AHC: Imp Germany pulls a N/Korea, tunnels under Border.

[Curiousone]

So there are tunnels running from North Korea under the border to South Korea to be used in the event of invasion, bypassing fortifications behind the DMZ. Some have been found:

http://en.wikipedia.org/wiki/Third_Tunnel_of_Aggression
http://www.f-106deltadart.com/Korea-DMZ/tunnels.htm
"More than 30,000 troops could move, three to four abreast (a division in strength), per hour."
Other are rumoured to exist.

By way of looking at tunneling technology, serious proposals were put forward for the Channel tunnel in the mid-1800's.

Say Imperial Germany decides gaining a strategic advantage in any offensive against France is just too tempting, starts a covert tunnel going under/past the French Forts on the border.

Can it be built without being discovered? How large an effect can it have in 1914?

 

[TRH]

I somehow doubt it could the French would fail to discover it, and they could easily collapse it once they do. More to the point, something like that would be a terrible bottleneck as far as supplying troops goes, so I don't see the value in it. Oh, and the discovery of such a thing could easily cause a war by itself, which the German government likely wouldn't want to play around with, so that's another problem.

 

[Dathi THorfinnsson]

A massive tunnel under the Polish corridor connecting east and west prussia would have had interesting sequelae.

 

[katchen]

So there are tunnels running from North Korea under the border to South Korea to be used in the event of invasion, bypassing fortifications behind the DMZ. Some have been found:

http://en.wikipedia.org/wiki/Third_Tunnel_of_Aggression
http://www.f-106deltadart.com/Korea-DMZ/tunnels.htm
"More than 30,000 troops could move, three to four abreast (a division in strength), per hour."
Other are rumoured to exist.

By way of looking at tunneling technology, serious proposals were put forward for the Channel tunnel in the mid-1800's.

Say Imperial Germany decides gaining a strategic advantage in any offensive against France is just too tempting, starts a covert tunnel going under/past the French Forts on the border.

Can it be built without being discovered? How large an effect can it have in 1914?

Well that depends. We need the input of someone local to the Lorraine area if there is someone on the list from Lorraine. I know that there are a lot of coal mines in the Ardennes and in French Artois. If the German tunnels could connect up with coal mines on the French side, working and not, the Germans could come boiling out of those mines, completely unexpected. And that could have a major impact on the war. So are there mineral workings with a lot of tunnels in areas of Lorraine (or Alsace) straddling the then German border?

 

[Herzen's love-child]

Sizable tunnels long enough to go past the French border forts and be able to accommodate a significant number of German troops would probably take considerable foresight to construct. Given the amount of time it would take to construct them, the French, who are not brain dead and do have an espionage apparatus, would have an excellent chance of discovering a tunnel or tunnels and such a discovery would be considered a casus bellum before an intentional war was started.

The longest tunnel built prior to WW1 was the Mt. Cenis tunnel under the Alps:
http://en.wikipedia.org/wiki/Mont_Cenis_Tunnel
...for an idea of the time and energy required for a major engineering tunneling effort at the time.

 

[Mikestone8]

Guido Morselli did something like that in Past Conditional, though on the Italian front, and iirc the tunnel was a natural one.

 

[LHB]

What if instead of trying to tunnel past the French they went for tunneling under and collapsing them to break up French trenches and fortifications? Tactics like that were used as late as the Civil War for taking on fixed field fortifications, was anything like that ever done during WWI?

 

[katchen]

What if instead of trying to tunnel past the French they went for tunneling under and collapsing them to break up French trenches and fortifications? Tactics like that were used as late as the Civil War for taking on fixed field fortifications, was anything like that ever done during WWI?

I seem to recall the British and French doing something like that to Turkish positions in Gallipolli. Or was that an AH?

 

[katchen]

I somehow doubt it could the French would fail to discover it, and they could easily collapse it once they do. More to the point, something like that would be a terrible bottleneck as far as supplying troops goes, so I don't see the value in it. Oh, and the discovery of such a thing could easily cause a war by itself, which the German government likely wouldn't want to play around with, so that's another problem.

It's not that the French would fail to discover these tunnels. The North Koreans after all, got quite a way with THEIR tunnels before they got caught. And cavity detection radar had not been invented in 1914. It's that nobody really expected a general war like this until the Russians, more than the Austrio-Hungarians and the Serbs made it happen. These are the kind of preparations one makes when one does expect hostilities to break out at any time; not when one dosen't expect hostilities to break out tomorrow or the next day.
That said, I repeat my question: Were there any mines on the French side of the border close to German territory? Because that might have made all the difference.

 

[Nick P]

The geology of the French-Belgian-German border does have a coal field beneath it. I'd be amazed if there were no mines of any sort that extended under the battlefields of WW1 in at least one place.
http://en.wikipedia.org/wiki/File:CoalDNLBF.png

It took a few years for the use of tunnels to be fully considered and those were moderately successful for causing large explosions that disrupted the enemy lines. Much use was made of underground listening posts to detect the enemy digging towards them and creating counter-attacks.

A very deep tunnel might be possible but the need for ventilation and creating a chamber large enough for a good sized asault force to wait close to the surface before breaking out and creating havoc would take great care and consume much time and resources. Need to estimate how long it would take to dig a tunnel of at least 2 miles in what sort of ground and how to hide the entrance point with thousands of troops heading in.

 

[Alex1guy]

What if instead of trying to tunnel past the French they went for tunneling under and collapsing them to break up French trenches and fortifications? Tactics like that were used as late as the Civil War for taking on fixed field fortifications, was anything like that ever done during WWI?

I want to say the British did something like that. Tunneled under a German position and placed a whole lot of explosives before an attack.

 

[Captain Jack]

I want to say the British did something like that. Tunneled under a German position and placed a whole lot of explosives before an attack.

I believe it was Hill 60

http://en.wikipedia.org/wiki/Battle_of_Hill_60_(Western_Front)

 

[Curiousone]

I want to say the British did something like that. Tunneled under a German position and placed a whole lot of explosives before an attack.

http://en.wikipedia.org/wiki/Battle_of_Messines_(1917)

Battle of Messines.

5,453 Meters of tunnels. 447 Tonnes of Explosives (it was heard in Dublin). 10,000 dead Germans. Allied Success.

22 Mines, two didn't detonate at first. One of those did in 1955. The other is lost. Hill 60 was just one of the locations of the mines.

The thing I had in mind was more of a pre-war 'undermining' of ones enemy, like the fifth columnists planted before WW2 rather than a 'during the war' operation. I suppose Messines shows that mining in warfare wasn't something they couldn't consider doing at least.

 

[Curiousone]

Sizable tunnels long enough to go past the French border forts and be able to accommodate a significant number of German troops would probably take considerable foresight to construct. Given the amount of time it would take to construct them, the French, who are not brain dead and do have an espionage apparatus, would have an excellent chance of discovering a tunnel or tunnels and such a discovery would be considered a casus bellum before an intentional war was started.

The longest tunnel built prior to WW1 was the Mt. Cenis tunnel under the Alps:
http://en.wikipedia.org/wiki/Mont_Cenis_Tunnel
...for an idea of the time and energy required for a major engineering tunneling effort at the time.

Thanks for the reference, it's something to work with.

So.. tunneling completed in 1870, took thirteen years, holds two trains side by side. 13km long.

The tunnels in NK are a fraction the width, about enough for a two or three men abreast & considered enough to pour a Division through in an hour.

Not sure whether you'd want to go for a longer tunnel or have more than one.

Reminds me of the 'Cuban Missile Plan', whole idea was to have it in place before it got discovered, to do it to make up for a perceived strategic weakness.