Fifth Gear [20x01] - Ford Focus 120mph Crash Test

[Dammy]

Note: 120 MPH can easily be achieved when two vehicles hit head on at 60 MPH.

 

[faethor]

While the US has highway speeds above 60MPH we do not require cars to be tested at these rates. Some of the most deadly roads are those with high rates of speed and no dividers between oncoming traffic.

The article does a brief bit at the beginning explaining how modern cars, even Focus sized, are superior in crash worthiness compared to the big cars. This test should be more of a warning, not of a Focus, but of the reality of roads and cars.

 

[Dammy]

While the US has highway speeds above 60MPH we do not require cars to be tested at these rates. Some of the most deadly roads are those with high rates of speed and no dividers between oncoming traffic.

Not even that, even moderate speeds on two lane roads have the highest death percentages because it might be awhile before someone calls it in for emergency response. On the interstates, less it's out in BFE with little traffic, it gets called in immediately by passing cars. Golden hour rule applies to survival rates.

 

[faethor]

The University of Minnesota as a map to the USA's Deadliest Roads.
http://www.saferoadmaps.org/

It does a great job in Minnesota. Other states are there. I don't have any 'ins' into the accidents in other States so I can't vouch for the data.

 

[FluffyMcDeath]

And it's amazing how quickly a vehicle can suddenly show up in your lane.

Though crash dynamics are highly variable. The guy in this crash apparently lived, though the way he was driving he hardly had a right to.

 

[Fade]

Fifth Gear = Bogus info.

Two cars colliding head on at 60mph is not the same as one car hitting a stationary wall at 120mph. In the first case, the force is divided between two cars. In the second case, only one car receives the force.

 

[FluffyMcDeath]

Fifth Gear = Bogus info.

Two cars colliding head on at 60mph is not the same as one car hitting a stationary wall at 120mph. In the first case, the force is divided between two cars. In the second case, only one car receives the force.

Good point. Since the concrete barrier is effectively immovable is can decelerate the car without the nose progressing beyond the initial impact point. For a head on collision to achieve the same then the 120mph Focus would need to be decelerated by an opposing Focus traveling in the opposite direction with the same speed. In other words, what they are simulating is a 120mph to 120mph head-on, not a 60mph to 60mph.

Plus, normal vehicle head-ons aren't usually so perfectly balanced and are more usually off-center.

Still, "don't drive into a concrete block at 120mph" is a valuable lesson to walk away with.

 

[ilwrath]

Fifth Gear = Bogus info.

Two cars colliding head on at 60mph is not the same as one car hitting a stationary wall at 120mph. In the first case, the force is divided between two cars. In the second case, only one car receives the force.

Well, actually 5th Gear has it right. At the start of the video they state. "This force is a worst-possible case scenario. Two vehicles, each travelling 120mph, colliding head-on." It was just Dammy's summary that is wrong.

This was all covered in a Mythbusters episode a season or two back, as well. It was a correction and verification of this after Jamie made the same mistake in quoting the force of two semi-trucks they were trying to collide.

Still, "don't drive into a concrete block at 120mph" is a valuable lesson to walk away with.

Yeah, no kidding, there.

To me, at least, it looked more like the point was "Let's use a really cool machine to smash the heck out of an old 2nd hand Focus we picked up for 50 quid." It's been over 6 years since the last Focus Mk1 was available new in Europe. I wonder how much structure of the car was degraded over time, as well. This really didn't prove anything other than the obvious. (Extremely high speed accidents can be hazardous!)

I guess maybe Mannequins on the Highway is more acceptable today than blood.

 

[faethor]

Fifth Gear = Bogus info.

Two cars colliding head on at 60mph is not the same as one car hitting a stationary wall at 120mph. In the first case, the force is divided between two cars. In the second case, only one car receives the force.

I understand what you're saying but how you said it is technically not true. Each force is met with an opposite and equal force. In the case of the two Focii (hahaha) each car takes F=ma. The Forces here are the weight of the car+driver X acceleration for the two cars. In the case of the car + wall each object takes F=ma. The Force is a lot greater as this is car+driver X acceleration along with the weight of the earth X acceleration. Assuming the wall doesn't give or isn't damaged we would consider it the same as the earth. In both accidents all objects move. In the Focii accident both cars move. In the car + wall both the car and the earth move. Of course the earth being larger and more massive more easily absorbs the force and probably wouldn't move anything we'd measure. Again each Force meets with an opposite and equal reaction.

(NOTE: In the real world there's some more vectors and forces to consider and lots of math but I tried to make this as simple an explaination as possible while still being technical enough)

 

[Fade]

er uh, don't think so.


"Two cars crashing into each other at 50 mph will result in the same damage (for each car) as a single car hitting a wall at 50 mph.

confirmed
In their small scale tests, the Mythbusters compressed clay at 1x and 2x speeds. Their results showed that two objects hitting each other at 1x speed will cause 1x damage. In their full scale tests, the Mythbusters crashed two cars into a wall at 50 and 100 mph as references. They then had two cars going at 50 mph collide into each other. After surveying the results, it was clear that the two cars suffered damage identical to the car that crashed into the wall at 50 mph. The Mythbusters explained that was possible through Newton’s third law of motion. Although the total force was doubled by having two cars, that force also had to be divided between both cars during the crash."

 

[Glaucus]

Hmm... Now who wants to figure out the formulas for the scenario where the two Fords were traveling at the speed of light?

 

[Karlos]

Hmm... Now who wants to figure out the formulas for the scenario where the two Fords were traveling at the speed of light?

Due to the effective mass increase as a function of speed, as you approach c, your ford simply becomes more massive the more energy you try to put into accelerating it. If you could just put an infinite amount of energy into it...

 

[faethor]

Due to the effective mass increase as a function of speed, as you approach c, your ford simply becomes more massive the more energy you try to put into accelerating it. If you could just put an infinite amount of energy into it...

1.21 gigawatts should do ya just fine.

 

[Karlos]

1.21 gigawatts should do ya just fine.

Great Scot!

 

[metalman]

And it's amazing how quickly a vehicle can suddenly show up in your lane.

My parents where in a head on collision on a 2 lane section of US36, My father saw a Suburban cross the center line, so he swerved to the shoulder, the Suburban swerved to the shoulder, my father swerved to the ditch, the Suburban hit them head on in the ditch, they were driving a Ranger. The Suburban bumper went over the top of the Ranger bumper. The Ranger engine ended up in the front seat of the Ranger. My father had only internal injuries from the crash, but was in ICU for 2 weeks, my mother had broken arm, broken wrist, 4 broken ribs, broken hip socket, broken leg, and internal injuries, and in ICU for a month. The driver of the Suburban only had minor injuries, he had a seizure (for the 4th time found out later).

They had to be cut from the vehicle, then driven 90 miles to the Regional Medical center, all on 2 lane highways that went through each cities downtown.

Mass of each vehicle makes a difference, and the amount of crumple zone that the vehicle has in the impact makes a difference.