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Why are there so many tunnels under London?

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Re: Why are there so many tunnels under London?

#31

Post by alexkus »

jdsnape wrote: post #20
junto wrote: post #18

There are lots of secret MOD tunnels as well. Some of them run out of London across the country with rail tracks to nuclear bunkers that were to be used when nuclear war broke out. To put the scale of it in perspective, one if the tunnels runs to a bunker in Wales south of Aberystwyth.

Do you have a source for that last example? Seems like it would be a bit difficult to keep a tunnel of that scale secret.

It doesn't exist.

There is a tunnel in Aber that was used to store valuables (Crown jewels, etc) during WWII, but it's certainly not a tunnel all the way from London.

Source: http://www.everythingaberystwyth.co.uk/aberystwyth-fact-of-t...

Re: Why are there so many tunnels under London?

#32

Post by nemesisj »

therobotking wrote: post #25
claudius wrote: post #16

Earlier quoted context omitted.

And I am very thankful that the undergrounds in the cities where I spent most of my time were built much later: Tunnelling techniques evolved quickly during the late 18th and early 19th century, allowing for much more ‘comfortable’ tunnel diameters – there is a reason the London Underground is called the tube, it’s difficult to stand in most of its trains.

This is complete nonsense. It's perfectly easy to stand up in the underground train cars.

There are two sizes of tube trains - "deep tube" and "sub surface" trains. The deep tube trains are much smaller, and they are difficult to stand in if you're near the doors for anyone who's over 6 feet (I'm 6'4"). That said, it's not the end of the world, as you're only standing there when it's crowded, but it does happen.

See here: http://en.wikipedia.org/wiki/London_Underground#Trains

Re: Why are there so many tunnels under London?

#33

Post by TranceMan »

junto wrote: post #18

There are lots of secret MOD tunnels as well. Some of them run out of London across the country with rail tracks to nuclear bunkers that were to be used when nuclear war broke out. To put the scale of it in perspective, one if the tunnels runs to a bunker in Wales south of Aberystwyth.

A List of all known "Cold War" Nuclear Bunkers and Subterranean Complexes in the UK.

http://www.freerepublic.com/focus/fr/873564/posts

Re: Why are there so many tunnels under London?

#34

Post by tallanvor »

alister wrote: post #19
mjn wrote: post #4

Earlier quoted context omitted.

Just new enough that you can usually safely dig without too many delays, though. A problem with tunnel construction in very old cities, in places like Italy and Greece, is that you have a high probability of running into an interesting archaeological site, and then you have to pause construction and decide what to do about it. E.g.: http://www.bbc.co.uk/news/world-europe-21743758

> in very old cities ... running into an interesting archaeological site Why are archaeological sites are so far underground? Are ancient cities actually getting higher in altitude as old ruins get covered up? Why Pompeii was buried is clear. I am more curious about continuously occupied cities like Rome. How did the ruins get underground there ? The best answer I could find was this: http://www.straightdope.com/colu…

Well, it's not so much that the ruins are likely to be found "deep" underground, but some are as much as 3 or 4 stories underground. It used to be that it was easier to build on top of existing structures - or the remains thereof - rather than cart the trash out and start fresh.

If you ever go to Rome, you'll notice that the Colosseum, for example, is at surface level, but most of the land around it is raised up. During street work, you can see parts where they've uncovered foundations, often digging down quite a ways to get to what was the street level at the time. In a place like Rome, when they uncover new ruins, they'll generally be studied for a while and then covered back up because it's the easiest way to preserve the site because they still need the land above it to be usable.

Re: Why are there so many tunnels under London?

#35

Post by groupthinker »

junto wrote: post #18

There are lots of secret MOD tunnels as well. Some of them run out of London across the country with rail tracks to nuclear bunkers that were to be used when nuclear war broke out. To put the scale of it in perspective, one if the tunnels runs to a bunker in Wales south of Aberystwyth.

There's another, called Burlington, on the Great Western mainline - after you go through Chippenham en route to Bristol, there's a point in the long tunnel, which leads to the bunker station. It was where the government were supposed to scurry off to in event of nuclear war. Enough space to support thousands.

Re: Why are there so many tunnels under London?

#36

Post by filpen »

alister wrote: post #19
mjn wrote: post #4

Earlier quoted context omitted.

Just new enough that you can usually safely dig without too many delays, though. A problem with tunnel construction in very old cities, in places like Italy and Greece, is that you have a high probability of running into an interesting archaeological site, and then you have to pause construction and decide what to do about it. E.g.: http://www.bbc.co.uk/news/world-europe-21743758

> in very old cities ... running into an interesting archaeological site Why are archaeological sites are so far underground? Are ancient cities actually getting higher in altitude as old ruins get covered up? Why Pompeii was buried is clear. I am more curious about continuously occupied cities like Rome. How did the ruins get underground there ? The best answer I could find was this: http://www.straightdope.com/colu…

> Are ancient cities actually getting higher in altitude as old ruins get covered up?

I recently watched a TV show from a relatively old series about underground cities where they showed the underground of Istanbul. Very interesting, but I can't remember the name of the show.

From http://en.wikipedia.org/wiki/Hippodrome_of_Constantinople for instance:

"The course of the old racetrack has been indicated with paving, although the actual track is some 2 m (6.6 ft) below the present surface. The surviving monuments of the Spina (the middle barrier of the racecourse), the two obelisks and the Serpentine Column, now sit in holes in a landscaped garden."

Re: Why are there so many tunnels under London?

#37

Post by lnanek2 »

alister wrote: post #19
mjn wrote: post #4

Earlier quoted context omitted.

Just new enough that you can usually safely dig without too many delays, though. A problem with tunnel construction in very old cities, in places like Italy and Greece, is that you have a high probability of running into an interesting archaeological site, and then you have to pause construction and decide what to do about it. E.g.: http://www.bbc.co.uk/news/world-europe-21743758

> in very old cities ... running into an interesting archaeological site Why are archaeological sites are so far underground? Are ancient cities actually getting higher in altitude as old ruins get covered up? Why Pompeii was buried is clear. I am more curious about continuously occupied cities like Rome. How did the ruins get underground there ? The best answer I could find was this: http://www.straightdope.com/colu…

Don't forget that things aren't the same everywhere. The land in Alaska and New York is rising pretty fast, geologically speaking, since the weight of glaciers came off. Meanwhile New Orleans is sinking. Chicago took matters into their own hands and raised street level an entire floor to combat flooding. We still have ancient caves at ground level in New York, but I'm sure stuff buried under a city survives better.

Re: Why are there so many tunnels under London?

#39

Post by junto »

jdsnape wrote: post #20
junto wrote: post #18

There are lots of secret MOD tunnels as well. Some of them run out of London across the country with rail tracks to nuclear bunkers that were to be used when nuclear war broke out. To put the scale of it in perspective, one if the tunnels runs to a bunker in Wales south of Aberystwyth.

Do you have a source for that last example? Seems like it would be a bit difficult to keep a tunnel of that scale secret.

I was dubious too, but I trust the source of that information.

The bunker in question isn't on any of the lists you'll find on the Internet. The bunker is also very well hidden. I can't find the entrance on Google Maps, but I'm very sure of the location within a few kms.

Re: Why are there so many tunnels under London?

#40

Post by junto »

TranceMan wrote: post #33
junto wrote: post #18

There are lots of secret MOD tunnels as well. Some of them run out of London across the country with rail tracks to nuclear bunkers that were to be used when nuclear war broke out. To put the scale of it in perspective, one if the tunnels runs to a bunker in Wales south of Aberystwyth.

A List of all known "Cold War" Nuclear Bunkers and Subterranean Complexes in the UK. http://www.freerepublic.com/focus/fr/873564/posts

I don't believe it is known. It is still in use. See my other comment.
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