EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: Lord of nothing on January 04, 2019, 10:11:30 am
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There are Subtitles in Youtube Avaiable:
https://www.youtube.com/watch?v=Ybveol56BNc (https://www.youtube.com/watch?v=Ybveol56BNc)
:clap:
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All of the concrete blocks that I saw this Christmas were joined together with thick steel rope and I suspect that this has solved the problem. In any event, I saw lots of happy and smiling police officers and about half of them had machine guns, anyone contemplating doing something stupid in the name of their favorite sky fairy probably gave up at this point.
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machine guns are a better deterrent.
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This was glaringly obvious, wasn't it?
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machine guns are a better deterrent.
A machine gun isn't going to stop a truck at speed before it's too late. Not to mention that active measures are inherently more likely to fail than passive ones.
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I can't see the video. Can someone summarize it?
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Preformed concrete blocks are crap at stopping terrorists with heavy trucks.
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terrorists with heavy trucks.
Freedomfighter and Winter Markets is the right therm.
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I think those self-raising solid steel cylinders (one shown in the video) are probably the best long term solution. Better than forever lugging unsightly concrete blocks around. More expensive, but it's not a problem I can see going away... ever.
The angled steel blade looks very impressive, but there are few situations where you could tolerate the cartwheeling cab. 'Wrapping' the vehicle round a pole looks the best way of absorbing all that kinetic energy in the structure of the vehicle itself.
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terrorists with heavy trucks.
Freedomfighter and Winter Markets is the right therm.
Crap!
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Conservation of momentum, innit?
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Merkel Blocks aren’t useful for much when the vehicle is larger than a car.
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The first test in the video at least destroyed the front wheels on the truck, and although the truck retained a lot of its velocity it would at least no longer be maneuverable, which counts for something. Clearly if you want to STOP a truck you need something deeply anchored into the ground, and ideally tall enough to catch any major flying cargo or truck bits (a couple of the tests showed what appeared to be cargo from the bed crashing through the cab and over the barrier).
Installing such systems is a heck of a lot more expensive and invasive than just setting down some concrete blocks, though. Perhaps blocks that are shaped to wedge under a truck would be more effective, or blocks fastened down to large flat steel plates. If the plates wind up under the wheels, then perhaps the combination would be able to rob enough momentum from the truck to be effective, especially if the plates can be staked into the ground.
A lot of those types of concrete barriers shown in the video appeared around buildings in the US after 2001. My impression was that they weren't primarily intended to stop a heavy truck at high speed, but to keep vehicles laden with bombs or armed personnel from being driven up next to a building. Buildings put up since then tend to have deeply-set bollards or permanent concrete barrier structures, and a lot of existing buildings have been retrofitted with such features where possible. If you drive around Washington D.C. you'll see plenty of driveways and access roads with those big steel wedge plates protecting them.
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And this has to do with electronics exactly in what?
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This has little to do with electronics specifically, but it is an excellent example of engineering. There is no such thing as a perfect solution. Every answer is a compromise between many competing and often contradictory needs. If this thread can bring some understanding of this to many on this forum who seem to think the world works some other way it has some value.
Think of this problem in this way.
A perfect anti-terrorist barrier would have no visual impact on the installed location, would not have any impact on normal traffic, would prevent all damage from any terrorist attack (damage to include injury and loss of life) and would cost nothing either for installation, operation or maintenance.
A perfect terror attack weapon would be undetectable until use, would be useable by anyone who wanted to do this, would be easy to obtain anywhere, would cause massive damage/and or casualties, and would cost nothing.
No such things exist. Those trying to solve these problems from both sides have come up with approaches which they deem adequate to the moment. In general the more successful one side is, the harder the other side has to work, which is why development slows or stops eventually.
Same kind of reasoning applies in all electrical designs that I am aware of, though with vastly different requirements. The requirements are always there, sometimes stated explicitly, sometimes only inferred. The compromises are also always there, sometimes overt, sometimes not even consciously understood by the designer.
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And this has to do with electronics exactly in what?
Nothing!
There's only one important reason these things don't work:
www.youtube.com/watch?v=VeWi3Rg4658 (http://youtube.com/watch?v=VeWi3Rg4658)
Excuse the OT
(removed intentionally the "http" from yt-link)
Excuse the german content...
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I've seen them used a lot for narrowing down carriageways when roads are being re-surfaced, that is if the road is wide enough, otherwise they use lines of traffic cones. Also used as temporary barriers to divert traffic if there are going to be large crowds of people when there is say an international match.
I noticed today when I went into town a lot more steel columns had popped up, maybe 1m high and 350mm diameter, best guess. They're probably mounted in steel tubes and might have additional reinforced concrete all depending on the ground underneath. They might go down 0.5m or 1m, I can only guess as I haven't actually seen the construction work and it's been a long time since I did any civil engineering so I can't do a back of the envelope calculation. There are probably a lot of restrictions as to where you can site steel columns due to sewage, water, gas and electric services underneath.
@CatalinaWOW, totally agree it's not electronics but it's engineering, you still have to test these things and it's quite obvious looking at the video that a concrete "Lego" block isn't going to stop a heavy goods vehicle at speed. The block is not anchored down so it's going to be deflected out of the way.
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Most of this is just security theatre. If a terrorist can't use a truck at that particular place there is always some other place with a lot of people. And if you can't use a truck there are other ways of killing people. The only way to prevent it from happening is to create a social climate where people doesn't want to kill each other.
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The only way to prevent it from happening is to create a social climate where people doesn't want to kill each other.
Thanks to Merkel who invited every scum to Europe now it get much more unsafe. :-- The Crime in Germany rised up. Here Drug Dealer and other grow like Mushrooms. :palm: