[eVitO]

Originally Posted by JasonCSU

Not likely. The point of a full welded roll cage is to protect the occupant space no matter what the vehicle hits. Ever see some of the videos of WRC cars flying off ledges, hitting trees, or rolling for hundreds of yards? The cars are completely trashed, but the cage keeps the occupants from becoming crushed. Even if that SUV had a full roll cage and 5 point harness, the outcome still wouldn't be good.

Dude, the human body can only take about 10G's of acceleration. Let's say they were each going 100kmh each. That's 120mph of instantaneous acceleration in the opposition direction. The energy transfer for sure would have killed him, no matter if the car was more solid or not.

Originally Posted by RevsPlease

You guys are probably right about the average cage being ineffective in this kind of situation since there is such a huge transfer of energy, but you gotta wonder what they are capable of. Anyone remember the Allan McNish crash last year at Le Mans? High speed (200mph) impact into a crash barrier going sideways and the man climbs out of the wreckage unharmed and walks away. Granted we aren't talking about the average steel roll cage or LeMans car, but the point still stands.

I didn't see the crash, but I assume he crashed into a metal barrier, which is designed to bend and absorb energy and transfer it throughout the rail.

[Blayne]

Originally Posted by RevsPlease

You guys are probably right about the average cage being ineffective in this kind of situation since there is such a huge transfer of energy, but you gotta wonder what they are capable of. Anyone remember the Allan McNish crash last year at Le Mans? High speed (200mph) impact into a crash barrier going sideways and the man climbs out of the wreckage unharmed and walks away. Granted we aren't talking about the average steel roll cage or LeMans car, but the point still stands.

Wall had no momentum, that now that truck on the other hand p=mv.....can't even imagine. I would go into detail more but to be honest, I hated physics and would probably get the rest wrong as I can't remember it all to well. Though, I can tell you that a roll cage would have done fuck all.

[mike the snake]

I didn't mean to start a debate about whether this crash was survivable. There will always be some instance that is not survivable no matter how much safety gear is used.

Today's race cars have incredible cage systems, and we see the drivers survive high speed crashes all the time. If more of these safety systems were employed on street cars, they would be even safer than they are now.

Today, our everyday cars are SOO much safer than the cars our parents drove, designs that absorb energy, airbags, and now electronic safety devices, traction control, etc.

This crash however is extra brutal. One can only speculate on surviving.

[RevsPlease]

Originally Posted by Blayne

Wall had no momentum, that now that truck on the other hand p=mv.....can't even imagine. I would go into detail more but to be honest, I hated physics and would probably get the rest wrong as I can't remember it all to well. Though, I can tell you that a roll cage would have done fuck all.

I agree with you about it being useless, but for the sake of argument the speed differential and impact absorption in both situations are likely very similar. 200mph LM car into stationary metal barrier = 200mph impact. Let's assume that both vehicles in the video were traveling ~60mph each, that makes their impact speed 120mph. Like I said you can't really compare an LM car to a standard vehicle but I don't think it would be beyond reason to claim that a cage/harness would have enhanced the drivers survivability be it ever so slightly.

[JasonCSU]

Originally Posted by eVitO

Dude, the human body can only take about 10G's of acceleration. Let's say they were each going 100kmh each. That's 120mph of instantaneous acceleration in the opposition direction. The energy transfer for sure would have killed him, no matter if the car was more solid or not.

I guess I should have elaborated a bit more. The point I was wanting to make was that the SUV wouldn't have exploded as such if it had a full roll cage in it. With the rapid acceleration change and transfer of energy, I agree the driver would still be seriously injured, possibly fatally.

Like RevsPlease mentioned, I've seen some crazy wrecks in racing vehicles with cages hitting a stationary object at speed. I wouldn't think some of those wrecks were survivable, but the occupants did survive. You're right though, this case is different with the truck traveling in the opposite direction also at speed.

[Wakka]

Originally Posted by RevsPlease

I agree with you about it being useless, but for the sake of argument the speed differential and impact absorption in both situations are likely very similar. 200mph LM car into stationary metal barrier = 200mph impact. Let's assume that both vehicles in the video were traveling ~60mph each, that makes their impact speed 120mph. Like I said you can't really compare an LM car to a standard vehicle but I don't think it would be beyond reason to claim that a cage/harness would have enhanced the drivers survivability be it ever so slightly.

you are not understanding how those metal barriers are made. they are designed to absorb the impact. a fucking semi truck does not absorb shit.

[Blayne]

Originally Posted by RevsPlease

I agree with you about it being useless, but for the sake of argument the speed differential and impact absorption in both situations are likely very similar. 200mph LM car into stationary metal barrier = 200mph impact. Let's assume that both vehicles in the video were traveling ~60mph each, that makes their impact speed 120mph. Like I said you can't really compare an LM car to a standard vehicle but I don't think it would be beyond reason to claim that a cage/harness would have enhanced the drivers survivability be it ever so slightly.

I guess the roll cage could have helped like .0000001 but it's not making this guys chance of living any better. I'd take my chances crashing into a wall at 250mph, rather then getting hit by that semi the way he did.

Heres the equation if you want to figure out the forces of semi vs truck and car vs wall. Not going to do it cause I know the end result, but if you think you can prove me wrong, have fun.

(W1+W2+F12+F21) (Delta t) = (m1vf1+m2vf2)-(m1vi1+m2vi2)

W=Weight
F=Force
t=time
m=mass
vf=velocity final
vi=velocity initial

[Blayne]

Originally Posted by Wakka

you are not understanding how those metal barriers are made. they are designed to absorb the impact. a fucking semi truck does not absorb shit.

He doesn't understand that speed is only part of it, and even if he's not taking into account that the walls absorb the F. A solid wall still beats the fucking semi, which is most likely caring a large load, which is devastating to anything in its path.

[RevsPlease]

No I get it, I'm just playing the devils advocate. Yes the metal barrier is built to absorb an impact, but so is the SUV and so is the truck, that's what I'm saying.

[scorcherjf]

Well, the front or the rear of the car is meant to absorb an impact... the side has virtually no crumple zone which was what happened here.

RIP =(

Originally Posted by RevsPlease

No I get it, I'm just playing the devils advocate. Yes the metal barrier is built to absorb an impact, but so is the SUV and so is the truck, that's what I'm saying.

[MadDog]

OK, here's a great example of when two objects collide. This is the system I work on.

The infrared imagery shows the pure kinetic energy given off.

[Blayne]

Originally Posted by RevsPlease

No I get it, I'm just playing the devils advocate. Yes the metal barrier is built to absorb an impact, but so is the SUV and so is the truck, that's what I'm saying.

Do the equation above. You can leave out W, and use a standard of 1 for time. Use 60 for the speed of the SUV and truck and 200 for the car. SUV weighs about say 5000 and the race car 4000 (could be to heavy but who cares) now the semi, 80,000 comes up a lot but to be fair let's say it weighs 60,000. Now the momentum of the semi alone is 3,600,000 now compare that to the car of having 800,000.....get it yet it? The car is now going into something with NO momentum. Now the truck has a momentum itself of 300,000 crashing into the truck. You can complete the question if you don't see what am getting that. The roll cage helps in the car, but times that crash by like 4-7 (just guess cause I'm not completing it) and you have what the driver of the SUV experienced.

[BMWinNorthdakota]

Same thing happened to 4 girls from my college just this past week.

They however were broadsided by a SUV as apposed to a Semi/tractor trailer

Their car jumped across the ditch on the interstate and flew broadside into oncoming traffic. The SUV hit their car. You can faintly see the remains of their car and the other car (Toyota) that rear ended the SUV in this picture.



These 4 did not make it unfortunately . It leaves no doubt in my mind that the individual driving this SUV was virtually disintegrated on impact

[Blayne]

And for the above, yes I know I didn't use SI units, just wanted to give a picture of what it was like.

N may the girls above this post RIP as well.

[Wakka]

guys... you really dont need to give equations. Trust me, anyone that thinks that was avoidable is beyond helping at this point. please stop arguing physics.

[RevsPlease]

Got it. Thanks for the explanation. I failed to account for weight&momentum.

[stimpy]

Originally Posted by Bakeme521

A roll cage wouldn't have done shit but contain his remains a little bit better. Fully loaded semi vs. an SUV, semi will win no matter what the suv is made of. Straight physics.

[Nutballa]

I said "OH f*&k" out loud! 18 wheelers can pummel anything in their path.

[yakev724]

Originally Posted by MadDog

OK, here's a great example of when two objects collide. This is the system I work on.

The infrared imagery shows the pure kinetic energy given off.

Cool stuff, thx for sharing

[sanf]

Aside from roll cages..I am thinking a good set of snow tires would probably have saved him. RIP

[RevsPlease]

Originally Posted by sanf

Aside from roll cages..I am thinking a good set of snow tires would probably have saved him. RIP

Yea probably the best suggestion so far lol. That and a day on a skip pad could save your life.

[ideliver]

Originally Posted by sanf

Aside from roll cages..I am thinking a good set of snow tires would probably have saved him. RIP

my wife thinks i'm nuts becuase I buy winter tires for every vehicle...our Infiniti QX 56 included...AWD + Blizzaks = snow machine

RIP....those accidents were not survivable...