# How to destroy an underground tunnel ? **URL:** \ **Category:** Factual Questions\ **Created:** [July 26, 2014, 2:06pm UTC](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096 "2014-07-26T14:06:47Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![The\_Second\_Stone](https://avatars.discourse-cdn.com/v4/letter/t/bbe5ce/32.png) [@The\_Second\_Stone](https://boards.straightdope.com/u/The_Second_Stone)\ **Post date:** [July 27, 2014, 12:18am UTC](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096/41 "2014-07-27T00:18:56Z")
Why destroy the tunnels? Charge tolls for their use and monitor them. You know exactly where the entrances and exits are, and periodically you can send the bots through to map the new branches. This way contraband is strictly prohibited at the exits. ---
**Author:** ![Projammer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/projammer/32/559_2.png) [@Projammer](https://boards.straightdope.com/u/Projammer)\ **Post date:** [July 27, 2014, 1:30am UTC](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096/42 "2014-07-27T01:30:05Z")
Would running lengths of det cord along the ceiling and blowing it be enough to cause substantial collapse? Or would shaped line cutting charges work better? ---
**Author:** ![Senegoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senegoid/32/6606_2.png) [@Senegoid](https://boards.straightdope.com/u/Senegoid)\ **Post date:** [July 27, 2014, 1:50am UTC](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096/43 "2014-07-27T01:50:55Z")
> [@Chronos](#): > > Where does it happen and remain stable that one layer of gas is trapped under another layer of gas? [San Fernando Valley.](http://en.wikipedia.org/wiki/Inversion_%28meteorology%29) (ETA: My childhood is my cite. I grew up there.) ---
**Author:** ![Urbanredneck](https://avatars.discourse-cdn.com/v4/letter/u/ea5d25/32.png) [@Urbanredneck](https://boards.straightdope.com/u/Urbanredneck)\ **Post date:** [July 27, 2014, 5:46am UTC](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096/44 "2014-07-27T05:46:38Z")
I read once that in old east Berlin people would tunnel under the Berlin wall all the time. Many times running into previously dug tunnels. I think the East Germans had some sort of sound detection equipment and if they heard someone digging below, they could drill straight down and then pump in water. ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [July 27, 2014, 8:30am UTC](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096/45 "2014-07-27T08:30:48Z")
> [@The\_Second\_Stone](#): > > Why destroy the tunnels? Charge tolls for their use and monitor them. You know exactly where the entrances and exits are, and periodically you can send the bots through to map the new branches. This way contraband is strictly prohibited at the exits. These aren’t contraband tunnels - they’re attack tunnels. ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [July 28, 2014, 3:01pm UTC](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096/46 "2014-07-28T15:01:59Z")
> [@Chronos](#): > > I am not. You’re underestimating the fact that sulfur hexafluoride is a gas. It will diffuse according to the exact same laws as any other gas. The collection of dangerous gases in mines,pips and pipes is well known, it can be as simple as just a big hole and be danger, it can simply collect a gas (eg CO2 or methane) because there’s no wind. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 28, 2014, 5:52pm UTC](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096/47 "2014-07-28T17:52:04Z")
But they don’t stay full without a continual supply of gas. ---
**Author:** ![Shodan](https://avatars.discourse-cdn.com/v4/letter/s/9f8e36/32.png) [@Shodan](https://boards.straightdope.com/u/Shodan)\ **Post date:** [July 28, 2014, 5:55pm UTC](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096/48 "2014-07-28T17:55:12Z")
> [@aceplace57](#): > > Empty three bags of rattlesnakes throughout the tunnel. Add ten bags of rats… They want fewer Hamas in the tunnels, not more. Regards, Shodan ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [July 28, 2014, 5:55pm UTC](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096/49 "2014-07-28T17:55:30Z")
I usually just step on the tunnel, collapsing it. But the durn moles keep making new ones. ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [July 28, 2014, 6:36pm UTC](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096/50 "2014-07-28T18:36:51Z")
[Earthquake bomb](http://en.wikipedia.org/wiki/Grand_Slam_(bomb)). Job done. ---
**Author:** ![Isamu](https://avatars.discourse-cdn.com/v4/letter/i/7c8e57/32.png) [@Isamu](https://boards.straightdope.com/u/Isamu)\ **Post date:** [July 29, 2014, 2:31am UTC](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096/51 "2014-07-29T02:31:42Z")
> [@ToughLife](#): > > Many of them are up to 5 km or more in length and have multiple entrances. So, many of them are between 0 and infinity kms long, and have more than one opening. Interesting. ---
**Author:** ![prbeck](https://avatars.discourse-cdn.com/v4/letter/p/9d8465/32.png) [@prbeck](https://boards.straightdope.com/u/prbeck)\ **Post date:** [July 29, 2014, 3:17am UTC](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096/52 "2014-07-29T03:17:56Z")
If you don’t care about collateral damage the ideal weapon is a thermobaric weapon. [Thermobaric weapon - Wikipedia](http://en.wikipedia.org/wiki/Thermobaric_weapon) To quote: “A fuel-air explosive (FAE) device consists of a container of fuel and two separate explosive charges. After the munition is dropped or fired, the first explosive charge bursts open the container at a predetermined height and disperses the fuel in a cloud that mixes with atmospheric oxygen (the size of the cloud varies with the size of the munition). The cloud of fuel flows around objects and into structures. The second charge then detonates the cloud, creating a massive blast wave. The blast wave destroys unreinforced buildings and equipment and kills and injures people. The antipersonnel effect of the blast wave is more severe in foxholes, on people with body armor, and in enclosed spaces such as caves, buildings, and bunkers.” Sounds good for a tunnel. Since you would be able to see any openings by the fire wall emerging it would be easy to map all exits that weren’t destroyed. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [July 29, 2014, 4:45pm UTC](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096/53 "2014-07-29T16:45:20Z")
I strongly suspect [this](http://palestine-studies.org/journals.aspx?id=11424&jid=1&href=fulltext) will be of interest. ---
**Author:** ![DingoelGringo](https://avatars.discourse-cdn.com/v4/letter/d/9d8465/32.png) [@DingoelGringo](https://boards.straightdope.com/u/DingoelGringo)\ **Post date:** [July 29, 2014, 4:51pm UTC](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096/54 "2014-07-29T16:51:04Z")
> [@watchwolf49](#): > > Pump CO[sub]2[/sub] into them. Try a more permanent poison to blanket the interior. DDT or such ---
**Author:** ![ToughLife](https://avatars.discourse-cdn.com/v4/letter/t/8797f3/32.png) [@ToughLife](https://boards.straightdope.com/u/ToughLife)\ **Post date:** [July 29, 2014, 10:23pm UTC](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096/55 "2014-07-29T22:23:20Z")
Thanks **Leo Bloom** great article an eye opener for me. So much for “poor” Gazans living on the breadline … ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 29, 2014, 11:34pm UTC](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096/56 "2014-07-29T23:34:14Z")
DDT is terrible for birds, since it ruins their eggshells, but it doesn’t do much to humans until you get to absolutely ludicrous quantities. ---
**Author:** ![GrizzRich](https://avatars.discourse-cdn.com/v4/letter/g/7ba0ec/32.png) [@GrizzRich](https://boards.straightdope.com/u/GrizzRich)\ **Post date:** [July 30, 2014, 3:34pm UTC](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096/57 "2014-07-30T15:34:12Z")
what about thick, steel-reinforced, concrete walls that block the tunnels at several locations along their length? Less expensive than filling them with concrete and provides some additional support to guard against possible collapse. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [July 30, 2014, 3:53pm UTC](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096/58 "2014-07-30T15:53:53Z")
> [@GrizzRich](#): > > what about thick, steel-reinforced, concrete walls that block the tunnels at several locations along their length? > Less expensive than filling them with concrete and provides some additional support to guard against possible collapse. That leaves most of the tunnel usable; all they would need to do in order to salvage it is dig a short detour around each one of these barriers. I wonder about laying one or more [mine-clearing line charges](http://en.wikipedia.org/wiki/Mine-clearing_line_charge) in the tunnel. [Here’s an M58 MICLIC deployment demonstration.](https://www.youtube.com/watch?v=LU33PrFJI4Q) you wouldn’t need the rocket deployment system that’s used on the battlefield; assuming your soldiers control access to both ends of the tunnel, you could just manually lay out the line charges along the length of the tunnel. It should shatter the thin concrete walls and arched ceilings that I saw in a video of one tunnel, and hopefully upheave the soil enough to cause collapse. ---
**Author:** ![drachillix](https://avatars.discourse-cdn.com/v4/letter/d/48db29/32.png) [@drachillix](https://boards.straightdope.com/u/drachillix)\ **Post date:** [July 30, 2014, 7:07pm UTC](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096/59 "2014-07-30T19:07:55Z")
> [@Chronos](#): > > But they don’t stay full without a continual supply of gas. No love for Chlorine Triflouride? ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [July 31, 2014, 9:03am UTC](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096/60 "2014-07-31T09:03:17Z")
Nearby here the undergound coal mine caused cracking in the park land. The cracks are like faults… and present a risk that some person might walk through the bush and fall into a crack … never to be seen again. So anyway so they were filling the crack with grout, and let it run down the valley filling the stream with the grout, where it solidified and made the stream into something of a pavement. > **[Mining company's failed environmental repair job creates concrete creek](https://www.smh.com.au/environment/mining-companys-failed-environmental-repair-job-creates-concrete-creek-20130829-2ssgi.html)** > > It was meant to be a remediation program to repair extensive mine subsidence damage to Sugarloaf State Conservation Area in the Lower Hunter. Just saying they could use this sort of grout … fill the tunnels with this is easy as they can let it flow down the tunnels knowing it flows pretty well. [Previous page](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096.md?page=2) [Next page](https://boards.straightdope.com/t/how-to-destroy-an-underground-tunnel/694096.md?page=4)