Mammoth "Metal Moles" Tunnel Deep Beneath London 294
Hugh Pickens writes "BBC reports that the first of eight highly specialized Tunnel Boring Machines (TBM), each weighing nearly 1,000 tonnes, is being positioned at Royal Oak in west London where it will begin its slow journey east. It will carve out a new east-west underground link that will eventually run 73 miles from Maidenhead and Heathrow in the west, to Shenfield and Abbey Wood in the east. Described as 'voracious worms nibbling their way under London,' the 150-meter long machines will operate 24 hours a day and move through the earth at a rate of about 100m per week, taking three years to build a network of tunnels beneath the city's streets. Behind a 6.2-meter cutter head is a hydraulic arm. Massive chunks of earth are fed via a narrow-gauge railway along the interior of the machine, which is itself on wheels, as the machines are monitored from a surface control room which tracks their positions using GPS. Hydraulic rams at the front keep them within millimeters of their designated routes. 'It's not so much a machine as a mobile factory,' says Roy Slocombe, adding that the machine is staffed by a 20-strong 'tunnel gang' and comes with its own kitchen and toilet. Meanwhile, critics complain that the project is a peculiarly British example of how not to get big infrastructure schemes off the ground, because almost 30 years will have elapsed from its political conception in 1989 to its current projected completion date of 2018."
Mind you, if they run into voids, we're in trouble (Score:4, Funny)
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GPS? (Score:3, Informative)
GPS?? Underground? Cool, so my scuba GPS is just around the corner too then.
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From TFA:
The machines are monitored from a surface control room which tracks their positions using GPS.
So this would be more like having GPS in your dive boat than having GPS underwater.
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I'm pretty sure they know where the surface control room. It's the position of the machine that needs monitored, not the stationary control room.
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So they track the control room? In case it starts moving around??
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So they track the control room? In case it starts moving around??
That was the sense I got. These are *civil* engineers, after all. My wife once visited the Fundy Tidal Power Project. It had a million dollar visitor center, but the engineers still worked in white trailers.
The impression I got was that they were going to communicate with the device from the surface near the tunnel face rather than from the tunnel mouth or bore holes. They only way GPS would make sense in this situation is if they used acoustic methods to locate the actual boring machine from a movable st
Re:GPS? (Score:5, Insightful)
Sometimes a white trailer is the right tool for the job. I've worked with civil engineers for years, and the ones I've worked with were pretty full-on professional. If a job needs a white trailer, that's what they trot out. If the job needs a million dollar visitor centre, then that goes into the spec.
It's probably worth mentioning that there's GPS, and then there's GPS. The sort that we are used to ("In 400 metres, exit ramp, on left, to Proposed Western Freeway"*) depends entirely on trig between orbiting satellites, another more sophisticated type augments that with intertial guidance systems. If you can read the RF from the satellites, you can use the former - and that depends on a combination of antenna design and how much (generally metal) is in the way that might soak up the radio frequency energy before it gets to the box. To a point, you can make up a lot of signal strength with a higher-spec antenna.
The latter type of (what's erroneously, but conveniently called GPS), the inertial guidance system, measures and sums accelerations and gives you a vector -- sort of like summing the movements of a small mass in an enclosed box over time. These can use accelerometers and gyroscopes to add up quite small movements and tell a computer in summary that it's gone this far, in this direction, over this interval of time. If it sounds complex, you're right -- but the technology has been available since the advent of the ICBM.
The Wikipedia entry on the subject is really quite good -- http://en.wikipedia.org/wiki/Inertial_guidance_system [wikipedia.org] -- worth reading (warning, there is a lure and fascination in these things, especially when you get to laser gyroscopes...)
And as much as I like my little Garman Nuvi (*yes, it really did give me that direction once) it wouldn't be the GPS of choice for locating a major piece of underground tunnelling kit.
Re:GPS? (Score:5, Informative)
I don't know the specifics of this, but from my former work in an oilfield services company, I know that oil well drilling systems can track their own position within a few inches. One example [wikipedia.org] from about 30 years ago was a set of wells drilled under an estuary in the UK. The gov. allowed the drilling company a one-acre island to do all the drilling from. They drilled down about a mile, then branched off into 10 separate holes that were drilled horizontally, following an oil seam that at times was only one foot high. The longest horizontal hole was about 10 kilometers (34000+feet, 6.6+ miles) long. Here is another reference [greeningofoil.com], including info on a new well system on the North Slope that extends even farther - two miles down, then over 10 km horizontally, then back down another km or two so they can use an existing oil processing facility.
Drilling systems are among the most sophisticated technological marvels going - they include seismic signalling, mass spectrometry, neutron activation analysis, nuclear magnetic resonance, gamma ray spectral analysis [wikipedia.org], and other really geeky stuff. The bit knows where it is geographically and where it is relative to the geological structures that it is following. The computers that sit 10 feet behind the actual bit meet tougher specs than military or aerospace - 1000 G shock, very high pressures (I forget the PSI), 400 degree F temperatures. Cooling is accomplished by the drilling fluid that is going past the outside of the drill string. Truly oil well technology is the perfect geekly combination of extreme "big heavy dangerous machines" plus extreme high tech.
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I'm with you; I'd rather see hydrocarbons used as lubricants/raw materials for manufacture than burned as energy. Which makes my job at Halliburton somewhat ironic, but life's funny that way.
The good news is that energy companies (and energy service companies) are eying the alternative energy market as an exit strategy from oil-as-energy. Halliburton does geothermal well cementing [halliburton.com], and is trying to advance the art so the wells and plants can be more productive. Challenges include seismic instability, hig
Re:GPS? (Score:4, Insightful)
Lasers are used underground to determine the location. If there are turns, mirrors are used.
Re:GPS? (Score:5, Interesting)
GPS?? Underground? Cool, so my scuba GPS is just around the corner too then.
Unless your SCUBA activities consist of walking around above the water level, I don't think you're going to find a GPS based solution to help you - water attenuates the signals too much.
However, if you're underground, there are a number of companies that can sell you GPS repeaters that will help you navigate even when you can't receive any satellite signals directly:
http://www.vialite.co.uk/gps_band_overview.php [vialite.co.uk]
http://www.leica-geosystems.us/en/GPS-Machine-Guidance_1939.htm [leica-geosystems.us]
Why exaggerate? (Score:4, Insightful)
From the summary:
the 150-meter long machines...
From the article:
The 140 metre long, fully assembled tunnel boring machine...
At 140 metres, each TBM would just fit just inside the boundaries of a cricket oval.
Was 140 meters not impressive enough, so the submitter had to add 10 meters?
Re:Why exaggerate? (Score:4, Funny)
TIL 140 metres = 150 meters. It's not just a wonky British spelling.
Re:Why exaggerate? (Score:5, Funny)
Was 140 meters not impressive enough, so the submitter had to add 10 meters?
He's a guy - exaggerating a bit about length is reflexive.
Re:Why exaggerate? (Score:5, Funny)
Obviously the submitter is American and did the conversion from British-meters to American-meters.
Re:Why exaggerate? (Score:5, Funny)
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Sulfur (Score:2)
Some counter points.
Sulfur (the US spelling) is more archaic than Sulphur (the English spelling).
Meter is English, Metre is French (they invented the metric system).
I suppose you would also want all other homophones to be spelled the same way, right, rite, wright, write?
English has never been a phonetic language, neither the UK nor the US version.
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I suppose you would also want all other homophones to be spelled the same way, right, rite, wright, write?
I made no such claim, however, it would actually help linguistic clarity to have all homophones be homographs.
English has never been a phonetic language, neither the UK nor the US version.
Yes, it was. Old English and Middle English are phonetic, but Modern English has adopted many words never officially in the precursor languages. Bureau is not phonetic, but is an English word, even if it retains its French spelling and approximately French pronunciation. But such adoptions post-date the inception of the language called "English."
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It originates from the French word metre [accent lost on slashdot], and before that the Greek word metron (to measure). Obviously in French the r is pronounced first. There's plenty of examples of American English taking on archaic spellings or words wholesale from other languages, so I don't think there's much room to boast of American linguistic pragmatism here.
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Uh.. What accent? ê? é? è? ë? (ê é è ë)I can't find any resource that suggests there's an accent.
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Nah, we just like to spell like we pronounce. mee - ter, not mee - tray ( or meh - tray) :)
We would also spell Chalmondeley [wikipedia.org] 'Chumly' - much more efficient. For some reason we still use Worcester, in honor of the Olde Lande, rather than the more common-sense Wooster.
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Can you explain to me why you pronounce "Aluminium" as "Aluminum"?
And why you spell Sulfer with an f, but Phone with a P?
Re:Why exaggerate? (Score:4, Informative)
Humphrey Davey called it Aluminum... and some jerk in a British publication reviewed his work and said "Aluminium" sounded more Latin. From then onward... chaos.
http://en.wikipedia.org/wiki/Aluminium#Etymology [wikipedia.org]
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Meh. (Score:4, Funny)
Call me when they can load one up on a big green supersonic aircraft and deploy it anywhere in the world on a moment's notice.
Re:Boring. (Score:2)
Dune (Score:3, Funny)
We may as well get all of the Dune references out of the way here in this one thread.
Nothing 'peculiarly British' about it... (Score:3, Insightful)
There's nothing peculiarly British about partisan politics resulting in funding taking years to be approved and plenty of NIMBYs protesting the plans!
TBM installation for Crossrail is old news (Score:2)
ISTR reading about this somewhere three weeks ago, it was old news then...
Already done in post-Civil war Seattle (Score:2)
Boneshaker, anyone?
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Boneshaker, anyone?
If the rails were laid end-to-end, it would be a big improvement.
What kind of transport is it? (Score:2)
Ugh, terrible journalism, they've buried the lede. You have to read to the very last sentence to figure out that it's a heavy commuter rail corridor, not a subway, bus, or car tunnel. Maybe this is obvious to British readers, but I found it confusing as hell.
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Heavy rail v subway, fair enough. But I would have thought that the "rail" in Crossrail, which appears in bold on the first line, would rule out buses and cars.
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wasn't particularly obvious as to whether it was a rail line or a tube line. Don't think anyone would have thought it was a road tunnel though.
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Ugh, terrible journalism, they've buried the lede. You have to read to the very last sentence to figure out that it's a heavy commuter rail corridor, not a subway, bus, or car tunnel. Maybe this is obvious to British readers, but I found it confusing as hell.
Do you mean the BBC article? The project has been going on for a long time with other work (excavating the big underground stations in central London) for ages now, so everyone in London is familiar with it. I think the article was only in the BBC's local news for London. The rest of the country ought to be aware of it -- it was a big expenditure that was definitely not going to be cancelled for any short-term savings, and rail spending has been in the news in other regions of the UK quite a lot recently.
Good on London for supporting public transport (Score:2)
Good to see London going for public infrastucture development during the recession. Definitely will be great to have a fast Crossrail service and add to the options of moving around London. I was standing waiting for a bus at Angel the other day and I realised all the people sitting in the cars between the two sets of lights in that section could fit into one bus (or a train carriage). Public mass transport got to be the way to go in cities like London. Could you imagine London without the tube? (Mind you
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Re:Good on London for supporting public transport (Score:4, Interesting)
About 10 years ago I was commuting via the bus for a while, and was curious about the true efficiency. So I took the total amount of fuel that the bus system was reported to use in a year, and divided by the number of passengers and total miles driven (all part of their annual report). My conclusion was that the bus system got about 12 passenger miles per gallon averaged over all their routes and schedules. Unfortunately for most people the real price of taking the bus, besided the bus fare, was the loss of time. My commute took over an hour each way, and could be driven even in bad traffic in about 25 minutes. At the time I was only making $15/hour, so the opportunity cost to me of taking the bus was very conservatively over an hour per day or $15 per day (not even counting the time to walk out to and wait for the bus, and the restriction on my work schedule - the last bus home went by at about 6:30 PM) - enough to buy a very nice car if I wanted to.
Life doesn't begin at conception (Score:5, Insightful)
You can't count the life of a project from the date someone first thought of it. By that measure, the Apollo moon landing project took at least 100 years. You should start counting from the date significant funding began, which in this case is 2010. Not bad, compared to, say, Boston's Big Dig.
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30 years only seems like a long time to people in their 20s.
A Bave New World, with just a handful of men (Score:3)
ARTILLERYMAN: We're gonna build a whole new world for ourselves. Look, they
clap eyes on us and we're dead, right?
So we gotta make a new life where they'll never find us. You know where?
Underground.
Have they .... (Score:3)
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Yes. Lasers are commonly used. It's not uncommon for two underground boring machines to meet at the center of a ten mile tunnel and be less than a centimeter off.
Took the Brits only 30 years? (Score:3)
I've seen this before (Score:2)
Brunel (Score:2)
The fundamental approach to digging appears to broadly resemble that of Brunel's ideas [wikipedia.org] for digging the Thames Tunnel [wikipedia.org] in the early-mid 1800's.
Re:comparative position? (Score:5, Informative)
It's older than any other subway system.... Which would make them the original leader, eh?
Re:comparative position? (Score:5, Informative)
No. London's predates New York's by about 41 years. (1863 vs 1904). Glasgow's is dated to 1896, so even the Scots beat the Yanks to this.
http://en.wikipedia.org/wiki/List_of_metro_systems [wikipedia.org]
Re:comparative position? (Score:5, Funny)
Re:comparative position? (Score:4, Interesting)
London's system appears to be conveniently bi-directional. [q-dog.co.uk]
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Never mind, Penrith is Australian. Still funny though.
Re:comparative position? (Score:4, Informative)
Sorry, but no, it's in Cumbria, in the North of England. http://g.co/maps/4f64r [g.co]
And I lost one mod point for you...
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Good to know, thank you. We're actually both right. [google.com] And thanks.
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Re:comparative position? (Score:5, Funny)
It has more gaps than any other system - you have to constantly mind them.
That's why I prefer the Moscow Metro. Because there, the gap minds you.
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This isn't about the London Underground at all, it is a heavy rail link.
Re:comparative position? (Score:5, Informative)
Re:comparative position? (Score:5, Informative)
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"The Tube", like most major metropolitan underground systems is extremely overloaded, but actually a pretty good network, and well integrated with the mainline. It has its problems, the main one being expense. It is a major target of investment, mainly because the city depends on it to operate. Many parts of it are pretty old, but this is more a case of "if it ain't broke, don't fix it".
Re:comparative position? (Score:4, Informative)
London's Underground is what is usually considered its "subway" system. It's the oldest in the world, and one of the most comprehensive.
This, however, is something else. This is a mainline railway route which is going under central London. Tube trains (on the London Underground) are small vehicles with an odd cross-section, so that they can go through smaller tunnels, and are powered by "four rail electrification". This new Crossrail line is designed for full-sized intercity trains, with normal overhead-wire electrification. This is part of why it's such a big project.
Re:comparative position? (Score:4, Informative)
In fairness, there are genuine improvements coming down the line. (Sorry...) These are at least partly driven by a desire not to look like idiots when a few million extra people are around for the Olympics later this year.
New trains with air-conditioning and a walk-through design [bbc.co.uk], as used in underground networks such as those in Paris and Rome, have been rolling out for a year or so. They are replacing one line at a time and due to cover 40% of the network by 2015.
Also, a deal was announced just last week for Virgin Media to provide WiFi access on the London Underground during the 2012 Olympics [independent.co.uk], though it only covers station areas and not the trains themselves while they are in the tunnels. Its stated goal is to allow travellers to respond more quickly to disruption and avoid the busiest areas (which are almost certainly going to be flooded far beyond capacity at peak times during the Olympics, whatever happens).
The system is still nowhere near the level of, for example, the other European capitals I mentioned, though, and won't get there any time soon.
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You can tell you don't go on the underground much. Even in the height of winter, it gets pretty hot down there. It's pretty far underground though, so I don't think surface temperatures affect it all that much. Still, it makes the train arriving twice as nice, since it often brings a lovely blast of cool air with it.
All your other points are completely accurate, though. It's overpriced and cramped.
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97% of services run to schedule, which isn't too bad.
It's not great, though. With more than a billion passenger journeys taken on the Underground per year, that 97% still represents more than 30 million significantly disrupted journeys, or if you prefer, regular commuters being late to work (or late home) once or twice every month.
Of course, there is only so much even the most hard-working staff could do with the limited resources available, and there is only so much money that can be available without putting fares (or taxpayer subsidy) up to politically int
Re:comparative position? (Score:4, Informative)
They are actually retrofitting AC systems into the newer rolling stock. It's just difficult due to the size of the tunnels, which places quite strict limits on the size of the train but more importantly, the ability to dump all that waste heat - you can't just pump it into the tunnels as it's already quite warm down there.
You need to be able to use heat exchangers that are very efficient, or cycle the heat out of a transfer medium when the train comes up above ground (as they all tend to do outside of the centre).
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Re:Whitechapel (Score:4, Funny)
Whitechapel already has a station with 3 lines.
In fact, you know that things are strange in Whitechapel, because the underground trains run overground, and the overground trains run underground.
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The place is a complete dump.
To be fair, many people not from London would say the same about all of our illustrious capital.
Buy now (Score:3)
You wait til a superfast train connection stops there. House prices will go up again... Fast connection across London stopping there will mean it's going to go up in the world.
Rules Change Re:Whitechapel (Score:5, Funny)
They had to add the stop because the Alternate Thursday Rule, when applied in conjunction with the Left-Hand Turns Only Method, caused too many people to end up in the middle of the Thames.
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Re:"Peculiarly British" (Score:4, Funny)
" . . . well, instead of a Mammoth Metal Mole, we could build this Giant Wooden Rabbit . . . "
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Actually, except for the color scheme and the fact that the NYC machine isn't named after the Mayor, they look nearly identical.
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it's not unique at all - the design of the TBMs is identical to those used in the Eden (Channel Tunnel) Project, the Gotthard Base Tunnel, others at Orlovski, Niagara, Yucca... only difference being the number of tunnels excavated, the number of TBMs used in each project, and the type of rock chewed through.
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um... no. And, no. Oh, and no.
The Tunnel boring project was named Eden in its concept phase through planning, the TBMs used in the probe tunnels were identical. Both built by the same company and both designed to chew chalk. When the tunnels met, one TBM was directed downwards and buried, the other was sent off to become one of four TBMs chewing through the Alps for the GBT. About the only thing that needed to be replaced was the cutting head since it was going from chewing chalk to chewing basalt and grani
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they build exciting and reliable sports cars, too
Actually it's German technology, the British merely bought a couple (and will sell them back to the German's when they're done with them).
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The Griffith had a Rover V8 (derived from a Buick engine) as I recall, and since the parent didn't name the monstrosity one could only guess what it used.
I used to have a Reliant Scimitar, which used a 3-litre Ford V6. Could that be what you're thinking about?
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Just checked & you are right, the Griffith had a V8
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I was never troubled by Lucas electrics. Having been burned by one too many Lucas-blighted cars I decided to rip out all the wiring and do it again properly.
It was nice being able to turn the headlights on without the smell of burning insulation.
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Someone hasn't played Jenga, apparently.
Hoping not to disturb your world view overmuch, but there is this interesting concept of reality.
You might try it sometime - it's different enough at any rate.
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People being unnecessarily offensive on the internet or off, alas, does not disturb my present world view.
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Appreciated, thank you. It all looks smaller on Google Maps, but a 1:1 scale would probably be unfeasible.
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Do you honestly think it's all just bits of soft sandy soil under the ground?
No, and I hadn't been trying to give that impression.
Neither do I think that quantities of houses and automobiles are made of foam rubber. If you excavate large swaths of the foundation, island or not, there's going to be trouble.
My parents were homeowners, and the city decided it would pump the freshwater under the neighborhood and sell it. That alone caused significant property damage as the land settled due to the lowered water table. And that was just water; I wouldn't like to think what would happen removing massive amounts of the earth.
Bring land ashore from the North Sea.
Re:Tunnelling under London... (Score:5, Informative)
Well, it isn't going to do anything, because they don't want the tunnels collapsing...
This isn't like pumping water, gas or oil out from under the ground - the tunnels need to be servicable and usable after the fact, otherwise there isn't any point in making them, so they get lined with concrete or some other material which keeps them rigid and bearing the weight of the ground above them.
Bear in mind that they've been doing this in London for 200 years or more, what with the London Underground, service tunnels, Royal Mail tunnels, BT telecommunications tunnels etc etc etc. London is criscrossed with tunnels already, 99% of them not having any issue on the surface at all. They've got experience in this.
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That's sincerely reassuring then, and I thank you. I hadn't thought they could successfully reinforce tunnels a tenth of a kilometer wide.
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Re:Tunnelling under London... (Score:4, Insightful)
That's sincerely reassuring then, and I thank you. I hadn't thought they could successfully reinforce tunnels a tenth of a kilometer wide.
Um, what?
The tunnel diameter is 6.2 metres, i.e. a bit bigger than the cross section of a train + emergency walkway. The new, underground station platforms will be 250 metres long (wow!) but still only ~18m diameter (my guess from the mock-up video [bbc.co.uk]). Presumably they've planned for enough space for most of the "some 1,500 passengers ... carried in each train at peak periods" to get off at a single station.
Tunnelling can cause problems though. For example, London's local Quake II level [wikipedia.org] (see picture) required some special work to avoid the Houses of Parliament collapsing.
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That's sincerely reassuring then, and I thank you. I hadn't thought they could successfully reinforce tunnels a tenth of a kilometer wide.
Um, what?
My mistake. The article brief sizes the equipment at 150 metres, corrected in the comments to 140 metres.
What I'd missed was that they were 140 metres long, not wide. Naturally I freaked.
Thanks for the correction.
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Modern engineering can do some quite remarkable things, but for what it's worth, I think you've misunderstood the scale of the tunnels involved here by about an order of magnitude.
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the Crossrail project is talking about a 73-mile East-West network made up of three lines*, which at 100m/week in the tunnel sections will take about three years to dig. What complicates matters is the fact that the Crossrail coachwork will be full height and riding on standard gauge rails - which will make it completely incompatible with the London Underground network, also means that the rails that will need laying will be brand new, on virgin bed - while avoiding breaching existing tunnels! Most of the r
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I'm not sure how 3 years * 5.2km adds up to 73 miles.
Uhm. (Score:4, Insightful)
You have heard of the Channel Tunnel haven't you?
They dug from both ends and met in the middle, under much deeper water than the Thames, and were only a centimetre out.