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Post by silverdragon on Jan 15, 2016 10:44:43 GMT
Just a question....
I know not-that-much-but-more-than-nothing abut Hovercraft, the basics and how they fly, but not figures.
One thing I know is that they cant do much more damage than a very stiff breeze to the floor they float over.
Its not that good trying to float over a floor that is being blown away, after all, you tend to get that sinking feeling....
In saying that, how many Storms have triggered land mines?..
Maybe anti-personnel mines have more sensitive triggers, but, the ones that are triggered by Vehicles, just how much weight does it need to trigger one, and then onwards, how much weight in PSI does a hovercraft have?..
(In the sense that once its flying, how much force downwards...)
In my thinking, a Hovercraft having a much much much bigger footprint than a tyre, its almost a safe bet that downward thrust in PSI is going to be almost negligible compared to either footfall or tyre down force.
I expect their force per square meter to be much less than say a heavy storm, and land mines should be almost storm proof?..
Also, if magnetically triggered, would a carbon fibre of Glass fibre build have enough metal to trigger that.
Presuming a lightweight Aluminium engine.
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Post by The Urban Mythbuster on Jan 15, 2016 14:04:11 GMT
Just a question.... I know not-that-much-but-more-than-nothing abut Hovercraft, the basics and how they fly, but not figures. One thing I know is that they cant do much more damage than a very stiff breeze to the floor they float over. Its not that good trying to float over a floor that is being blown away, after all, you tend to get that sinking feeling.... In saying that, how many Storms have triggered land mines?.. Maybe anti-personnel mines have more sensitive triggers, but, the ones that are triggered by Vehicles, just how much weight does it need to trigger one, and then onwards, how much weight in PSI does a hovercraft have?.. (In the sense that once its flying, how much force downwards...) In my thinking, a Hovercraft having a much much much bigger footprint than a tyre, its almost a safe bet that downward thrust in PSI is going to be almost negligible compared to either footfall or tyre down force. I expect their force per square meter to be much less than say a heavy storm, and land mines should be almost storm proof?.. Also, if magnetically triggered, would a carbon fibre of Glass fibre build have enough metal to trigger that. Presuming a lightweight Aluminium engine. The episode will answer all the weight/density questions in regard to the specific craft they were using. I believe the one they had worked out to 0.625 PSI (correct me if I'm wrong). I don't want to give too much away though because I don't believe you've been able to see the episode yet. |
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Post by the light works on Jan 15, 2016 15:33:15 GMT
I am sure they have mines designed to sense hovercraft and in fact - spoiler alert - they said in the episode they were only talking about one kind of mine, even though there were other models out there.
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Post by Cybermortis on Jan 15, 2016 15:41:27 GMT
Off the top of my head the ground pressure of a modern tank is around 15 psi.
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Post by the light works on Jan 15, 2016 16:09:23 GMT
Off the top of my head the ground pressure of a modern tank is around 15 psi. as of the 70s, when the statistic was originally printed, the ground pressure of a fully loaded semi truck is the same as the ground pressure of the average woman wearing high heels. |
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Post by silverdragon on Jan 16, 2016 9:24:32 GMT
Off the top of my head the ground pressure of a modern tank is around 15 psi. as of the 70s, when the statistic was originally printed, the ground pressure of a fully loaded semi truck is the same as the ground pressure of the average woman wearing high heels. Which is why so many of them get bogged down in the mud. |
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Post by the light works on Jan 16, 2016 12:23:43 GMT
as of the 70s, when the statistic was originally printed, the ground pressure of a fully loaded semi truck is the same as the ground pressure of the average woman wearing high heels. Which is why so many of them get bogged down in the mud. both of them  |
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Post by silverdragon on Jan 17, 2016 6:31:42 GMT
Which is why so many of them get bogged down in the mud. both of them The high heel exerts as much pressure as a fully loaded elephant. Per square inch of an elephants flat foot that is. And why do elephants have flat feet?... to stamp out flaming ducks. 'cept you dont see elephants stuck in the mud.... they dont get stuck that often.. Maybe its because the flaming ducks dont get that deep. |
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Post by silverdragon on Jan 17, 2016 7:47:49 GMT
**Spoliers alert**
[copy-and-paste-]https://www.youtube.com/watch?annotation_id=channel%3A5674f31d-0000-23e8-86b7-94eb2c0933ee&feature=iv&src_vid=3Mb1lEwY4Ow&v=Q0UVNt3iNv8
Leads you to Mythbusters Mini Myth Minefield......
If as you state the pressure of a tank is 15psi, a Tank would not have set off the minefield?.... they set them to 300 lbs.
The caption said anti-personnel 35lb
Anti-Vehicle 300lb.
Looking at that trigger, at a guess, maybe a size of 3inch square max, so even that would be 100lbs per square inch, the tank would not have set off that trigger....
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Post by silverdragon on Jan 17, 2016 8:00:12 GMT
just for laughs....
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Post by the light works on Jan 17, 2016 16:05:35 GMT
**Spoliers alert**[copy-and-paste-]https://www.youtube.com/watch?annotation_id=channel%3A5674f31d-0000-23e8-86b7-94eb2c0933ee&feature=iv&src_vid=3Mb1lEwY4Ow&v=Q0UVNt3iNv8 Leads you to Mythbusters Mini Myth Minefield...... If as you state the pressure of a tank is 15psi, a Tank would not have set off the minefield?.... they set them to 300 lbs. The caption said anti-personnel 35lb Anti-Vehicle 300lb. Looking at that trigger, at a guess, maybe a size of 3inch square max, so even that would be 100lbs per square inch, the tank would not have set off that trigger.... the you add in trigger plate protrusion, friction, pressure dispersal in any cover medium, and the math gets really entertaining and complex. |
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Post by silverdragon on Feb 5, 2016 9:15:02 GMT
I have waited until I managed to talk with my friend who is also a huge fan of the show, and, like me, a lot sceptical, in that we look for strange things.
Now we have seen the episode and discussed it....
We call questionable on the MacGyver.
The initial response to the first concrete pouring, we ask, as the results were very much the same as what was seen in the TV clip, isnt that "Valid"...
This is because who says that what MacGyver did didnt exactly match what they got, in that the very act of pouring concrete in may have dislodged explosives and triggers, thus preventing the full blast.
On the second pouring, we also agree "questionable", in that the explosives were put in a sealed box that was fixed to the floor, thus, the explosives were by design a "shaped charge", having no wet concrete below that box and little above it, it would force an up-and-down shaped charge, which is what they commented on.
Either way, the exercise was well worth the filming, we cant question their expertise.
On the subject of the hovercraft, what was it, 0.06lbs per square inch downward pressure....
We both hoped the military were watching that, as it shows an excellent way to navigate minefields.
Also.
Thinking on, if the hovercraft could say TOW, on a long length of rope, a Lawn Roller, maybe a lot longer length of rope in case the minefield is set to trigger off multiple charges, would that be a good way to clear minefields?..
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Post by mrfatso on Feb 5, 2016 12:15:51 GMT
I have waited until I managed to talk with my friend who is also a huge fan of the show, and, like me, a lot sceptical, in that we look for strange things. Now we have seen the episode and discussed it.... We call questionable on the MacGyver. The initial response to the first concrete pouring, we ask, as the results were very much the same as what was seen in the TV clip, isnt that "Valid"... This is because who says that what MacGyver did didnt exactly match what they got, in that the very act of pouring concrete in may have dislodged explosives and triggers, thus preventing the full blast. On the second pouring, we also agree "questionable", in that the explosives were put in a sealed box that was fixed to the floor, thus, the explosives were by design a "shaped charge", having no wet concrete below that box and little above it, it would force an up-and-down shaped charge, which is what they commented on. Either way, the exercise was well worth the filming, we cant question their expertise. On the subject of the hovercraft, what was it, 0.06lbs per square inch downward pressure.... We both hoped the military were watching that, as it shows an excellent way to navigate minefields. Also. Thinking on, if the hovercraft could say TOW, on a long length of rope, a Lawn Roller, maybe a lot longer length of rope in case the minefield is set to trigger off multiple charges, would that be a good way to clear minefields?.. Had pretty much the same thought about the shape of the box that the explosives and its orientation, standing it upright meant the coverage of concrete at the top was much less than the sides, the blast wave would focus downwards and upwards rather than to the sides. Explosives placed on shelves to the side of the truck as in the clip,of the TV show would have had less concrete to the outer skin of the truck compared to a large mass in the centre would the shockwaves have travelled outwards to a greater degree? |
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Post by silverdragon on Feb 6, 2016 7:55:49 GMT
Concrete being sand gravel mud and water mix is uncompress-able, so yeah, you have a point, the original clip may have created shape charges by the position of explosives in the mud. Those shape charges would have pushed away from the mud, so creating an even greater debris field than an empty van. It has been shown on this site in slow-mo (the slow-mo guys) how explosives in water create a bubble that shapes a charge to where the bubble bursts, I am expecting similar from concrete?... Except, is concrete more of a "stiffened water", or, does it constitute a non-Newtonian fluid in its makeup, and would that change the blast much?. Either way, if you compress explosives, it will make the bang bigger, which is the premise of firecrackers being held in tight cardboard tubes, or any black powder explosive, such as bullets, that are more fast burn than pure explosive. Therefore a true concrete wrapped explosion is going to be MUCH greater than an open van explosion. Unfortunately this has given me ideas for the show=, far to late to enter for the show. Just what would be the difference between an underwater explosion and one in cornstarch non-Newtonian fluid. I MUST keep this one away from Urban though, I have a feeling the next ESM food fight will be full of flying explosive custard?...  |
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