
Tunnel Boring Machines (2018) - luu
http://www.cat-bus.com/2018/01/far-from-boringmeet-the-most-interesting-tunnel-boring-machines/
======
spectramax
There is a quality about TBMs which vaguely reminds me of the feeling of
getting a new LEGO set and building stuff. Imagine if we had cheap ways to
build tunnels, no more traffic, no more congestion, roads and parking lots
would only exist underground and cities would have more space for gardens,
parks, buildings, and walkways. We have these things - Subways but its very
expensive to build that system. Elon has an itch to solve this problem and I
want this dream to succeed! While that's going on, please someone make a game
out of building tunnels, it would be super cool!

~~~
bArray
> Imagine if we had cheap ways to build tunnels, no more

> traffic, no more congestion, roads and parking lots would

> only exist underground and cities would have more space

> for gardens, parks, buildings, and walkways.

Or, skip the tunnel building and just ban cars from major cities.

Building more infrastructure to "reduce traffic" only makes using vehicles
more attractive. The amount of congestion is approximately equal to the amount
of congestion the average person using the infrastructure is willing to
accept, so making it less congested just means more people use the
infrastructure until the limit is reached again.

The real answer to the problem is to simply ban all but buses and delivery
vehicles - even then you can incentivize that they are electrically driven.
Space increases and infrastructure maintenance costs are reduced, not
increased.

The real golden use for TBMs is for efficiency - i.e. Go around some mountain
or go straight through it? Go around a city or go under it? I imagine
buildings sharing a service elevator down to the tunnel where delivery
vehicles can offload to and send goods up (rather than Musk's idea of trying
to lift a several tonne vehicle in some personal elevator).

Would likely make sense for all kinds of maintenance this way to, servicing
water/gas pipes or electricity/internet lines for example could be as simple
as removing a service panel from the side of a tunnel, rather than the
terrible solution we have today involving digging up streets over and over.

~~~
rklaehn
Why have technical innovation at all, let's just outlaw stuff...

I really don't get this desire to outlaw cars. I like walkable cities, but I
also like the comfort and privacy of car transport. I live in a place
(Germany) with good public transport. I used to live in cities with very good
public transport. I still don't enjoy being squeezed in with thousands of
other people. Does that mean that people like me have to be reeducated and/or
forced to see the error of their ways?

~~~
enjeyw
Well, maybe actually. It’s reasonable to suggest that your driving is creating
personal gain at the expense of others (pollution, congestion etc), and thus
should be treated like many other things that fall into this category (theft,
speeding) and be outlawed.

Of course it’s also totally reasonable to suggest that the harm to others is
so small that it doesn’t justify the erosion of personal liberty.

Point being, the question warrants reasonable consideration rather than
immediate dismissal.

~~~
thereisnospork
> Point being, the question warrants reasonable consideration rather than
> immediate dismissal.

Sure, but it takes quite a bit of negatives to override the obvious and
glaring benefits of anyone being able to transport oneself, one's family,
one's stuff, at a moments notice, to any destination, in (almost) any weather,
at an average speed of 30-60miles per hour, all at an amortized cost of
approximately 50cents per mile.

The willingness and readiness of some people to disregard the large personal,
societal, and economic benefits of having functioning automotive
infrastructure - in concert with other methods of transit - quite frankly
bewilders me.

~~~
Xylakant
> Sure, but it takes quite a bit of negatives to override the obvious and
> glaring benefits of anyone being able to transport oneself, one's family,
> one's stuff, at a moments notice, to any destination, in (almost) any
> weather, at an average speed of 30-60miles per hour, all at an amortized
> cost of approximately 50cents per mile.

The current discussion mostly centers on banning cars in cities or large
agglomerations. In no city you'll reach average speeds even approaching 30
miles an hour - something around 20km/h is a more reasonable number to expect.
That's btw. easily reachable with an electric bicycle or public transport. I
can call a cab or a transport for larger goods at pretty much a moments
notice, there's even car sharing services that have some parked in the street.

Also, you're disregarding that cars in cities have massive externalities - the
current estimate for Berlin is that infrastructure for cars (roads and parking
spaces) cost about 30% of the cities surface area at substantial cost to
society (increased rent and building costs, maintenance etc) which is paid by
the majority of people _not_ owning a car. Not all of that could be recouped
if private car usage is reduced, but substantial chunks could. Not to speak of
noise and other pollution, risks of accident and injury etc.

So you're overplaying the advantages and disregarding the very real cost that
other people shoulder for a minority driving.

~~~
bluGill
You are correct for the dense part of large cities, once you get outside that
things change fast. Anyone not living in those areas sometimes need to get to
the dense part of the city, and driving their own car overall has the speeds
of the non-dense part they pass through not the slow dense part near their
destination.

~~~
kuschku
That’s what park+ride is for — drive to a subway or train station at the edge
of the city, leave your car there, and use transit in the city.

------
vpribish
"The cost of a TBM doesn’t get much higher as you increase its diameter."

This is the key assertion, and it is unsupported.

\- heat extraction will become a bigger problem

\- debris extraction too

\- cost of parts, cost and speed of logistics like transport and installation
of the machine will be worse

\- small number of exotic large TBMs will scale worse than large number of
small TBMs in manufacturing cost and operating experience

\- I've seen elsewhere (citation missing) that small borers move much faster
than large so any costs that scale with time will be worse.

\- risk-wise: a portfolio of small borers will have less risk than an all-
eggs-in-one-basket gamble. a broken part delaying a big machine incurs more
cost than ona smaller machine.

unless your project requires a single enormous bore I think you would prefer
to use the smallest you can get away with.

The author does not seem to have any relevant experience, so I'm not going to
take this on his authority; he's a programmer who has done scheduling software
on metro projects and is working on an MBA. Interesting summary of types of
machines though!

~~~
astrodust
Key word "much".

------
ksec
I have many questions,

1\. Are any of these TBM considered state of art? I dont see any tech inside
those TBM that could not be done 10 years ago other than the cost of the
machine. We are entering new Space Race era and yet some fundamental stuff
still looks very, should I say "traditional".

2\. Why cant we build even bigger TBM? Like Double the current diameter. Or
Bigger TBM that are Rectangular rather than Circle.

3\. The biggest problem with TBM is that they are slow. Even if we had made
them 10 times faster I would still consider them very slow. Surely there could
be technology that improve on it?

4\. Are there any reason why we dont use TBM for small pipes, ( like for
electricity or fibre optics, )

~~~
bluGill
Is there any improvement that can be made? Every time some engineer comes up
with an improvement that is one more improvement invented. There is only so
much improvement possible.

Slow is not a problem. A few meters a day sounds slow, but if you are going
long distances you can scale by buying more TBNs putting them in a line and
having each meet up to the next. Assuming you have the money. In practice the
cost to build a tunnel is high enough that you probably can't afford to scale
up too much that way.

~~~
jonwachob91
>>> you can scale by buying more TBNs putting them in a line and having each
meet up to the next

What I'm picturing from your statement is two TBM drilling towards each other
like ---> <\----.

Which would require the digging of a third hole where the TBM "drill heads"
meet. After every TBM dig, the drill heads are left at the end of the tunnel
b/c they are bigger than the new tunnel (as the head digs the tunnel, workers
install support structure to prevent a collapse, so the just drilled tunnel is
smaller than the being drilled tunnel). A 3rd dig would be required where the
two TBM drill heads meet to retrieve them and connect the tunnels. That's a
lot of $$$ :/

~~~
Swannie
> Which would require the digging of a third hole where the TBM "drill heads"
> meet.

In most projects it's called a station.

[http://www.crossrail.co.uk/construction/tunnelling/meet-
our-...](http://www.crossrail.co.uk/construction/tunnelling/meet-our-giant-
tunnelling-machines/)

Occasionally you'll have dive sites that are not at/near stations, but not
that often.

[https://www.sydneymetro.info/station/blues-point-
temporary-r...](https://www.sydneymetro.info/station/blues-point-temporary-
retrieval-site)

[https://www.sydneymetro.info/tunnelling](https://www.sydneymetro.info/tunnelling)

------
pugworthy
I'm not out to analyze the clearly knowledgeable content of this article, but
I'd not be surprised if someone wrote something just like it when he (Musk)
started the whole illogical "make a rocket come back and land" stuff.

It's not logical, but I'm giving him the benefit of the doubt. Let him do his
thing. Who knows?

~~~
progfix
The difference is we are building tunnels for many decades and making them
smaller, reusing the ground material are not ground breaking ideas.

~~~
rusticpenn
The ground breaking part is not the tunnel but the vehicles. Its extremely
dangerous to use ICE vehicles in long tunnels without complex ventilation
schemes. Electric vehicles solve this issue.

~~~
progfix
You need complex ventilation anyway. Imagine a fire breaks out.

~~~
rusticpenn
True, however that requirements are more relaxed. The invention of electric
train removed most of the problems with coal based (and other vehicles and
helped in creation of subways).I think the movement to electric will create
the same oppurtunity for cars.

------
dlgeek
Side note: Missed opportunity for the title "Interesting Boring Machines"

~~~
ant6n
Actual title of article: "Far From Boring: Meet the Most Interesting Tunnel
Boring Machines"

------
Animats
Musk could help with the back end of the problem. The TBM up front gets all
the attention. Behind the TBM is usually a temporary two-track narrow gauge
railway line, with muck cars carrying dirt and rock out, segment cars carrying
tunnel wall segments forward, plus tool cars and worker cars now and then.[1]

Hanging off the back of the TBM is all the machinery to move all those heavy
items around.[2] Including the machinery for laying more railroad track behind
the TBM.

Self-driving electric muck cars, segment cars, etc, might replace that
temporary rail infrastructure. That's something Musk's company could address.

The back end of the process seems to get less attention than the front end.
Most of the length of the TBM is devoted to material handling, though, as is
the rest of the tunnel all the way back to the entry. A big fraction of the
cost is in moving all that stuff around.

[1]
[http://www.zslocomotive.com/products](http://www.zslocomotive.com/products)
[2] [https://youtu.be/SY3Q9GqUYro?t=115](https://youtu.be/SY3Q9GqUYro?t=115)

------
LargoLasskhyfv
I'm uninpressed because it lacks _Nuclear Tunnel Boring Machines_ like in [1]
and [2] as envisioned by [3] for [4] and [5] in 1972 and 1978. Which all
Hyperloop afficionados should read, if they haven't done so already :-)

[1]
[https://patents.google.com/patent/US3693731](https://patents.google.com/patent/US3693731)
(I'm wondering about steam explosions when hitting ground water, which is not
unheard of. But... _NUKULAR!_ )

[2]
[https://en.wikipedia.org/wiki/Subterrene](https://en.wikipedia.org/wiki/Subterrene)

[3]
[https://en.wikipedia.org/wiki/Robert_M._Salter](https://en.wikipedia.org/wiki/Robert_M._Salter)

[4]
[https://www.rand.org/pubs/papers/P4874.html](https://www.rand.org/pubs/papers/P4874.html)

[5]
[https://www.rand.org/pubs/papers/P6092.html](https://www.rand.org/pubs/papers/P6092.html)
(Lacking cheaply mass produced super-conductors here)

------
rmason
I'm not sure that I agree with the author on Elon Musk's tunneling ambitions.
Far more people are betting against him on Tesla and SpaceX without much
success.

One thing lost in the debate is if the costs are lowered it will also increase
the number of cities where a subway is possible financially. I see cities
spending huge money on dedicated bus lanes. The bus companies adore it but I'm
pretty certain that the return on investment is abysmal.

They tried to implement it locally and the grass roots groups put up such a
huge fight the politicians withdrew support for it.

As far as the cost of the stations I wonder if anyone has given thought to
using 3D concrete printing? Admittedly it would be easier if you excavated
from the surface as opposed to widening a tunnel but I still think it has the
possibility of losing costs.

[https://all3dp.com/2/concrete-3d-printing-how-to-do-it-
and-a...](https://all3dp.com/2/concrete-3d-printing-how-to-do-it-and-applic)

~~~
walkingolof
"Musk says he can build tunnels cheaper if he just makes them smaller. But in
reality, it’s not small TBMs that are the future, but big ones. The cost of a
TBM doesn’t get much higher as you increase its diameter. Tt is therefore
cheaper to build one very large tunnel, rather than two smaller ones."

If that is true, then Elon is betting on the wrong horse.

~~~
rmason
I can remember articles promoting hydrogen powered cars as the future. They
even said Elon made the wrong bet with electric. Some company's are still
hawking hydrogen as the future, the difference is no one is paying any
attention to them any longer.

Someone else has made the bet for bigger tunnels and they're using a PR agency
to push back. PG called out this tactic a few years back:

[http://www.paulgraham.com/submarine.html](http://www.paulgraham.com/submarine.html)

~~~
bluGill
The bigger tunnel people have proven success, while the small tunnel people
just have hype.

People shut up about electric cars over hydrogen when electric proved itself.
Note that back when this started there were many hydrogen naysayers who
pointed out all the problems the hydrogen proponents have faced. The electric
car people got lucky that lithium batteries advanced to where they could work
- 20 years ago this wasn't a given to battery experts.

------
baddox
These animations are great, but for some puzzling reason they only advance
while I am scrolling the page. To watch an animation I have to hold my thumb
on the screen and subtly scroll up and down. This is on an iPhone X.

------
asdff
Is there a reason why cut and cover isn't used very much these days, apart
from mild disruption to car traffic?

~~~
KaiserPro
it is ridiculously labour intensive.

First, all utilities have to be mapped out, then any basements shored up.

Then once the cut and cover is in progress, all utilities have to be re-
routed, during, then replaced after the tunnel is cut.

Then, the disruption of having major transit ways shut for _n_ weeks.

Lastly, there isnt a machine to do it. The TBM is pretty efficient labour
wise.

~~~
koheripbal
This is only if you build subway tunnels which are very shallow.

Deeper tunnels for longer distance transport do not have any of these
limitation.

~~~
bluGill
Deeper tunnels cut and cover get expensive fast, bored tunnels are about the
same cost at any depth.

------
topmonk
I know this is probably a very stupid idea, but I was thinking what if we shot
ourselves out of rail guns into the air into a bullet shaped craft with fins?

You could be shot out of one rail gun in San Francisco, glide for awhile, fall
to the earth and caught by a “reverse” railgun in San Jose.

It'd be cheaper and safer than planes since no need to carry fuel or an engine
on board, and could have an emergency parachute incase something went wrong.

Or maybe I've been dreaming about Kerbal Space Program projects too much
lately. (I'm fully expecting to be flamed and jided for this)

~~~
lmm
Humans are comfortable with accelerations of maybe 1 m/s/s. So to accelerate
comfortably to a plane-like speed of say 300 m/s, your railgun would have to
be 600m long - comparable to the tallest skyscraper in the world - and likely
pointing at 45 degrees up.

On the way down the vehicle would be going the same speed it went up at - so
you're talking about plummeting ballistically towards the ground at 300 m/s.
Even assuming you can steer perfectly, what happens if something goes wrong
with the receiving railgun? You've got no way to abort and go around, and no
time to do... well, anything, really.

Parachutes for vehicles the size of a passenger aeroplane are not practical. A
few very small planes have emergency whole-aeroplane parachutes, but they're
not to be relied upon. The German army experimented with parachuting a light
buggy with two soldiers in and gave up after several failures. And even if you
had a working parachute, it still requires a skilled operator and a safe
landing zone - what if you hit power lines, or trees, or buildings?

~~~
ProZsolt
Just gravity is more than 1m/s^2, around 9.8m/s^2

~~~
sean-duffy
Is the implication that most humans are comfortable with freefall?

~~~
zaroth
No, the implication is that humans are perfectly comfortable with way more
than 1m/s^2, particularly if it is linear and you are comfortably seated.

~~~
projektfu
As an example of Fermi estimation, it's pretty reasonable. 10 m/s is too much,
given that most people wouldn't want to spend a lot of time accelerating at
the rate of a Corvette on a drag strip. So the correct number is between 1 and
10.

~~~
zaroth
First, we’re talking about a short burst of acceleration, not a multi-day burn
on the way to Mars. 1g of lateral acceleration is not a big deal for a few
seconds. Most people think it’s fun.

Unfortunately that was actually the least wrong thing about lmm’s comment.
We’re not launching a rock, it will not come down as fast as it goes up. And I
don’t know what the mixup is around a “receiving railgun”.

~~~
projektfu
Perhaps, though not really. Commercial aircraft generally accelerate at
takeoff at around 2-3m/s. For most people, that is quite enough, and that only
gets you to 140kt. By comparison, doing 1g for 5 seconds (being generous) only
gets you to 95kt. So you aren't really going to be able to get much flight out
of that. More realistically, a gun would have to accelerate you to nearly the
speed of sound or more. Mannned rocket ships have a (throttled) peak
acceleration of 3G, so that sets a realistic upper bound and probably way over
what might be considered reasonable. I've read that the Willis tower elevators
accelerate downward at 8m/s and that is uncomfortable and just for a short
time. It's likely the case that such acceleration would feel better if one
were lying down. It's a curious question.

------
newnewpdro
The vertical shaft sinking machine process is basically just an automated form
of the old-school manual method of digging a well with men and shovels.

Laborers excavate at the bottom while new bricks are laid incrementally
forming the casing at the top. The whole column of bricks slides down as a
cylinder whenever progress is made at the bottom.

I've long wanted to dig a well that way, it's gotta be surreal to be at the
bottom digging away with a little shovel and seeing a towering column of
bricks move as one to fill in the progress.

It can't be terribly safe :)

~~~
lstodd
Here's an absolutely insane guy's channel

[https://www.youtube.com/channel/UCti7FZiCHC5fhvgN_Ns_5ew](https://www.youtube.com/channel/UCti7FZiCHC5fhvgN_Ns_5ew)

He digs wells by hand. Very scary videos.

~~~
goatsi
There we go:
[https://youtu.be/5-j-EHXhBh8?t=465](https://youtu.be/5-j-EHXhBh8?t=465)

~~~
mannykannot
Whatever you do, keep your fingers and toes out from under the lip of the
lining - and have a pump running to keep the water level down, in case you do
get snagged.

------
choeger
I _think_ one of the major causes for the high cost of tunneling is that it is
done too seldom. Any major city in the world probably has room for 10 or so
additional tunnels, so why do they not operate a fleet of TBMs constantly for
the next n years?

------
morekozhambu
> Rather than including a facility for assembling the tunnel lining (out of
> multiple segments) inside the TBM, complete rings are inserted at the
> insertion shaft, and the whole tunnel is jacked forward one segment at a
> time.

This seems inefficient.

~~~
bluGill
Looks to me like they are looking at only going a short distance. I doubt you
could get more than 100 meters like that, but if you only need 100 meters of
tunnel it is probably cheaper because it is faster.

------
spullara
Or you could just move the surface streets a couple of stories up like they
did in the early 20th century in Chicago. Trucks (for deliveries, etc) are not
allowed on the surface, only below.

~~~
djsumdog
A lot of early cities jacked up their buildings. Chattanooga did due to
flooding.

I somehow doubt such things could happen today considering the superstructure
foundations under a lot of our modern buildings.

~~~
spullara
Definitely easier to keep the buildings at their current level and just make a
new entrance on the second (or higher) floor.

~~~
lmm
You can't bootstrap having a nice walking environment at above-ground level
that way. Who's going to open the first cafe where there's no foot traffic?
Why will anyone spend a lot of money on entrances that no-one's going to walk
to? What pedestrian is going to want to keep walking up and down stairs while
the network is partially complete. The City of London tried to do what you're
suggesting and it was a total failure, because while it might have worked if
it could have magically all been done in one go, there's no way to get to
there from here.

------
sytelus
Here's interesting tidbit: Vast majority of underground railway network in
Moscow was built in 1950s. Cost of building a mile of interstate highway in US
is about $5M. Interestingly this cost hasn't changed since 1956 in inflation
adjusted dollars when new 41,000 miles of interstate highway in US was laid
out. It seems major cost is not tech but quite possibly regulation and/or
government inefficiency/corruption.

~~~
wongarsu
We have also use highways a lot more and accordingly require better
construction. I'm not saying nothing interesting is going on, but
construction+maintenance over 20 years, adjusted for vehicle miles traveled
(or rather semi-truck-miles traveled) would be a much better indicator.

------
k_sze
Is Elon Musk a Samuel Beckett fan? I can totally picture a city council asking
what's taking a tunnel project so long to complete, and Musk answering, with a
straight face, "Oh, we're just waiting for Godot."

------
tiku
Why can't we just vaporise stone with lasers..

~~~
wongarsu
The boiling point of limestone is around 825°C or 1515°F. Heating up a tube of
multiple meters diameter and multiple kilometer length to that temperature
would require insane amounts of energy. A laser makes it possible to
efficiently heat a small spot to that temperature which helps reduce waste
heat, but you still have to heat every spot at some point.

~~~
polemic
I wonder what you do with a jet of vapourized rock too, once you've got it to
that temperature!

~~~
lstodd
Well I guess one can suck the plasma into a condenser unit and then on to a
conveyor belt for extraction.

Now what you do when those lasers hit a high-water-content sediment and cause
a vapor explosion, loss of integrity of surrounding rock and flooding?

------
lazysheepherd
Article does not seem to understand what Booring Company trying to achieve. It
does not even seem try to understand.

We all know it's very popular to love Elon Musk. But it's generally more
attractive to one-up those who do and hate Elon and his "fans".

As a disclaimer: I am in the wagon of "please leave this guy alone so he can
do his thing, whatever it might turn out to be".

And I do not see any value in this article. Booring Co. is about creating rich
network of very small tunnels _to solve urban traffic,_ whereas article only
talks about creating huge tunnels for longer distance transportation.

Article seem to be making a comparison while things it compares aren't in the
same category nor does they try to solve the same problem to begin with.

Incoherent and poorly thought-out", if not straight clickbait.

~~~
projektfu
The article only briefly mentions the Boring company and Elon Musk, because
it's mainly about how cool these large tunnel are and how the machines are
large enough to allow multimodal transportation in a tunnel. The comparison to
Musk is that his company is making a bet the rest of the industry has
rejected. They are all building large, versatile tunnels. Musk is betting that
small tunnels will be the future. Who knows?

What I got out of the article was definitely not an "anti-Musk" vibe. Not even
super critical of the Boring company approach. It was more of a "modern
marvels" type of article.

