The Boring Company's First Tunnel Is All Dug Up (arstechnica.com)

Elon Musk has tweeted images of his tunnel-boring machine with the caption "Congratulations @BoringCompany on completing the LA/Hawthorne tunnel! Cutting edge technology!" The update comes a couple weeks after Musk showed off the Boring Company's LA tunnel and said it was "on track" for an opening party on December 10th. Ars Technica reports: The tunnel appears to end at what The Boring Company calls "O'Leary Station," which is located on a piece of commercial property that The Boring Company purchased in Hawthorne. This location is close to, but not the same as, the location for which The Boring Company recently received approval to build a tunnel entrance within a residential garage. "O'Leary Station" references a SpaceX/Boring Company employee who recently passed away. The Hawthorne tunnel is just a test tunnel for The Boring Company, which also plans to complete a second, 3.6-mile, one-way tunnel from Los Angeles Metro to Dodger Stadium. Eventually, the company wants to dig a tunnel in Chicago between O'Hare International Airport and the city's downtown.

Comments

Not sure what is new here.

[SuricouRaven]

It's a standard TBM. Making a tunnel. Cool, yes, but what's the advancement here? Is is any faster or cheaper than existing tunnel-making machines? Can it make smaller tunnels, which could be quite valuable in urban areas? Why all the excitement?

Re: Not sure what is new here.

[K. S. Kyosuke]

You have to start with existing equipment before you find out what's wrong with it. Isn't that how it usually works?

Re: Not sure what is new here.

[Rei]

Indeed. They're not magically jumping straight to Prufrock. Godot is mostly (but not entirely) standard. Prufrock is their target, which involves continuous casing, hot swappable cutting discs, and much faster head speeds. Linestorm is intermediary between them.

Godot is operational now. Linestorm is under construction. Prufrock is in design.

Re:Not sure what is new here.

[Joce640k]

Nope, it's because they can do it much faster/cheaper than before.

If you can make holes cheaply then it opens up a lot of possibilities.

Re:Not sure what is new here.

[Rei]

Meanwhile in the real world, Tesla consumes more EV batteries than everyone else in the world combined, with Giga alone making about half of the world's total (~20GWh/yr out of ~40GWh/yr). Tesla's US sales make everyone else's look like a rounding error.

As for Boring Company, their goals are low-cost PRT. That's the whole point of Loop and Hyperloop. But maybe you'd feel better if the rich were banned from riding? Even their first non-demonstration-scale project (the Chicago Loop) is to charge half as much as an Uber ride. By the time they're up to Prufrock, fares are supposed to be cheaper than bus tickets (but go straight to your destination at high speeds).

It's one thing to be dubious about their probability of success. But it's an entirely different thing to misrepresent their goals.

As for your comments about turning "this tunnel"... "this tunnel" is simply a demonstrator. Little more than an amusement park ride for the general public. It's neither meant as a transportation solution nor to make money; it's meant to inform their engineering for their subsequent tunneling activities. Heck, they're outright planning to have it end at a watchtower made from compressed tailings bricks, manned by a knight who shouts insults at passers-by in a bad French accent.

Re:Not sure what is new here.

[Gavagai80]

The fact that it makes much smaller tunnels than standard boring machines is a large part of the cost-saving strategy (although not the only part). The Loop going into it on which people will travel up to 150 MPH is notable for being optimized to work in small spaces, as opposed to subway trains.

Basically, Elon found that small tunnels have drastic cost savings which can make them economical to build many more of... if they have a use. So he got some engineers to design a transport system (Loop, not Hyperloop) which can fit into what we can afford to tunnel. And that's how The Boring Company was born, although they also have a bunch of other theoretical cost reduction ideas largely drawn from SpaceX strategies.

Re:Not sure what is new here.

[bluegutang]

Nope, it's because they promise that someday they will be able to do it much faster/cheaper than before, but not yet.

FTFY

Re:Not sure what is new here.

[140Mandak262Jamuna]

The standard tunnel boring machine uses diesel engines. The boring company is using electric motors and battery packs to power the drill head. That is where the innovation and technology comes in. Tesla cars have the same four wheels and the body and the steering. Is it same as an gasoline car?

The diesel engine in confined space will asphyxiate the workers. Supplying air and taking away the exhaust is a very complex operation, adding to the costs. Especially on long tunnels.

Having said that, competition will catch up quickly. They can house the diesel engines at the entrance or tap into the grid and send power by cables to the drill head. Not sure how feasible it would be though. Also looks like the boring company is planning on autonomous self driving tubs to take the tilings away and to bring fresh batteries. This too could reduce the cost of tunneling. Again, other can easily copy.

Tunneling has changed for ever. Whether The Boring Company will get a big slice of the market and windfall, I am not sure. But 20 years from now, all tunnel boring ops will be like what the boring company is doing now.

Re:Not sure what is new here.

[SuricouRaven]

We'll see. SpaceX is certainly delivering on their technological promises, and they have the serious contracts to prove it. If nothing else, Musk is able to hire people who can make stuff work. I just think we should save some of the hype until he actually shows they can do something new and better, even if it's only a contract for someone relatively mundane, like construction of a fairly contentional tunnel but at lower cost than is currently achievable.

Re:Not sure what is new here.

[140Mandak262Jamuna]

Rei, glad you are back. You seemed to be missing for a while, vacation perhaps?

Anyway, please do some reading up on the reports about battery pack + electric motors replacing the diesel engines in the boring head. Saves on fuel costs, and ventilation costs. Also tiling being carried away in self driving autonomous tubs, saving conveyor belt costs.

People are thinking of the skates and fast urban commuting over several miles. But If the cost savings come through tunnels become competitive to over pass building, so we might see a few stacks of the over passes buried underground.

Re: Not sure what is new here.

[c6gunner]

the upright-landing thing goes wrong quite a lot they just don't show you

Your entire post is completely wrong and very stupid, but this conspiracy-mongering is egregiously stupid. The history of every booster ever built by SpaceX is completely public, and wikipedia has a good breakdown of them. There are hundreds of people tracking every launch and recovery, and even an android app with all the relevant details. You're just making up complete nonsense.

For the record, spacex has attempts to land 37 boosters and has succeeded 31 times. The first 5 failures all occurred between 2014 and 2016. In 2017 every recovery attempt was a success. The single failure in 2018 happened while attempting to recover all 3 segments of the Falcon Heavy; 2 were recovered on land while the third crashed near the drone ship after running out of ignition fluid.

Re:Not sure what is new here.

[Marxist Hacker 42]

And he hasn't done that yet- this came in over budget and about twice the cost of a conventional tunnel.

Re: Not sure what is new here.

[Rei]

Ignoring the troll above me.

Continuous casing - I'm assuming by this you mean concrete. This method can only be used when the ground is pretty strong and self supporting.

No. I mean exactly what I said: the TBM does not stop for casing. They're designing for casing of new segments - regardless of the type of casing - to be conducted while the TBM is still pushing off the previous casing segment(s), and without it having to stop to advance the segments that it pushes off of. In-situ concrete casting - what you suggested as an alternative - has never been publicly discussed by TBC.

Hot swappable discs - as by definition the discs installed are all required to excavate the complete face area, if any are withdrawn from service you have incomplete excavation. You could only possibly do this by having overlapping cutter heads, which would duplicate costs for negligible gain

Correct on everything but "negligible gain". The cost of extra cutter heads is far smaller than the cost savings of not having to stop the TBM.

considering typical downtime for cutter heads is a few hours every 3 days or so

Where are you getting "a few hours every 3 days or so"? That's in no way normal. The average TBM only spends about 40% of its time actually boring (see Figure 5).

Even if you did only have a 24:1 operation:downtime ratio, that would still justify the use of extra cutter discs and hot swapping. Tunneling costs are linearly proportional to tunneling speeds. Cutting disc costs are a small fraction thereof. And the more discs you have, the more the wear is spread out.

Faster head speeds - the cutting ability of a cutting disc is dictated by the rotational head speed and pressure applied at the cutting edge. Too much pressure/speed and you get accelerated wear and too much heat generated which also leads to accelerated disc wear.

Precisely. Which is why TBC's plan to increase head speeds is to use highly cooled, advanced alloy cutting discs. Because - to reiterate - disc costs are a small fraction of the total project costs, so increasing their costs to dramatically increase tunneling speeds is a no-brainer.

The best material we have is tungsten carbide mounted in a ceramic matrix

Carbide bits (not very commonly used on TBMs) are used for abrasion resistance, not for overcoming thermal limitations. Generally TBM cutting discs are simple martensitic steel alloys, and wear is by tribocorrosion. The limited use of carbide bits on TBMs has generally been in soft ground, to avoid slip-related wear on the discs. Cutting discs cut via pressure-induced fracture of the rock, and tungsten carbide is a more brittle material than steel. When you use carbide bits on hard rock, they tend to fracture, and then the uneven load quickly causes the rest of the bits to fracture.

There are few companies in the US that have more experience with advanced heat-and-corrosion-resistant alloys - and keeping them cool under extreme conditions - than SpaceX. You don't get more hostile conditions than rocket engines, and SpaceX has been pushing the bounds on them to extremes (check out the sort of conditions that Raptor operates in, it's nuts). TBC's goal is to apply that knowledge to cutting discs.

Re:Not sure what is new here.

[Rei]

There's some confusion here. As a general rule, TBMs are powered by high voltage lines carrying a couple megawatts of power. Diesel-powered trains carry the spoils away, where conveyors are not used. Powering a TBM with HV lines requires laying the lines, a quite expensive affair that TBC is replacing with hot-swapped battery packs (simple calculations show that it should only take about half a million dollars in batteries), carried in and out by the spoils trains. Diesel trains require powerful ventilation systems, for obvious reasons, which are also another significant capital cost which is eliminated by the use of battery-powered electric trains.

Re:Not sure what is new here.

[apoc.famine]

No, no we can't.

Surface trains already kill a lot of people (and animals) every year, and to add more surface lines requires eminent domain and the destruction of existing buildings and habitats. People die on the order of daily at at-grade railroad crossings. We simply can't improve our rail connections between cities at the surface level. Sure, we could elevate all of the tracks, but that's expensive and really shitty to live near.

Train tracks are a significant barrier for everyone, and the more trains you have, the more of a barrier they become.

Going underground gets rid of all of these problems. If The Boring Company can really get tunnel costs down as far as they think they can, it will indeed revolutionize transport. And if it turns out that people aren't interested in traveling in a high-speed coffin underground, that's fine. We can still replace a lot of our trucking and train shipments, which will free up a lot more space on the surface for the humans.

Re:Not sure what is new here.

[serviscope_minor]

Buses are crap and the only reason we use them is that drivers are expensive and it's hard to get rail into places these days.

Depends where you live. There's an excellent bus network in London. Expense of drivers is not by a long way the reason we use buses. They're also a much higher density form of transport than cars. A double decker in rush hour can hold nearly a hundred people and takes up less space than two cars when you take stopping distance into account. It's only a little over 2 when everything's stacked up.

If you visit a major transport hub at rush hour, the number of people arriving by bus is huge. Regardles of the price of drivers, a 6 lane motorway would not be able to deliver people that fast if it was one commuter per car (or even 4) and you don't even hav a dual carriage way available.

Re:Not sure what is new here.

[nukenerd]

Surface trains already kill a lot of people (and animals) every year,... daily at at-grade railroad crossings.

You quote USA statistics, where at-grade crossings and car drivers seeking Darwin awards seem to be the norm. OTOH, in the UK for example the numbers killed at crossings (or elsewhere or anyhow on the railway) are tiny compared with eg general road accidents, although when they occur they get bigger headlines just for their rarity. Even so, that does not stop more road building.

Unlike in the USA, UK railways are fenced, even in remote areas, and fencing is orders of magnitude less expensive than tunnels or tracks on stilts (like Hyperloop). In any case, no new railway would be built in the UK with any at-grade crossings. As for making a "barrier", you are just not conscious of railways as barriers in the UK, and I believe that half the population are scarcely aware that the railways even exist.

We simply can't improve our rail connections between cities at the surface level.

USA outlook again. Funny that the rest of the world is improving rail connections all the time, even from a starting point well in advance of the USA's present position. The UK's High Speed 2. for example.

Re: Not sure what is new here.

[adolf]

When you own the world's largest battery factory, you build things that use batteries.

Re:Not sure what is new here.

[mikael]

In many cases, tunnel boring machines are custom built and buried in a side channel once construction is complete...

https://untappedcities.com/201...

There are hundreds of such machines buried across the world. They are just written off as part of the construction expense, as no one really wants the cost of extracting them overground.