Slightly different footage of Senna's crash...

[anonymous-user]

[quote=The Surveyor]

So the appeal says Patrick Head was culpable, but you still feel the chap who welded it was guilty?

The bit I still don't get is the focus on the steering column modification being a modification done in haste, you have made a big thing about the modification being bodged in a rush. Yet your saying it was actually done to both cars ( not just Sennas) at the factory before the cars went out to Italy. So this is either a standard factory modification done under factory condition, or was it a bodge done in haste which is why I'm confused.

Also it's a welded tube, it broke past the last support bracket. That's the point where the column will not only be subjected to normal twisting force, but also bending from the driver leaning on the wheel. If the column was so badly bodged why didn't it fail earlier, either when the 'wheel was being clipped on or off ( when the team / driver would be putting latteral strain on the column, or when Senna was qualifying the car putting even greater forces through the column, or when he was putting extra strain on the column whilst frustrated behind the slow pace car, weaving to keep the tyres warm. The column would be least expected to fail on the entry to a swift but gentle curve (albeit a high G corner) rather than a sharp corner where the driver would be leaning most on the wheel and pulling it into the corner. The column wouldn't break under a twisting force associated with smooth cornering.

If the column had failed where it's shown at the side of the car post-accident, it wouldn't have just turned like that Porsche video, it would have gone to one side of the cockpit or the other, or pulled out of the car completely. For Senna to snap the column, he would have been leaning on it (not just turning it) going into the corner, and the 'wheel would have moved very clearly, even the external cameras would have picked that up. Turning into a fast left, the snapped column would move to the left or up, out of the car but none of the videos show that.



The in car video shows very little as it just happens to cut as the car starts moving off towards the wall.

Senna's helmet moves to the left before the clip cuts and this "yellow button" which people refer too which was on the steering wheel moves out of shot.

The external camera shot was from distance and no chance of seeing what was going on.

https://www.youtube.com/watch?v=A-J22HNdcb0

[number 46]

This link to an book about the possible causes of Sennas crash is very interesting reading. Its seems to conclude that steering failure is the most likely cause.

http://martinzustak.com/files/Tamburello_PDF_versi...

[anonymous-user]

number 46 said:

This link to an book about the possible causes of Sennas crash is very interesting reading. Its seems to conclude that steering failure is the most likely cause.

http://martinzustak.com/files/Tamburello_PDF_versi...

Cheers for that. Was trying to find it online.

[jm doc]

The Surveyor said:

ELUSIVEJIM said:

Should Head have been the only one to be found guilty? No. But poor design and badly executed modifications are very telling however way you decide to dress it up.

So the appeal says Patrick Head was culpable, but you still feel the chap who welded it was guilty?

The bit I still don't get is the focus on the steering column modification being a modification done in haste, you have made a big thing about the modification being bodged in a rush. Yet your saying it was actually done to both cars ( not just Sennas) at the factory before the cars went out to Italy. So this is either a standard factory modification done under factory condition, or was it a bodge done in haste which is why I'm confused.

Also it's a welded tube, it broke past the last support bracket. That's the point where the column will not only be subjected to normal twisting force, but also bending from the driver leaning on the wheel. If the column was so badly bodged why didn't it fail earlier, either when the 'wheel was being clipped on or off ( when the team / driver would be putting latteral strain on the column, or when Senna was qualifying the car putting even greater forces through the column, or when he was putting extra strain on the column whilst frustrated behind the slow pace car, weaving to keep the tyres warm. The column would be least expected to fail on the entry to a swift but gentle curve (albeit a high G corner) rather than a sharp corner where the driver would be leaning most on the wheel and pulling it into the corner. The column wouldn't break under a twisting force associated with smooth cornering.

If the column had failed where it's shown at the side of the car post-accident, it wouldn't have just turned like that Porsche video, it would have gone to one side of the cockpit or the other, or pulled out of the car completely. For Senna to snap the column, he would have been leaning on it (not just turning it) going into the corner, and the 'wheel would have moved very clearly, even the external cameras would have picked that up. Turning into a fast left, the snapped column would move to the left or up, out of the car but none of the videos show that.

This is a load of rubbish. It failed when it failed. It could have failed earlier, or later. No one can ever say why it failed then, except that it was being subject to a twisting force at the time which is supporting evidence for the failure. And what qualifications do you have to deny the decision of the Italian courts, which examined in forensic detail all of the evidence including metallurgical analysis of the steering column and reached the conclusion that it's failure caused the crash. And since you lay claim to be such an expert, what forces acted on the column after the car went off the track to cause it to shear??

There are truly some bizarre posts on this thread

[jm doc]

angrymoby said:

jm doc said:

angrymoby said:

jm doc said:

No, the car went straight on, just like Senna. The oversteer was related to the speed into to the bend and throttle position, and was possibly exaggerated by the steering failure.

We also don't know what actually broke on that car (the video is actually labelled 'steering rack' failure)

Well the steering broke didn't it, rack or column, it's effectively the same, no response to steering input and the car straightens up and carries on until something intervenes.

I'm not sure what your point is?

that JIM is possibly comparing apples & oranges ...& that a sheering column failure doesn't necessarily behave in the same way that a sheering pinion on a steering rack does (you'd need an motorsport engineer to confirm)

He's not comparing apples to oranges, he's just showing what happens when the steering fails on a car to help some to understand. ie, it goes straight ahead. Your reply shows that you still don't get it.

[Sergie Lavrov]

Hey Fella's newbie here.

I watched the San Marino GP live back in 94, sat about two feet back from the TV with a beer in my hand.

There is and I guess there will always be great debate as to whether Senna's steering column broke or whether He pushed it to hard and the rear stepped out as His car bottomed out over the bumps in Tamburello.

I'm pretty sure that the live footage back then of the race covered by Channel 9 wide world of sports in Australia showed the full impact from Senna's in car camera as it hit the wall. I recollect seeing the front right hand wheel come up and clock Senna's Helmet. They replayed it several times.

Now all the footage seem to cut out before He impacts the wall.

Many have said that if the steering column broke it would have sent Him off in a straight line.

If you look at the footage in this youtube clip, the Car does not go off in a straight line but rather is pulled to the right.

https://www.youtube.com/watch?v=GCZIMwtooR4

You'll also not that Senna has the steering wheel turned slightly left and the front left wheel is pointing left as it takes Tamburello. For a fraction of a second in the vid, you will see Senna turn the steering right in what looks like a flurry and blur of rapid movement and His head bobs to the left then straightens up.

In this 2nd video from schumacher's Car you can see Senna's Car bottoming out right as it exits the track and again it does not go off in a straight line, it pulls to the right.

https://www.youtube.com/watch?v=8qYXVfY_9IE

You thoughts?

I am not saying that His steering column did not break, but it looks to Me in both the above vids Senna's car leaves the track and is pulled to the right at the exact moment it bottoms out. I believe it was the momentary loss of down force from bottoming out that sent Senna into the wall.

I believe the Renault stats from it's ECU showed Senna go to half throttle as well. I would have thought if the steering column broke, He'd have applied full brakes.

Anyways, my views may well be wrong.

[angrymoby]

jm doc said:

He's not comparing apples to oranges, he's just showing what happens when the steering fails on a car to help some to understand. ie, it goes straight ahead. Your reply shows that you still don't get it.

You don't seem to understand that we're all well aware that a car goes straight on when its steering fails.

What JIM is attempting to show in that vid, is that you can get oversteer once it's failed/ failing- i.e contradicting Newey (even though we have no other data to look at in JIM's vid)

Edited by angrymoby on Tuesday 17th January 10:49

[angrymoby]

Sergie Lavrov said:

Hey Fella's newbie here.

I watched the San Marino GP live back in 94, sat about two feet back from the TV with a beer in my hand.

There is and I guess there will always be great debate as to whether Senna's steering column broke or whether He pushed it to hard and the rear stepped out as His car bottomed out over the bumps in Tamburello.

I'm pretty sure that the live footage back then of the race covered by Channel 9 wide world of sports in Australia showed the full impact from Senna's in car camera as it hit the wall. I recollect seeing the front right hand wheel come up and clock Senna's Helmet. They replayed it several times.

Now all the footage seem to cut out before He impacts the wall.

Many have said that if the steering column broke it would have sent Him off in a straight line.

If you look at the footage in this youtube clip, the Car does not go off in a straight line but rather is pulled to the right.

https://www.youtube.com/watch?v=GCZIMwtooR4

You'll also not that Senna has the steering wheel turned slightly left and the front left wheel is pointing left as it takes Tamburello. For a fraction of a second in the vid, you will see Senna turn the steering right in what looks like a flurry and blur of rapid movement and His head bobs to the left then straightens up.

In this 2nd video from schumacher's Car you can see Senna's Car bottoming out right as it exits the track and again it does not go off in a straight line, it pulls to the right.

https://www.youtube.com/watch?v=8qYXVfY_9IE

You thoughts?

I am not saying that His steering column did not break, but it looks to Me in both the above vids Senna's car leaves the track and is pulled to the right at the exact moment it bottoms out. I believe it was the momentary loss of down force from bottoming out that sent Senna into the wall.

I believe the Renault stats from it's ECU showed Senna go to half throttle as well. I would have thought if the steering column broke, He'd have applied full brakes.

Anyways, my views may well be wrong.

This would be my view.

To me it was eerily similar to Gordon Smiley's crash & no one seems to be pointing to Gordon's steering column failing beforehand ...even though it was certainly broken after.

[The Surveyor]

jm doc said:

This is a load of rubbish. It failed when it failed. It could have failed earlier, or later. No one can ever say why it failed then, except that it was being subject to a twisting force at the time which is supporting evidence for the failure. And what qualifications do you have to deny the decision of the Italian courts, which examined in forensic detail all of the evidence including metallurgical analysis of the steering column and reached the conclusion that it's failure caused the crash. And since you lay claim to be such an expert, what forces acted on the column after the car went off the track to cause it to shear??

There are truly some bizarre posts on this thread

For the record, this whole thread is a discussion based upon supposition, guess work and questions. There are no 'experts' on here and if you think my challenges to the earlier comments on the steering column failure is a load of rubbish then happy days. Now take a breath and look at what you have typed there:-

jm doc said:

It could have failed earlier, or later. No one can ever say why it failed then, except that it was being subject to a twisting force at the time which is supporting evidence for the failure. ...

Sorry are you agreeing with the Italian Court here or not? I do know a little about structural properties of steel, albeit limited to shear forces and bending moments rather than pure torque failures. My comments were primarily aimed at the accusation that the column had been extended as a hasty lash-up job, a negligent bodge and that's the only reason for the crash. That's at odds with the information confirming that both Senna and Hills columns were extended in the factory as a normal modification done under normal factory conditions. To me this still remains unclear.

My comments also suggest that the column would not have only been subject to twisting force as there was around 12 inches of column sticking out past the last column support in the tub meaning any turning on the 'wheel would put both a 'twisting' force and a lateral bending force on the column as the driver leans into the corners with his arms. The biggest bending force being just up from the column support in the tub, exactly where the column is shown to have snapped in the post-accident photos. A tube is very difficult to snap by twisting alone, even one which has been weakened by a weld, but is very easy to snap if you clamp one end and bend it. Agree?

Also, as I said, had the column snapped it wouldn't leave Senna spinning the 'wheel with no effect, the whole lot would have come away in his hands, again just like it's shown on the post-accident photo. I just find it hard to believe that the whole 'wheel and column came away before Senna left the track and nobody saw it, not the in-car footage which cuts off just after the accident started, or any other camera view. Yes, it may well have done, but it just doesn't add up.

jm doc said:

.... And since you lay claim to be such an expert, what forces acted on the column after the car went off the track to cause it to shear??

What forces acted on the column? Well hitting a wall side-on would impose quite a force on the column don't you think? The steering wheel with its controls and potentially still with Senna holding it (unless he lets go as he should) and 12 inches of modified column projecting from the tub upper support smacking the wall sideways is (for me) just as likely to snap the small tubular column as normal power-assisted steering forces.

Remember, these things are designed to the absolute minimum so there just isn't the 'factor of safety' tolerances and testing in the column design that you would see on a production car. Maybe Williams took the old Chapman philosophy 'adding lightness' too far, maybe it was the weld that weakened the column, maybe it was extended beyond it's design limit, or maybe it was fine and failed as the car hit the wall? Many questions and no definitive answer which everybody agrees with.

Sadly I just don't think there will ever be a conclusive reason why Senna hit that wall all those years ago.

[number 46]

Having read the information in the link I posted earlier, the column modification is not as simple as a piece of thinner tube being welded into the old column to extend it as I thought. It is not all that easy to explain with out a diagram, but, the added section seems to have been machined so that at the bush end of the column the new section goes over the old column and runs in a bush mounted under the dash, the remainder of the old column is then pushed over the upper end of the new section and welded. The new piece has a larger diameter at the inboard end, this means that there is a rebat at the point where the new tube diameter reduced, at the upper outside egde of the bush, this is where the fatigue/crack happened and where the column broke. There is a lot of detailed information covering all the possible scenarios in the link and it also explains the steering wheel movement and the telemetry. It is not as simple as looking at a column turning the front wheels via a rack, with telemetry reading the angular movement of the column. The whole power steering design and operation means that the data can be interpreted in a number of conflicting ways.

I still think the the column failed at the cracked joint/flange due to fatigue ,poor design (90 deg flange at the diameter reduction) and load over a number of races. I don't think is just broke off, rather that the column started to fracture and the steering wheel moved down and to the left in the cockpit as Senna was rounding Tamberello, leaving Senna with very time time do anything about it other than just brake as hard as he could.

Edited by number 46 on Tuesday 17th January 14:27

[George29]

The Surveyor said:

That's at odds with the information confirming that both Senna and Hills columns were extended in the factory as a normal modification done under normal factory conditions. To me this still remains unclear.

It was modified at the factory. I have been reliably informed that the reason for the modification wasn't to add any length to it, but to stop the steering column fouling on the minimum size template that the internal bit of the chassis had to conform to. Hence the smaller diameter. The majority of the stuff claiming why and how the column was modified is just made up, and looking for conspiracy.

The Surveyor said:

Remember, these things are designed to the absolute minimum

They aren't really, they are still designed to be fairly robust, else you would see many failures of components like steering columns throughout the years.

[heebeegeetee]

number 46 said:

Having read the information in the link I posted earlier, the column modification is not as simple as a piece of thinner tube being welded into the old column to extend it as I thought. It is not all that easy to explain with out a diagram, but, the added section seems to have been machined so that at the bush end of the column the new section goes over the old column and runs in a bush mounted under the dash, the remainder of the old column is then pushed over the upper end of the new section and welded. The new piece has a larger diameter at the inboard end, this means that there is a rebat at the point where the new tube diameter reduced, at the upper outside egde of the bush, this is where the fatigue/crack happened and where the column broke. There is a lot of detailed information covering all the possible scenarios in the link and it also explains the steering wheel movement and the telemetry. It is not as simple as looking at a column turning the front wheels via a rack, with telemetry reading the angular movement of the column. The whole power steering design and operation means that the data can be interpreted in a number of conflicting ways.

I still think the the column failed at the cracked joint/flange due to fatigue ,poor design (90 deg flange at the diameter reduction) and load over a number of races. I don't think is just broke off, rather that the column started to fracture and the steering wheel moved down and to the left in the cockpit as Senna was rounding Tamberello, leaving Senna with very time time do anything about it other than just brake as hard as he could.

Edited by number 46 on Tuesday 17th January 14:27

I thought Senna's column was modified at the circuit and thus hadn't done a number of races?

[JNW1]

heebeegeetee said:

I thought Senna's column was modified at the circuit and thus hadn't done a number of races?

No, the steering columns for all three cars (Senna's, Hill's and the T-car) were modified at the factory before the first race in Brazil. Given Hill's car had completed more than twice as many laps as Senna's in the first two races you'd have thought his was more likely to show the first signs of failure if there was a design problem. However, I guess it's not necessarily as simple as that and if the modification was done in part by welding pieces together manually there's immediately a chance of the work not being carried out to the same standard on each column (nothing intentional, just the reality of a task being done by a person not a machine). Given they appear to have had the time I've never really understood why they didn't arrange for new (longer) columns to be made rather than modifying the originals....

Edited by JNW1 on Tuesday 17th January 16:52

[number 46]

The way the column was modified seems somewhat odd, Newey says that the design was not great. From what I have read it seems that the column was too thick and perhaps foiling the drivers knees/legs and I did think that Senna also wanted the steering wheel,closer, but maybe that was not the case. The suggestion in the linked article is that a tool mark on Sennas column together with the poor design may have caused the fatigue. The in cockpit video of Sennas last lap does seem to show exsisive steering wheel movement just prior to his off. Hills in car footage seems not to show so much movement. From the drawings of the steering column, there is around 22cms of unsupported column between the bush support and the steering wheel, Senna liked a large diameter wheel, therefore the load on his column compared to Hills may have been more?? Perhaps Sennas more aggressive line over the bumps at Tamberello caused more shock loading on his column compared to Hills also?

[anonymous-user]

number 46 said:

The way the column was modified seems somewhat odd, Newey says that the design was not great. From what I have read it seems that the column was too thick and perhaps foiling the drivers knees/legs and I did think that Senna also wanted the steering wheel,closer, but maybe that was not the case. The suggestion in the linked article is that a tool mark on Sennas column together with the poor design may have caused the fatigue. The in cockpit video of Sennas last lap does seem to show exsisive steering wheel movement just prior to his off. Hills in car footage seems not to show so much movement. From the drawings of the steering column, there is around 22cms of unsupported column between the bush support and the steering wheel, Senna liked a large diameter wheel, therefore the load on his column compared to Hills may have been more?? Perhaps Sennas more aggressive line over the bumps at Tamberello caused more shock loading on his column compared to Hills also?

Hills line through Tamburello was exactly the same as Senna's

https://www.youtube.com/watch?v=m8BoQzAVd8A

As we all know the steering column was cracked before the accident.

As mentioned in the book Tamburello the bumps could have been the reason the crack then became the issue.

Edited by anonymous-user on Tuesday 17th January 18:34

[George29]

ELUSIVEJIM said:

As we all know the steering column was cracked before the accident.

Do we? Do you really think if the mechanics knew a steering column had a crack in it then they would allow it on track? What evidence have you got to support this claim?

[anonymous-user]

George29 said:

Do we? Do you really think if the mechanics knew a steering column had a crack in it then they would allow it on track? What evidence have you got to support this claim?

Perhaps reading the whole thread again would save posting this again.

Newey quote

"The steering column failure, was it the cause, or did it happen in the accident?" said Newey, speaking in an exclusive interview broadcast on 5 live F1 on Thursday.

"There is no doubt it was cracked. Equally, all the data, all the circuit cameras, the on-board camera from Michael Schumacher's car that was following, none of that appears to be consistent with a steering-column failure.

[George29]

ELUSIVEJIM said:

Perhaps reading the whole thread again would save posting this again.

Newey quote

"The steering column failure, was it the cause, or did it happen in the accident?" said Newey, speaking in an exclusive interview broadcast on 5 live F1 on Thursday.

"There is no doubt it was cracked. Equally, all the data, all the circuit cameras, the on-board camera from Michael Schumacher's car that was following, none of that appears to be consistent with a steering-column failure.

That doesn't prove it was cracked beforehand

Why would I want to re-read the entire thread again? Most of it is full of made up "facts" with nothing to back it up

[anonymous-user]

George29 said:

That doesn't prove it was cracked beforehand

Why would I want to re-read the entire thread again? Most of it is full of made up "facts" with nothing to back it up

So Newey states this FACT and it proves nothing to you.

Williams stated this was fact at the trial.

Another interview by Newey

It had fatigue cracks and would have failed at some point. There is no question that its design was very poor.

Trot on.

Edited by anonymous-user on Tuesday 17th January 19:55

[George29]

ELUSIVEJIM said:

So Newey states this FACT and it proves nothing.

Williams stated this was fact at the trial.

Another interview by Newey

It had fatigue cracks and would have failed at some point. There is no question that its design was very poor.

Trot on.

He didn't state a fact, he stated his opinion of what went wrong

Please show me where it says Williams stated this at the trial?