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Post by WhutScreenName on Jun 15, 2013 3:23:54 GMT
I was watching the movie Rise of Planet of the Apes and at one point the now intelligent apes have to stop some police cars. One picks up a manhole cover and throws it at the police car which is racing towards them at probably 20 MPH from about 100 feet away. The cover makes a nice arc and comes down hitting the police car squarely in the middle of the windshield and literally sticks about half way in without going through.
My question/myth is this:
1)Would a man hole cover ONLY go half way in from that distance, or would it go clear through (which is my guess) and injure or kill the police in the car.
2) are police cars possibly equipped with bullet resistant windshields that might make the results different than that of a normal vehicle?
Feel free to not only give your thoughts on this, but also post any other myths from the movie you may think of.
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Post by Cybermortis on Jun 15, 2013 11:52:19 GMT
As far as I know Police cars do not contain bullet resistant material/sections - it is a matter of cost and safety.
Fitting police cruisers will bullet resistant glass cost a fortune to provide a function/ability that 99.99% of the time simply isn't needed. It would also pose a serious hazard if the cruiser is involved in a crash (which is much more likely).
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Post by the light works on Jun 16, 2013 3:01:05 GMT
standard police cruisers have standard windshields. this I know.
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Post by OziRiS on Jun 23, 2013 16:45:06 GMT
Having worked a little with bullet resistant glass, I can tell you two reasons why it's unlikely to be found in regular police vehicles.
1: It's incredibly expensive, not only to buy and fit onto the car, but maintenance costs go up because of the effect of the weight on the rest of the vehicle's parts (especially springs, shock absorbers and breaks) - which brings us to the next point...
2: It's extremely thick and therefore heavy. Using it for the windscreen is one thing, but it would be pointless if you stopped there. You'd have to do all the other windows too and once you'd done that, reinforce the rest of the vehicle as well for it to make any kind of sense at all, bringing the vehicle to more than double its original weight. That would lead to a need for a much more powerful engine, in turn leading to a much higher fuel cost. This may also lead to criminals just upgrading the type of weapons they use. Occasional stray bullets in public are dangerous enough. Stray RPG grenades are a different matter...
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Post by Cybermortis on Jun 23, 2013 17:29:58 GMT
Having worked a little with bullet resistant glass, I can tell you two reasons why it's unlikely to be found in regular police vehicles. 1: It's incredibly expensive, not only to buy and fit onto the car, but maintenance costs go up because of the effect of the weight on the rest of the vehicle's parts (especially springs, shock absorbers and breaks) - which brings us to the next point... 2: It's extremely thick and therefore heavy. Using it for the windscreen is one thing, but it would be pointless if you stopped there. You'd have to do all the other windows too and once you'd done that, reinforce the rest of the vehicle as well for it to make any kind of sense at all, bringing the vehicle to more than double its original weight. That would lead to a need for a much more powerful engine, in turn leading to a much higher fuel cost. This may also lead to criminals just upgrading the type of weapons they use. Occasional stray bullets in public are dangerous enough. Stray RPG grenades are a different matter... To add to that bullet resistant glass is considerably thicker than normal glass as well. So its not just a case of pulling the 'old' glass out and shoving the 'new' stuff in. You'd have to modify the rim where the glass is held in place - and in the case of the side windows you'd also have to beef up the system that opens the windows. That's an absurd amount of work and money to add features that would only really be useful every decade if that. As to cost, consider that armoured cars such as the Presidential Limo or the 'Popemobile' cost in excess of $300,000. Compare this to a low end police cruiser which costs around $35,000 (this depends on what equipment is fitted and can be more). So you are faced with the choice of having 9-10 regular cruisers or a single 'super-cruiser'. Since several large police forces in the USA (The NYPD and LAPD to name two) have not had the funds to update/replace their existing fleet of vehicles for a decade it is fairly clear which option they would pick. (If they had an option anyway.) |
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Post by OziRiS on Jun 24, 2013 11:11:41 GMT
To add to that bullet resistant glass is considerably thicker than normal glass as well. So its not just a case of pulling the 'old' glass out and shoving the 'new' stuff in. You'd have to modify the rim where the glass is held in place - and in the case of the side windows you'd also have to beef up the system that opens the windows. That's an absurd amount of work and money to add features that would only really be useful every decade if that. Also two good points. When I was in Iraq, we drove around in armored Toyota Land Cruisers. On the first generation we had, they'd attempted to keep the vehicle's ability to roll down the side windows with beefed up electric motors. Those motors died pretty quickly because they simply weren't designed for that kind of weight, so on the next generation of vehicles they took away that function and opted to instead reinforce the armor in the doors in the places where the motors had been. As you say, you also have to factor in how often you actually expect police vehicles to be shot at. In most western countries that's far from an everyday occurence, so the cost of armoring a police vehicle versus the risk of not doing it just don't add up in the long run. |
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Post by WhutScreenName on Jun 24, 2013 18:09:39 GMT
I've learned a lot about police vehicles in this thread. That said, my intent on asking about the possible bullet resistant glass, was to attempt to give a possible explanation as to why the manhole cover MIGHT act the way it did in the movie. I can't imagine regular glass stopping a thrown manhole cover from 100 feet away, even if the car was completely stopped and not adding it's own speed into the equation.
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Post by the light works on Jun 24, 2013 19:55:00 GMT
To add to that bullet resistant glass is considerably thicker than normal glass as well. So its not just a case of pulling the 'old' glass out and shoving the 'new' stuff in. You'd have to modify the rim where the glass is held in place - and in the case of the side windows you'd also have to beef up the system that opens the windows. That's an absurd amount of work and money to add features that would only really be useful every decade if that. Also two good points. When I was in Iraq, we drove around in armored Toyota Land Cruisers. On the first generation we had, they'd attempted to keep the vehicle's ability to roll down the side windows with beefed up electric motors. Those motors died pretty quickly because they simply weren't designed for that kind of weight, so on the next generation of vehicles they took away that function and opted to instead reinforce the armor in the doors in the places where the motors had been. As you say, you also have to factor in how often you actually expect police vehicles to be shot at. In most western countries that's far from an everyday occurence, so the cost of armoring a police vehicle versus the risk of not doing it just don't add up in the long run. Doesn't rolling down the window kind of defeat the purpose? |
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Post by the light works on Jun 24, 2013 19:56:10 GMT
I've learned a lot about police vehicles in this thread. That said, my intent on asking about the possible bullet resistant glass, was to attempt to give a possible explanation as to why the manhole cover MIGHT act the way it did in the movie. I can't imagine regular glass stopping a thrown manhole cover from 100 feet away, even if the car was completely stopped and not adding it's own speed into the equation. I believe the answer to the question is "hollywood" |
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Post by WhutScreenName on Jun 24, 2013 20:21:14 GMT
I believe the answer to the question is "hollywood" I would agree. That said, MB's have had unexpected results before. Every time I think of unexpected results I think of Spinning Ice bullet. I, for one, never expected it to be true. |
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Post by Cybermortis on Jun 24, 2013 20:44:13 GMT
Also two good points. When I was in Iraq, we drove around in armored Toyota Land Cruisers. On the first generation we had, they'd attempted to keep the vehicle's ability to roll down the side windows with beefed up electric motors. Those motors died pretty quickly because they simply weren't designed for that kind of weight, so on the next generation of vehicles they took away that function and opted to instead reinforce the armor in the doors in the places where the motors had been. As you say, you also have to factor in how often you actually expect police vehicles to be shot at. In most western countries that's far from an everyday occurence, so the cost of armoring a police vehicle versus the risk of not doing it just don't add up in the long run. Doesn't rolling down the window kind of defeat the purpose? If you want to talk to someone by the side of the road stopping the car and getting out is not always practical. Besides, what happens if it is the height of summer and the AC stops working? Well, as I recall car windows stood up well to being hit by a moose. |
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Post by the light works on Jun 24, 2013 21:01:13 GMT
I believe the answer to the question is "hollywood" I would agree. That said, MB's have had unexpected results before. Every time I think of unexpected results I think of Spinning Ice bullet. I, for one, never expected it to be true. true. however, I have seen documentation of the aftermath of a medium large rock hitting a windshield, and a manhole cover hitting edge on has more focused force than a rock. really, what there is to stop that manhole cover - because the glass will shatter - is the polymer film. what we use to remove windshields is either a coarse toothed saw - similar teeth to a sawzall with a combination cut blade. or we will chop it out with an axe. the saw works great - the axe takes a lot of control. it's kind of like trying to cut out a paper doll by poking the paper with a chisel. |
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Post by the light works on Jun 24, 2013 21:04:36 GMT
Doesn't rolling down the window kind of defeat the purpose? If you want to talk to someone by the side of the road stopping the car and getting out is not always practical. Besides, what happens if it is the height of summer and the AC stops working? Well, as I recall car windows stood up well to being hit by a moose. moose are a bit less of a focused impact than manhole covers. |
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Post by OziRiS on Jun 24, 2013 21:37:33 GMT
Doesn't rolling down the window kind of defeat the purpose? When you're stopped at an Iraqi Police checkpoint in the middle of the Red Zone that you know from intel reports is tageted by snipers, what would you rather do when the officers ask for your credentials: Crack a window an inch or two or open the whole door? |
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Post by the light works on Jun 24, 2013 21:43:13 GMT
Doesn't rolling down the window kind of defeat the purpose? When you're stopped at an Iraqi Police checkpoint in the middle of the Red Zone that you know from intel reports is tageted by snipers, what would you rather do when the officers ask for your credentials: Crack a window an inch or two or open the whole door? That was somewhat tongue in cheek. I certainly wouldn't expect them to be cruising around a combat zone with the window all the way down. |
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