In the latest Bond movie, hovercrafts are used to “glide” across minefields without detonating the mines. Now, my understanding of both hovercrafts and mines is sketchy at best, but hovercrafts need to be supported somehow (don’t they do it by generating an air cushion?), and however they do it, they still push down with their entire weight, which should trigger the mines… or am I wrong?
I know, I shouldn’t look to Bond films for scientific knowledge. That’s why I look to you guys instead.
A quick google search revealed this site.
About 3/4 down the page is this line:
So it would appear that, no, the cushion of air generated by a hovercraft does not detonate mines.
As a side note, on that same site a few lines down from the quote was this little tidbit:
God, I love politics.
-Ozzy
Nah, thats beaurocracy.
Anyway, you could build some mines that would go off with a hovercraft.
Specifics? Why don’t ordinary mines trigger off a hovercraft, and what would you do differently to make them trigger?
Different mines accomplish different things. Anti Tank mines don’t go off when a grunt steps, skips, or jumps up and down on them. It’s all in the trigger. It wouldn’t be difficult to design a trigger for air pressure.
I by no means reccoment jumping up and down on a mine to determine if it is anti tank or not.
Metal detectors might work, too.
It would be very easy to design a hovercraft-sensitive mine.
Heck, just use a little propeller to activate the fuse somehow. Or even a standing part with a flat face that gets knocked down by the air blast.
For every measure, there is a counter-measure.
depends on the pressure exerted on the ground. A typical AT mine will detonate with 100-500 kg pressure. I can’t find a cite for how much ground pressure a hovercraft (such as the Navy’s LCAC) exerts, but many AT mines can be equipped with tilt rod actuators, which would cause the mine to detonate regardless of how much actual pressure is exerted.
“100-500 kg”? Over what area? And it’s force anyways, not mass, so wouldn’t that be in newtons?
Assuming you mean an submerged anti-ship mine, you’d need an extrodinarily sensitive one for triggering by air-cushion vehicle. I forget the exact number, but the pressure is only a few psi above atmospheric. ACV’s don’t depend on high air pressures to generate the cushion, it’s based more on volume of air flow.
Correct me if I’m wrong–and I know you will–but I think a skirted hovercraft should have a near-uniform “footprint” which would effectively disperse the weight of the vehicle across its entire underside. At any given point on the ground it would exert far less pressure than a tank tread, or worse, a tire.
It should sort of work like those folks you see lying on a bed of nails, right?
This isn’t really that useful because, militarily speaking, ACV are water craft only. They are completely impractical on land and cannot even begin to do the job a tank or APC does.
Why would you build a landmine specifically for hovercrafts? you would have to place them in a wide area just so one would detonate.
http://www.howstuffworks.com/landmine2.htm
Try looking into Smart Alndmine technology
In case you were still wondering about this, you’re not wrong. Like a helicopter, the total force on the ground will be the same, but what changes (compared with more conventional vehicles) is how it’s distributed.
Priceguy, you are correct. The weight would be distributed around the entire area under the skirt, instead of just the track or portion of tire that a conventional vehicle has in contact with the ground at any given time. From what I know ACVs currently are only practical on relatively flat surfaces such as the ocean or beach. I don’t think any sort of “new” mine would be needed to deny a hovercraft access to a beach. I think a tilt rod with a built in delay would do just fine. I would wonder about the effect of a bounding AP mine detonating under the skirt/fan assembly as a viable option as well.