Chassis Improvements - Grosjean accident

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Just_a_fan
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Re: Chassis Improvements - Grosjean accident

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Hoffman900 wrote:
30 Nov 2020, 19:33
I saw where the impact was an estimated 50g’s +.

I wonder how many of those are logged in NASCAR and Indy Car over the course of a season. I bet it’s a lot more than they would ever want to let on.
Hitting solid concrete walls is never going to be good. ISTR that Ralf Schumacher suffered 78g in a crash in 2004 at Indy. Luckily that one went in backwards but still ended up with him having a couple of "minor" spinal fractures (if a spinal fracture can be minor).
If you are more fortunate than others, build a larger table not a taller fence.

Hoffman900
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Re: Chassis Improvements - Grosjean accident

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Just_a_fan wrote:
30 Nov 2020, 19:41
Hoffman900 wrote:
30 Nov 2020, 19:33
I saw where the impact was an estimated 50g’s +.

I wonder how many of those are logged in NASCAR and Indy Car over the course of a season. I bet it’s a lot more than they would ever want to let on.
Hitting solid concrete walls is never going to be good. ISTR that Ralf Schumacher suffered 78g in a crash in 2004 at Indy. Luckily that one went in backwards but still ended up with him having a couple of "minor" spinal fractures (if a spinal fracture can be minor).
NASCAR and Indy Car have several incidents resulting in 90g’s +, sometimes a few a season.

Safer barriers are reported to be good for a 30g reduction with the impact speeds they routinely see.

Not saying it’s a good thing or Grosjean’s crash wasn’t bad, just that there are good lessons to be learned from other series and that the rate of Grosjean’s impact, fire not withstanding, is pretty typical in other series, where drivers walk away. It’s clear those lessons were learned as he was able to fight his way out of a fire. Clear issues to me then is the Armco and the fire issue.

Just_a_fan
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Re: Chassis Improvements - Grosjean accident

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Hoffman900 wrote:
30 Nov 2020, 19:39
Jolle wrote:
30 Nov 2020, 19:35
Hoffman900 wrote:
30 Nov 2020, 19:29


Got it.

So do we know if the fuel cell is suppose to pull away with the rear? It seems like a huge oversight to have it so that stays attached to the driver cell in a break away accident.
The fuel cell supposed to sit inside the safety cell, just like any race car. Last thing you want is a 100kg of fuel been thrown without the safety of the survival cell across the track or worse, the public.
I’m not saying toss the cell, I’m saying it stays attached to the rear bit with the drivetrain.

Seems counterintuive to have the mechanical bits sitting there nice and dry as the driver cell is up in flames.

What does 100kg relate to in terms or gallons. Anyone know the weight / volume of the fuel F1 is using?
Approx. 30 Imperial / 35 US gallons I think.
If you are more fortunate than others, build a larger table not a taller fence.

Rodak
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Re: Chassis Improvements - Grosjean accident

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Do current cars have an air supply for the driver as they did in the past? I haven't seen any connecting hoses; he was in that fire for a long time and air could quickly become an issue.......

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MtthsMlw
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Re: Chassis Improvements - Grosjean accident

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Rodak wrote:
30 Nov 2020, 20:51
Do current cars have an air supply for the driver as they did in the past? I haven't seen any connecting hoses; he was in that fire for a long time and air could quickly become an issue.......
No, they don't.

roy928tt
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Re: Chassis Improvements - Grosjean accident

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Hi folks, good to see a robust discussion regarding Romain's accident.

To my mind, the very first conclusion is, that bare Armco no longer has a place on F1 circuits. I'm of the opinion that bare concrete (as the Armco was replaced with for the race) would have been a better (safer) barrier.

Seeing the tangle of Halo and Armco that Romain extricated himself from, made me very thankfull that he was conscious after the impact. No one could have pulled him unconscious from that burning wreck.

I was of the understanding that drivers wear a biometric device that transmits the driver's vital signs back to the team? Is this true? I understood it was a tool for monitoring their wellbeing with an eye to fitness but could also be used in such incidents.

Thanks Cheers Roy

Edax
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Re: Chassis Improvements - Grosjean accident

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roy928tt wrote:
01 Dec 2020, 00:18
Hi folks, good to see a robust discussion regarding Romain's accident.

To my mind, the very first conclusion is, that bare Armco no longer has a place on F1 circuits. I'm of the opinion that bare concrete (as the Armco was replaced with for the race) would have been a better (safer) barrier.

Seeing the tangle of Halo and Armco that Romain extricated himself from, made me very thankfull that he was conscious after the impact. No one could have pulled him unconscious from that burning wreck.

I was of the understanding that drivers wear a biometric device that transmits the driver's vital signs back to the team? Is this true? I understood it was a tool for monitoring their wellbeing with an eye to fitness but could also be used in such incidents.

Thanks Cheers Roy
Are you sure? Armco has in this case dissipated a lot of energy. Concrete would IMHO lead to higher g-forces and risk the monocoque bouncing back on track, like in Canada (kubica). That could give a second collision like in Spa.

Sure there would be better solutions like the Indy safer wall, but I am afraid that would not be economical to operate on a track like this.

The only thing I did not like was that the monocoque wedged itself between the rails. But it seems that there was no vertical fixation between the rails. That should be solvable with a couple of bolts.

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nzjrs
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Re: Chassis Improvements - Grosjean accident

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Perhaps it is worth reading either the summary https://www.bbc.com/sport/motorsport/51415685 or full accident report from the Hubert accident.

It is food for thought considering the impact angle, the G forces, the ejection of the car back onto the track, etc.

Edax
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Re: Chassis Improvements - Grosjean accident

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Hoffman900 wrote:
30 Nov 2020, 19:29
Jolle wrote:
30 Nov 2020, 19:28
Hoffman900 wrote:
30 Nov 2020, 19:25


If it did that, it would have likely take Grosjean’s belts (and him) with it.
The back of the tub behind the fuel tank, not the part behind the driver. That was intact.
Got it.

So do we know if the fuel cell is suppose to pull away with the rear? It seems like a huge oversight to have it so that stays attached to the driver cell in a break away accident.
My guess is that the monocoque is the safest place in the car and the fuel cell belongs there even though it is next to the driver.

It might be a crude thing to say. But we have seen complete cars being shredded on catch fences, even throwing engine parts close to the crowd. If that amount of fuel ever gets spilled on the spectators it would be a nightmare and possibly the end of F1.

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void
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Re: Chassis Improvements - Grosjean accident

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In my opinion fuel cell was disrupted by armco fixation bar that in this picture. And I believe that no fuel cell were designed from a botton impact like this.
Image

Just_a_fan
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Re: Chassis Improvements - Grosjean accident

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Edax wrote:
01 Dec 2020, 00:32
Sure there would be better solutions like the Indy safer wall, but I am afraid that would not be economical to operate on a track like this.

The only thing I did not like was that the monocoque wedged itself between the rails. But it seems that there was no vertical fixation between the rails. That should be solvable with a couple of bolts.
Cheap tyres and a conveyor belt facing would have done a reasonable job of absorbing impact energy and preventing penetration of the armco. But to think that a country such as Bahrain couldn't afford to throw some Tecpro barrier up in front of that section of armco seems a bit unlikely.

There was vertical posts supporting the horizontal barrier sections. Indeed, it's possible that one of those very vertical supports is what caused the failure of the chassis in the way that it did.

Armco isn't designed to stop a pointy shaped vehicle - it's intended to stop blunt objects that engage the horizontal "beams". The beams then dislocate from the vertical supports, the beams bend and stretch, sliding junctions between beams allow for extension of the beams. This all absorbs energy. It also expects the vehicle to be moving along the barrier when the impact occurs. Unfortunately, Grosjean's nose structure and then the front of the survival tub punched through a horizontal beams just before a vertical post (you can see the post in the image below). The tub stopped and the engine/gearbox mass pivoted around the vertical post and snapped off the rear of the car. It appears to be an unfortunate "choice" of impact locations. It's very telling that the rear of the car is very close to the tub after both came to rest. Almost all of the energy was absorbed by the barrier and the car being torn in half. There was little energy left to carry the rear of the car along after the impact.

Image
If you are more fortunate than others, build a larger table not a taller fence.

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jjn9128
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Re: Chassis Improvements - Grosjean accident

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Hoffman900 wrote:
30 Nov 2020, 19:39
What does 100kg relate to in terms or gallons. Anyone know the weight / volume of the fuel F1 is using?
The density of petrol is about 750-770kg/m^3 depending on air temperature, which is why they go by weight and why it's best to fill your car up early in the morning, so 105kg is about 135-140litres which is 29.7-30.8gallons.
#aerogandalf
"There is one big friend. It is downforce. And once you have this it’s a big mate and it’s helping a lot." Robert Kubica

Just_a_fan
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Re: Chassis Improvements - Grosjean accident

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jjn9128 wrote:
01 Dec 2020, 11:05
Hoffman900 wrote:
30 Nov 2020, 19:39
What does 100kg relate to in terms or gallons. Anyone know the weight / volume of the fuel F1 is using?
The density of petrol is about 750-770kg/m^3 depending on air temperature, which is why they go by weight and why it's best to fill your car up early in the morning, so 105kg is about 135-140litres which is 29.7-30.8gallons.
That's Imperial gallons, not the smaller US gallon. About 35-36 of those.
If you are more fortunate than others, build a larger table not a taller fence.

DChemTech
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Re: Chassis Improvements - Grosjean accident

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roy928tt wrote:
01 Dec 2020, 00:18
Hi folks, good to see a robust discussion regarding Romain's accident.

To my mind, the very first conclusion is, that bare Armco no longer has a place on F1 circuits. I'm of the opinion that bare concrete (as the Armco was replaced with for the race) would have been a better (safer) barrier.

Seeing the tangle of Halo and Armco that Romain extricated himself from, made me very thankfull that he was conscious after the impact. No one could have pulled him unconscious from that burning wreck.

I was of the understanding that drivers wear a biometric device that transmits the driver's vital signs back to the team? Is this true? I understood it was a tool for monitoring their wellbeing with an eye to fitness but could also be used in such incidents.

Thanks Cheers Roy

To me, the incident echoed Gordon Smiley's crash in indycar a bit. Weird-angle impact, basically head-on into a barrier where no head-on impact would be expected - resulting in a huge fireball. Of course, the speed at which Smiley was travelling was even higher, and the safety precautions were less those days, but there were similarities for sure. But there was also a big difference; Grosjean crashed into an Armco barrier, Smiley into a concrete wall. In case of Grosjean, the barrier disintegrated. In case of Smiley, he did.

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jjn9128
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Re: Chassis Improvements - Grosjean accident

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Just_a_fan wrote:
01 Dec 2020, 11:29
jjn9128 wrote:
01 Dec 2020, 11:05
Hoffman900 wrote:
30 Nov 2020, 19:39
What does 100kg relate to in terms or gallons. Anyone know the weight / volume of the fuel F1 is using?
The density of petrol is about 750-770kg/m^3 depending on air temperature, which is why they go by weight and why it's best to fill your car up early in the morning, so 105kg is about 135-140litres which is 29.7-30.8gallons.
That's Imperial gallons, not the smaller US gallon. About 35-36 of those.
Bleugh.. Americans. :lol:
#aerogandalf
"There is one big friend. It is downforce. And once you have this it’s a big mate and it’s helping a lot." Robert Kubica