inanimate reject: wheel tethers

[Jack O Malley]

I noticed that in the first five 2009 races wheel tethers have failed too often. AFAIK they were introduced in late 90s, and strengthened in 2000 and 2001, after the unlucky deaths of Ghislimberti at Monza and Beveridge at Melbourne (both were hit in the chest by an out-of-control wheel). Since then, the only shunts with wheels flying over the track that I can remember are Webber-Alonso's in Brazil 2003 and Kubica's in Montreal 2007, but both (especially the latter) were absolutely horrific crashes.
In the first five races of 2009 we've seen wheels flying around after Vettel's and Kubica's crash in Oz, Sutil's in China (not a big shunt, indeed), and the first-corner melee in Barcelona. What's going wrong with wheel tethers? I am pretty scared when I see wheels flying away at 300 kph. Are we waiting for another tragedy, maybe? So I award reject status to 2009 wheel tethers.

[PayasYouDNPQ]

It's more complicated than that. I remember seeing a thread on another forum about precisely this issue.

The tether must be weaker than the attachment points on the tub. This may seem odd but if they were stronger then the attachment points would break, resulting in the tub being damaged and weakened. The energy of the crash has to go somewhere.

Breaking something takes energy. In the case of the wheel tethers, it comes from the kinetic energy of the wheel. So while the wheel might still come loose, it will be travelling much slower than if the tether had not been present. In the crashes this year the wheels have come off relatively slowly, posing less of a danger to marshalls and spectators.

I hope that explains it.

[CarlosFerreira]

In the crashes this year the wheels have come off relatively slowly, posing less of a danger to marshalls and spectators.

I think the problem this year hasn't been in the crashes, it has been wheel tethers spontaneously letting go of the wheels at high speed. Like Captain Planet's shield.

[Fitch]

So why not tether the wheels to each other??

Pass a bar through the nose piece and Fasten the tethers to that.....Thus, the wheels would hold each other on.....

[Salamander]

So why not tether the wheels to each other??

Pass a bar through the nose piece and Fasten the tethers to that.....Thus, the wheels would hold each other on.....

There's already a bar (the axle) passing through the nose piece that connects both the wheels.

[Ross Prawn]

So why not tether the wheels to each other??

Pass a bar through the nose piece and Fasten the tethers to that.....Thus, the wheels would hold each other on.....

There's already a bar (the axle) passing through the nose piece that connects both the wheels.

The only cars that have a continuous front axle like that are driven by Fred Flintstone.

[Captain Hammer]

It's simple physics. No matter how tensile you make the thethers, no matter how hard you anchor them, if you get the conditions just right, they will break. You will notice in every single accident so far, the wheels have two things in common: one, they come off. Two, they have not become airborne. When Vettel and Kubica hit each other, there was no way the wheel tethers would have held: each sheared the others' wheels off. When Sutil impacted with the wall in Shanghai, the entire nose was destroyed; there was nothing for the tethers to hold onto. And when we had the pile-up in Catalunya, it was a relatively low-speed accident; both Trulli and Sutil re-joined at a speed less than the rest of the field. Not once have wheels been in an accident where they could have potentially hurt or killed someone. They are designed to break like that.

[Jack O Malley]

Not once have wheels been in an accident where they could have potentially hurt or killed someone. They are designed to break like that.

So, let's hope they go on this way... and not to see another "space rocket take-off" like in Monza 2000.

[DonTirri]

Not once have wheels been in an accident where they could have potentially hurt or killed someone. They are designed to break like that.

So, let's hope they go on this way... and not to see another "space rocket take-off" like in Monza 2000.

Or like 94 Imola...

Cause thats basically what killed Senna, the wheel getting wedged between the car and the wall and then shooting back like a rocket into Ayrtons head.

Had there been a tether, it probably wouldnt've had shot backwards with such a force,,,,

[Faustus]

Not once have wheels been in an accident where they could have potentially hurt or killed someone. They are designed to break like that.

So, let's hope they go on this way... and not to see another "space rocket take-off" like in Monza 2000.

Or like 94 Imola...

Cause thats basically what killed Senna, the wheel getting wedged between the car and the wall and then shooting back like a rocket into Ayrtons head.

Had there been a tether, it probably wouldnt've had shot backwards with such a force,,,,

Not quite. What killed him was the carbon fibre shard from the one of the front wishbones that went through his visor and eye, not the impact of the wheel. Carbon-fibre has, does and will shatter and it is near impossible to predict how it will shatter in any given situation, especially such a dynamic situation as a high-speed impact.
The tether would not have saved him. It was a freak accident.

[RejectSteve]

To throw another story of it into the thread, the story I had was the suspension wishbone went through the top of the visor into his forehead.

If we have two more explanations, a certain group of theorists may want to stand up.

[Reverie Planetarian]

So why not tether the wheels to each other??

Pass a bar through the nose piece and Fasten the tethers to that.....Thus, the wheels would hold each other on.....

Hey, cool! Wheel-chaku!

[Fitch]

Steve is correct...it was a Suspension piece went through his visor and far enough into his head to kill him........There is a website that actually as the pics of his Helmet and Visor, and it is simply amazing how small the hole is.........

and As was said before and as I continue to say, Senna's was a Freak Accident, when it's your time, it's you time.....Which is partially what pisses me off about the FIA, they went overboard and destroyed many a great circuit.......if Tambuerello was such a Dangerous Corner why was it not Reconfigured after Berger had his Massive Crash there?

[Captain Hammer]

Look, the thing about any of these accidents is that if you change one variable, you change the entire outcome of the event. Look at Villeneuve's accident in Melbourne, the one where the marshall died: the gap in the wall was forty-seven centimetres wide. The flying tyre was just forty-six. If Villeneuve had been going two kilometres faster or slower when he hit Ralf, if he had been six inches over to the left or right, if his tyres had been half a degree warmer or cooler, the outcome would have been completely different.

That's part of the controvesry surrounding Senna's death: the last few seconds of on-board footage when he went into Tamburello are lost, destroyed in the accident. We'll never know precisely what happened; the darkest rumours suggest the steering wheel literally came off in his hands - the reason why Frank Williams was the subject of a manslaughter case was that the team had cut a section out of Senna's steering column because it was too long (as opposed to manufacting a newer one) - and that the tape was deliberately and knowingly destroyed in the aftermath of the crash because Italian law dictates that in the event of a death during any kind of sporting match, the match must be cancelled immediately and indefinately pending a full investigation; Senna was not decalred dead until two hours after the chequered flag fell, but Sid Watkins testified that the Brazilian died in his arms at the scene of he accident.

The reason I'm saying this is because we can only speculate as to what caused Senna's accident. A lot of theories have been put forward, even to the point where a documentary team re-created the accident as best they could and hypothesised that the accident was the result of a safety car in the wake of the JJ Lehto-Pedro Lamy collision. The documentary team concluded that because of the long safety car period - five laps - and tyres that were not up to the favoured warmth, Senna's car was actually lower that it was supposed to be and the skid plate impacted with the ground. Senna's reflexes automatically corrected it by jinking right, but when he hit a bump on the surface, the car suddenly regained all its grip and Senna's correction meant that the car was now angled on a course that would take him off the circuit. If he had actually been slower, the documentary claims,he would have lived. But Michael Schumacher refutes this, as he had been closely following Senna, and other drivers like Alboreto claim that by the time of the accident, Senna's tyres would have been up to the correct temperature.

The point is, vehicular aerodynamics is a very complex branch of physics, and no matter how much you plan for it, there's always going to be an accident that plays out in a way you never anticipated. Change one variable, you change the end result. But that's not to say the FIA were wrong: they obviously had to act in such a way to guarantee the safety of the drivers. Personally, I think they took it too far with adding the Villenueve chicane: when Ratzenberger had his accident, you could go flat out from the Start/Finish line, through Tamburello and all the way up to Tosa. By adding a chicane at Tamburello, the cars would have naturally been slower on the approach to the right-hander before Tosa. But then, the problem with Imola has always been too many chicanes; Acque Minerale, Variante Alta and Variante Bassa are all fiddly little things. Seriously, get rid of the first two and the run from Piratella, down through the gully and then up over the hill to Rivazza could be another Eau Rouge. Fortunately, the owners of Imola have remove the Bassa chicane, so it's now flat out from Rivazza down to Tamburello.

[CarlosFerreira]

And yesterday, another dustbin lid incident, with Nakajima losing a possible points scoring position because the tether on the left front wheel wouldn't go after the second refuel. I'm glad these things are going, next year. I wonder if it wasn't possible to eliminate them right now, on safety grounds.

[Waris]

And yesterday, another dustbin lid incident, with Nakajima losing a possible points scoring position because the tether on the left front wheel wouldn't go after the second refuel. I'm glad these things are going, next year. I wonder if it wasn't possible to eliminate them right now, on safety grounds.

They've been bothering me to no end since that Nakajima incident, because now Nakajima is dead last in the Driver's Championship. I can see them sneak in a 3rd place at the ROTY award if this continues.

[Alianora La Canta]

They'd better do it this year - they're due to be banned in 2010 (in theory).

[Fitch]

What do you guys mean by dustbins and why are they going to be banned??..........


Also, I just realized I never clarified my Tether Idea.....I'm not talking about using a Single Axle...I'm talking about a Single Bar that ONLY the Tethers are attached to....it could even be placed in a position and made to a specification that it would Fail if a specific amount of force were applied to it.....but the failure would be, in essence, Controlled.....

[Captain Hammer]

They're talking about the covers that go over the hollow section of the tyre.

[Faustus]

What do you guys mean by dustbins and why are they going to be banned??..........

Also, I just realized I never clarified my Tether Idea.....I'm not talking about using a Single Axle...I'm talking about a Single Bar that ONLY the Tethers are attached to....it could even be placed in a position and made to a specification that it would Fail if a specific amount of force were applied to it.....but the failure would be, in essence, Controlled.....

Interesting idea that might work.

[shinji]

This is a poignant thread now...

[CarlosFerreira]

Yes, but still, how could this have helped in the case of Henry Surtees' accident? As someone pointed out, the wheel tethers did help in that case, slowing down the speed at which the wheels broke loose from the axle, and it was the car that impacted the slow moving wheel. At the end of the day, it was the energy from the car, not the wheel travelling at full speed.

It's probably possible to design a wheel tether that wouldn't allow a wheel to break loose except under very extreme circumstances, but at what cost? Remember in Ayrton Senna's accident, the wheel rebounded and hit his helmet. That's not a desirable outcome as well.

[shinji]

Yes, but still, how could this have helped in the case of Henry Surtees' accident? As someone pointed out, the wheel tethers did help in that case, slowing down the speed at which the wheels broke loose from the axle, and it was the car that impacted the slow moving wheel. At the end of the day, it was the energy from the car, not the wheel travelling at full speed.

It's probably possible to design a wheel tether that wouldn't allow a wheel to break loose except under very extreme circumstances, but at what cost? Remember in Ayrton Senna's accident, the wheel rebounded and hit his helmet. That's not a desirable outcome as well.

I agree, I just meant that what people were discussing had come to fruition in a very unfortunate and tragic way.

[CarlosFerreira]

Yes, but still, how could this have helped in the case of Henry Surtees' accident? As someone pointed out, the wheel tethers did help in that case, slowing down the speed at which the wheels broke loose from the axle, and it was the car that impacted the slow moving wheel. At the end of the day, it was the energy from the car, not the wheel travelling at full speed.

It's probably possible to design a wheel tether that wouldn't allow a wheel to break loose except under very extreme circumstances, but at what cost? Remember in Ayrton Senna's accident, the wheel rebounded and hit his helmet. That's not a desirable outcome as well.

I agree, I just meant that what people were discussing had come to fruition in a very unfortunate and tragic way.

Sure, I understand. It's just that both accidents were, arguably, caused by the fact that these are open-wheel races, where cockpits are open, some area of the pilots' bodies is exposed, and so are large and heavy parts of the cars, such as wheels, brakes and suspension linkages. Could we have a girder connecting the wheels? Sure, but in extreme cases the whole assemble would come loose, ripping the cars apart. In a crash, when energy must be dissipated, something's got to give. Formulae these days are so safe (remember Kubica, Canada, 2007!) that the one thing that has the potential to really hurt pilots these days is the laws of probability.

I don't want to sound silly or stupid, but in the end of the day it was the fact that there's always a non-zero probability of a freak accident occurring that caught up with Henry Surtees, unfortunately. Every pilot, in every open-wheel championship, probably had a shiver when he understood this fact.

Maybe in some of these cases extreme solutions could help, such as rolling starts or a move towards covered-wheel cars?

[Nuppiz]

I've read that the F2 cars don't actually have wheel tethers

[noisebox]

Yes, but still, how could this have helped in the case of Henry Surtees' accident? As someone pointed out, the wheel tethers did help in that case, slowing down the speed at which the wheels broke loose from the axle, and it was the car that impacted the slow moving wheel. At the end of the day, it was the energy from the car, not the wheel travelling at full speed.

It's probably possible to design a wheel tether that wouldn't allow a wheel to break loose except under very extreme circumstances, but at what cost? Remember in Ayrton Senna's accident, the wheel rebounded and hit his helmet. That's not a desirable outcome as well.

Thethers probably would've saved Senna - the wheel broke away completely and a loose suspension piece punctured his helmet. Tethers are designed to hold the wheel that it can only move in an arc around the location of the mounting point of the tether on the chassis.

This arc stays well clear of the cockpit. The problem with strengthening tethers is that you will eventually move the point of failure to the chassis itself, so I guess the only solution is for chassis to made stronger so that they can cope with stronger wheel tethers.

[CarlosFerreira]

Thethers probably would've saved Senna - the wheel broke away completely and a loose suspension piece punctured his helmet. Tethers are designed to hold the wheel that it can only move in an arc around the location of the mounting point of the tether on the chassis.

This arc stays well clear of the cockpit. The problem with strengthening tethers is that you will eventually move the point of failure to the chassis itself, so I guess the only solution is for chassis to made stronger so that they can cope with stronger wheel tethers.

Oh, I see. Thanks for clearing that out.

[CarlosFerreira]

I've read that the F2 cars don't actually have wheel tethers

They do. But the issue of their feebleness has been raised:

I notice in John Surtees' own account of Henry's first race of the weekend at Brno on June 20th that he lost a wheel himself during a first corner melee. As his father put it: "Henry's rear wheel was detached, breaking the tether by the impact whilst he was still on the track, and he vividly recalls this rear wheel passing him at great speed, only to realise it was his."

Clearly tethers do break - we see it occasionally in Formula One - but in the Williams-engineered Formula Two cars, it seems there could be an issue with this vital safety component. One Formula One observer was surprised to see wheels coming off. "For sure, in a junior category like that, it should be remarkably easy to achieve a tether that would hold a wheel on," he said.

Source: http://timesonline.typepad.com/formula_ ... a-two.html

[Captain Hammer]

I'm too lazy to type to it all out again, so I'm just going to quote myself:

Look, the thing about any of these accidents is that if you change one variable, you change the entire outcome of the event. Look at Villeneuve's accident in Melbourne, the one where the marshall died: the gap in the wall was forty-seven centimetres wide. The flying tyre was just forty-six. If Villeneuve had been going two kilometres faster or slower when he hit Ralf, if he had been six inches over to the left or right, if his tyres had been half a degree warmer or cooler, the outcome would have been completely different.

That's part of the controvesry surrounding Senna's death: the last few seconds of on-board footage when he went into Tamburello are lost, destroyed in the accident. We'll never know precisely what happened; the darkest rumours suggest the steering wheel literally came off in his hands - the reason why Frank Williams was the subject of a manslaughter case was that the team had cut a section out of Senna's steering column because it was too long (as opposed to manufacting a newer one) - and that the tape was deliberately and knowingly destroyed in the aftermath of the crash because Italian law dictates that in the event of a death during any kind of sporting match, the match must be cancelled immediately and indefinately pending a full investigation; Senna was not decalred dead until two hours after the chequered flag fell, but Sid Watkins testified that the Brazilian died in his arms at the scene of he accident.

The reason I'm saying this is because we can only speculate as to what caused Senna's accident. A lot of theories have been put forward, even to the point where a documentary team re-created the accident as best they could and hypothesised that the accident was the result of a safety car in the wake of the JJ Lehto-Pedro Lamy collision. The documentary team concluded that because of the long safety car period - five laps - and tyres that were not up to the favoured warmth, Senna's car was actually lower that it was supposed to be and the skid plate impacted with the ground. Senna's reflexes automatically corrected it by jinking right, but when he hit a bump on the surface, the car suddenly regained all its grip and Senna's correction meant that the car was now angled on a course that would take him off the circuit. If he had actually been slower, the documentary claims,he would have lived. But Michael Schumacher refutes this, as he had been closely following Senna, and other drivers like Alboreto claim that by the time of the accident, Senna's tyres would have been up to the correct temperature.

The point is, vehicular aerodynamics is a very complex branch of physics, and no matter how much you plan for it, there's always going to be an accident that plays out in a way you never anticipated. Change one variable, you change the end result. But that's not to say the FIA were wrong: they obviously had to act in such a way to guarantee the safety of the drivers. Personally, I think they took it too far with adding the Villenueve chicane: when Ratzenberger had his accident, you could go flat out from the Start/Finish line, through Tamburello and all the way up to Tosa. By adding a chicane at Tamburello, the cars would have naturally been slower on the approach to the right-hander before Tosa. But then, the problem with Imola has always been too many chicanes; Acque Minerale, Variante Alta and Variante Bassa are all fiddly little things. Seriously, get rid of the first two and the run from Piratella, down through the gully and then up over the hill to Rivazza could be another Eau Rouge. Fortunately, the owners of Imola have remove the Bassa chicane, so it's now flat out from Rivazza down to Tamburello.