Non-effective wheel tethers

[twig]

What i am talking about here is the cause of Alonso's accident. As we all saw, Webber spun off, ripping the two front wheels of his car, now the wheel tethers should have worked, but did not, and whilst amongst all of the other debris on the track, Alonso hit one of Webber's tyre and wheels, and lost control, subsequently, colliding with the tyre wall. Why did the tethers not work? sure, it was a hard impact, but they should be working, they are designed to stop the wheel from detatching from the car, and they failed.

God only knows that if Alonso or anybody else would have hit one of the stricken tyres on the track at a different angle, it most certainly could have gone flying into the crowd, i could easily imagine more injuries or fatalities caused by a wheel landing in the grandstand, seeing it is very close to the track, the fences are not all that high, its a very fast part of the track, and there are a lot of people there.

Even moreso, Alonso's wheels also went flying, again, they could have gone into the crowd from the accident, or similarly, someone else could have hit them.

It should be improved, or even speculated on, so far, i have seen or heard noone even mention them, in relation to this accident.

Tom.

[Armco Bender]

Its like wearing a bullet proof jacket and being hit by a cruise missile,you can only make things so strong.

[DNQ]

Nice analogy Armco Bender, there is only so much force that can be withheld by these tethers. You're never gonna keep a wheel on with that amounnt of force.

[jetsetter]

This is a very valid point as i was under the opinion that the wheel tethers were supposed to stop the wheels from parting with the car, hopefully the FIA looks to rectify the situation before someone gets seriously injured or killed by a stray tyre.

[twig]

sure, but say the wheel had gone into the crowd. Then the media attention and inquiries would be made to solve the problem, but nobody has mentioned a thing on the potentially fatal subject.
Imagine if after the first year of wheel tethers they said, okay, that'll do.

[Armco Bender]

I thought the tethers were mainly to stop the wheel bouncing back into the drivers head.Theres no way you can ever keep the wheels attached on the cars in a big accident.
A loose wheel on the track should be an instant red flag until its removed,you're right it doesnt take much to pitch one into the crowd.At speedway here loose wheels=red flag,as they've had several fatal accidents with tyres in the crowd.

[Peter Mallett]

Oops. I just posted about this in another thread.

I suspect the tethers work on an angular impact where the car hits the wall and runs alongside rather like we see in IRL or Cart oval races.

Clearly that didn't happen in Webber's case. He seemed to bounce and spin along the wall before finally coming to rest.

On the same point though, did Firman lose his wheel or did the tether do its job?

[Glen]

Tether held for Firman, and several others have worked in "modest" incidents. The heavier accidents will always have wheels flying. The automatic car slowing that has been proposed would have prevented this danger.

[twig]

i beleive the tether held it

[ljakse]

I think that there is just no way they could have 'em strong enough to keep the wheels on in this kind of accident. I mean, what material could hold on to that much?

Well, at least they can't as long there is 'open wheel racing'.

[Miss Hardt]

Originally posted by ljakse
I mean, what material could hold on to that much?

Either someting illegal or something too heavy

[Jack racer]

even when they do brake they have still helped buy slowing the wheel down if you get my point.

[mac]

The teathers did work. Without them, the wheels would have flown away from the car at warp speed, in God knows what direction. Webber's front left wheel was the first thing to hit the wall, and if it wasn't for the teathers, who knows where the wheel would have ended up.

Other than that, it was a massive, hit and would be truly miraculous if the wheels and car did not part company. The teathers can't withstand THAT amount of force.

[Valve Bounce]

More to the point: There was debris right across the track after Webber's crash. Why was the red flag not shown then? Especially when Mark was in a very dangerous situation at the side of the track.

[KC]

The tethers have to attached to the monocoque somewhere, and if that section of monocoque is gone or destroyed as we saw happen to two different cars, the wheels and suspension are going with it.

[Adam43]

The tethers aren't/can't be designed to keep the wheels on in every accident. However even when they do come off the energy require to break the tether means that the kinetic energy that the wheel possesses is much less. Therefore it doesn't fly off with as much force and is safer.

[paulzinho]

Don't the tehers have a certain strength that they can withstand, I heard if they were designed to survive larger impacts they would become ineffective as the chassis itself would be ripped apart.

[Adam43]

That is probably true.

It is better that the weakest point is in the tether than the chassis. Especially if the weak point is broken in the first crash of a multi crash accident.

I wonder if the weakest point is the actual tether or the join between the tether and the car?

[Don K]

Originally posted by jetsetter
This is a very valid point as i was under the opinion that the wheel tethers were supposed to stop the wheels from parting with the car

If I remember correctly, the wheel tethers are supposed to prevent the wheels from parting with the car with high speed / kinetic energy, without endangering the driver himself.
So in case of an accident, they are probably supposed to first absorb as much kinetic energy as possible, and then let the wheels go in order to decrease the danger to the driver on impact with the wall/tyres.

I think there were some good threads on this subject after the first race of 2001.

[shiny side up!]

I think the mounting goes to a plate on the inboard side of the carbon fibre of the monocoque, so that shouldn't be the weak point (would have to pull the attachment THROUGH the monocoque to fail that way, which would be disastrous). The attachment at the wheel may be the weak point, but I would guess that it is the cable itself that is designed to be the weak point. It is easy to build cables with consistent and predictable strength properties...

[Snrub]

I don't know, I tend to think if they used the kitchen sink approach they could keep the wheels on there. (maybe they use multiples cables each of which are thicker) There was an indicent a few years ago @ MI Speedway when Fernadez hit the wall and multiples spectators died as a result of the tire going into the crowd.

[Mr V]

Originally posted by twig
As we all saw, Webber spun off, ripping the two front wheels of his car, now the wheel tethers should have worked, but did not,

Agreed about Webbers wheel tethers, but i truly believe they might just have saved Firmans life yesterday. When his suspension collapsed, the front right wheel was heading straight back and for his head, fortunatly in this instance, the tether worked, it could have been alot worse.

[mac]

The problem is, if you make the join between the teathers and the car SO STRONG that wheels stay on in impacts like Webber's, then you could well have the problem of wheels pulling parts of the car to pieces as a result of a big impact.

There must be an appropriate balance.

In regards to Webber's incident, I believe the teathers did their job EXACTLY as intended. That is, wheels didn't go flying of into the crowd, a la Michigan. If you look, the Jag actually travelled further than the wheels. The safety breach had nothing to do with the teathers, rather the speed with which Alonso arrived at the scene (however it happened).

[avsfan733]

I think Mac has a good point. Think what might happen if by some fluke of a chance, a tire came loose, but stayed on the tether, and then hooked onto a catch fence or something else trackside.

[elf Tyrrell]

They have made the wheel tethers stronger, they did it after Melbourne when the marshall died.

And what I had kept noticing is how the wheels actually did stay attached to the cars in several heavy accidents during the past year. But no one noticed that.

There's just some things that can't be made strong and safe at the same time.

As avsfan733 mentioned the wheels could get caught in fences and to me it looked like they got caught in the barriers and thats why they were ripped off.