Thoughts on WRC and Group N roll cage issues

[Mark]

Bad linkage, Smee. That's my job

[ernysp76]

Just got this through from Prodrive I didn't know that the FIA crash test every new model, is anyone else aware of this or what the crash tests involve?

John Ernst

From Prodrive UK.....


John

Thank you for your recent email. I am sorry we have taken so long to come back to you.

I can confirm that Khalid Bakhressa was driving a Prodrive-built Impreza Group N rally car.

The relevant authorities in Tanzania are investigating the tragic incident, as is normal in such cases, and we await their findings.

You are absolutely correct when you say that Prodrive takes safety seriously, indeed it is our number one priority. This is why with every new model of Group N and World Rally Car we continually improve the design of the safety roll cage to make sure it is not only stronger, but offers more protection to the occupants. As you would expect, each new model is fully crash tested by the FIA to ensure it complies to its ever more stringent standards.

I hope this helps answers your questions.

Best regards

Ben

[Bede]

I have mentioned this before. Including giving you a link to the thread that I mention it, in 'the' thread about AASA...

Originally Posted by Bede

... This means you can use less material (thinner tubing and/or smaller tubing - hence the weight saving) for the same overall roll cage strength and performance*.




* ‘Roll cage strength’ being the amount of deflection per amount of force applied – as used by the FIA to homologate roll cage designs. If they meet the deflection criteria, they pass. ‘Roll cage performance’ being the overall stiffness (or resistance to twisting), which is good for suspension response or behaviour.

[ernysp76]

I saw that but I wasn't aware of actual crash testing of the whole car by FIA as suggested by Prodrive in their letter. How would you read crash testing of new models? Does this mean computer modeling of new roll cage designs? Prodrive are the manufactures reps on the FIA so have big input into their own standards.

[Kaptainballistik]

One big one, The teams wont want to risk killing a driver.

Besides the fact that They are a person, They are quite expensive pieces of gear and are THE MOST important piece of equipment in the car. They take longer to develop, Can self Homoligate, and are easily moved to a new car.

After the Atkinson incident they probably said "OH POOP" first!

[Marcus]

Originally Posted by Kaptainballistik

After the Atkinson incident they probably said "OH POOP" first!

Probably about five nano seconds after they saw Atkinson coming to personally explain the above to them in person with a very large bat

[wbell]

The crash of Atkinson looked very similar to that of Possum and Roger in Perth some 12 years ago.
Behind the main hoop there are no intrusion bars for that area. If a tree hits behind the hoop it will penetrate the car and the forward momentum of the car tares the rear half of the cage back and away form the hoop. That is what killed Roger, the seat belt straps were connected to a bar that ran along the parcel shelf and when that was forced back the Shoulder Belts literally crushed Rogers chest.

I would say that Atko was lucky the tree actually hit the main hoop otherwise the same thing could have happened.

With Solberg’s crash that car landed several times on the same spot on the roll cage and that happened to be on top of a concrete anti tank thingo. The cage was crushed more and more every time the car landed on that point.

You may remember Colins big crash where he was trapped for along time as the roll cage had crushed down on him. Again a very high impact onto a large rock right on top of the A pillar.

The point is that high impact over a small area will crush anything. Thin wall CoM has high tensile strength but it is not so good in shear or tearing. That is why some of the cages tear apart because the force applied is in sheer not compression.

Sideways into a tree is not good at any speed because there is little between the occupant and the object being hit. If you are unlucky like the case involving Peter Brock, 1 foot either way and he most likely would have walked away.

[Jme]

Originally Posted by wbell

If you are unlucky like the case involving Peter Brock, 1 foot either way and he most likely would have walked away.

Brock unlucky...

I think in this case it's been hinted at that the car didn't have any side intrusion bars. Also Brocky did a really amateurish thing by flying into the event late and not participating in recce, using someone else's notes etc

Not hammering him, it's a tragedy- but many experienced rally people would never have put themselves in Brock's position. The same can probably be said with regard to Paul Flintoff.

Ultimately all of this is about managing yourself and the risks involved.

[Daz555]

Originally Posted by ernysp76

I saw that but I wasn't aware of actual crash testing of the whole car by FIA as suggested by Prodrive in their letter. How would you read crash testing of new models? Does this mean computer modeling of new roll cage designs? Prodrive are the manufactures reps on the FIA so have big input into their own standards.

They don't crash test the cars... Admittedly a few drivers have had a go at that... The cages are first manufactured on a jig and weight applied to them to simulate a crash test... I believe this became a requirement around 03 or maybe for the 04 season... Perhaps the actual process has changed since and may now be able to be carried out using some funky CAD software or similar by someone such as Mick Myers at Concentric... I recall looking into this when we built our current car and were deciding whether to build another CroMo cage or using steel...

[ernysp76]

I've forwarded the letter to the FIA for clarification, as has been pointed out the F1 tubs are crash tested as are the Indy Cars. The suggestion from Prodrive seems to be that they do. I'll let you all know of the outcome. Further to the recent fatality in the Prodrive Group N the FIA are NOT conducting an investigation this is being done only locally in Tanzania. This was what I feared would happen and as such there will be no links made by the investigation authorities into other roll cage issues in other countries. Given the FIA is all pervading in CAMS and we use their standards to dictate nearly all aspects of CAMS sanctioned motor-sport I would have thought when there appears to be a major issue resulting from what may turn out to be a major flaw in the FIA standard that they would be in there investigating. I believe that now that the FIA have been alerted as have CAMS there may be a look see at what is going on.

[onkar]

Hi

I dont know if any of you are on facebook, but there are two or three groups paying tribute to Khalid, they have pictures of the car and snapped cage post accident.

[ernysp76]

Originally Posted by onkar

Hi

I dont know if any of you are on facebook, but there are two or three groups paying tribute to Khalid, they have pictures of the car and snapped cage post accident.

I'm surprised these photo's are already up I had heard about them, there are more taken by friends of the navigator.

[onkar]

There were up pretty quick, well before Moses Matovu (navigator) had been discharged.

I was always sceptical of these prodrive cages. Its a good thing they have gone for a more traditional cage in the new N14. Whatever the case as a fellow East African Khalids loss is way too great. Only 22 years old.

RIP Khalid, forever in our hearts.

[airhead]

After seeing Khalid Bakhresa's roll cage, I can only say that avoid those computer designed cages - especially Prodrive Subarus built from 2001-2007. The cage literally broke into pieces right over the crew's head and the navigator survived with a piece of rollcage stuck in his helmet only because he is known to sit lowdown and way back in the car.

Prodrive's design may look fancy but the pipes/bars are of a flimsy material and the quality of wield leaves alot to be desired. FIA seemed to be interested in whether the poor kid was wearing homologated gear etc.

However it must be noted that Prodrive's 2008 computer designed rollcage seems to be quite strong... only another accident will be able to test its rigidty.

[onkar]

He was definitely wearing FIA approved gear, in Tanzania it was only made mandatory this year but he always wore it, in fact he had a very nice overall with his name and sponsors very nicely stitched on.