In response to the linked idea, which advocated rear- facing seats, crash helmets and bondageuse degrees of webbing.
Obviously, the logical extension of this is to fill the car completely with water (or a very viscous form of Special Air). Vision and respiration would be catered for in the usual subaquatic manner.
In the event of a crash, not only are the occupants cushioned in the most effective possible way, but the chances of a conflagration are greatly diminuted.
Plus you could take your goldfish with you to work.-- MaxwellBuchanan, Sep 15 2011 Unspired by: crash_20seats [MaxwellBuchanan, Sep 15 2011] Inevitable outcome... Integral_20Side_20A..._20Window_20Breaker [normzone, Sep 15 2011] Scuba House Self_20Contained_20...eathing_20Apparatus [theircompetitor, Sep 16 2011] Top Gear Water-filled Car Challenge http://www.youtube....watch?v=roS_MT8xiwM [DrBob, Sep 16 2011] "Home James." http://funnyartpict...ish-tank-truck.html [2 fries shy of a happy meal, Sep 16 2011] carsequencer [xenzag, Sep 17 2011] Aquareep Aquareepby [wagster] [csea, Sep 20 2011] Queen Elizabeth's Pocket Pistol http://en.m.wikiped...eth's_Pocket_PistolShe must have had quite big pockets… [8th of 7, Sep 21 2011] For [8th] http://en.wikipedia...tt_(nuclear_device) [MaxwellBuchanan, Sep 21 2011] I imagine that an occupant would accelerate through the water at about the same speed, displacing it, and the water would add extra crushing force.-- rcarty, Sep 15 2011 Not so. The human body is about as dense as water, and therefore, if the water stopped dead, so would your body.
Yes, it's true that the four tons of water behind you would collapse your ribcage, but that's a small price to pay for avoiding brain injury.
In any case, that problem can be simply avoided by breathing that fluorocarbon stuff whilst in the vehicle.
Alternatively, the airbag system could be cunnishly adapted and coupled to your snorkel, providing a violent burst of highly compressed air directly into your respiratory tract at the moment of impact. With a bit of fine tuning, this could offset the huge pressure spike at the moment of collision.
Prefinally, the windscreen would need to be thickened to withstand the impact. Otherwise, the driver and water would be ejected, more or less as a contiguous unit. Your last appearance on earth would be as a besnorkelled and alarmed figure suspended in an airborne, car-interior- shaped block of high-speed water. Possibly minus legs.
Finally last, the thickened windscreen could have small breakable ports in it. In this case, the water would burst out of these ports in a controlled flow, thereby decelerating the driver (and goldfish) in the optimal manner.
The future of motoring is assuredly aquatic.-- MaxwellBuchanan, Sep 15 2011 With all the stupid things people do to their cars these days, expect an increase in koi breeding experiments. Maybe you could breed them to resemble those pine tree shaped deodorizers.-- normzone, Sep 15 2011 Yet another Halfbakery first: "Fish-scented car deodourisers".
We would like to point out that the interior dimensions of most passenger cars are very approximately 2m x 2m x 1m, which is 4 cubic metres, hence 4 metric tonnes, of water.
Being generous about the volume of the occupants, furnishings, trim, etc., at least two tonnes of water will be needed to fill the space.
Since an average car is about a tonne (more or less), this will require a 200% increase in engine power and equivalent braking performance.
Of course, in a train .....-- 8th of 7, Sep 15 2011 "Would you, could you, on a train?"
Thanks Dr. Suess.-- normzone, Sep 15 2011 "What the hell happened? All of the sudden, this car turned into a cannoli."-- RayfordSteele, Sep 15 2011 You could get one of those fishy pedicures at the same time [+]-- AbsintheWithoutLeave, Sep 15 2011 //the four tons of water behind you would collapse your ribcage// That might happen if your car actually decelerated. But, in collision with anything less massive than a cement truck, your vehicle might enjoy, shall we say, an advantage?
Agreed, there should be controlled rupture to allow egress of water in an energy dissipating manner. But shouldn't the relief valves be in the *sides* (assuming a head-on collision)? There should be turbulent flow, so that 1) no bulk flow of water carrying the occupants towards a solid obstacle and B) energy dissipated as heat. Since water flowing out means air flowing in, the latter should be admitted in a frothy manner: more opportunity to dissipate energy, and also, a chance to add elastic resistance to the inertial and viscous resistance provided by the water.
Also, if your ribcage *were* collapsed, but the remaining, water-filled portions of your anatomy survived reasonably intact, then you could survive, provided positive-pressure ventilation was started immediately. Which, since this is, after all, a SCUBA system, seems perfectly feasible.
Why stop at mandatory seatbelts? Mandatory prophylactic endotracheal intubation would be even safer.-- mouseposture, Sep 15 2011 //Mandatory prophylactic endotracheal intubation//
If you can put that to music, you've got a winner.-- MaxwellBuchanan, Sep 15 2011 //the four tons of water behind you would collapse your ribcage, but that's a small price to pay for avoiding brain injury.//
Wouldn't your brains still slosh within your skull with the same force as any other full stop?-- 2 fries shy of a happy meal, Sep 16 2011 Eventually, yes.
But brain function is unlikely to be a significant issue for the sort of individual who would drive such a vehicle.-- 8th of 7, Sep 16 2011 Oh ye of little faith. Might I point out that the number of fish injured in car accidents is far lower than the number of people injured in car accidents. I think this speaks for itself.-- MaxwellBuchanan, Sep 16 2011 It's impossible to argue with figures like that.
Your logic is, as ever, flawless.-- 8th of 7, Sep 16 2011 Baked-ish by those wacky Top Gear chaps, for reasons other than road safety obviously.-- DrBob, Sep 16 2011 // Of course, in a train ..... //
Trains with liquid-filled cars already exist. They're very difficult to stop once moving, and occasionally tip over, catch fire, and destroy suburban neighborhoods in southern California.-- Alterother, Sep 16 2011 "January 9th, 2012. Monday. Car is still frozen solid. Haven't been to the grocery store in two weeks, and it looks like I won't make it to work this week either. I can see Goldie, just above the dashboard..."-- lurch, Sep 16 2011 //water amplifies shockwaves//Oh dear. Skipped physics lectures, did we, 21Q?-- AbsintheWithoutLeave, Sep 16 2011 // Car is still frozen solid //
Ooops ... who forgot to add the methanol/glycol blend to their car this winter ? Easy to tell - the one with the passenger compartment that's 9% bigger than it was before the temperature dropped below 0C....
Has the problem been considered that ingress to and egress from the vehicle would have to be through roof hatches, and that a level compensation reservoir would be needed to allow for the displacement produced by different sized drivers and variable numbers and sizes of passengers ?-- 8th of 7, Sep 16 2011 //Has the problem been considered...//
Yes.-- MaxwellBuchanan, Sep 16 2011 After reading this idea and being somewhat skeptical I decided to fill the bathtub and slide around in the water, displacing and shifting water etc. Interestingly enough I noticed later that this idea was also about being in water. Coincidences like that always amaze me.-- rcarty, Sep 17 2011 I was trying to think of some reason why this was not practical. The only minor thing I could think of was trying to operate the pedals with flippers on.-- Ling, Sep 17 2011 Max - thought you might like Carsequencer (see link)-- xenzag, Sep 17 2011 Nice!-- MaxwellBuchanan, Sep 17 2011 //The only minor thing I could think of was trying to operate the pedals with flippers on.//We divers call then "fins".-- AbsintheWithoutLeave, Sep 19 2011 And why would the pedals have flippers on anyway?-- MaxwellBuchanan, Sep 19 2011 To make a better seal ?-- 8th of 7, Sep 19 2011 Tssh boom.
---*-- MaxwellBuchanan, Sep 19 2011 Yes, well, admit it - you kinda walked into that one.-- 8th of 7, Sep 19 2011 Admitted. No need to make a flap.-- MaxwellBuchanan, Sep 19 2011 I thought it was finny.-- normzone, Sep 19 2011 [8th] water known better.-- MaxwellBuchanan, Sep 19 2011 //We divers call then "fins"//
Don't the fins get upset about that? The Swedes, I hear, can take a joke better. Not much better, mind you.-- Ling, Sep 20 2011 You would look stupid trying to d(r)ive with a turnip strapped to each foot.-- pocmloc, Sep 20 2011 I think that pales into insignifance compared to driving with a dead Fin on each foot (unless they also have rather long snorkels).-- Ling, Sep 20 2011 Because water is (nearly) incompressible it transmits shock-waves very well. So, if the exterior of your water-filled car interior suffered a sudden impact - e.g as a result of a soon-to-be-dead motorcyclist's helmet hitting the windscreen - the shock of that impact would be transmitted with great efficiency to you, probably with sufficient power to turn your brain to mush.-- hippo, Sep 20 2011 I'm not sure that's necessarily so. A sharp shock will be worse through water than through air (a bullet passing three inches from your face in air makes a noise; in water it might do serious damage). A smooth acceleration will be worse in air than in water (which is why water-couches have often been proposed to soften g-forces in spaceflight; the water transmits all the forces, but that's better than having them all transmitted through a few points of contact with a rigid seat).
A car crash is intermediate between those two extremes, thanks to the crumple zone (or, on older British Leyland cars, the crumble zone).
Consider the airbag: it spreads the force of impact across a larger area of your body, which is better than all the force being absorbed by a few ribs on the steering wheel. The force _will_ be with you, and it's best to absorb it over as much body area as possible.
Of course, this is probably nonsense, but I will defend it to the hilt. If needs be, I nominate [8th] to duel with any naysayers.-- MaxwellBuchanan, Sep 20 2011 //Of course, this is probably nonsense, but I will defend it to the hilt// Likewise, in the spirit of the Halfbakery, I would rather slice off my eyelids with rusty razorblades than admit that my hastily-cobbled-together pseudoscientific waffle is incorrect. Anyway, you'll note that the example I gave was of a hard, heavy object (crash-helmet worn by an overweight biker) hitting a part of the car without crumple zones (the windscreen) so that the impact, when represented on some kind of graph, would would show as a sharp 'spike', rather than being spread out over time.-- hippo, Sep 20 2011 I say nay.
This might work in some ways if the water were somehow supended only in front of the occupant.
As mentioned above, pressure waves travel quickly through water due to it's high bulk modulus. In a collision, the object is to reduce peak acceleration of the occupant to a minimum. This is best achieved by smoothing the acceleration to a near constant level for the entire duration of the event. Crash structures are designed to do this.
Airbags play some part in smoothing acceleration. In the distance between the occupant and the vehicle interior there is some opportunity for energy absorbtion.
The function of the airbag is mostly to spread acceleration loads over a large area, avoiding local trauma.
Water in front of the occupant would spread load, but would not provide any further energy absorbtion.
Of course, all this is quite academic, since the practicalities of a car filled with water prohibit driving. The Top Gear guys must have seriously modified those cars to be able to fill them with water. Even modern cars doors are not stiff enough to keep the seal in place with a metre head of water acting on their area. Quite apart from that, items like the gearlever gaiter, the card which seperates the boot space and all the grommets for wiring and hoses would all allow rapid egress of water.-- Twizz, Sep 20 2011 Hey, I never said I was right...-- MaxwellBuchanan, Sep 20 2011 [wagster] did the "car-pool" idea back in '04. [link]-- csea, Sep 20 2011 Well I'll be knighted - [Wag] beat me to it. [marked- for-deletion] redundant.-- MaxwellBuchanan, Sep 20 2011 //No, you won't.// Will too. I'm saving up.-- MaxwellBuchanan, Sep 20 2011 //Likewise, in the spirit of the Halfbakery, I would rather slice off my eyelids with rusty razorblades than admit that my hastily-cobbled-together pseudoscientific waffle is incorrect.// This sums up the halfbakery perfectly but is sadly too long for taglinery.-- calum, Sep 20 2011 [21], I think you have those two mixed up.-- normzone, Sep 20 2011 Bun for whisky filled cars.-- Voice, Sep 20 2011 //I'd take 8th on any day.//
OK, [8th], you're up. I'm sorry to put you on the spot, but duelling is something I've never really felt qualified to handle in person. I choose pistols.-- MaxwellBuchanan, Sep 20 2011 As regards Code Duello, Irish, Marquess of Queensbury, or Southern?-- normzone, Sep 20 2011 I'll ask [8th] to go by Queensbury. It'll be tough, if [21quest] is using pistols, but at least honour will be maintained.-- MaxwellBuchanan, Sep 20 2011 I read an article about a special, super-effective shock resistant case for a phone made from a non-Newtonian material that hardened under sudden impact.
...
If only there was some kind of water-based non-Newtonian fluid available that we could fill our cars with.-- mitxela, Sep 20 2011 Hey! Were'd my custard anno go?-- 2 fries shy of a happy meal, Sep 20 2011 was it eaten?-- mitxela, Sep 20 2011 // you're up //
Our pleasure. We complement you on your choice of weapons, as it permits us to employ our favourite handheld firearm. <link>-- 8th of 7, Sep 21 2011 A fine choice, as long as you can find a brace of them. Might I suggest an alternative (link)?-- MaxwellBuchanan, Sep 21 2011 //We complement you// - aaah! - how sweet!-- hippo, Sep 21 2011 //Webley// Adj., the feeling that comes over a person who has just realized that they are, after all, going to vomit.-- MaxwellBuchanan, Sep 21 2011 random, halfbakery