In short: It’s the cube rootinverse square law. The damage force from an explosion goes down with distance by an exponential factor (1/x^2).
So the blast force (per unit area) at 2" should be about 1/4^th the damage at 1". At 6", the force would be 1/36^th the force per unit area at 1" distance.
Think of a surface of a balloon. If the skin of the balloon (and it’s thickness) represents concussive force, as the balloon gets bigger, the skin (and the force) gets smaller.
The boots work by ensuring that if you set off a mine, the mine is under one of the four prongs and away from your foot (distance = ~6") vs just under your foot (distance <1" or the thickness of your soles).
Edit: corrected damage to force. Shrapnel complicates things a bit, but in general, the further you are from the blast, the less concussive (read bone pulverizing) force you receive and the fewer and more spread out shrapnel fragments you get.
If your bones aren’t pulverized and the shrapnel is less concentrated, then there’s a better chance the medics can save your leg and foot.
Copying a comment on the study these boots came from:
From the study on the boots, they were way better at lowering the odds of needing an amputation after stepping on a mine than the alternatives. Even when tested against the larger mines (249g of explosive)
Check out figure 4 in the study. The competing alternatives were tested against 25g of explosive (first data point) and the measured acceleration on the test leg was 4000 -11,000 g’s. The spider boots tests registered about 700 g’s or less.
An alternate source to read the whole study on the spider boots:
The anti-personnel mines used in this study included the VS50 (43g RDX/TNT) and the PMA2 (100g TNT). For the Spider Boot, in all cases of detonation of the landmine under one of the pods, the limb was found to be salvageable (no amputation). In contrast, tests with conventional blast boots against the VS50 mine resulted in MTS scores requiring amputation, and contamination was observed. With the PMA2 mine (100g TNT), the foot was totally destroyed, resulting in a required amputation and severe contamination.
It seems that the most expensive part of this boot is the snowboard bindings. If they release the file, maybe people can start printing BYOB (Bring Your Own Bindings) versions at home to donate to the troops.
Yep. Maiming-size mines are smaller and cheaper, and a wounded soldier that requires evacuation and treatment is actually more of a burden to a force than a dead one.
Can someone tell me how these help?
In short: It’s the
cube rootinverse square law. Thedamageforce from an explosion goes down with distance by an exponential factor (1/x^2).So the blast force (per unit area) at 2" should be about 1/4^th the damage at 1". At 6", the force would be 1/36^th the force per unit area at 1" distance.
Think of a surface of a balloon. If the skin of the balloon (and it’s thickness) represents concussive force, as the balloon gets bigger, the skin (and the force) gets smaller.
The boots work by ensuring that if you set off a mine, the mine is under one of the four prongs and away from your foot (distance = ~6") vs just under your foot (distance <1" or the thickness of your soles).
Edit: corrected damage to force. Shrapnel complicates things a bit, but in general, the further you are from the blast, the less concussive (read bone pulverizing) force you receive and the fewer and more spread out shrapnel fragments you get.
If your bones aren’t pulverized and the shrapnel is less concentrated, then there’s a better chance the medics can save your leg and foot.
Copying a comment on the study these boots came from:
From the study on the boots, they were way better at lowering the odds of needing an amputation after stepping on a mine than the alternatives. Even when tested against the larger mines (249g of explosive)
Check out figure 4 in the study. The competing alternatives were tested against 25g of explosive (first data point) and the measured acceleration on the test leg was 4000 -11,000 g’s. The spider boots tests registered about 700 g’s or less.
An alternate source to read the whole study on the spider boots:
https://www.researchgate.net/figure/Spider-Boot-tested-with-a-mechanical-surrogate-leg-at-DRDC-Suffield-Actual-and-simulated_fig3_265925569
I prefer my bones not pulverised, so this seems like a good thing.
Umm… those two things are not equivalent. b^(-x) would be exponential, x^(-k) is inverse-power for whatever k
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The boot “legs” are destroyed instead of your foot.
Here’s a video about it.
https://youtu.be/g9xj5GLzT8A
It seems that the most expensive part of this boot is the snowboard bindings. If they release the file, maybe people can start printing BYOB (Bring Your Own Bindings) versions at home to donate to the troops.
I head a small local 3D printing group for stuff like this! We were busy early COVID. Would love to help.
Some articles about the 3d printing:
Https://www.rferl.org/a/ukraine-engineers-3d-printing-anti-mine-boots/32541203.html
https://www.thedefensepost.com/2023/08/18/ukraine-3d-anti-mine-boots/
Igor Yefimenko is the engineer leading the effort in Ukraine.
This might be him?
https://www.linkedin.com/in/igor-yefimenko-69732730
These are the boots they are duplicating:
https://www.researchgate.net/figure/Spider-Boot-tested-with-a-mechanical-surrogate-leg-at-DRDC-Suffield-Actual-and-simulated_fig3_265925569
I saw someone posted them on either the fosscad community here or on Reddit a bit ago.
I need to be honest - that video explained nothing lol
But what about the rest of the body?
The mines they are preventing are small, they will destroy your foot if you step on it, but not much else. These boots protect your foot.
That’s honestly kind of horrific. Like I was expecting mines to be like something they step on and BOOM lights out.
This sounds more like “boom” now you bleed out in agony as your foot is torn into small chunks
Yep. Maiming-size mines are smaller and cheaper, and a wounded soldier that requires evacuation and treatment is actually more of a burden to a force than a dead one.