# Shotcrete & Landmines **URL:** \ **Category:** Factual Questions\ **Created:** [July 5, 2023, 3:20am UTC](https://boards.straightdope.com/t/shotcrete-landmines/986615 "2023-07-05T03:20:19Z")\ **Posts on this page:** 17\ **Page:** 3
**Author:** ![Tripler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripler/32/21807_2.png) [@Tripler](https://boards.straightdope.com/u/Tripler)\ **Post date:** [July 6, 2023, 12:53am UTC](https://boards.straightdope.com/t/shotcrete-landmines/986615/41 "2023-07-06T00:53:06Z")
> [@Sage\_Rat](#): > > I’d expect that to be a tactical decision, based on the technology and how it performed under testing. If you could target either or both, that would be the best. Whether that’s feasible, I have no way of knowing. > [@Sage\_Rat](#): > > Concrete-like materials might not be the best. For all I know, you might want to do some sort of AB foam and then follow it with a quick-spray of fiberglass for rigidity. I’m not married to any particular material. Is there some material that would work better? I think some unknown bias you may have is getting in the way here: We’re telling you it’s not feasible, and recommending other already-proven techniques for area clearance/breaching. There isn’t a material that’s “better” or “best” for an “overlay” surface. Is there any particular reason you _want_ to do an overlay? (My term.) Tripler I’m drawing a blank on why you’re stuck on this method. ---
**Author:** ![I\_Love\_Me\_Vol.I](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/i_love_me_vol.i/32/521_2.png) [@I\_Love\_Me\_Vol.I](https://boards.straightdope.com/u/I_Love_Me_Vol.I)\ **Post date:** [July 6, 2023, 6:02am UTC](https://boards.straightdope.com/t/shotcrete-landmines/986615/42 "2023-07-06T06:02:16Z")
> [@thorny\_locust](#): > > > [@Sage\_Rat](#): > > > > Your first step is to travel _through_ the minefield, so that you can capture the territory and hopefully one day have the freedom to leisurely go minesweeping. > > True. But you need to try not to leave it in massively further damaged condition behind you. Thoughtful, considerate armies always leave a minefield better than they found it. Like a campground. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [July 6, 2023, 5:39pm UTC](https://boards.straightdope.com/t/shotcrete-landmines/986615/43 "2023-07-06T17:39:36Z")
Seem to be talking in circles … Are you aiming to clear a minefield after the war? I assume it’s the other one, you want a quick way to advance _through_ a minefield, a moderately narrow path, quickly while under fire. Pouring concrete or some such, as others point out, means the time to cure - which gives away the position and path you want in 24 hours. Plus, a cemet truck delivers 8-10 yards of concrete. Let’s say you want to lay down 3 inches (i think that’s too thin for protection) and a minimal path 9 feet (3 yards) wide. One cement truck will lay 120 square yards x 3", or about 40 yards - 120 feet of roadway. But how do you get the wet concrete more than 120 feet away? You need one helluva pump system, and presumably it’s in range of defending artillery. What if the minefield is half a mile long? Doing a couple of hundred feet a day, wating for cure, then advancing, is making you and the cement gun sitting ducks. Glue or such to “gum up the works” relies on the susbstance penetrating the soil; again, it’s the problem of apply the stuff and then letting it set or cure. how far forward can you project this? How much do you need to saturate the ground to ensure it works? Can that process be defeated by wrapping the mine in a plastic bag? Presumably most mines are waterproof and ensured against, say, wet soil working a chunk of gravel into blocking the plunger, etc. What then is the goal? Cover mines so they can’t feel the pressure to trigger? Set them off ahead of time? Again, the flail with chains on front of a tank is the best bet. The only question is whether new mines are smart enough to not react ot too much pressure… I’ll recommend the Desert Storm approach… it worked best in sandy desert, the Americans just followed their tanks that had big plows on them, and the tanks plowed a path 2 feet deep or more across the no-mans-land. Critics said that burying the Iraqi soldiers alive in their trenches at the end was inhumane, to which I thnk it was Schwarzkopf who agreed, “it would have been more humane to blow their limbs off with artillery, I suppose.” ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [July 6, 2023, 7:13pm UTC](https://boards.straightdope.com/t/shotcrete-landmines/986615/44 "2023-07-06T19:13:23Z")
> [@TroutMan](#): > > Give me an estimate - you want to lay concrete through a minefield, high enough to match the height of dragon’s teeth (using shotcrete so it hardens instantly and doesn’t require any framing, but not shotcrete since the impact will detonate the mines). I’ll note that I never specified concrete nor shotcrete in the actual OP question, and I’ve said about 20 times now that concrete-like products are not central to the question. Let’s say that we can mix in 5% kevlar threads into a firm polyurethane mixture. We expect the mixture to expand by 30 times. We want to cross a field that our intelligence tells us is 1000 feet wide. To cross the dragons teeth and gain sufficient height that our weight is distributed sufficiently, we need about 6 feet height. To have a wide enough path to sneak our vehicles across, we need a 10 foot width. In total, we need to fill 60,000 cubic feet of space (103,680,000 cubic inches). Since we expect a 30x expansion, we need 3,456,000 cubic inches of liquid. A single gallon holds 277.4194 cubic inches, so that’s 12,458 gallons. One military fuel truck holds about 2,500 gallons but we’re losing 5% of volume to kevlar threads. Five trucks will build you a road over terrain that the enemy believed was impassable. ---
**Author:** ![smithsb](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/smithsb/32/12107_2.png) [@smithsb](https://boards.straightdope.com/u/smithsb)\ **Post date:** [July 6, 2023, 7:29pm UTC](https://boards.straightdope.com/t/shotcrete-landmines/986615/45 "2023-07-06T19:29:18Z")
Magic kevlar and foam. Also tanks like the Leopard 2 are more than 12 feet wide. We’re going to need to see cure times, weight capability, wear characteristics, application hardware, pumps, etc… So far, only fantasy. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [July 6, 2023, 7:52pm UTC](https://boards.straightdope.com/t/shotcrete-landmines/986615/46 "2023-07-06T19:52:54Z")
Space frame filled with pumped in foam. The frame is plastic, sort of like an air mattress, rolled up and then expanded with foam. Some chambers are isolated and don’t get filled. Channels direct separate foam components that can be pumped the full length of the frame. The components will mix as they enter the chambers to be filled. There is also a system for filling ravines with large horizontal tubes that stack up to fill the open space. Some sort of flexible roadway material on top allows tanks to cross over. The same principle might be sufficient to cross a minefield. The tubes have to cover an area significantly wider than the lane that heavy equipment like tanks cross over so that the weight is spread over a wide area. Possibly an air mattress is the bottom layer to absorb shocks. No matter what anti-personnel mines will not be buried deep and triggered by anything used so some kind of clearing process has to be used to detonate them first. Remote operating mine clearing machines could do that job. ---
**Author:** ![Tripler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripler/32/21807_2.png) [@Tripler](https://boards.straightdope.com/u/Tripler)\ **Post date:** [July 7, 2023, 12:22am UTC](https://boards.straightdope.com/t/shotcrete-landmines/986615/47 "2023-07-07T00:22:26Z")
> [@TriPolar](#): > > No matter what anti-personnel mines will not be buried deep and triggered by anything used so some kind of clearing process has to be used to detonate them first. Remote operating mine clearing machines could do that job [True Story] There I was, at Bagram Airfield in Afghanistan, in a RED HORSE squadron before going EOD. Just outside the main perimeter fence, the [Hydremas](https://hydrema-defence.com/products/mcv/mine-clearing-vehicle/the-910mcv) were doing surface “clearance” to expand the fenceline for a new ammo depot. They were about a mile away from my constuction site, but we would occasionally hear a “pop” in directions _away_ from the Hydremas. We finally figured things out when one of our access roads to the site had two AP mines strewn in the middle of it . . . _Hydremas are equally good (if not better) at **scattering** landmines as they are detonating them._ It seems the flails were adept at catching corners of things, and flinging them hinter and yon. Talking with the EOD folks at the time, they too were not fans: EOD had to respond every time a ‘kickout’ into the perimeters occurred. [/True Story] The morals of the story, as I verified later on in life is that: 1. Good ideas, engineering, and machines are not 100% effective all the time (but they are better’n nothing) 2. _There is no such thing as a 100%-cleared minefield._ Tripler Ahhh, I have fond, _fond_ memories of the AO. Tripler ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [July 7, 2023, 1:13am UTC](https://boards.straightdope.com/t/shotcrete-landmines/986615/48 "2023-07-07T01:13:37Z")
FWIW how they currently do try to get tanks across mine fields and their limitations. > **[Russian Tanks Have Crude Mine-Defenses. They Don’t Work Against The Latest...](https://www.forbes.com/sites/davidaxe/2023/03/01/russian-tanks-have-crude-mine-defenses-they-dont-work-against-the-latest-american-mines/?sh=2d6b86161d21)** > > It’s not enough for the Ukrainians to mine the roads and fields where they expect the Russians to advance. For mines to work, Russian mine-countermeasures have to not work. Pressure is not the only trigger in today’s mines. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [July 7, 2023, 2:01am UTC](https://boards.straightdope.com/t/shotcrete-landmines/986615/49 "2023-07-07T02:01:44Z")
One issue with the relatively narrow road approach (from a podcast I heard a while back), is the same as any of these single lane clearing methods: there are often enemy positions on the other side of the field and their tactic is to disable the lead vehicle in the lane, blocking traffic behind it. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [July 7, 2023, 2:55am UTC](https://boards.straightdope.com/t/shotcrete-landmines/986615/50 "2023-07-07T02:55:43Z")
I wonder if the solution too might be, instead of creating an inflated carpet, to create a giant pair of caterpillar treads made of inflated foam that go completelly over the vehicle and with several foot thick tread pieces that hold it several feet above the ground and spread the load across a much wider area. Might not be practical for something the weight of a tank, but a lighter vehicle? How far above the mine does a vehicle have to be to avoid magnetic triggering? I think it was the sea mines in Vietnam I read about that randomly turned off and on, so a mine-clearing effort would not get all the mines, some were passive at each time. ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [July 7, 2023, 3:01am UTC](https://boards.straightdope.com/t/shotcrete-landmines/986615/51 "2023-07-07T03:01:53Z")
Most modern anti-tank mines aren’t weight-triggered (or exclusively weight-triggered), somply because depending on a tread or a wheel to roll directly over a mine misses out on a lot of the width of the vehicle, and mine detonations at the edge of the vehicle (where the tracks are) misses out on the juicy targets that are always in the middle of the vehicle – the weapon, the crew, and the engine. So many mines use a tilt-rod fuze, which is basically a stick projecting out of the top of the mine and high enough to snage the undercarriage of a vehicle. When the rod gets pushed over, it triggers the explosive. > **[Tilt-rod fuze](https://en.wikipedia.org/wiki/Tilt-rod_fuze)** > > A tilt-rod fuze is a device used to trigger anti-vehicle landmines. Typically it consists of a vertical pole, normally around a meter high, which is connected to the top of a landmine. When the track or main body of a vehicle passes over the mine, the rod is tilted, releasing a spring-loaded striker which triggers a pyrotechnic delay of approximately half a second, followed by detonation of the main explosive charge. The small time delay allows the vehicle to continue over the mine before detonat... So approaches designed to minimize ground pressure are missing out on an entire common fuzing technique. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [July 7, 2023, 11:59am UTC](https://boards.straightdope.com/t/shotcrete-landmines/986615/52 "2023-07-07T11:59:40Z")
A rod sticking up 3 feet? Doesn’t sound too stealthy. i assume it relies on the idea that tanks are ahead of the walking troops and probably rolling thorugh scrubby underbrush? ---
**Author:** ![smithsb](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/smithsb/32/12107_2.png) [@smithsb](https://boards.straightdope.com/u/smithsb)\ **Post date:** [July 7, 2023, 10:50pm UTC](https://boards.straightdope.com/t/shotcrete-landmines/986615/53 "2023-07-07T22:50:05Z")
You keep the tank ‘buttoned up’ with artillery and small arms fire. The driver’s view sucks out of the vision blocks, especially with lots of reactive armor blocks piled up on the front… A thin tilt rod sticking up in a scrubby forest or field of straw is almost invisible. Other triggering mechanisms are magnetic influence and sound/vibration. ---
**Author:** ![smithsb](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/smithsb/32/12107_2.png) [@smithsb](https://boards.straightdope.com/u/smithsb)\ **Post date:** [July 7, 2023, 11:01pm UTC](https://boards.straightdope.com/t/shotcrete-landmines/986615/54 "2023-07-07T23:01:30Z")
> [@Tripler](#): > > There I was, at Bagram Airfield in Afghanistan, in a RED HORSE squadron before going EOD. Just outside the main perimeter fence, the [Hydremas](https://hydrema-defence.com/products/mcv/mine-clearing-vehicle/the-910mcv) were doing surface “clearance” to expand the fenceline for a new ammo depot. They were about a mile away from my constuction site, but we would occasionally hear a “pop” in directions _away_ from the Hydremas. We finally figured things out when one of our access roads to the site had two AP mines strewn in the middle of it . . . _Hydremas are equally good (if not better) at **scattering** landmines as they are detonating them._ It seems the flails were adept at catching corners of things, and flinging them hinter and yon. I was there the 1st time Feb 2002 to Dec 2002. The flails would be out on the perimeter - pop…pop…pop from the anti-personnel mines, then poppoppoppop in the high density fields; finally a BOOM from hitting a single or multiple stack of AT mines. No noise, shortly the vehicle would return with blown off flails and the driver heading for a well deserved break to get his head back together. They’d flail an area, then plow it with an armored bulldozer, then the dogs. Any hit or visual and they’d flail/bulldoze again. There was one area along a taxiway that was still off limits when I was back there in 2005-06. The first time there, the path from the tents to the shower trailers had the wires with “MINE” banners on them strung along on both sides. EOD would be hand probing the ditch on the runway side of Disney about 50 feet from us in the evening chow line. Good times indeed. ---
**Author:** ![Tripler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripler/32/21807_2.png) [@Tripler](https://boards.straightdope.com/u/Tripler)\ **Post date:** [July 8, 2023, 4:02pm UTC](https://boards.straightdope.com/t/shotcrete-landmines/986615/55 "2023-07-08T16:02:38Z")
The tilt rods are usually painted green to match local foliage. You’ll also normally mix AP with AT to prevent dismounted infantry from wanting to wander in, helping hide the fact of AT mines. It’s also common to booby-trap AT mines with AP mines to _really discourage_ their manipulation once laid (to include RSP/disposal). I’m not going to get into how to lay booby-traps or get into RSP/disposal procedures on a public message board. Lots of obvious reasons. . . > [@smithsb](#): > > Any hit or visual and they’d flail/bulldoze again. There was one area along a taxiway that was still off limits when I was back there in 2005-06. The first time there, the path from the tents to the shower trailers had the wires with “MINE” banners on them strung along on both sides. EOD would be hand probing the ditch on the runway side of Disney about 50 feet from us in the evening chow line. Good times indeed. You and I might have crossed paths then. My first ‘exotic, extended stay’ was from Nov '05-Jun '06. IIRC, my ‘resort-like accommodations’ were up in Camp Cherry-Beasley, up ‘North’. My construction was on the East Side of the runway. Tripler I lived on the West Side, yo. . . ---
**Author:** ![smithsb](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/smithsb/32/12107_2.png) [@smithsb](https://boards.straightdope.com/u/smithsb)\ **Post date:** [July 8, 2023, 4:16pm UTC](https://boards.straightdope.com/t/shotcrete-landmines/986615/56 "2023-07-08T16:16:20Z")
My tour during that time was mostly way east in Jalalabad and the 28 (or so) outposts we supported. Some side trips to Kandahar and Bagram for brief fill-ins. Lovely accomodations 150’ from the runway centerline on the west side. ---
**Author:** ![Tripler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripler/32/21807_2.png) [@Tripler](https://boards.straightdope.com/u/Tripler)\ **Post date:** [July 8, 2023, 4:53pm UTC](https://boards.straightdope.com/t/shotcrete-landmines/986615/57 "2023-07-08T16:53:15Z")
> [@smithsb](#): > > Lovely accomodations 150’ from the runway centerline on the west side. Mmmm, I imagine your fine abode was surf-side adjacent to “Steel Beach.” Tripler Good times, good times. . . [Previous page](https://boards.straightdope.com/t/shotcrete-landmines/986615.md?page=2)