[evanh]

Obviously just round numbers, but US media still can't bring themselves to use the quoted numbers. Instead they leave them out and do their best to convert to specific imperial numbers. Duh!

Re:200 to 250 km/h

[Rei]

1) The curves are at the start and end (accel / decel). The trip will be purely accel and then decel.

2) This is just a 3km test tunnel. I seriously doubt the top speeds will be anywhere near those of Loop.

3) It's not even clear that Loop is going to use rails at all. As of the last discussions, it was still under investigation as to which option would be best.

4) Boring Company's goal isn't to make some sort of uber-sepecial-fancy tunnels. Their goal is to make tunnels cheaply and quickly.

5) The test tunnel's TBM (Godot) is only the first phase of that. They still have two more generations of TBMs to go through (Linestorm, and ultimately Prufrock). Godot is still pretty standard, although they modified the means to remove tailings, switching from diesel to battery-powered locomotives. Linestorm will make tunnels with passing zones so inbound and outbound trains can pass each other, and the TBM will run on battery packs delivered by the inbound locomotives. These two changes will save them from having to lay A) the powerful ventilation systems normally used to clear locomotive exhaust, and
B) the expensive power cables. I'm not sure if Linestorm is going to take the first steps toward automatic continuous casing or whether that's going to wait for Prufrock (same with the hot-swappable chilled cutting discs). Continuous casing and hot-swappable discs would on their own double tunneling speeds. But ultimately their goal is to additionally push cutting head speeds up to several times higher than they are today, since they're nowhere near physical limits.

You walk before you run.

Subways

[bluegutang]

Musk proposes that each vehicle carry only 8 to 16 passengers. A full subway train, in contrast, carries over 1000 passengers. Musk plans for a vehicle every 30 seconds, compared to every 90 seconds for a modern subway line. So Musk's system will be able to carry 16-32 people per minute, compared to a subway which carries around 700 people per minute.

Construction costs would also be higher for Musk's system. He plans for tunnels to have 14' diameter. However, subway tunnels are often constructed with 12' or smaller diameter. Musk claims to be lowering the cost of tunneling, but those cheap tunnels could be used for any purpose, including a subway.

At higher costs for a tiny fraction of the capacity, why would a city ever choose Musk's system?