The Zhou crash, and the rollbar issue

I think many of us are aware that I am not only NOT an engineer, but lack many engineer-like skills. Yet, I watched this short video on the discussion and destruction of the Alfa roll hoop at Silverstone, and just shook my head:

www.youtube.com/watch?v=tVXCwuvQz1U

A single-post roll hoop is a "thing" in F1?? Really? We go all-in on the halo, but we "glue" on (if indeed it is glued on) a single post roll hoop and expect it to perform in a rollover (which, almost by definition, means that the angle of impact of the bar is changing relative to the ground it is travelling upon) as the accident unwinds? Yes, Zhou was saved by the halo, but only because the halo did the job that the basic rollbar structure failed to do. Alfa ought to be taken to the woodshed on this.

I post this as there is talk in our FF paddock of adopting a halo structure on our cars. There was a competitor at a race recently with a retrofitted halo on a FC/Libre car that started a few "conversations". I don't intend to get that argument started, but only illustrate that the folks on the side of the halo should be cautious in citing this recent incident as definitive proof that the halo is needed at the amateur level.

cheers,
BT

The roll hoop very obviously failed when it never should have. It will be interesting to (hopefully) see the "why" behind that.

The gravel trap outside turn 1 that took the life of an upside down IMSA open cockpit driver at Homestead about 15 years ago is long gone. I was surprised to see it as part of an F1 track.

The halo arguably saved two drivers from serious injury or worse last Sunday: Zhou (obviously), but also Nissany in the F2 race. Here's video of that overshadowed incident.

Basically all open-wheel cars at the F4 / USF2000 level and up, everywhere in the world, are now equipped with a halo or equivalent. The halo is rapidly cementing its place in the standard silhouette of an open-wheel car in the mind of the public, especially among the younger generations. It won't be long until the ranks of cars without them begin to look antiquated.

As for when and whether club racing open-wheel cars will be required to have a halo, I think that will happen sooner rather than later in spec classes akin to FE2, but I don't see it coming to true formula classes for decades at least. It would simply be too difficult and too expensive to retrofit all of the existing formula cars.

Jeff

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Originally Posted by billtebbutt

I think many of us are aware that I am not only NOT an engineer, but lack many engineer-like skills. Yet, I watched this short video on the discussion and destruction of the Alfa roll hoop at Silverstone, and just shook my head....

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This is a classic case of evaluating something by the way it looks. The blade roll structure has been used for many years. Its effectiveness is well established. The roll structures are designed and test to specifications provided by the FIA. There was nothing particularly dramatic about the roll over. I am sure they are going to find the forces involved well within the limits set in the design.

The roll structure failed very early during the first impact while on the track. It is my opinion that this was a structure failure do to a bad fabrication process. The quality of a carbon fiber structure can be very hard to verify.

Brian

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Originally Posted by EYERACE

The gravel trap outside turn 1 that took the life of an upside down IMSA open cockpit driver at Homestead about 15 years ago is long gone. I was surprised to see it as part of an F1 track.

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Just because someone dies in a particular safety system does not mean it is a failure. All safety systems are a compromise. If you create a situation that that is outside a systems design limits , you pay the price.

Also remember that almost all tracks see just as much motorcycle racing as they do car activities. Motorcycles require a whole different set safety requirements.

Brian

I'm glad the posted analysis also mentioned the gap between barrier and fence where the car wound up. So lucky there was no fire.

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Originally Posted by Hardingfv32

This is a classic case of evaluating something by the way it looks. The blade roll structure has been used for many years. Its effectiveness is well established. The roll structures are designed and test to specifications provided by the FIA. There was nothing particularly dramatic about the roll over. I am sure they are going to find the forces involved well within the limits set in the design.

The roll structure failed very early during the first impact while on the track. It is my opinion that this was a structure failure do to a bad fabrication process. The quality of a carbon fiber structure can be very hard to verify.

Brian

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And, as a non-engineer, I am only equipped to judge something by the way it looks and add-in my version of basic common sense. I am in no position to either understand the technical requirements, or comment on their appropriateness. My common sense tells me that a blade is inferior to a triangle in terms of rollover protection, all else being equal. And, that maybe sometimes gluing things together is inferior to bolting them together.

Now, back to the shop with my antique RF90....Which uses neither carbon or glue to hold it together ;)

cheers,
BT

Having spent many decades of my life designing and certifying aircraft engines (whose potential failures can be both catastrophic and very public), I want to reiterate what Brian said above. A design is only as good as it’s design input parameters, and while I’m sure the Alfa designers thought of many many possible scenarios, it’s the nature of racing (and aerospace) that sadly occasionally reveals something no one foresaw….

If one designed an aircraft that “couldn’t fail”, it would be too heavy to fly.
if one designed a 100% safe race car, I suspect it would be so boring to drive that no one would….

YMMV

Perhaps I am just a glass half-full kind of guy, but my impression was just the opposite of Bill's. I was impressed that the overall safety systems on the car did their job, in that Zhou was wearing a clean shirt (and shorts I presume) and visiting his friends in the paddock shortly thereafter.

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Originally Posted by Teuobk

It won't be long until the ranks of cars without them begin to look antiquated.

As for when and whether club racing open-wheel cars will be required to have a halo, I think that will happen sooner rather than later in spec classes akin to FE2, but I don't see it coming to true formula classes for decades at least. It would simply be too difficult and too expensive to retrofit all of the existing formula cars.

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Only because you see a halo and think that's the solution. Just put a midget cage on top of a FF. Been done many times. Works fine, but it's a bit ugly and draggy.

Honestly the halo doesn't really change the look of an ugly F1 cars at all. Kinda makes that pill easier to swallow.

A midget cage would just make an FC kinda look like a supermodified.

Having raced FV since the early 80's and have built a few, I don;t think a halo would be to difficult to add to most open wheel cars. Disclaimer! I am not a school taught engineer just someone who has been around a little while. Over the years of building FV cars and doing retro fit of higher roll bars I come to a pretty simple way to guesstimate a project cost. For every location I have to weld two things together will take an hour, that includes shaping or fish mouthing the part to fit. and another hour to bend the top piece so a basic halo without gussets would be 5 hour job. Note it is a good way to explain to someone what is involved so they can easier understand what goes into a job. I usually don't charger for engineering time just actual fab time. Materials are additional. I just a few days ago bought a length of 1 1/4"OD x.095 DOM tubing and picking it up at my local place was just short of $8 a foot.

Back to the F1 halo's, why is the rear of the halo attached below the top of the driver's head? Remember last year when Max and Lewis had a disagreement of who had the lead and Max ended on top of Lewis halo? The spinning rear tire was inched away from Lewis's helmet. Just remember what you see on TV is not the actual shape of the halo but it's aero cover. I have seen an F3 car displayed at a local race and they had the cover off of it. It was just tubing and the upright piece was possibly flat tubing or solid.

Ed

Unless someone's garage built halo can withstand the weight of a city bus and all the other forces an F1 halo can, it'll likely be more of hindrance/danger than a help if ever put to the test.

Out of curiosity do you have a rear roll bar on your car? So adding additional bracing and or support is not what you want to potential help in an accident? If so does it come with an engineering certificate?

You can spend thousands of dollars to get a stamped approved design that is as worthless as the paper comes on. I am retired and worked in the construction industry and last twenty years as various jobs in inspection. Where I worked an engineers certification was always accepted without question because it was a passing of responsibility for any problem that would come up and they sometimes did and it then becomes a blame game.

So any garage that is capable of doing acceptable workmanship regardless of wither they have the proper credentials is kinda laughable excuse for not following acceptable standards of design and construction.

Ed

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Originally Posted by Ed Womer

Back to the F1 halo's, why is the rear of the halo attached below the top of the driver's head?...

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1) The rear mounting position needs to have a wide base to maintain reasonable driver access. A raised chassis structure at that point to helmet height would create a major aero obstruction. Obviously a compromise begin made.

2) I think the lower rear base helps form a brace to the highest point of the halo adding to its vertical strength at this point, a slight pyramid. The strength of the halo at its forward highest point is the highest priority.

Brian

If anyone wants to see what a well designed and executed roll bar / SCCA spec meeting cage looks like, just look at a Steve Lathrop Citation. Not it is not a midget / sprint car cage but could very easily be one.

I was not impressed with the construction of the Alfa. There is no, repeat no excuse for the primary roll structure to break off the car. I understand that carbon fiber is designed to be strong for the forces the engineer/designer intends to DESIGN FOR. In many cases such parts are subject to catastrophic failure when subjected to unanticipated forces.

As I recall Scott Liebler died in a incident in the 1989 Runoffs when the roll bar structure of his car was sheared off in the incident. That form of construction was outlawed subsequent to the incident.

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Originally Posted by mmi16

In many cases such parts are subject to catastrophic failure when subjected to unanticipated forces.....

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Not sure of the point that you are trying to make.

Engineers can design for any force level that you specify. They cannot design for 'unknown' unanticipated forces. There is always going to be events bigger than you ever imagined.

Brian

If I had to guess, the FIA has a test and it's designed to pass the test. In the hypercompetitive world of F1, additional safety margin (for those unanticipated loads) is likely near zero.

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Originally Posted by mmi16

I was not impressed with the construction of the Alfa. There is no, repeat no excuse for the primary roll structure to break off the car. I understand that carbon fiber is designed to be strong for the forces the engineer/designer intends to DESIGN FOR. In many cases such parts are subject to catastrophic failure when subjected to unanticipated forces.

As I recall Scott Liebler died in a incident in the 1989 Runoffs when the roll bar structure of his car was sheared off in the incident. That form of construction was outlawed subsequent to the incident.

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Scott was driving a Martini which has the roll bar bolted to the aluminum monocoque. And he also went about 30 feet in the air after running over Jim Brouk's rear tire. I think this was an unplanned overload condition, while still tragic.

The Liebler crash was used in the opening sequence of the crap movie “Freejack” — without permission. Seems the Producers were sued...

Regardless, the outcome is pretty predictable if seeing it — and I don’t think Martini is to blame. The car plunged through the Turn 11 bridge at over 100 mph, and effectively in aftermath destroyed the best turn in American road racing.

Regardless, poor Scott, one of only two to die during a Runoffs in like 60 years and over 1,000 races.

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Originally Posted by Rick Kirchner

If I had to guess, the FIA has a test and it's designed to pass the test. In the hypercompetitive world of F1, additional safety margin (for those unanticipated loads) is likely near zero.

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For the engineer it is a lot less stressful to design to the FIA specification that make a guess about how much extra strength to add. A scientific study was done by the FIA to develop the crash structure. Most studies like this are a committee made up of volunteer team engineers. There was some research that went into the specifications.

I think it is safe to state that for the truly competitive professional driver, performance has priority over safety. Not many drivers walked away from a Lotus drive for example.

Brian

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Originally Posted by Hardingfv32

The roll structure failed very early during the first impact while on the track. It is my opinion that this was a structure failure do to a bad fabrication process. The quality of a carbon fiber structure can be very hard to verify.

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'Alfa Romeo has revealed that initial data from Zhou Guanyu"s crash at the British Grand Prix showed the roll structure took twice as much force as Formula 1's crash tests demand.'

So my 'observation' was wrong and there was nothing wrong with the fabrication process. So much for observations.

Brian

this is what safety margin is for. Since the teams won't add it, perhaps the FIA will up the specs. so now we know they need 2x, if they were smart they's make it 3x

This video states that every chassis built gets the FIA tests, so fabrication failures during an accident are much less likely to be seen.

https://www.youtube.com/watch?v=oQUi9kwemDY

Brian

If every chassis gets tested, then I'd be concerned about latent failures.....

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Originally Posted by Hardingfv32

This video states that every chassis built gets the FIA tests, so fabrication failures during an accident are much less likely to be seen.

https://www.youtube.com/watch?v=oQUi9kwemDY

Brian

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That is mis-stated. Every chassis DESIGN is tested but not each individual chassis

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Originally Posted by Steve Demeter

If anyone wants to see what a well designed and executed roll bar / SCCA spec meeting cage looks like, just look at a Steve Lathrop Citation. Not it is not a midget / sprint car cage but could very easily be one.

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A couple of years ago I chatted with Steve about installing halos on FC/FF cars. He was cautious with his words, but I took it that he thought it would possible on his chassis, very difficult on most others. He said it would be easier to answer if the spec was defined as to what loads he would have to design for.

https://www.apexspeed.com/forums/att...d=103853&stc=1
Oval racers put cages on everything from karts to WoO cars. Some safety-conscious road racers have run them on formula cars for decades. It is not rocket science. We need the will to do it .... technology is not the problem.
https://www.apexspeed.com/forums/att...d=103854&stc=1

A few weeks ago the sanctioning body for Formula Ford racing in Australia put out a press release that they will debut a new generation Formula Ford chassis that will include a halo and other protective crash structures in 2024. They state in the article that the chassis will be one of the first tube frame chassis to incorporate all these safety features.

https://www.motorsport.com/openwheel...lia-/10326882/

The formula cars I've seen so far with the halo have all been monocoque designs, so I'm very interested to see the designs of a tube frame chassis with this feature included. Trying to retrofit a halo on to most existing chassis would be a non-starter, but I'm curious what the engineering challenges to including a halo onto a new tube frame chassis design would be vs a monocoque design?

Given that the Australians are far enough along in their process to announce this move for 2024, is anyone aware of any US or European sanctioning bodies having similar discussions or plans in the works? As the halo is now standard for all major open wheel formula car categories in the professional ranks worldwide, it's only a matter of time before National and club level motorsports begins to move in this direction as well. Clearly it will take far longer for club level racing to make this change and existing classes would likely need to be grandfathered in. However, I think as younger generations (and their parents) come out of karting to look at formula car options, anything without a halo will likely be left in the dustbin of history.

Man, talk about scope creep. This thread started with a discussion about a F1 roll hoop failure and somehow morphs into us needing halo protection in FF and FC, two classes that haven't seen more than two new chassis per year for the last decade.

The Press release about Australian Formula Ford's with Halo's on a tubular chassis might be getting a little ahead of itself. Rumour has it the engineering is OK in principle but there is a lot of work to do yet. And they might be 12-18 months away from a finished product.

I suspect the media stuff was more signaling a direction and an intent than demonstrating a finished car ready to race. What is proposed is a whole new car (with halo) and you would have to buy a new one to race the Championship. I doubt if anyone will do a retrofit either. Aus tried this new car idea with F4 and the fields were very small and in the end it disappeared.

Having said that the idea of halo's is to be applauded.