Recent reports indicate that a car going as slow as 5 miles per hour can still do well over a thousand dollars in damage in a collision with a stationary object. The existing bumpers are clearly not effectively protecting the car. The simple solution would be to make an aftermarket bumper out of depleted uranium. Depleted uranium is a vital material in the same chobbam armor that makes the newest tanks impervious to damage, it would certainly improve the ability of a car bumper to prevent damage to the car. No more need to worry about light poles and rural route mailboxes harming the finish!-- DonBirnam, Jan 22 2004 Rubber Baby Buggy Bumpers http://www.iihs.org...s/qanda/bumpers.htmBumper Facts [Giblet, Jun 26 2005] DU ammunition http://cseserv.engr...c/ResearchPaper.htm [david_scothern, Jun 27 2005] depleted uranium... do you want it in your garage? http://en.wikipedia...ki/Depleted_uranium [sophocles, Jun 28 2005] Buy a tank.-- skinflaps, Jan 22 2004 <foreman looking over new arrival in salvage yard> “The bumpers are still good, everything else, melt it down.”-- ldischler, Jan 22 2004 What about weight? How about how well your frame is going to hold up under even light impact? How about going sterile from the radiation?-- Letsbuildafort, Jan 22 2004 For weight, it depends on how much depleted uranium is required for the desired effect. We're not trying to protect the car from shaped charges, just the occasional mailbox. You may need some shock absorbing behind the bumper to reduce stress to the frame. As for radiation, what little there is would be blocked by the motor and the firewall. The goal is to protect the car and it's occupants, after all.-- DonBirnam, Jan 22 2004 There's a reason bumpers are made out of soft plastic rather than metal. I'm not entirely sure what it is (absorbing impacts by deforming? price of replacing? cosmetic effect of minor scrapes?) but I'm sure there's a reason.-- kropotkin, Jan 22 2004 There is usually steel behind all of that plastic and foam. I always figured that the plastic and foam are there to absorb very low energy collisions and bolster body shop revenues.
They should be engineered to be a bit more owner-friendly. I wonder how much energy can be absorbed by the polystyrene packing peanuts that are sitting in those boxes cluttering my guest room.-- half, Jan 22 2004 Kudos, have some bread. That would for sure keep my ride from being smashed up from errant drivers, but what about having some of that armor to protect me from getting capped in the head?-- Baron of the Ghetto, Jan 22 2004 If your car bumper, as well as the rest of the car, will survive the industry-standard 500 mph impact test with an immovable object, let's say a block of boron-carbide (hard as diamonds), then yes, why not? It would be a marvel in overengineering. Shattering the vehicle's occupants, though, may be more than a mild oversight.-- ThunderYak, Jan 22 2004 With this bumper and armour for the occupants this may well work, were it not for the problem of the 'third collision'. The first is the vehicle hitting an object, teh second is you hitting the inside of the vehicle and the third is your insides hitting your outsides. The impact of your brain hitting the inside of your head at that speed would pretty effectively purée it.-- oneoffdave, Jan 22 2004 Half: Bumpers used to be chromed steel. However, if that got chipped (like with, say, a shopping cart, much less an accident), it would cost thousands to replace.
Covering the bumper with foam and plastic instead of chrome is cheaper, and can make the car more aerodynamic (saving a few gallons per mile). For that reason, I'm fishboning this idea.
(Also note that chobham armor is also used with a layer of ERA armor... in other words, it's one-use. A car that bangs into a wall at 5 mph can usually be driven back again...)-- Almafeta, Jan 22 2004 "The impact of your brain hitting the inside of your head at that speed would pretty effectively purée it. oneoffdave "
Concussion reduction gel This would stop your brain from splattering in side of your skull
http://www.halfbakery.com/idea/Concussion_20reduction_20gel#1074536871-- duroncrush, Jan 22 2004 I assume it to be widely known that all modern cars have 'crumple zones' that deform to reduce the impulse of the collision in the occupant's safety zone. While laudable, and apparently mandatory in construction, I would cynically suggest that the cost of repairs to these crumpled parts (including bumpers on relatively low speed collisions) is hiked by the after sales/repair centres in order to mitigate the lower cost of cars due to 'competition'. This results in a greater number of 'write offs' which helps the insurance industry to raise their premiums.Hoorah!-- gnomethang, Jan 22 2004 Prices are hiked by the OEM's and suppliers to cover the costs of maintaining the outdated tooling, equipment, and capital necessary to generate those parts. These machines are enormously expensive, especially when they are no longer building their
There is a huge profit factor however, which is exacerbated because the OEM's can't make money to save their lives, by the time they pay out their bills.
Here's how it works: Company X is given a contract to build assembly Y for OEM Z for 4-5 years, given the vehicle program length. In the contract, they negotiate the service parts coverage. Sometimes the original supplier builds parts after the vehicle is done; sometimes they warehouse them, depending on what facilities are available, and what makes financial sense. Sometimes third party companies handle the service parts. Because there are literally millions of these parts to build in comparitively few quantities, tracking all of them is a monstrous task, and only companies with the capital to sink into the production machines get into the market. There isn't the profitability to devote much engineering time to them, so they are usually poorer quality than the originals.
Think of those steel pendulum balls that swing and hit eachother. Most of that energy finds its way to the one ball on the end that *can* move. In a car, that ball is you.
The stiffer you make the car, the more energy your body is going to absorb during the crash. If you make the first ball out of a softer material, the last one won't swing nearly as much.-- RayfordSteele, Jan 22 2004 Yup! Gottit!-- gnomethang, Jan 22 2004 Not many cars can go 500mph and I dont care what the bumper is made of, if you hit anything going that speed, you are in deep shit.-- python, Jan 22 2004 <bad day anno>My personal opinion is that, if you hit any stationary object at more than 5mph, you meet at least one of the following criteria: A) You were going too fast/had little control of your car at the time of the collision (the cause of many crashes with lampposts) B) You do not know how far away from you the edges of your car are (common for parking lot collisions, unless someone couldn't see around other parked cars) C) You were not paying enough attention to driving to avoid the object (coughcellphonescough)
Many people (at least in the US, considering the 5mph bumpers) often have all three conditions, which is why accidents are as frequent as they are. Granted, this is a case of where you only hear about the people who mess up, not the majority who do OK for themselves. 5mph bumpers should be unnecessary, if only people would learn how to drive properly. </bda>-- tekym, Jan 22 2004 [python]
If your bumper is made out of, say, 2 miles of foam, then the car should be able to handle a 500 MPH impact.. tho I'm unsure if 30 secs or so of deceleration counts as impact.-- benjamin, Jan 22 2004 Oh well, there goes another paycheck.-- Thoughtnaper_1, Jun 25 2005 [MFD] Bad Science. Depleted uranium is not an ingredient of Chobbam armor, although it is sometimes used *in conjunction* with Chobbam armor in order to provide specialized protection against certain types of armor-piercing rounds. As a genrral purpose armor though, depleted uranium is useless.-- 5th Earth, Jun 26 2005 No one uses depleted uranium as armor. Its higly flameable. Just to let you know chobham armor cannot stop a depleted uranium round. But British and American tanks dont have to worry about that because they are the only militaries equiped with such a round. Chobham armor will stop the tungston round which the russians use. Our armor relies on a complex honeycomp steel composite. As well as angled plates to deflect an incoming round.-- 10clock, Jun 26 2005 "But British and American tanks dont have to worry about that because they are the only militaries equiped with such a round"
Friendly fire is a worry-- DenholmRicshaw, Jun 26 2005 Yes but since when do armies design weapons (not the systems) that wont hurt friendlys.-- 10clock, Jun 26 2005 Just a note, people do enough stupid things when they feel their car can be scratched by errent children. Give someone a car which seems as though it can take out a Humvee (or Hummer, as you're more likely to meet on the road, now-a-days), and everyone else will suffer for it... The thing about depleted uranium being used as ammo, not armor, is true too, as is the fact that it would create terrible disposal problems, since it's already wreaking havoc among ex-battlefields around the world. And imagine what getting a splinter of that stuff in your skin'd do, during a collision, say.-- {WhiteFang}, Jun 27 2005 [10clock], Uranium's highly flammable? Also, it's not just Britain and the US who have DU ammunition. "There are at least 15-17 countries that currently possess DU ammunition (e.g. US, Britain, France, Israel, Egypt, Russia, South Korea, Taiwan, etc.)" (see link)-- david_scothern, Jun 27 2005 What oneoffdave said. Crumple zones are there for a reason.-- st3f, Jun 27 2005 Simplest explanation for crumple zones: when your car hits an immovable object at a significant speed, there's a certain amount of damage that's going to occur to something. Auto engineers get to make a choice: should that something be
-1- the car
-2- you
Producing a car that could survive a 60mph impact unscathed would not be overly difficult. Unfortunately, any occupant of such a car would almost certainly be killed, and would likely suffer severe injury even in a much slower (e.g. 30mph) crash.
To be sure, automotive designs could be made to be much less damage-prone at lower speeds while retaining their effectiveness at higher speeds. Marker lights, for example, could be mounted away from impact-prone areas of bumpers. On the other hand, the tradeoff between vehicle and occupants is generally a good one.-- supercat, Jun 27 2005 [-] the annos are correct as to the many severe problems with this idea.
...& this reminds me of how we'd all be safer with a driver's side spear....-- sophocles, Jun 27 2005 random, halfbakery