12 ms·

The Evolution of Tunnel Boring Machines

149 points by jseliger 3y ago

thebradbain 3y ago
Wow, as someone who follows the construction progress of Los Angeles' Purple Line (the only heavy rail transit line currently in active boring in the US) I did not know how fast that even reaching the speed of a snail would be: If we assume the tunnels are being bored at somewhere near the average of ~100meters/week, and the snail is about ~1000meters/week, that's a 10x speedup in the time to dig right there! The total length of the three segments is about 9 miles (~14,500 meters)[1], with the last segment projected to open in 2027. Digging started in Fall of 2018[2]. Los Angeles is using what looks like 6 TBMS, two for each segment, to dig parallel tunnels. Segment one completed digging in January of 2022[3], and as of August 2023 Metro has delayed full completion of segment one to 2025[4], therefore it appears that even though digging is not the end-all-be-all, it does take up >50% of the entirety of the construction timeline (~4 years digging + 3 years other construction for segment 1, including stations, track, electrical, and testing). Using the article as a guide, then, somehow speeding up the digging by a factor of 10 would mean digging could take as little as 21 weeks or ~5 months months, rather than ~4 years, and reduce the project timeline by 50% from 7 years to 3.5 years! This would be huge for when Los Angeles eventually begins to bore the heavy rail tunnel under the Sepulveda mountain pass, which would be 14 miles, most of it likely tunneled [5]. [1] https://www.metro.net/projects/westside/ https://www.metro.net/projects/westside/ [2] https://twitter.com/metrolosangeles/status/1045831796234113025 https://twitter.com/metrolosangeles/status/10458317962341130... [3] https://thesource.metro.net/2022/01/31/purple-line-tunneling-completed-between-century-city-and-wilshire-rodeo/ https://thesource.metro.net/2022/01/31/purple-line-tunneling... [4] https://twitter.com/numble/status/1709258555117777016 https://twitter.com/numble/status/1709258555117777016 [5] https://www.metro.net/projects/sepulvedacorridor/ https://www.metro.net/projects/sepulvedacorridor/
ggm 3y ago
L.T.C. Rolt's biography of I.K Brunel is in its first section really a biography of Marc, the development of one of the worlds first production lines (the block factory at the Portsmouth docks, some of the machines are now in the Science Museum london and the factory is a grade I listed building. His boot factory cost him big-time when the war ended) -And covers the thames tunnel digging in some detail. https://www.goodreads.com/en/book/show/1828514 https://www.goodreads.com/en/book/show/1828514
ggm 3y ago
The projection for boring company is interesting at least. They seem to argue most of the "wins" are procedural, and relate to business practices, paperwork and general business efficiency, the "we can do 1km a day" claims not withstanding (they don't claim this. But, it is definitely an out-there claim of their speed) -The reality of the equipment and process they use is still an advance on most, but it's more normal pace of improvement not the 10x people like to dream about. I wish we had the "Thunderbirds" Corkscrew TBM. Michael Moorcock writes about subterranian ground-melting craft too in his multiverse 'Oswald Bastable' series.
- jtriangle 3y ago
  We had nuclear tbm's in the early 70's, but nobody thought to develop them further than a few prototypes. They worked though, and were very fast for their time, still quite fast even by today's standards.
  - ggm 3y ago
    We didn't have them we had non nuclear test instances and patents, and nobody ever scaled it up to use nuclear power.
- deleted 3y ago
  [deleted]
mckn1ght 3y ago
What an awesome writeup. Just wanted to add a link to a good website tracking the progress of the Hampton Roads Bridge Tunnel expansion project, something near and dear to me as someone who has suffered much frustration driving through the current one. The three bridge tunnels around HR themselves are pretty cool engineering feats. I found the explainers at this website about the TBM in use quite interesting. - the main project site: https://hrbtexpansion.org/ https://hrbtexpansion.org/ - TBM page: https://hrbtexpansion.org/tunnel-boring/ https://hrbtexpansion.org/tunnel-boring/ I can no longer find the exact page there that has the details of the TBM but these are pretty close: - good slide with diagram: https://www.virginiadot.org/VDOT/Business/asset_upload_file129_3638.pdf https://www.virginiadot.org/VDOT/Business/asset_upload_file1... - some cool stuff but lots of broken links: http://www.virginiaplaces.org/transportation/hrbt.html http://www.virginiaplaces.org/transportation/hrbt.html
_8j50 3y ago
Does anyone know why such machines aren't being used to create artificial rivers? It seems civilization and therefore economic activity follows where fresh water sources are. And there is already a problem in the US west with water shortage.
- wilg 3y ago
  I assume it’s easier not to. https://en.wikipedia.org/wiki/Aqueduct_(water_supply) https://en.wikipedia.org/wiki/Aqueduct_(water_supply)
  - _8j50 3y ago
    If all you care about is delivering to the destination I guess that makes sense, but since it aims to minimize water loss, it does not enrich the environment along the path. Normally, sediment and other things get transported downstream and the arid landscape in the path might get greener and attract wildlife and eventually people.
- lstodd 3y ago
  A river is mostly its watershed and not the waterway which while very visible doesn't matter that much. No amount of machines would help create the watershed, so no, there's no point.
  - _8j50 3y ago
    There are lakes such as superior in michigan or even mammoth lakes in cali. I also wondered why not instead of recycling desalinated water after use, have it fill up a lake. Use nuclear powered (dedicated power plant) desalination to fill up artificial lakes. People talk about colonizing mars but if we can't even do this on earth then how is that more practical?
    - krisoft 3y ago
      > There are lakes such as superior in michigan or even mammoth lakes in cali. Yes. Lakes as a concept exist. There are many examples. What are you proposing? > I also wondered why not instead of recycling desalinated water after use, have it fill up a lake. Okay. Just for the aesthetic value? Or to evaporate it? Let me get it straight: you are proposing to pipe the output of wastewater treatment plants to an open basin (also known as artificial lake). Ones whose waste input was generated by humans drinking desalinated water. So your proposal is to desal, consume water, turn it into waste, clean waste, fill lake. Do I understand you well? And you are asking “why not”. Let me turn it around: why exactly? > People talk about colonizing mars but if we can't even do this on earth then how is that more practical? It is not.
gabcoh 3y ago
Potentially also of interest is this [0] article which describes the attempts to build a nuclear powered boring machine that worked by melting rather than cutting the rock. [0] http://atomic-skies.blogspot.com/2012/07/those-magnificent-men-and-their-atomic.html http://atomic-skies.blogspot.com/2012/07/those-magnificent-m...
Animats 3y ago
Little or no mention of the back end of the machine. The front end, where cutting takes place, gets all the attention. The segment placing arm got a mention. But most of the length of the machine does other things. The usual TBM setup has a two-track narrow gauge railroad behind it. Segment cars bring ring segments forward, and muck cars remove the spoil. Track cars bring more railroad track. Tool cars and worker cars are in the mix occasionally. All this is happening on an unfinished railroad, because the back end of the TBM has to lay the track and move cars from one track to the other. All the stuff for this takes up more length than the cutting part. A tunneling project is an entire construction site compressed into a long, narrow hole. So logistics in the tunnel are a big deal. Now, this is where The Boring Company was expected to innovate. Something involving driverless Tesla chassis, maybe. But they never did. Others have built such systems.[1] But not The Boring Company. [1] https://tunnelingonline.com/mobiletronics-demonstrates-autonomous-tbm-supply-vehicle/ https://tunnelingonline.com/mobiletronics-demonstrates-auton...
- foota 3y ago
  Just curious, if the rails are such an issue, is it not just cheaper to drive the cars (no need for self driving?) or is paying someone to do it not worth the complexity savings? Or are there other downsides to not having the rail?
  - bluGill 3y ago
    A tunnel is round, driving cars on that and passing is hard. Narrow tunnels especially
  - Animats 3y ago
    Either each car needs a driver or you need something to keep all the trailers precisely lined up. One new system has that; a human drives the "locomotive" and the trailers have automated steering to follow the lead vehicle precisely enough to not bump into traffic in the other direction. This is still experimental. At the other end of the line, outside the tunnel, there's a whole rail yard. The different kinds of cars have to be sorted out, loaded, and unloaded. So there's a need for a big staging area. Here's an overview of traditional tracked systems.[1] I've tried to find a video of the back end system and yard, but nobody seems to make such videos. It's too boring. [1] https://www.robbinstbm.com/products/tunnel-boring-machines/back-up-systems/ https://www.robbinstbm.com/products/tunnel-boring-machines/b... [2]
jauntywundrkind 3y ago
Anyone else immediately search for Subselene, the nuclear-powered thermal tunnel boring idea proposed in 1986? I tend to think they pretty heavily underbid how much heat input it would have taken? The design review for a 3m diameter tunnel going 30/m a day was 56 MW. I am not an expert, but a couple horsepower of thermal energy seems low to melt through the moon. https://www.osti.gov/biblio/5262838 https://www.osti.gov/biblio/5262838
- zardo 3y ago
  75000 horsepower is more than a couple.
deleted 3y ago
[deleted]
swader999 3y ago
This was a great article but sad that they didn't mention the top secret nuclear powered plasma tunnel machines that you just know they actually have: https://www.wired.com/story/new-tech-cuts-rock-without-grinding-it/ https://www.wired.com/story/new-tech-cuts-rock-without-grind...
sschueller 3y ago
Here is a very interesting video of the challenges of digging a new pump station tunnel at a steep angle and all the unknown difficulties that can show up. https://youtu.be/6AV2NcyX7pk?si=cGvHD4eUp6zQSef2 https://youtu.be/6AV2NcyX7pk?si=cGvHD4eUp6zQSef2
- ofrzeta 3y ago
  +1 for that video. I've discovered it accidentally and was blown away. Then I watched the other videos by Marti Group and was continued to be impressed. Unfortunately they don't have many videos on YT (there are not many projects of that size I guess)
ofrzeta 3y ago
related: documentary on the Gotthard base tunnel: https://www.youtube.com/watch?v=TaYtrsvzfh0 https://www.youtube.com/watch?v=TaYtrsvzfh0 better video, only German though: https://www.youtube.com/watch?v=93O7YmBEb7A https://www.youtube.com/watch?v=93O7YmBEb7A The last video is also interesting to watch today because they mention a lot of the safeguards they put into the system (such as measuring the temperature of the train axles some km before they enter the tunnel and redirect the train to the old Gotthard track if the temperature higher than some threshold). But still recently on August 23 there was this accident where a freight train derailed inside the tunnel.
aitchnyu 3y ago
Tangential, is Elon Musk's idea of small diameter tunnels constructed rapidly a currently unviable idea or the future of the industry?
- littlelady 3y ago
  I know it's a big ask to send you a 40 min youtube video, but grab some popcorn and enjoy: https://www.youtube.com/watch?v=4dn6ZVpJLxs https://www.youtube.com/watch?v=4dn6ZVpJLxs TL;DW No. Tunnels are hard to rapidly dig (esp. in the US where property rights exist underground), they require safety elements like proper ventilation, and they are still subject to congestion at the destination exits.
jtriangle 3y ago
And no mention of nuclear tbm's, even though NTBM's were remarkably fast and fixed many of the issues with traditional tbm's...
- pjc50 3y ago
  Were any of these ever built? Googling suggests Los Alamos patented one, but I can't see examples of one being built and tried. How bad is the resulting contamination, and how do you keep it out of the groundwater?
  - jtriangle 3y ago
    Couple prototypes from what I gather. No contamination because it's a sealed system, and they're flowing molten salt through the working end to melt the rock in front of the machine as it pushes through.
rolph 3y ago
this is likely to become critical tech in the coming years.
- peterpost2 3y ago
  How is this not already critical tech?
  - rolph 3y ago
    we dont have to abandon the surface quite yet, but soon
    - atoav 3y ago
      If you're talking about climate change, the number one threat is going to be food. Climate change is correlated with worse crops because it brings more droughts and harsher weather extremes and this will become a real problem.
      - rolph 3y ago
        yes crops will have to be included, as well as a, cohort of supportive biotypes. very much a noahs ark scenario, but we may best use a number of avenues, such as exoplanetary colonies.
        ben_w 3y ago
        There is nothing that we can do to this planet that would render the environment a tenth as inhospitable as any known other planet. IIRC we've not even found one that has free oxygen in the atmosphere yet. Even if we did, anything with that and water would be extremely exiting by the standards of exoplanets, even if it had an average temperature of 75 C which would kill humans.
        thombat 3y ago
        Being the splendidly reactive stuff that it is, molecular oxygen doesn't survive very long in any atmosphere: generally there's always something that needs oxidising. So it's thought to be a good indicator of life, only arising on Earth after photosynthesis began: https://en.m.wikipedia.org/wiki/Great_Oxidation_Event https://en.m.wikipedia.org/wiki/Great_Oxidation_Event
pugworthy 3y ago
That was an entertaining and educating read. I had not realized just how relatively recent rock tunneling advancements were. Also the idea of adding grout between the rough bored tunnel and the tunnel lining - what a great way to create a full physical connection given the probable irregularities of the tunnel.
bilsbie 3y ago
Why can’t we copy how tree roots or worms tunnel?
- atoav 3y ago
  Because we need a straight tunnel in a year and not a winded one in a few decades?
- teruakohatu 3y ago
  The article addresses this. The early tunnel boring machines were inspired by worms that bore through wood.
  - DFHippie 3y ago
    Well, shipworms, which are actually clams.
- psd1 3y ago
  Because biology is hard to replicate with machines. But even if we could, it wouldn't be useful, because we want to burrow where we choose and leave behind a usable tunnel.
- IshKebab 3y ago
  We probably can if you want to build 1 inch tunnels that go in random directions...
teruakohatu 3y ago
> During construction of the Hudson River Tunnel in 1889, 25% of the workers died from decompression sickness. Less interesting but of far greater value to humanity has been the innovation in heath and safety regulations. According to this article [1] one worker died per foot of the Hudson River Tunnel. > In 1906, attitudes toward the sandhogs changed after a series of accidents beneath the East River. Blown-out tunnels put the dangers of the profession on display in a way few New Yorkers could ignore, and the Progressive-Era press worked to publicize them. Suddenly, sandhogs were big news, and people started to complain about their high death rates. [1] https://daily.jstor.org/the-sandhogs-who-built-the-new-york-subway/ https://daily.jstor.org/the-sandhogs-who-built-the-new-york-...
- Aeolun 3y ago
  You’d think that they’d stop working if they saw 1/4th of their compatriots just drop dead.
  - mschuster91 3y ago
    It was a well-paid job for the time. Most of dangerous or otherwise physically taxing construction jobs still are well-paid, and for good reason.
    - culi 3y ago
      They were paid $2.50 a day. Which is around $91 in today dollars. On top of that wage theft was all too common. And that's a wage that they had to fight to unionize to get up to
      - Retric 3y ago
        Assuming I am reading this right in 1905 1/4 of male workers over 16 made 8$/week or less. https://babel.hathitrust.org/cgi/pt?id=nnc1.cu56779232&seq=14 https://babel.hathitrust.org/cgi/pt?id=nnc1.cu56779232&seq=1... For unskilled labor 6 days a week at 2.50/day = 15$/week which would have been quite tempting especially if the risks where unclear. It’s worth remembering when doing inflation calculations just how poor people used to be. Take the average person’s budget today and remove their car, gadgets, AC, subscriptions, most of the pricy food options, etc. Healthcare was cheap and largely ineffective, collage was rare and minimalist by todays standards. Most of what people spend money on today simply didn’t exist so not having it was normal.
dieselgate 3y ago
Very cool article as someone who has had little to no exposure on this topic. A very interesting youtube channel [1] I recently came across is Cutting Edge Engineering Australia - they do mostly heavy equipment repair/fab. Some common tools used are air-arc gougers for clean and rapid removal of material along with mill/lathe machining. Had never really considered the conceptual transfer over to something like tunnel boring (air powered debris and rotational removal) but it seems similar. [1] Repair & Upgrade DAMAGED Bucket for 30T Excavator | Gouging & Welding: https://www.youtube.com/watch?v=qzi7eOr-3lA https://www.youtube.com/watch?v=qzi7eOr-3lA
- jcims 3y ago
  Holy cow it's a small world. I just subbed to that channel last week. Love seeing someone so practical and capable and the bloopers at the end are a lot of fun.
ttyyzz 3y ago
Funnily enough, my father is at the 11th international symposium on “Ground Freezing” in London at this very moment. Most of the time you have to freeze the ground before you can drill. He has been working in specialist civil engineering for many years and builds tunnels all over the world. He has told me many exciting and hard-to-believe stories about tunnel construction and tunnel boring machines. E.g. during the work on the Eurotunnel. Here the British tunnel boring machine was diverted into the rock near half the length of the tunnel and left there. It was cheaper than somehow taking it out again. Anyways, since my dad is always very stressed due to his job, I am happy to have gained a foothold in IT and not tunnel boring :D
- Gare 3y ago
  > E.g. during the work on the Eurotunnel. Here the British tunnel boring machine was diverted into the rock near half the length of the tunnel and left there. It was cheaper than somehow taking it out again. AFAIK it was not just the cost, but the problem of two TBMs (British and French) meeting head to head. The british were driven out of the way so that the French ones could proceed.
  - benj111 3y ago
    I wonder how many political meetings were had, to decide who got out of the way of who. Or maybe it was the toss of a coin? But then a franc or a pound?
- rurounijones 3y ago
  > E.g. during the work on the Eurotunnel. Here the British tunnel boring machine was diverted into the rock near half the length of the tunnel and left there. It was cheaper than somehow taking it out again. Dara O`Briain has a hilarious stand-up about this: https://www.youtube.com/watch?v=uFglJ3DyqK0 https://www.youtube.com/watch?v=uFglJ3DyqK0
- pjc50 3y ago
  Burying TBMs is not uncommon. The HS2 ones are being buried for an indefinite period due to UK government flipflopping. https://www.ianvisits.co.uk/articles/hs2-will-bury-two-tunnel-boring-machines-at-old-oak-common-64929/ https://www.ianvisits.co.uk/articles/hs2-will-bury-two-tunne... There's one in New York. https://untappedcities.com/2017/02/09/the-200-ton-tunnel-boring-machine-buried-below-park-avenue-used-for-east-side-access/ https://untappedcities.com/2017/02/09/the-200-ton-tunnel-bor...
jcims 3y ago
Sometimes when I'm stuck in construction traffic I wish someone would invent the Highway Widening Machine. A machine that in one fell swoop can grind, grade, prep, pour and paint a new lane into a road.
- digging 3y ago
  A common but misguided desire.
  - jcims 3y ago
    Of course, but it would be fun to design and build. And since it will obviously never happen it seems pretty harmless to think about?
    - digging 3y ago
      As an engineering challenge, yeah, the machine itself is super interesting. But "more road" isn't the answer to road congestion so it's a machine without a purpose (unless the purpose is propping up the oil & auto industries?).
- bluGill 3y ago
  We need a lot more than one more lane. Traffic continues at high speeds long after it isn't safe. You are supposed to see 2 seconds between cars, yet when I get on a busy road and do that I often see 5 cars in the lane next to me in that distance. Little des moines where I live needs Huston levels of lanes to allow for safe travel. For a city with significant population you need a lot more. Or of course better public transit. The vast majority of what people are driving for could be done without driving if transit was better.
  - andbberger 3y ago
    car travel would be a lot less appealing in throughput if subject to the same stringent separation requirements as rail travel.
mmanfrin 3y ago
It's essentially a long ad for the company that makes the machines, but this video (and some of the others they've put out) are fascinating and describe the whole process of tunnel making (with a very high production value): https://www.youtube.com/watch?v=6AV2NcyX7pk https://www.youtube.com/watch?v=6AV2NcyX7pk
- andbberger 3y ago
  Marti is unmatched. Herrenknecht also puts out some nice material
- greazy 3y ago
  Thanks for sharing this was fascinating. Some of the music is very heist-movie.
- pstuart 3y ago
  A subterranean submarine: http://www.paulgraham.com/submarine.html http://www.paulgraham.com/submarine.html
aaron695 3y ago
[dead]

149 points by jseliger 3y ago

Wow, as someone who follows the construction progress of Los Angeles' Purple Line (the only heavy rail transit line currently in active boring in the US) I did not know how fast that even reaching the speed of a snail would be: If we assume the tunnels are being bored at somewhere near the average of ~100meters/week, and the snail is about ~1000meters/week, that's a 10x speedup in the time to dig right there! The total length of the three segments is about 9 miles (~14,500 meters)[1], with the last segment projected to open in 2027. Digging started in Fall of 2018[2]. Los Angeles is using what looks like 6 TBMS, two for each segment, to dig parallel tunnels. Segment one completed digging in January of 2022[3], and as of August 2023 Metro has delayed full completion of segment one to 2025[4], therefore it appears that even though digging is not the end-all-be-all, it does take up >50% of the entirety of the construction timeline (~4 years digging + 3 years other construction for segment 1, including stations, track, electrical, and testing). Using the article as a guide, then, somehow speeding up the digging by a factor of 10 would mean digging could take as little as 21 weeks or ~5 months months, rather than ~4 years, and reduce the project timeline by 50% from 7 years to 3.5 years! This would be huge for when Los Angeles eventually begins to bore the heavy rail tunnel under the Sepulveda mountain pass, which would be 14 miles, most of it likely tunneled [5]. [1] https://www.metro.net/projects/westside/ https://www.metro.net/projects/westside/ [2] https://twitter.com/metrolosangeles/status/1045831796234113025 https://twitter.com/metrolosangeles/status/10458317962341130... [3] https://thesource.metro.net/2022/01/31/purple-line-tunneling-completed-between-century-city-and-wilshire-rodeo/ https://thesource.metro.net/2022/01/31/purple-line-tunneling... [4] https://twitter.com/numble/status/1709258555117777016 https://twitter.com/numble/status/1709258555117777016 [5] https://www.metro.net/projects/sepulvedacorridor/ https://www.metro.net/projects/sepulvedacorridor/

ggm 3y ago

L.T.C. Rolt's biography of I.K Brunel is in its first section really a biography of Marc, the development of one of the worlds first production lines (the block factory at the Portsmouth docks, some of the machines are now in the Science Museum london and the factory is a grade I listed building. His boot factory cost him big-time when the war ended) -And covers the thames tunnel digging in some detail. https://www.goodreads.com/en/book/show/1828514 https://www.goodreads.com/en/book/show/1828514

ggm 3y ago

The projection for boring company is interesting at least. They seem to argue most of the "wins" are procedural, and relate to business practices, paperwork and general business efficiency, the "we can do 1km a day" claims not withstanding (they don't claim this. But, it is definitely an out-there claim of their speed) -The reality of the equipment and process they use is still an advance on most, but it's more normal pace of improvement not the 10x people like to dream about. I wish we had the "Thunderbirds" Corkscrew TBM. Michael Moorcock writes about subterranian ground-melting craft too in his multiverse 'Oswald Bastable' series.

jtriangle 3y ago
We had nuclear tbm's in the early 70's, but nobody thought to develop them further than a few prototypes. They worked though, and were very fast for their time, still quite fast even by today's standards.
- ggm 3y ago
  We didn't have them we had non nuclear test instances and patents, and nobody ever scaled it up to use nuclear power.
deleted 3y ago
[deleted]

mckn1ght 3y ago

What an awesome writeup. Just wanted to add a link to a good website tracking the progress of the Hampton Roads Bridge Tunnel expansion project, something near and dear to me as someone who has suffered much frustration driving through the current one. The three bridge tunnels around HR themselves are pretty cool engineering feats. I found the explainers at this website about the TBM in use quite interesting. - the main project site: https://hrbtexpansion.org/ https://hrbtexpansion.org/ - TBM page: https://hrbtexpansion.org/tunnel-boring/ https://hrbtexpansion.org/tunnel-boring/ I can no longer find the exact page there that has the details of the TBM but these are pretty close: - good slide with diagram: https://www.virginiadot.org/VDOT/Business/asset_upload_file129_3638.pdf https://www.virginiadot.org/VDOT/Business/asset_upload_file1... - some cool stuff but lots of broken links: http://www.virginiaplaces.org/transportation/hrbt.html http://www.virginiaplaces.org/transportation/hrbt.html

_8j50 3y ago

Does anyone know why such machines aren't being used to create artificial rivers? It seems civilization and therefore economic activity follows where fresh water sources are. And there is already a problem in the US west with water shortage.

wilg 3y ago
I assume it’s easier not to. https://en.wikipedia.org/wiki/Aqueduct_(water_supply) https://en.wikipedia.org/wiki/Aqueduct_(water_supply)
- _8j50 3y ago
  If all you care about is delivering to the destination I guess that makes sense, but since it aims to minimize water loss, it does not enrich the environment along the path. Normally, sediment and other things get transported downstream and the arid landscape in the path might get greener and attract wildlife and eventually people.
lstodd 3y ago
A river is mostly its watershed and not the waterway which while very visible doesn't matter that much. No amount of machines would help create the watershed, so no, there's no point.
- _8j50 3y ago
  There are lakes such as superior in michigan or even mammoth lakes in cali. I also wondered why not instead of recycling desalinated water after use, have it fill up a lake. Use nuclear powered (dedicated power plant) desalination to fill up artificial lakes. People talk about colonizing mars but if we can't even do this on earth then how is that more practical?
  - krisoft 3y ago
    > There are lakes such as superior in michigan or even mammoth lakes in cali. Yes. Lakes as a concept exist. There are many examples. What are you proposing? > I also wondered why not instead of recycling desalinated water after use, have it fill up a lake. Okay. Just for the aesthetic value? Or to evaporate it? Let me get it straight: you are proposing to pipe the output of wastewater treatment plants to an open basin (also known as artificial lake). Ones whose waste input was generated by humans drinking desalinated water. So your proposal is to desal, consume water, turn it into waste, clean waste, fill lake. Do I understand you well? And you are asking “why not”. Let me turn it around: why exactly? > People talk about colonizing mars but if we can't even do this on earth then how is that more practical? It is not.

gabcoh 3y ago

Potentially also of interest is this [0] article which describes the attempts to build a nuclear powered boring machine that worked by melting rather than cutting the rock. [0] http://atomic-skies.blogspot.com/2012/07/those-magnificent-men-and-their-atomic.html http://atomic-skies.blogspot.com/2012/07/those-magnificent-m...

Animats 3y ago

Little or no mention of the back end of the machine. The front end, where cutting takes place, gets all the attention. The segment placing arm got a mention. But most of the length of the machine does other things. The usual TBM setup has a two-track narrow gauge railroad behind it. Segment cars bring ring segments forward, and muck cars remove the spoil. Track cars bring more railroad track. Tool cars and worker cars are in the mix occasionally. All this is happening on an unfinished railroad, because the back end of the TBM has to lay the track and move cars from one track to the other. All the stuff for this takes up more length than the cutting part. A tunneling project is an entire construction site compressed into a long, narrow hole. So logistics in the tunnel are a big deal. Now, this is where The Boring Company was expected to innovate. Something involving driverless Tesla chassis, maybe. But they never did. Others have built such systems.[1] But not The Boring Company. [1] https://tunnelingonline.com/mobiletronics-demonstrates-autonomous-tbm-supply-vehicle/ https://tunnelingonline.com/mobiletronics-demonstrates-auton...

foota 3y ago
Just curious, if the rails are such an issue, is it not just cheaper to drive the cars (no need for self driving?) or is paying someone to do it not worth the complexity savings? Or are there other downsides to not having the rail?
- bluGill 3y ago
  A tunnel is round, driving cars on that and passing is hard. Narrow tunnels especially
- Animats 3y ago
  Either each car needs a driver or you need something to keep all the trailers precisely lined up. One new system has that; a human drives the "locomotive" and the trailers have automated steering to follow the lead vehicle precisely enough to not bump into traffic in the other direction. This is still experimental. At the other end of the line, outside the tunnel, there's a whole rail yard. The different kinds of cars have to be sorted out, loaded, and unloaded. So there's a need for a big staging area. Here's an overview of traditional tracked systems.[1] I've tried to find a video of the back end system and yard, but nobody seems to make such videos. It's too boring. [1] https://www.robbinstbm.com/products/tunnel-boring-machines/back-up-systems/ https://www.robbinstbm.com/products/tunnel-boring-machines/b... [2]

jauntywundrkind 3y ago

Anyone else immediately search for Subselene, the nuclear-powered thermal tunnel boring idea proposed in 1986? I tend to think they pretty heavily underbid how much heat input it would have taken? The design review for a 3m diameter tunnel going 30/m a day was 56 MW. I am not an expert, but a couple horsepower of thermal energy seems low to melt through the moon. https://www.osti.gov/biblio/5262838 https://www.osti.gov/biblio/5262838

zardo 3y ago
75000 horsepower is more than a couple.

deleted 3y ago

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swader999 3y ago

This was a great article but sad that they didn't mention the top secret nuclear powered plasma tunnel machines that you just know they actually have: https://www.wired.com/story/new-tech-cuts-rock-without-grinding-it/ https://www.wired.com/story/new-tech-cuts-rock-without-grind...

sschueller 3y ago

Here is a very interesting video of the challenges of digging a new pump station tunnel at a steep angle and all the unknown difficulties that can show up. https://youtu.be/6AV2NcyX7pk?si=cGvHD4eUp6zQSef2 https://youtu.be/6AV2NcyX7pk?si=cGvHD4eUp6zQSef2

ofrzeta 3y ago
+1 for that video. I've discovered it accidentally and was blown away. Then I watched the other videos by Marti Group and was continued to be impressed. Unfortunately they don't have many videos on YT (there are not many projects of that size I guess)

ofrzeta 3y ago

related: documentary on the Gotthard base tunnel: https://www.youtube.com/watch?v=TaYtrsvzfh0 https://www.youtube.com/watch?v=TaYtrsvzfh0 better video, only German though: https://www.youtube.com/watch?v=93O7YmBEb7A https://www.youtube.com/watch?v=93O7YmBEb7A The last video is also interesting to watch today because they mention a lot of the safeguards they put into the system (such as measuring the temperature of the train axles some km before they enter the tunnel and redirect the train to the old Gotthard track if the temperature higher than some threshold). But still recently on August 23 there was this accident where a freight train derailed inside the tunnel.

aitchnyu 3y ago

Tangential, is Elon Musk's idea of small diameter tunnels constructed rapidly a currently unviable idea or the future of the industry?

littlelady 3y ago
I know it's a big ask to send you a 40 min youtube video, but grab some popcorn and enjoy: https://www.youtube.com/watch?v=4dn6ZVpJLxs https://www.youtube.com/watch?v=4dn6ZVpJLxs TL;DW No. Tunnels are hard to rapidly dig (esp. in the US where property rights exist underground), they require safety elements like proper ventilation, and they are still subject to congestion at the destination exits.

jtriangle 3y ago

And no mention of nuclear tbm's, even though NTBM's were remarkably fast and fixed many of the issues with traditional tbm's...

pjc50 3y ago
Were any of these ever built? Googling suggests Los Alamos patented one, but I can't see examples of one being built and tried. How bad is the resulting contamination, and how do you keep it out of the groundwater?
- jtriangle 3y ago
  Couple prototypes from what I gather. No contamination because it's a sealed system, and they're flowing molten salt through the working end to melt the rock in front of the machine as it pushes through.

rolph 3y ago

this is likely to become critical tech in the coming years.

peterpost2 3y ago
How is this not already critical tech?
- rolph 3y ago
  we dont have to abandon the surface quite yet, but soon
  - atoav 3y ago
    If you're talking about climate change, the number one threat is going to be food. Climate change is correlated with worse crops because it brings more droughts and harsher weather extremes and this will become a real problem.
    - rolph 3y ago
      yes crops will have to be included, as well as a, cohort of supportive biotypes. very much a noahs ark scenario, but we may best use a number of avenues, such as exoplanetary colonies.
      - ben_w 3y ago
        There is nothing that we can do to this planet that would render the environment a tenth as inhospitable as any known other planet. IIRC we've not even found one that has free oxygen in the atmosphere yet. Even if we did, anything with that and water would be extremely exiting by the standards of exoplanets, even if it had an average temperature of 75 C which would kill humans.
        thombat 3y ago
        Being the splendidly reactive stuff that it is, molecular oxygen doesn't survive very long in any atmosphere: generally there's always something that needs oxidising. So it's thought to be a good indicator of life, only arising on Earth after photosynthesis began: https://en.m.wikipedia.org/wiki/Great_Oxidation_Event https://en.m.wikipedia.org/wiki/Great_Oxidation_Event

pugworthy 3y ago

That was an entertaining and educating read. I had not realized just how relatively recent rock tunneling advancements were. Also the idea of adding grout between the rough bored tunnel and the tunnel lining - what a great way to create a full physical connection given the probable irregularities of the tunnel.

bilsbie 3y ago

Why can’t we copy how tree roots or worms tunnel?

atoav 3y ago
Because we need a straight tunnel in a year and not a winded one in a few decades?
teruakohatu 3y ago
The article addresses this. The early tunnel boring machines were inspired by worms that bore through wood.
- DFHippie 3y ago
  Well, shipworms, which are actually clams.
psd1 3y ago
Because biology is hard to replicate with machines. But even if we could, it wouldn't be useful, because we want to burrow where we choose and leave behind a usable tunnel.
IshKebab 3y ago
We probably can if you want to build 1 inch tunnels that go in random directions...

teruakohatu 3y ago

> During construction of the Hudson River Tunnel in 1889, 25% of the workers died from decompression sickness. Less interesting but of far greater value to humanity has been the innovation in heath and safety regulations. According to this article [1] one worker died per foot of the Hudson River Tunnel. > In 1906, attitudes toward the sandhogs changed after a series of accidents beneath the East River. Blown-out tunnels put the dangers of the profession on display in a way few New Yorkers could ignore, and the Progressive-Era press worked to publicize them. Suddenly, sandhogs were big news, and people started to complain about their high death rates. [1] https://daily.jstor.org/the-sandhogs-who-built-the-new-york-subway/ https://daily.jstor.org/the-sandhogs-who-built-the-new-york-...

Aeolun 3y ago
You’d think that they’d stop working if they saw 1/4th of their compatriots just drop dead.
- mschuster91 3y ago
  It was a well-paid job for the time. Most of dangerous or otherwise physically taxing construction jobs still are well-paid, and for good reason.
  - culi 3y ago
    They were paid $2.50 a day. Which is around $91 in today dollars. On top of that wage theft was all too common. And that's a wage that they had to fight to unionize to get up to
    - Retric 3y ago
      Assuming I am reading this right in 1905 1/4 of male workers over 16 made 8$/week or less. https://babel.hathitrust.org/cgi/pt?id=nnc1.cu56779232&seq=14 https://babel.hathitrust.org/cgi/pt?id=nnc1.cu56779232&seq=1... For unskilled labor 6 days a week at 2.50/day = 15$/week which would have been quite tempting especially if the risks where unclear. It’s worth remembering when doing inflation calculations just how poor people used to be. Take the average person’s budget today and remove their car, gadgets, AC, subscriptions, most of the pricy food options, etc. Healthcare was cheap and largely ineffective, collage was rare and minimalist by todays standards. Most of what people spend money on today simply didn’t exist so not having it was normal.

dieselgate 3y ago

Very cool article as someone who has had little to no exposure on this topic. A very interesting youtube channel [1] I recently came across is Cutting Edge Engineering Australia - they do mostly heavy equipment repair/fab. Some common tools used are air-arc gougers for clean and rapid removal of material along with mill/lathe machining. Had never really considered the conceptual transfer over to something like tunnel boring (air powered debris and rotational removal) but it seems similar. [1] Repair & Upgrade DAMAGED Bucket for 30T Excavator | Gouging & Welding: https://www.youtube.com/watch?v=qzi7eOr-3lA https://www.youtube.com/watch?v=qzi7eOr-3lA

jcims 3y ago
Holy cow it's a small world. I just subbed to that channel last week. Love seeing someone so practical and capable and the bloopers at the end are a lot of fun.

ttyyzz 3y ago

Funnily enough, my father is at the 11th international symposium on “Ground Freezing” in London at this very moment. Most of the time you have to freeze the ground before you can drill. He has been working in specialist civil engineering for many years and builds tunnels all over the world. He has told me many exciting and hard-to-believe stories about tunnel construction and tunnel boring machines. E.g. during the work on the Eurotunnel. Here the British tunnel boring machine was diverted into the rock near half the length of the tunnel and left there. It was cheaper than somehow taking it out again. Anyways, since my dad is always very stressed due to his job, I am happy to have gained a foothold in IT and not tunnel boring :D

Gare 3y ago
> E.g. during the work on the Eurotunnel. Here the British tunnel boring machine was diverted into the rock near half the length of the tunnel and left there. It was cheaper than somehow taking it out again. AFAIK it was not just the cost, but the problem of two TBMs (British and French) meeting head to head. The british were driven out of the way so that the French ones could proceed.
- benj111 3y ago
  I wonder how many political meetings were had, to decide who got out of the way of who. Or maybe it was the toss of a coin? But then a franc or a pound?
rurounijones 3y ago
> E.g. during the work on the Eurotunnel. Here the British tunnel boring machine was diverted into the rock near half the length of the tunnel and left there. It was cheaper than somehow taking it out again. Dara O`Briain has a hilarious stand-up about this: https://www.youtube.com/watch?v=uFglJ3DyqK0 https://www.youtube.com/watch?v=uFglJ3DyqK0
pjc50 3y ago
Burying TBMs is not uncommon. The HS2 ones are being buried for an indefinite period due to UK government flipflopping. https://www.ianvisits.co.uk/articles/hs2-will-bury-two-tunnel-boring-machines-at-old-oak-common-64929/ https://www.ianvisits.co.uk/articles/hs2-will-bury-two-tunne... There's one in New York. https://untappedcities.com/2017/02/09/the-200-ton-tunnel-boring-machine-buried-below-park-avenue-used-for-east-side-access/ https://untappedcities.com/2017/02/09/the-200-ton-tunnel-bor...

jcims 3y ago

Sometimes when I'm stuck in construction traffic I wish someone would invent the Highway Widening Machine. A machine that in one fell swoop can grind, grade, prep, pour and paint a new lane into a road.

digging 3y ago
A common but misguided desire.
- jcims 3y ago
  Of course, but it would be fun to design and build. And since it will obviously never happen it seems pretty harmless to think about?
  - digging 3y ago
    As an engineering challenge, yeah, the machine itself is super interesting. But "more road" isn't the answer to road congestion so it's a machine without a purpose (unless the purpose is propping up the oil & auto industries?).
bluGill 3y ago
We need a lot more than one more lane. Traffic continues at high speeds long after it isn't safe. You are supposed to see 2 seconds between cars, yet when I get on a busy road and do that I often see 5 cars in the lane next to me in that distance. Little des moines where I live needs Huston levels of lanes to allow for safe travel. For a city with significant population you need a lot more. Or of course better public transit. The vast majority of what people are driving for could be done without driving if transit was better.
- andbberger 3y ago
  car travel would be a lot less appealing in throughput if subject to the same stringent separation requirements as rail travel.

mmanfrin 3y ago

It's essentially a long ad for the company that makes the machines, but this video (and some of the others they've put out) are fascinating and describe the whole process of tunnel making (with a very high production value): https://www.youtube.com/watch?v=6AV2NcyX7pk https://www.youtube.com/watch?v=6AV2NcyX7pk

andbberger 3y ago
Marti is unmatched. Herrenknecht also puts out some nice material
greazy 3y ago
Thanks for sharing this was fascinating. Some of the music is very heist-movie.
pstuart 3y ago
A subterranean submarine: http://www.paulgraham.com/submarine.html http://www.paulgraham.com/submarine.html

aaron695 3y ago

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