Underground Invasion

[walmart]

Only 44 km (27 miles) from Seoul, the incomplete tunnel was discovered in October 1978 following the detection of an underground explosion in June 1978, apparently caused by the tunnellers who had progressed 435 metres (1,427 feet) under the south side of the Korean Demilitarized Zone (DMZ). It took four months to locate the tunnel precisely and dig an intercept tunnel.[1][2]

Since 15 November 1974, South Korea has discovered four tunnels crossing the DMZ that had been dug by North Korea. The orientation of the blasting lines within each tunnel indicated they were dug by North Korea. North Korea claimed that the tunnels were for coal mining; no coal was found in the tunnels, which were dug through granite. Some of the tunnel walls were painted black to give the appearance of anthracite.[25]

The tunnels are believed to have been planned as a military invasion route by North Korea. They run in a north–south direction and do not have branches. Following each discovery, engineering within the tunnels has become progressively more advanced. For example, the third tunnel sloped slightly upwards as it progressed southward, to prevent water stagnation. Today, visitors from the south may visit the second, third and fourth tunnels through guided tours.

Would it be possible for a nation to launch a surprise large-scale invasion through underground North Korean-style tunnels? Maybe an underground invasion of the British Isles to bypass the royal navy? I'm not sure of many situations where this would be an advantage over an overground route beyond surprise or defense against aircraft. How well would such an invasion go? I imagine there would be quite a big shock and chaos to just have a bunch of enemy troops show up throughout the nation. One possibility I could see for attacking a major city would be having the tunnels link up with the sewer system enabling you to send troops all across the city.

Korean Demilitarized Zone - Wikipedia

en.wikipedia.org

Tunnel warfare - Wikipedia

en.wikipedia.org

 

[CaptainCalvert]

First, it's really hard to build big tunnels without other people noticing.

Second, it's quite slow - the channel took roughly six years, and that was working from both sides and during peacetime. Even if only building a single tunnel plus service tunnel, and assuming lower wartime safety standards [1] make up for modern tunneling equipment, that's as long as WW2, and roughly 2 years longer than the Germans held France for.

In short, probably fine for infiltration in siege type situations, but not for a full scale incursion.

[1] While people might have been more expendable then, the risk to the tunnel itself may require greater care than is possible with modern equipment.

 

[tonsofun]

I think the problem is that even if a nation can build a tunnel into another nation without getting noticed, it is going to have to be big enough to get an entire army through.
Even if North Korea were to build a tunnel into South Korea without getting noticed, the best they're going to achieve is a 9/11 level atrocity. Although there will be massive shock value, it will soon enough to be realised that a tunnel network is being used and it will be easily countered. If you're going to go to all the time and effort to build this tunnel, you might as well just invade the old fashioned way.

 

[Astrodragon]

SeaMole??

I'll go get my coat now...

 

[DougM]

The only practical way I can think of as a way this would work is if you have a place that is critical for your invasion taht you MUST take but can’t in any practical length of time. So you build a. Tunnel under/past the chok point and then when you start the attack you attack the choke point from behind taking them by surprise and securing your passage through the defenders choke point.

But I am not sure where in the world anything like this exists.

 

[Iam9Begea]

The only practical way I can think of as a way this would work is if you have a place that is critical for your invasion taht you MUST take but can’t in any practical length of time. So you build a. Tunnel under/past the chok point and then when you start the attack you attack the choke point from behind taking them by surprise and securing your passage through the defenders choke point.

But I am not sure where in the world anything like this exists.

Well, there is a place in Africa where 4 countries's borders meet (i cant remember the countries tho, f). Another scenario could be Italians sneaking commandos inside Vatican and San Marino to capture the Pope/Leader.

But yeah, in modern context it really isnt worth it. But in medieval times, where sneaking a single guy could mean opening the gates and taking a city, the tunnel strat had more uses.

 

[njslim]

Would it be possible for a nation to launch a surprise large-scale invasion through underground North Korean-style tunnels? Maybe an underground invasion of the British Isles to bypass the royal navy? I'm not sure of many situations where this would be an advantage over an overground route beyond surprise or defense against aircraft. How well would such an invasion go? I imagine there would be quite a big shock and chaos to just have a bunch of enemy troops show up throughout the nation. One possibility I could see for attacking a major city would be having the tunnels link up with the sewer system enabling you to send troops all across the city.

Korean Demilitarized Zone - Wikipedia

en.wikipedia.org

Tunnel warfare - Wikipedia

en.wikipedia.org

There is a 1967 sci fi file "BATTLE BENEATH THE EARTH whose premise is that the Red Chinese using advanced tunneling machines are burrowing under the Pacific to plant nuclear weapons under US cities A scientist named Arnold Kramer tries to warn thew US government about the plot, but is labelled insane and committed. A US Naval officer confirms Kramer and the US is able foil the plot.

Battle Beneath the Earth - Wikipedia

en.wikipedia.org

The film has been described as "deliriously paranoid"

Link to view video

battle beneath the earth 1967 - Search Videos

www.bing.com

 

[Orcbuster]

In short, no. This isn't practical in terms of logistics or protection. At most its a small scale diversion.

 

[DougM]

Digging tunnels for sappers/mines is a different story. That has been done for centuries. And WW1 was well known as an example of this.
They did a pretty interesting movie about one of the mines in WW1 called something like Under Hill 60. Or some such.

 

[Sekhmet_D]

I think the problem is that even if a nation can build a tunnel into another nation without getting noticed, it is going to have to be big enough to get an entire army through.

A crowded tunnel is going to be a recipe for disaster. All a defender will need to do is pump in huge quantities of something highly toxic or highly flammable, and its curtains for your invasion force.

 

[CaptainCalvert]

A crowded tunnel is going to be a recipe for disaster. All a defender will need to do is pump in huge quantities of something highly toxic or highly flammable, and its curtains for your invasion force.

Or water if under the channel.

 

[tonsofun]

A crowded tunnel is going to be a recipe for disaster. All a defender will need to do is pump in huge quantities of something highly toxic or highly flammable, and its curtains for your invasion force.

Exactly. Once discovered, it's easy to counter and the people inside won't have a happy end.