88 replies to this topic

[ExFlagMan]

dweller23, on 23 Aug 2015 - 10:21, said:

While sand traps are rather nasty, and grass is very dangerous on the outside of corners, I believe that gravel traps are fine. I am yet to see a nasty crash because of gravel trap. People always put on those sand trap crash videos (like the infamous Laguna Seca one), but they actually never show nasty stuff caused by gravel traps (obviously I am talking about car racing, not motorcycles).

This one might challenge that belief - https://www.youtube....h?v=__-0pYJNdhU

[SenorSjon]

There is always the fear of rolling over, but the last rollover I saw was due to the tires. Perez in Hungary was tossed over due to the tires staying onto the car (safety tethers not so safe?) and when cars bounce of another cars tire like Maldonado last year. It was actually quite rare to see a flipped car due to the gravel trap alone.

@Blinky. The car was lifting off due to the tap on the back and the kerbs. He was already flipping over. Actually, the sand made him lose speed and rolling over is a nice way to lose speed. If it was tarmac, the car would have just slid over it and crash hard into the barrier at the very end.

Edited by SenorSjon, 23 August 2015 - 10:41.

[ANF]

Requiem84, on 23 Aug 2015 - 06:50, said:

3)Lynn & King showed you can race two wide through Eau Rouge. We loved that move and applaud them for that. One should be able to rely on others to not make dangerous moves at 300 km/h.

That, in itself, was a dangerous move (and wholly unnecessary unless Lynn was dead slow down Kemmel Straight). So why shouldn't King be able to rely on Lynn to not attempt a bloody divebomb into Eau Rouge?

[ardbeg]

Requiem84, on 23 Aug 2015 - 06:50, said:

A lot of wrongs in this post.

1)Gasly had to see De Jong, otherwise he would have been far more to the right on the entry of Blanchimont. He left 'some space'. You don't do that if you think nobody is around.

2) Gasly should not have let DJ pass, he should have taken Blanchimont with a narrower entry, thus compromising his exit speed, while DJ could have taken it flat out due to his outside line, giving him the advantage on the run to the busstop

3)Lynn & King showed you can race two wide through Eau Rouge. We loved that move and applaud them for that. One should be able to rely on others to not make dangerous moves at 300 km/h.

If they can't take risks anymore, it will get rather boring.

First of all, I replied to a post saying Gasly should have backed off. Second, Gasly tweeted that he did not know De Jong was there and I believe him - DJ was never close enough for gasly to expect him to stay there and in such a corner, at that speed,  you do not leave your eyes in the mirror too long. DJ was probably in a blind spot much of the time also.

[Tapz63]

ANF, on 23 Aug 2015 - 10:18, said:

Up until that point, De Jong had stayed well within the track limits, so maybe he was hoping for Gasly's car to defy the laws of physics and stay glued to the left-hand side of the track throughout Blanchimont.

Did you see Felipe Nasr defy the laws of physics for the omnipotent Max Verstappen?

[ardbeg]

Tapz63, on 23 Aug 2015 - 12:32, said:

Did you see Felipe Nasr defy the laws of physics for the omnipotent Max Verstappen?

I knew someone would mention that in this thread. Situations are not comparable since Nasr was seconds slower than Verstappen with his new tires. Nasr was 100% aware of Verstappen being there and knew position was lost. He lifted.

[Tapz63]

ardbeg, on 23 Aug 2015 - 12:38, said:

I knew someone would mention that in this thread. Situations are not comparable since Nasr was seconds slower than Verstappen with his new tires. Nasr was 100% aware of Verstappen being there and knew position was lost. He lifted.

Ignorance of another cars position is understandable, it happens. It does not however absolve a driver from the responsibility of the crash.

My post was challenging the notion that the laws of physics would have to be broken to avoid contact.

[ANF]

Tapz63, on 23 Aug 2015 - 12:32, said:

Did you see Felipe Nasr defy the laws of physics for the omnipotent Max Verstappen?

I can't really tell if the Nasr's Sauber uses the air in a way that would allow a tighter exit line from the first apex compared to Gasly's GP2 car. But I did notice that Verstappen had to exceed the track limits and put all four wheels outside the track to avoid contact with the Sauber after the second apex.

[johnmhinds]

Verstappen was also right along side Nasr when they were going through the corner.

 

https://gfycat.com/UnawareBowedDrake

 

De Jong was further back when he tried his move.

[anneomoly]

Bigger pace difference between the two F1 cars than the GP2 cars as well. Gasly had no reason to think that de Jong would be there, Nasr did.

[hittheapex]

sabjit, on 22 Aug 2015 - 20:48, said:

Its an interesting concept. But the argument against gravel traps was that it wasn't as effective as slowing down cars as tarmac. But if a front wing is underneath the car, then it wont slow down until it either goes through some gravel or hits a barrier.

This has been my point for many years as well. Tarmac run offs also rely on a car not having a brake failure or stuck throttle. I hadn't seen this crash before the F1 race but for a split second did wonder if Verstappen was going to have a similar crash. Him and Nasr deserve praise for giving each other room, unlike Gasly but hopefully he will learn from this. Although de Jong was further back too, so maybe he genuinely didn't see him.

Edited by hittheapex, 23 August 2015 - 16:12.

[GTRacer]

I just want to go back to Burti's crash in 2001.

 

The grass/gravel actually made that crash worse as the suspension broke as soon as he hit the gravel so he lost both steering & brakes & thats a big part of why they replaced the gravel with tarmac at that corner for the following year. He also skipped over the grass/gravel so didn't actually lose that much speed before he hit the wall.

 

 

In the case of this GP2 crash the tarmac almost certainly helped him scrub off more speed as he was able to brake, Even with the brakes locked he woudl still have scrubbed off a lot of speed which is something he wouldn't have been able to do if he was skipping over the gravel.

Edited by GTRacer, 23 August 2015 - 16:14.

[Prost1997T]

Didn't stop him getting injured. The run-offs have encouraged more risk-taking in junior series (whether it be GP2, GP3, F3, F4) and caused more accidents, that much has become obvious.

[anneomoly]

Prost1997T, on 23 Aug 2015 - 17:32, said:

Didn't stop him getting injured. The run-offs have encouraged more risk-taking in junior series (whether it be GP2, GP3, F3, F4) and caused more accidents, that much has become obvious.

 

If the risk of breaking their backs - literally! - isn't enough to slow them down then I'm not sure a gravel trap would.

 

Perhaps if there was a limit on the number of penalty points a kid could move up the ladder with, it would help. No good rewarding the little fools with a better seat.

[Fisico54]

anneomoly, on 23 Aug 2015 - 18:15, said:

If the risk of breaking their backs - literally! - isn't enough to slow them down then I'm not sure a gravel trap would.

Perhaps if there was a limit on the number of penalty points a kid could move up the ladder with, it would help. No good rewarding the little fools with a better seat.

The point is at the tilke-dromes the acres of tarmac runoff mean there are no consequences for driving like that. When you do most of your races on them it's a big adjustment to the few circuits that still have risk and will punish driving errors

[anneomoly]

Fisico54, on 23 Aug 2015 - 18:35, said:

The point is at the tilke-dromes the acres of tarmac runoff mean there are no consequences for driving like that. When you do most of your races on them it's a big adjustment to the few circuits that still have risk and will punish driving errors

 

How much of F3 and F4 is on Tilkedromes, though? Not many. If they've got through ADAC F4/F3/GP3 driving around Spa and still not figured out how to do it, they probably don't belong in GP2. Blaming the circuit is easy: it means that neither the drivers nor the stewards need to change, and given the level of bonkers driving around in the junior formulae that's just not acceptable. I don't want them to be absolved of all responsibility for their idiocy. Stuff penalties making racing artificial, keep the children on the tracks and not crashing into each other and out of hospitals. Tell them that their penalties stay on their licence for 3 years and if they exceed a certain amount they cannot progress up the ladder. Make it clear: you will not be a Formula One driver until you can drive like one.

[Fastcake]

hittheapex, on 23 Aug 2015 - 16:09, said:

This has been my point for many years as well. Tarmac run offs also rely on a car not having a brake failure or stuck throttle. I hadn't seen this crash before the F1 race but for a split second did wonder if Verstappen was going to have a similar crash. Him and Nasr deserve praise for giving each other room, unlike Gasly but hopefully he will learn from this. Although de Jong was further back too, so maybe he genuinely didn't see him.

 

Tarmac isn't made of ice you know. Friction between the tyres and the surface will slow a car down, with or without brakes, as will a front wing or any other bodywork trapped beneath the car. This slows down an out of control car more effectively than bouncing through gravel.

 

You've also got to consider drag of course, which on an F1 car is effectively another set of brakes.

Edited by Fastcake, 23 August 2015 - 19:23.

[hittheapex]

Fastcake, on 23 Aug 2015 - 19:21, said:

Tarmac isn't made of ice you know. Friction between the tyres and the surface will slow a car down, with or without brakes, as will a front wing or any other bodywork trapped beneath the car. This slows down an out of control car more effectively than bouncing through gravel.

 

You've also got to consider drag of course, which on an F1 car is effectively another set of brakes.

Yes, I do know

 

Is there any scientific evidence tarmac slows a car that has had a front wing lodged under its wheels and lifting them up/stuck throttle/brake failure than gravel? It's hard to tell with just an eye and replays, speed and angle of which can be misleading sometimes, but as far as I can tell gravel has slowed cars down better. I'm not saying that tarmac doesn't slow them down at all, just that when the brakes can't be applied very well, gravel becomes more effective when laid properly.

 

I remember some complaints from then drivers and driver commentators when gravel traps were widespread that they hadn't been implemented properly, such as the depth of the gravel, its constitution or the way it was laid that made flipping more likely than other gravel traps.

 

The biggest problem I see with gravel is when it causes a car to flip and that can risk drivers hitting a barrier almost literally head first, akin to accidents such as Greg Moore or EJ Viso. It may still be safer to stick with tarmac given how the crash structure is designed in that specific situation.

Edited by hittheapex, 23 August 2015 - 19:46.

[PayasYouRace]

If you can understand why slick tyres offer more grip than treaded tyres you should be able to understand why tarmac is more effective at slowing a car than gravel.

Edited by PayasYouRace, 23 August 2015 - 19:52.

[ardbeg]

While sand traps might be more effective in some situations, there is sufficient data showing that tarmac is much better in most situations. Maybe one day there will be something better than tarmac, but it will not be sand.

Edited by ardbeg, 23 August 2015 - 19:52.

[MikeV1987]

ardbeg, on 22 Aug 2015 - 21:32, said:

He had the right to be there, yes. That does not mean it was wise to be there. If I go in to a bar and see it is full of Hells Angels, I have the right to shout "I can take anyone of you ugly motorheads", but it would not be a wise thing to do.

 

Attempting to pass on the outside at Blanchimont can only work if the driver on the inside is willing to cooperate and his decision is not in your hands.

 

a pass is a pass, your analogy doesn't work here. Drivers will use any chance they get. Also, that is the problem with GP2, a lot of those drivers are not cooperative.

Edited by MikeV1987, 23 August 2015 - 20:44.

[asdf24]

ardbeg, on 22 Aug 2015 - 21:32, said:

He had the right to be there, yes. That does not mean it was wise to be there. If I go in to a bar and see it is full of Hells Angels, I have the right to shout "I can take anyone of you ugly motorheads", but it would not be a wise thing to do.

 

I like how you intentionally left out the FIA stewarts and the penalities analogy (on duty armed police who are watching everything at the bar).

Edited by asdf24, 24 August 2015 - 00:47.

[ClubmanGT]

MikeV1987, on 23 Aug 2015 - 20:38, said:

a pass is a pass, your analogy doesn't work here. Drivers will use any chance they get. Also, that is the problem with GP2, a lot of those drivers are not cooperative.

 

It's endemic at all levels. No one leaves a car's width of room alongside anymore, not even the F1 drivers. You get inside someone and then you drift right out to the edge of the track. Even if they guy is alongside, he still either has to button off or run wide. The GP2 guys are just doing what they've seen Hamilton et al do for the last few years. 

[Kalmake]

GTRacer, on 23 Aug 2015 - 16:13, said:

I just want to go back to Burti's crash in 2001.

 

The grass/gravel actually made that crash worse as the suspension broke as soon as he hit the gravel so he lost both steering & brakes & thats a big part of why they replaced the gravel with tarmac at that corner for the following year. He also skipped over the grass/gravel so didn't actually lose that much speed before he hit the wall.

 

 

In the case of this GP2 crash the tarmac almost certainly helped him scrub off more speed as he was able to brake, Even with the brakes locked he woudl still have scrubbed off a lot of speed which is something he wouldn't have been able to do if he was skipping over the gravel.

Fortunately Burti was able to get some braking done on the track. There was data in a recent topic:

 

Luciano Burti (Prost/F1/Spa 2001)
Lost of control: 291 kph
Impact: 155 kph
Angle: 30 degrees forwards
Deceleration: 85.4 g

 

http://forums.autosp...ident-database/

 

 

I agree the tarmac is much safer. I dare say Burti would have walked away after a less than 100 kph impact.

[ardbeg]

asdf24, on 24 Aug 2015 - 00:44, said:

I like how you intentionally left out the FIA stewarts and the penalities analogy (on duty armed police who are watching everything at the bar).

 

Well, they are only a factor after the fact. Writing reports. Maybe handing out penalties. They won't pay the hospital bills. And no, there are no armed police hanging around in a HA bar and even if there was, they would not lift a finger to alter the sequence of events that would follow my initiative. They don't want to blow their cover.

[BlinkyMcSquinty]

SenorSjon, on 23 Aug 2015 - 10:36, said:

@Blinky. The car was lifting off due to the tap on the back and the kerbs. He was already flipping over. Actually, the sand made him lose speed and rolling over is a nice way to lose speed. If it was tarmac, the car would have just slid over it and crash hard into the barrier at the very end.

 

True, Andretti was already wrong side up when he arrived at the gravel, but once there, the car was completely out of control and a very wild ride ensued. In the crash the gravel did shorten the distance traveled.  I should have picked a better video, but the main point is once a car does get into the gravel the odds of a wild ride are much higher than asphalt.

[asdf24]

ardbeg, on 24 Aug 2015 - 01:40, said:

Well, they are only a factor after the fact. Writing reports. Maybe handing out penalties. They won't pay the hospital bills. And no, there are no armed police hanging around in a HA bar and even if there was, they would not lift a finger to alter the sequence of events that would follow my initiative. They don't want to blow their cover.

Do you have the analogies for the FIA stewarts and the penalities to make your analogy complete?

[hittheapex]

Kalmake, on 24 Aug 2015 - 01:10, said:

Fortunately Burti was able to get some braking done on the track. There was data in a recent topic:

 

Luciano Burti (Prost/F1/Spa 2001)
Lost of control: 291 kph
Impact: 155 kph
Angle: 30 degrees forwards
Deceleration: 85.4 g

 

http://forums.autosp...ident-database/

 

 

I agree the tarmac is much safer. I dare say Burti would have walked away after a less than 100 kph impact.

Was it really "only" a 155kph impact? It seemed so much quicker, but I think his impact was made worse by the car slowing down so quickly, no energy dispersed, it just went into the tyres and stopped. The thing that stands out from the link you posted, is that the danger to the driver is more dependent on angle of impact and deceleration than the intial speed of the accident. The general media prefer higher mph speeds for their headlines though.

Edited by hittheapex, 24 August 2015 - 07:58.

[SenorSjon]

Kalmake, on 24 Aug 2015 - 01:10, said:

Fortunately Burti was able to get some braking done on the track. There was data in a recent topic:

 

Luciano Burti (Prost/F1/Spa 2001)
Lost of control: 291 kph
Impact: 155 kph
Angle: 30 degrees forwards
Deceleration: 85.4 g

 

http://forums.autosp...ident-database/

 

 

I agree the tarmac is much safer. I dare say Burti would have walked away after a less than 100 kph impact.

 

I think he would have hit the barrier with the same speed or harder. I don't think there is much between skidding over a bad gravel trap or over tarmac. A gravel trap could be designed better, whereas you couldn't win much with tarmac. Do they still make that extra grippy stuff? I usually see quite normal tarmac at runoffs.

[anneomoly]

hittheapex, on 23 Aug 2015 - 19:43, said:

Yes, I do know

 

Is there any scientific evidence tarmac slows a car that has had a front wing lodged under its wheels and lifting them up/stuck throttle/brake failure than gravel? It's hard to tell with just an eye and replays, speed and angle of which can be misleading sometimes, but as far as I can tell gravel has slowed cars down better. I'm not saying that tarmac doesn't slow them down at all, just that when the brakes can't be applied very well, gravel becomes more effective when laid properly.

 

I remember some complaints from then drivers and driver commentators when gravel traps were widespread that they hadn't been implemented properly, such as the depth of the gravel, its constitution or the way it was laid that made flipping more likely than other gravel traps.

 

The biggest problem I see with gravel is when it causes a car to flip and that can risk drivers hitting a barrier almost literally head first, akin to accidents such as Greg Moore or EJ Viso. It may still be safer to stick with tarmac given how the crash structure is designed in that specific situation.

 

Is there any evidence - or common sense reason - to suggest that it wouldn't be? The amount of friction gravel vs tarmac offers remains the same whatever's going over it.

 

And I don't suppose you remember the gravel trap bitching being at its greatest oh, I dunno, when they introduced them? For a sport that's about innovation and cutting edge technology, it seems relatively resistant to the idea of innovating or introducing new things.

[hittheapex]

anneomoly, on 24 Aug 2015 - 18:25, said:

Is there any evidence - or common sense reason - to suggest that it wouldn't be? The amount of friction gravel vs tarmac offers remains the same whatever's going over it.

 

And I don't suppose you remember the gravel trap bitching being at its greatest oh, I dunno, when they introduced them? For a sport that's about innovation and cutting edge technology, it seems relatively resistant to the idea of innovating or introducing new things.

I'd settle for either, as it would answer the question. I'm not old enough to remember when gravel traps were first introduced so can't really comment on the rest of your post.

[anneomoly]

hittheapex, on 24 Aug 2015 - 18:34, said:

I'd settle for either, as it would answer the question. I'm not old enough to remember when gravel traps were first introduced so can't really comment on the rest of your post.

 

Deceleration data for various surfaces with/without ABS (also table 3 non typical surfaces)

 

This paper compares locked/unlocked wheels over different surfaces (but you'll have to buy it)

 

This paper is also buy only, but discusses race circuit barrier placement

 

FWIW I haven't bought them, but I'm happy with the deceleration curve I posted previously.

[hittheapex]

anneomoly, on 24 Aug 2015 - 19:03, said:

Deceleration data for various surfaces with/without ABS (also table 3 non typical surfaces)

 

This paper compares locked/unlocked wheels over different surfaces (but you'll have to buy it)

 

This paper is also buy only, but discusses race circuit barrier placement

 

FWIW I haven't bought them, but I'm happy with the deceleration curve I posted previously.

Thanks, I had missed your previous post.

[ANF]

Tapz63, on 23 Aug 2015 - 12:32, said:

Did you see Felipe Nasr defy the laws of physics for the omnipotent Max Verstappen?

I went back to the onboard video, and yeah, the touching of wheels had probably more to do with Gasly's steering wheel than the laws of physics.

Still, I think both De Jong and Verstappen were pushing their luck with their moves.

[ThisIsMischaW]

As motorsport becomes safer drivers just push their luck even more. That move by De Jong is just insane, you don't put your car in that position on a race track, there isn't a track in the world where you're not going to have a huge accident.

 

In terms of the original question in this thread, obviously not all gravel is the same, but in general you introduce cars leaping off the ground which is even worse.

[asdf24]

Make the run off area a banked gravel trap, gravity would slow cars down.

 

0.5 mv^2 = mgh

 

0.5 v^2 = gh

 

h = (0.5 v^2) / g

 

h = [0.5 (v max - v safe)^2] / g

 

where h is the change in elevation of the banking, v max is the departure speed, and v safe is the acceptable normal impact velocity to barrier.

Edited by asdf24, 26 August 2015 - 23:46.

[ExFlagMan]

Could you repeat the calculation factoring in the higher CofG effect for a saloon/GT car going sideways, with particular regard to the increased risk of it ending in a barrel roll?

[Peat]

Check out Scheivlak corner at Zandvoort. That has a big, banked gravel trap.

I've looked at a few vids of crashes there, hard to draw many conclusions.  

[ExFlagMan]

The straight-on gravel trap at the Old Hairpin at Donington had a sloping gravel trap.  I don't recall it being any more effective that any other gravel trap at slowing cars down, but it did seem to significantly increase the amount of gravel that got thrown up at the marshals post and into the spectator area.