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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.
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.
"Define 'interesting'". "Oh God, oh God, we're all gonna die?"
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.
No sig today...
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.
"Define 'interesting'". "Oh God, oh God, we're all gonna die?"
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.
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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.
And he hasn't done that yet- this came in over budget and about twice the cost of a conventional tunnel.
SJW: a person who perceives an injustice, and while correcting it, commits a greater injustice.
Ignoring the troll above me.
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.
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.
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.
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.
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.
"Define 'interesting'". "Oh God, oh God, we're all gonna die?"
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.
"Define 'interesting'". "Oh God, oh God, we're all gonna die?"
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.
SJW n. One who posts facts.