1970s F1 safety-minded regulations

Multiple websites when discussing history of F1 mention these regulations :

1976: "Safety structures" around dashboard and pedals.

1977: Pedalbox protection defined.

1981: Reinforced "survival cell" introduced and extended in front of driver's feet

 

What were these "safety structures"?

What kind of protection was defined?

How chassis design changed after regulations from 1981? Ferrari still used their hybrid chassis similar to tub: 

Does anyone get permission or honor photo credits anymore?

Does anyone get permission or honor photo credits anymore?

Why when I read this post did I think "Oh No, here we go again  " ?

All of the FiA regulations (Yellow Book, App J) are avaliable for download on the FiA website for the years in question. The only way to get a good understanding is to go through the F1 sections page by page, and then take a good look through the thousands of pictures avaliable on the web of the cars of the period ..

 

But very (very) briefly ;

 

1976 safety structures meant a second roll hoop at the dashboard which had to be tall enough so that a 'plank' resting over this and the main hoop behind the driver cleared his helmet. Yeah, right, good job the human neck is flexible . The safety structure at the pedal box (77) was supposed to imply double skinned box sections but was interpreted in diffferent ways by differerent constructors , and so..

 

1981: specific areas defined  that were to be boxed in with material cross sections defined in the box alongside the driver and 300mm forwards of his feet on the pedals.

 

In neither case was there any obvious outward effect on the appearence of the cars.

 

There, a whole post without infringing anybodies copyright...

Why when I read this post did I think "Oh No, here we go again  " ?

 

Possibly because you did not see the ©LAT sign in the corner of the photograph posted above and do not believe it is the right of photographers to make an honest living from honest work ?

 

Thanks for your input to the subject under discussion Peter

All of the FiA regulations (Yellow Book, App J) are avaliable for download on the FiA website for the years in question. The only way to get a good understanding is to go through the F1 sections page by page, and then take a good look through the thousands of pictures avaliable on the web of the cars of the period ..
 
But very (very) briefly ;
 
1976 safety structures meant a second roll hoop at the dashboard which had to be tall enough so that a 'plank' resting over this and the main hoop behind the driver cleared his helmet. Yeah, right, good job the human neck is flexible . The safety structure at the pedal box (77) was supposed to imply double skinned box sections but was interpreted in diffferent ways by differerent constructors , and so..
 
1981: specific areas defined  that were to be boxed in with material cross sections defined in the box alongside the driver and 300mm forwards of his feet on the pedals.
 
In neither case was there any obvious outward effect on the appearence of the cars.
 
There, a whole post without infringing anybodies copyright...

Just the pedants among us - Anybody's...

It is permissible to use copyright material for educational and/or research purposes - At least, that's what they told me when someone used one of my poems.

It is permissible to use copyright material for educational and/or research purposes - At least, that's what they told me when someone used one of my poems.

That's what happens with Vogon poetry, I guess ;-)

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In 1973, F1 rules defined that cars carried "deformable structures". And I still don't understand what they are about in any meaningful way. A simple pontoon structure, a bit of foam, protecting fuel tanks running beside the driver? Deformable structures are somethings that a manufacturer could retro-fit to an existing car although many manufacturers redesigned. Perhaps there was an absence of safety consciousness in journalists at the time, so they didn't ask the right questions, but I'd like to know.

 

The most significant safety change was a "relaxation" requested by Colin Chapman to allow most (all?) fuel to be held in a single cell between the driver's backside and engine for the Lotus 78 and 79. The request was made for performance reasons but it has turned out to be one of the best safety improvements. 

Just the pedants among us - Anybody's...

Not in Narfuk....

My understanding is that deformable structures were there to prevent or at least minimise fuel spills, up until that time the rubber bag cells inside fuel tanks were prone to rupture when cars were involved in collisions often with fatal consequences, by having a deformable structure around the fuel tank it was believed these fatalities could be avoided.

 

We now know that proved not to be the case, in particular with a March 721 fitted with deformable structures rechristened a March 731 at Zandvoort the year the deformable structures were introduced.

That's what happens with Vogon poetry, I guess ;-)

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In 1973, F1 rules defined that cars carried "deformable structures". And I still don't understand what they are about in any meaningful way. A simple pontoon structure, a bit of foam, protecting fuel tanks running beside the driver? Deformable structures are somethings that a manufacturer could retro-fit to an existing car although many manufacturers redesigned. Perhaps there was an absence of safety consciousness in journalists at the time, so they didn't ask the right questions, but I'd like to know.

 

The most significant safety change was a "relaxation" requested by Colin Chapman to allow most (all?) fuel to be held in a single cell between the driver's backside and engine for the Lotus 78 and 79. The request was made for performance reasons but it has turned out to be one of the best safety improvements. 

That was for all of the fuel and for the 79. The 78 had three tanks abreast. Previously there had been a limit of 80L per tank. the irony of that rule was that most fires originated from the unions and transfer pipes between tanks as when a heavy impact force distorted the chassis and the individual tanks, regulated to 'only' 80L for safety reasons , pulled away from one another, the union would rupture. We are talking bag tanks here Zandvoort 73 and i think the Lauda accident being two notorious examples. Chapman's request and the manner in which he executed the fuel system meant that there was only a feed and return from the top hatch and those were on breakaways, so if the chassis and engine did separate there would be at most a flash fire - Watson, Monza 1981 provided confirmation that it worked.

 

The deformable structure regulations were not well worded, in either French, English, or Franglais.. The intention was 100mm of foam over the full depth of the tank for 350mm of length, tapering to 10mm depth. But they didn't quite say that, so you could have a 100mm sided  triangle at the base of the tub (Brabham), a 100mm tall pyramid on its side (Tyrrell) or use the top and bottom sides of the radiator duct (Lotus and others) providing they were more than 100mm wide, which of course they were. In practice ther was no regulation on the height.

 

That regulation died a natural death about 10 years later when the general architecture of the car meant that it had a large narrow central tank and full width side pods.

Edited by PeterElleray, 22 May 2017 - 14:58.

My understanding is that deformable structures were there to prevent or at least minimise fuel spills, up until that time the rubber bag cells inside fuel tanks were prone to rupture when cars were involved in collisions often with fatal consequences, by having a deformable structure around the fuel tank it was believed these fatalities could be avoided.

 

We now know that proved not to be the case, in particular with a March 721 fitted with deformable structures rechristened a March 731 at Zandvoort the year the deformable structures were introduced.

Our posts crossed, see mine above - no, actually Williamson's tank didn't rupture, the union at the rear corner pulled away. In terms of preventing the tanks rupturing the def structure did work quite well - if they stayed attached. At Nurburgring the RH def structure on Lauda's car finished up some way down the road from where the car stopped from memory...

Thanks to Peter and Ralph for their contributions.

 

Fireproof Tanks, FPT -- from a time when companies didn't mess around explaining what they made -- were a supplier to many racing teams. They made fuel tanks which healed a bit following a small puncture.

 

Sadly, fuel tanks can't heal enough.

Yes, FPT in Portsmouth , largely replaced by ATL by the time i was drawing them. They still didn't fit...

Our posts crossed, see mine above - no, actually Williamson's tank didn't rupture, the union at the rear corner pulled away. In terms of preventing the tanks rupturing the def structure did work quite well - if they stayed attached. At Nurburgring the RH def structure on Lauda's car finished up some way down the road from where the car stopped from memory...

For someone like me who is fascinated by the detailed history f how the modern safety standards which contemporary drivers and fans take for granted evolved, this sort orf information, from someone in your position of first-hand experience, is invaluable.  I has long wondered how much of an improvement the '73 , deformable structure regulations represented in terms of tank protection, and, as a related point, whether the Williamson, Lauda and Peterson fires (the latter of which I previously learned here involved a small scuttle tank used on the 78) were due to ruptured tanks or connectors.  How ironic that Chapman, who is largely regarded as having a net negative influence on safety, happened to inadvertently introduce one of the greatest developments in fuel system safety on the 79!

I has long wondered how much of an improvement the '73 , deformable structure regulations represented in terms of tank protection

I hate to say it -- but, bugger all. Cars raced with fireproof tanks, didn't they? With just three and a half inches of foam on the side of the car.

 

GP and racing fans had known for years that it was essential to get drivers out of the cars quickly. That's safety -- get out of danger.

Thanks - but i have to mention that the info regarding the Zanvoort accident came from someone directly involved that day, who i have worked with several times over the years. it was about 10 years before my time! Nevertheless, i believe it's reliable info, my contact was 'hands on' that day, which brings you up a bit smart when you think about the sequence of events after..

 

The Lauda 'wreck' can be seen on video's as the car is brought back into the paddock, the pod is missing, and in one of the amateur cine films you can see what i believe to be that piece of bodywork flying off as the car pirouette's to a halt. Almost certainly due to the impact with the rock face, so we shouldn't be too harsh! The chassis stood up rather well, We should be careful about the fact that it fell off aswell, because it was still attached on impact and probably did its job as well as it could, by the time it fell off the car was already on fire. Incientally i find the official version of what was supposed to have happened at odds with the video evidence that has emerged since, and i think a plausible alternative can be argued but maybe thats not for the internet!

 

Again from first hand 'witness' info i believe your version of the Peterson fire is about right. Interesting to compare the injuries Lauda and Peterson sustained from their fires, one with his helmet on and the other without... I suppose by the mid 80's we were very conscious of what could happen and it was becoming increasingly unacceptable when it did, and so a lot of time went into researching this sort of thing, might seem a bit 'ghoulish' to the layman but necessary to understand what was going to be required. And there's always something that you haven't considered...

Edited by PeterElleray, 22 May 2017 - 16:44.

I hate to say it -- but, bugger all. Cars raced with fireproof tanks, didn't they? With just three and a half inches of foam on the side of the car.

 

GP and racing fans had known for years that it was essential to get drivers out of the cars quickly. That's safety -- get out of danger.

I'm not so sure.  Siffert in the Victory Race in 1971 hit a earth bank which contained flint fragments - they cut open one of the rubber bag tanks.  Two years later, Roger Williamson slams at high speed into incorrectly-mounted Armco which causes the car to be launched.  It then lands on the track heavily on the other side of the car, yet we've learned here that no tanks were ruptured -the fire was caused by a broken union.  Three years after that, Lauda goes sideways into an unprotected earth bank on the Nordschliefe, and, agin, no tanks rupture - his fire is also caused by severed unions within the fuel system.  To me, that suggests that the biggest fire hazard between '73 and the ground effect era was from severed unions rather than ruptured tanks.  Of course effective fire marshalling and resue was vital - a fire is a fire irrespective of cause - however, the point is that, to reduce risk as effectively and efficiently as possible, one needs to understand the main risk factors and concentrate on addressing them first. 

Thanks - but i have to mention that the info regarding the Zanvoort accident came from someone directly involved that day, who i have worked with several times over the years. it was about 10 years before my time! Nevertheless, i believe it's reliable info, my contact was 'hands on' that day, which brings you up a bit smart when you think about the sequence of events after..

 

The Lauda 'wreck' can be seen on video's as the car is brought back into the paddock, the pod is missing, and in one of the amateur cine films you can see what i believe to be that piece of bodywork flying off as the car pirouette's to a halt. Almost certainly due to the impact with the rock face, so we shouldn't be too harsh! The chassis stood up rather well, We should be careful about the fact that it fell off aswell, because it was still attched on impact and probably did its job as well as it could, by the time it fell off the car was already on fire. Incientally i find the official version of what was supposed to have happened at odds with the video evidence that has emerged since, and i think a plausible alternative can be argued but maybe thats not for the internet!

 

Again from first hand 'witness' info i believe your version of the Peterson fire is about right. Interesting to compare the injuries Lauda and Peterson sustained from their fires, one with his helmet on and the other without... I suppose by the mid 80's we were very conscious of what could happen and it was becoming increasingly unacceptable when it did, and so a lot of time went into researching this sort of thing, might seem a bit 'ghoulish' to the layman but necessary to understand what was going to be required. And there's always something that you haven't considered...

So would it be fair to say that Lauda's fire was probably directly caused by the failure of a connector within the fuel system, with a probable secondary factor involving the loss of a deformable structure from impact with the embankment?

I hate to say it -- but, bugger all. Cars raced with fireproof tanks, didn't they? With just three and a half inches of foam on the side of the car.

 

GP and racing fans had known for years that it was essential to get drivers out of the cars quickly. That's safety -- get out of danger.

Well, i think there are a few instances of where they did work, on cars built to both the letter and the spirit of the regs. It's a bit obscure but if you can find pics of Jochen Mass's M23 after its accident in Brazil in 1977 then the front section of the chassis is heavily deformed, but the tank bay not at all - previously that damage would have spread through the tank bay . Exactly the same but even more extreme is Hunt's M26 after his accident (with Mass!) in Canada later that year, the one where he famously decked the marshall trying (rather over enthusiastically) to man handle him away from the steaming wreckage...

 

Those McLaren's were bueatifully engineered and very clever.

So would it be fair to say that Lauda's fire was probably directly caused by the failure of a connector within the fuel system, with a probable secondary factor involving the loss of a deformable structure from impact with the embankment?

I can't say for sure on that one, stand to be corrected that the tank didn't rupture, but i think my info on the other two is good. But the loss of the d.s after the event could almost be considered irrelevant , a bit like shedding wheels and tyres after they have absorbed some impact energy.

 

Your point on the Siffert accident is well made.

Any ideas regarding the crash from 1:29 in the following video, Peter (Wilson Fittipaldi, Argentinian GP 1975)?

https://www.youtube....h?v=P_itOeTo4D0

I can't say for sure on that one, stand to be corrected that the tank didn't rupture, but i think my info on the other two is good. But the loss of the d.s after the event could almost be considered irrelevant , a bit like shedding wheels and tyres after they have absorbed some impact energy.

 

Your point on the Siffert accident is well made.

Thanks Peter.

Not in Narfuk....

How the hell do you manage to type, what with having 6 fingers and all - Ah you got a loight boiy?

How the hell do you manage to type, what with having 6 fingers and all - Ah you got a loight boiy?

Be you careful, bor - there's more than one of us here!

How the hell do you manage to type, what with having 6 fingers and all - Ah you got a loight boiy?

Only because i am from Lancashire - Duckworth country actually.

 

Narfuk is as much a mystery to me as it is to the rest of you. Many's the time we have crossed the  Narfuk 'frontier' near Mildenhall  with England and wondered if we just keep on going. These days you don't even need an entry visa or passport to get in here , but it can be trickier to get out again, as no Sat Nav yet devised works here. This is because all the algorithmns inside one assume a road network consisting of motorways, dual carriageways, and heavily congested town centres. Use one here and you will find yourself driving through a lane 6' wide covered in cow pats with odd looking locals sitting on the verge chewing grass and trying to work out which model of Austin , Morris or Standard you are driving. And they will all be related...  Consequently when out walking the dog you will get about 10' before a volvo towing a swift caravan pulls up next to you asking for directions. Every single one thinks they are the first to ask for them, i plan to get a sticker for my doggie walking coat which says "I do not give directions, I am not friendly, and I sometimes bite. The dog however is fine"

 

You can blame all of this on Colin Chapman (which will please at least one tnf member known to most of us), and his search from the air for a cheap, deserted airfield in 1965. Or maybe even Tony Rudd who suggested it to him? 

 

It has its advantages. It's not generally known that Norfolk never actually joined the EU in the first place and so Brexit is an established fact here. You can still find local shops that will take £sd and everything is measured in feet and inches.

 

Likewise we are relatively untroubled by new technology, industry (of any kind), electricity, motorways, brick buildings and so on. But If you are into tractors, land rovers (series 1) or caravans this is the definately the place for you. Or Carrots. We have lots of carrots. And turnips. Usually spread over the A47.

 

One day i plan to reapply for my English citizenship and head back up to Lancs, if they will have me. 

Any ideas regarding the crash from 1:29 in the following video, Peter (Wilson Fittipaldi, Argentinian GP 1975)?

https://www.youtube....h?v=P_itOeTo4D0

Was that one in the engine bay  rather than in the tanks themselves ? It started out as quite a small fire from the reports , maybe even oil rather than fuel,  the video doesnt capture this. Ricardo (Divilia) used to lurk around here, i could see if he can answer it on facebook? The TV feed is also on YT and that shows even less.

Norfolk is the home of Wymondham School, the only one that beat us at rugby in 21 years - My traitorous sister now lives there...

Was that one in the engine bay  rather than in the tanks themselves ? It started out as quite a small fire from the reports , maybe even oil rather than fuel,  the video doesnt capture this. Ricardo (Divilia) used to lurk around here, i could see if he can answer it on facebook? The TV feed is also on YT and that shows even less.

Cheers Peter.  I agree that the smoke makes it appear to be a oil fire.

Only because i am from Lancashire

Where I grew up, everyone was from Lancashire.

 

My dad was the charming lad on the horse drawn milk cart who won my mother's heart when the horse had the sense to go home.

Funny that, everyone i knew was from Lancashire as well, before 1976 that is. ... You're not that spotty kid with halitocis that set fire to himself in the Chemistry Lab in 1971 are you?

Funny that, everyone i knew was from Lancashire as well, before 1976 that is. ... You're not that spotty kid with halitocis that set fire to himself in the Chemistry Lab in 1971 are you?

It is embarrassing to admit childhood misdeeds.

 

I blew up the chemistry labs as a kid. I put a blank cartridge on top of a bunsen burner -- and everyone couldn't hear for a week. I did everything wrong. I'm all right.

 

 

 There is no point for a chemistry lab unless to blow it up.

It was usually the staff that blew it up at my place, and not always by accident.

 

Our week's deafness was caused by  Mr. Topping demonstrating how rockets work with a squeazy bottle and magnesium crystals. He demonstrated how they blow up on the launch pad instead.

 

One of his colleagues got the mix right and made a perfect launch, V1 style, horizontally on a ramp, but forgot to close the classroom door and the missile parted the deputy head's carefully brylecreemed hair as he strode purposefully up the Sixth Form Stairs..

 

Mr Oliver, who sounded exactly like Dr Cameron from Dr Finlay's casebook caused  mass evacuation ("everybody out....") by confusing potassium and magnesium ("Let's try a wee bit more....") The result was akin to  scene filmed on the Somme of a dazed platoon emerging from a gas attack.

 

etc etc.

 

Health and Safety 70's style - it's a miracle that any of us survived to adulthood.

Edited by PeterElleray, 22 May 2017 - 21:49.

It was still like that in the '80's at my school Peter, the Science teacher in my middle school blew up some glass beakers when demonstrating the uses of magnesium crystals. We were picking glass shards out of our hair (and some unlucky kids out of their flesh) for the rest of the day. The thing is, he had done the same thing to a class earlier in the day already!

Going back to cpbell's comment about 'the point is that, to reduce risk as effectively and efficiently as possible, one needs to understand the main risk factors and concentrate on addressing them first', that's part of what I do within my job in a road car parts manufacturer - it's called an FMEA for those who don't know (a Failure Mode Effects Analysis). Without teaching anyone to suck eggs on here as I'm sure a few have used or heard about them, it is basically a document that attempts to list every possible problem that could arise with your part, what the cause of that problem could be, what the effect of that problem could be, how severe it could be, how likely it is to happen, and how the design of your part will prevent that from happening, through prevention and detection methods. I say 'attempts to list' as it has to be generated by brainstorming and referring to an existing similar part, and no matter how many potential problems / scenarios you think you have covered, there will always be more out there waiting to happen.

To give an idea of the size of the document, for a simple mechanism such as a bonnet release cable, the last document we put together was over 50 pages long... If such a thing is used in racing car design (is it?), I think you could quite easily exceed the maximum number of blank cells in MS Excel!

If "such a thing" were used in racing, do you think it would have taken more than half a century to design simple devices such as a rollover bar? Or, perhaps the brainstorming session took so long to determine the probability of a scenario in which a racing car could possibly flip.

I say 'attempts to list' as it has to be generated by brainstorming and referring to an existing similar part, and no matter how many potential problems / scenarios you think you have covered, there will always be more out there waiting to happen.

The same consideration applies to PRINCE, the project management methodology. In PRINCE, project contributors write a risk assessment document. But if the team is doing something for the first time, there is no perfect way to assess risk.

 

If "such a thing" were used in racing, do you think it would have taken more than half a century to design simple devices such as a rollover bar? 

 

A rollover bar raises the height of the centre of gravity and creates drag (mostly). Sometimes you have to tell racing engineers to do the sensible thing.

 

 

A rollover bar raises the height of the centre of gravity and creates drag (mostly). Sometimes you have to tell racing engineers to do the sensible thing.

 

Go on then, tell us what we're doing wrong with the design of the roll over 'hoops' .....

Risk assesment....

 

Always done on an informal, common sense discussion basis, before the concept of a spreadsheet had been invented. Seemed to work rather well that way! God only knows what goes on inside a modern F1 team, do they have 'risk assesment', NHS style, i have no idea ?

 

My own approach was basically to study the history, analyse what had gone wrong (or right) and try and learn from it. The regulations would always guide you and there was always the conflict between doing more than the bare minimum and adding weight, bulk, and complication and slowing the car down. 

Edited by PeterElleray, 23 May 2017 - 17:45.

In modern F1 design, the job of risk assessment is (or can be) factored into the computer software that help design the vehicle hardware.

But it's not infallible & common sense is still needed to keep the tick box fanatics in check. 

Is that from personal experience ?

Risk assesment....

 

Always done on an informal, common sense discussion basis,

 

 

 

Yes,

 

and what you say can still apply. I'm on your side - there's a lot to be said for it. But instead of testing the theories for the first time on track, many things can now be simulated & verified by our masters, the computer.

In some ways better but it can lead to 'lazy design', knowing (or hoping) the computer will pick up anything missed.

 

One example of the more useful forms of RA was when the first KERS cars were introduced. A great deal of effort was put in studying how the mechanics, marshals & drivers would deal with potentially lethal electrical mishaps. Very sensible one would argue.

 

(In those early days, I do remember the pit crew being issued with a wooden stick that had a plastic hook attached to one end, so they could keep clear of a potentially 'live' car while hooking & pulling the electrical cut out.

I expect there are more elegant method these days...)

Interesting, thanks. 

 

Your point on lazy design is well taken and i expect we both have personal experience of that. The phrase 'designed by computer' always strikes terror, i would prefer 'Designed by a skilled and experinenced engineer using a computer instead of a pencil and calculator'.

Edited by PeterElleray, 24 May 2017 - 09:21.

Go on then, tell us what we're doing wrong with the design of the roll over 'hoops' .....

If we go back to the 1960s when Costin and Phipps wrote "Racing and Sports Car Chassis Design", rollover bars and hoops barely earned a mention. If I needed to remind myself how stresses in suspensions were calculated, I'd have a look at Costin & Phipps; for rollover hoops, I'd have to go to first principles (i.e. interpret and copy another period design).

 

My criticism was addressed to rule makers who did not develop a debate about rollover safety rather than designers interpreting vague rules.

 

My own approach was basically to study the history...

 

When discussing workplace risk assessment with a non-idiot boss, I once asked what he had learned from the "accident book". He squirmed because it had not occurred to him; his assessment was theoretical.

 

You have to get everyone talking in a no-blame environment (pub) if you expect to hear what nearly went badly wrong.

Or work in the industry because there is so much movement of staff...

*Bump*

 

I have to confess that I may be conspicuous by my long absence from TNF, but the subject of the 1973 deformable structures rules still leaves me with questions as I get to study F1 cars of the era close up at a Masters event or two each year these days.

 

Apart from the fact that the geometry of the deformable structures came with many different interpretations, it strikes me that quite a few cars had detachable, rather than integral with the chassis, deformable structures. Some of these appear to have been attached with just a few bolts.  I haven't been able to find any wording in the regulations regarding the attachment of the structures - yet some appear to me to have been fairly easy to knock off in an accident.

 

Thoughts, anyone?

I remember reading in the magazines of the time when describing the Brabham BT43 first and the BT44 the following year, the writers noted the designer's interpretation of the minimum width of the deformable structure. As the chassis section was trapezoidal, only at the base was that width respected. Fortunately, Reutemann, Pace, Robarts, Von Oppel, Watson and several others who drove those great cars never tested that deformable structure. I believe that in the eighties a top driver said more or less this: "I would like to know if the designers of these cars would let their children drive them...".

If "such a thing" were used in racing, do you think it would have taken more than half a century to design simple devices such as a rollover bar? Or, perhaps the brainstorming session took so long to determine the probability of a scenario in which a racing car could possibly flip.

So now they have a half assed rollbar called a halo.

So now they have a half assed rollbar called a halo.

 

The Surtees family might think otherwise, of course...

The Surtees family might think otherwise, of course...

I'd guess that Romain Grosjean does too.

I remember reading in the magazines of the time when describing the Brabham BT43 first and the BT44 the following year, the writers noted the designer's interpretation of the minimum width of the deformable structure. As the chassis section was trapezoidal, only at the base was that width respected. Fortunately, Reutemann, Pace, Robarts, Von Oppel, Watson and several others who drove those great cars never tested that deformable structure.

 

Claudio, I think you meant BT42 (BT43 was the one-off F5000 car).

 

Although they were massive, mostly frontal impacts, neither Watson's BT42 at Brands Hatch nor  DeAdamich's BT42 at Silverstone in 1973 leaked fuel or caught fire, which was a Godsend, as both required lengthy extraction processes with their conscious input to get them out of the wreckage. Watson's car was, however, pretty badly damaged in the right-hand fuel tank area, so the deformable structure there may have made a difference.

 

That Sheckter-precipitated pile-up at Silverstone in 73 did, IMO, vindicate the usefulness of the deformable structures. All cars were with full tanks but no bag tanks were ruptured. On the M23 the deformable structures protected not only the fuel tanks, but I think Jody was lucky the M23 had those integral radiator air ducts to protect his body, too. I've seen photos of the carnage where you can actually see that the full right-hand fuel bag popped off the double-skin-with-foam-in-the-middle off Beltoise's BRM P160. Fuel doesn't compress - but the bag did not rupture. Had the P160 not had the add-on-deformable structure, the wheel that hit the tank might have ruptured the bag.

 

Speaking of BRMs: Did the P201 have the same deformable structure concept as the BT42 and BT44 Brabhams - and what about the Surtees TS19 and TS20?

 

Further to BRMs: Were fuel bags ruptured in the Ickx-Oliver shunt at Jarama in 1970 and on Reggazoni's BRM P160 at Kyalami in 1973, or was it various couplings that were severed as was often the case?

Edited by Bonde, 12 February 2024 - 15:36.