Breakthrough

[Skybird]

Lights at the end of the tunnel, and a drilling machine in the middle.



The Swiss dig a hole...
http://www.spiegel.de/international/...723407,00.html

...and took pictures of it:
http://www.spiegel.de/fotostrecke/fo...cke-60566.html

It now is the longest "hole" in the world.

[SteamWake]

I'm always amazed at how they can dig two tunnels thousands of feet from opposite directions and end up joining right were they are supposed to.

Not so long ago they couldent even accomplish this task with roads.

http://en.wikipedia.org/wiki/Twenty_Mile_Bend,_Florida

[Oberon]

I heard that the Channel Tunnel missed on its first attempt...haven't found anything solid to back that rumour up though.

Amazing work though, but the Swiss are quite good at engineering on the quiet, and even better at defence works...

[krashkart]

I understand they also trained some very effective pikemen at some point in history.

[TLAM Strike]

Originally Posted by krashkart

I understand they also trained some very effective pikemen at some point in history.

They still do, who do you think guards the Emperor?

[Betonov]

I love it when they brake trough. Too bad I'm never invited to such events

[TLAM Strike]

Originally Posted by Oberon

I heard that the Channel Tunnel missed on its first attempt...haven't found anything solid to back that rumour up though.

Yea it happened when they hired German contractors to do it...

[Méo]

Originally Posted by SteamWake

I'm always amazed at how they can dig two tunnels thousands of feet from opposite directions and end up joining right were they are supposed to.

Yeah, I was thinking exactly the same.

...and wondering how they did it.

[Jimbuna]

Satellite precision I'm reckoning.

[Schroeder]

Originally Posted by jimbuna

Satellite precision I'm reckoning.

And how do you receive a satellite signal inside a mountain?
GPS doesn't work like that.
(no, I also don't know how they are doing this)

[krashkart]

The GPS data can probably be relayed. That's my guess anyway.

[Diopos]

Actually, simoultaneous "double tunel" digging is an ancient art!
Link: http://en.wikipedia.org/wiki/Tunnel_of_Eupalinos

.

[frau kaleun]

Originally Posted by SteamWake

I'm always amazed at how they can dig two tunnels thousands of feet from opposite directions and end up joining right were they are supposed to.

Not so long ago they couldent even accomplish this task with roads.

http://en.wikipedia.org/wiki/Twenty_Mile_Bend,_Florida

The ancient Greeks managed it on Samos in the 6th century BCE.

http://en.wikipedia.org/wiki/Eupalinian_aqueduct

[Skybird]

Relaying a signal to use satellites for navigation under a mountain makes no sense, since that way you only get the position of the relay you have set up, not the position of the main interest that it is linked to.

GPS also does not help you to determine your level precisely (="altitude").

They most likely have used extremely precise theodolites, or technical clones of these: instrumentations that developed the principle further for greater precision, but base on theodolites' basics. That is what I also take from the article Oberon has linked, as far as I understood it.

The woprk took ten years, but it was planned over decades. Also, they have had a referendum in Switzerland, where the people got asked whether to build it or not. A vast majority of the Swiss voted "Yes" back then.

There are plans and visions in Switzerland to tunnel even more traffic in the country, not only under mountains, but in flat areas as well - to get the traffic density disappearing from the surface. In parts of Swittzerland and Austria, truck traffic is a big problem, along the major axis of transit traffic from Northern to Southern Europe.

Hope the Swiss never find a Balrogh.

Relaying a signal to use satellites for navigation under a mountain makes no sense, since that way you only get the position of the relay you have set up, not the position of the main interest that it is linked to.

Errrrrr.....taking the fix from the known point is what works.
Since the relay is known the target becomes established.
So it makes perfect sense.

GPS also does not help you to determine your level precisely (="altitude").

I always wondered what datums were for.
So your GPS establishes your position and you get your level from an established benchmark and then use that info for your final target.

They most likely have used extremely precise theodolites, or technical clones of these:

Modern theodolites with built in sat recievers and computers where you no longer have to have a visible target to establish its location.....what will they ever think of in the last century

There are plans and visions in Switzerland to tunnel even more traffic in the country, not only under mountains, but in flat areas as well - to get the traffic density disappearing from the surface.

That has more to do with the local climate and alleviating the problems which snow causes on major routes