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Ferrari 126C2 and 'true' monocoque


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#1 bartez1000

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Posted 02 January 2014 - 09:13

Hi!

Ferrari 126C2 designed by Harvey Postlethwaite is sometimes said to have first "true monocoque" or "genuine monocoque" produced by Ferrari. What does it mean?  What was fake in 126CK's monocoque, and what was true in C2's? What was the last "fake monocoque" car that raced in World Championship? Thanks for any help.



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#2 D-Type

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Posted 02 January 2014 - 10:05

"Fake monocoque" is the wrong word.  I think what you mean is "Incomplete monocoque" or "semi-monocoque".


Edited by D-Type, 02 January 2014 - 11:03.


#3 scarbs

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Posted 02 January 2014 - 10:05

Before the cut, folded and bonded 126C2 moncooque, Ferrari chassis were steel space frames with riveted aluminium panels, much like a Lotus 7 chassis.  



#4 Tim Murray

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Posted 02 January 2014 - 10:39

This earlier thread may be of interest:

 

The first monocoque F1

 

It contains this very good analysis of the Ferrari method of chassis construction:
 

A very popular compromise that (almost!) combines the advantages of the space frame with those of the stressed skin structure used in some lesser formulae and sports racing classes was, and is, the ‘stress panelled space frame’ – i.e. a welded tubular steel ‘skeleton’ (bulkheads and longerons) with blind-riveted sheet metal skins providing the shear resistance normally provided by the diagonals of a truss structure. This type of construction invariably provides some structurally redundant material, so it will be heavier than a ‘pure’ stressed skin design, because more of the material is not located right at the surface where it does most good, but it often provides a more crashworthy design, and is also typically less prone to fatigue failure than ‘pure’ aluminium skin designs –perhaps this is why this method is still quite popular. ‘Tis also often dubbed ‘Ferrari aero style’ chassis, BTW.


My understanding is that the first pure Ferrari monocoque was the chassis built by John Thompson for the 312B3 in 1973. Ferrari then went back to their old technique until 1982.



#5 chr1s

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Posted 02 January 2014 - 22:41

Just to confuse the issue a little,  I found this passage about the 1976 British Grand Prix in the book "Four seasons at Ferrari" by Alan Henry :-  there were two revised chassis built from aluminium alloy without the traditional support from the latticework of small tubing around which the earlier monocoques had been manufactured.... 

 

    One of these new chassis was 028, which was written off two weeks later at the Nurburgring and in Laudas' book, (For the record) he says this:- "In this case the steel frame which reinforces the aluminium saved the day" which appears to contradict the passage in Henrys book. Of course it is possible that in the aftermath of his accident Lauda had forgotten about the "revised" chassis. Ferrari went on to build three more 312T2s but it's not clear wether they reverted to the steel frame construction on these later chassis? Also, apart from the above,  I have'nt  found any other evidence to confirm that chassis 028 was a full monocoque.



#6 guiporsche

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Posted 22 February 2018 - 21:44

Apologies for resurrecting this thread, but I stumbled upon it after trying to find an answer to my doubts by using the forum's search question.

 

And my doubts regard:

a) how exactly did Harvey Postlethwaite get the job at Maranello;

b) who in Ferrari came up with the decision to go to the market for a suitable engineer/designer;

and c) if there were other candidates besides Harvey to the job of bringing some added value on chassis technology?

 

From Forghieri's bio (and although he uses the 'we' as 'we the Ferrari team'), it seems evident to me that he was chosen by Furia himself on the basis of his experience with composite materials.

This would make sense, as Harvey was without a job while Forghieri did talk English and would be the most capable of headhunting British personnel (not to say that hierarchically such a choice would have to be made by him, to then be 'signed off' by Enzo Ferrari). 

 

Alan Henry on 'Ferrari, the Grand Prix Cars' (& Wikipedia too btw), on the other hand, states that he was selected by Enzo Ferrari himself, who allegedly had lost confidence on his men's ability to build decent chassis. The implied idea, IMO, was that Forghieri had nothing to do it. 

Every candidate to major positions at the Reparto Corse was certainly interviewed by the Old Man and hence personally chosen by him, but did he really narrowed the pool of available candidates himself, and most importantly, took the decision that a 'foreign element' was needed by himself?

 

More apologies in advance if this turns out to have already been asnwered here before.


Edited by guiporsche, 22 February 2018 - 21:45.


#7 Arjan de Roos

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Posted 23 February 2018 - 08:35

Ferrari (Enzo) was always on the look out for new technical staff. Forghieri is always mentioned as the great constructor of all competition cars from 1962 up to 1982ish, yet he worked with a strong team (Busi, Caliri, Rocchi to name just a few). He personally gave the call, also as he understood the Turbo project needed specialist reinforcements. Forghieri had to concentrate on the new 154C engine and deliver similar power as the BMW.

 

Ferrari was never shy to look outside of Italy, he already in the 50's ventured to find talent from over the border to help him set up Automobili. His special respect for English designers and constructors was formed in the 20/30sh. He worked with Rudge-Whitworth (also as a dealer) and his alliance with Vandervell is well known. Ferrari liked many English constructors and attempted to lure them to Maranello. For instance Gordon Murray received invitations every year. Postlethwaite was free from Fittipaldi and since they needed solutions for the chassis. Ferrari as a team had an eye on him early on, also as the Wolf was tested at Maranello. Not only Jody was of interest for the man to see in his back yard at that time. 

Likely also Piero advised his father, and a thrift was formed with Piero and Dottore Harvey on once side and Forghieri on the other. Later on leading to Barnard joining.



#8 guiporsche

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Posted 23 February 2018 - 12:04

Cheers Arjan, thank you for taking the time to answer!

I think that pretty much settles it. It's a whole topic in itself that would deserve some thorough attention. I completely forgot about Piero's increasing influence as he attempted to get a hold in the direction of the team. Which would then bring us to Piccinini and his shadowy and still relatively unknown - in it details - actions and goals...

 

Incidentally, after reading your post I recalled that in a recent podcast published by Motorsport Magazine, Murray did refer to invites from Ferrari (quite justified, as we all know he was hot property, and he seemed to have good relations with Forghieri). That would have been quite a combo. 

Btw, it's also a bit of a shame how little is known about the lives of Ferrari engineers besides Forghieri - either because of tragic reasons or out of a desire for anonimate.

Though, Antonio Tomaini just published his autobiography via driveexperience.it (but I have no idea about its actual contents).

 

Well, I'll stop rambling now, thank you once again!


Edited by guiporsche, 23 February 2018 - 12:05.


#9 Charlieman

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Posted 23 February 2018 - 15:26

Just to confuse the issue a little,  I found this passage about the 1976 British Grand Prix in the book "Four seasons at Ferrari" by Alan Henry :-  there were two revised chassis built from aluminium alloy without the traditional support from the latticework of small tubing around which the earlier monocoques had been manufactured.... 

Was the latticework of tubes a stress construction or a frame jig to which sheet aluminium was attached? 

 

Owing to photos of the front bulkhead of the Ferrari 312T2, we know that the car was very well conceived. The bulkhead is a big bit of metal designed to accept any sort of load.



#10 Bonde

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Posted 24 February 2018 - 01:46

I also remember being puzzled by that remark of Henry's in "Four seasons at Ferrari" - I don't ever recall seeing any images that would indicate any T2 tubs  being different from each other or with signs of being without the tubular substructure. The difference in detail parts design and manufacture would be quite different if Henry's statement is correct. Does anyone around here know anything about this?



#11 Bonde

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Posted 08 September 2019 - 21:23

Bump!

 

....still looking for evidence that there were T2 chassis both with ("aero") and without ("true" monocoque) inner tubular framework.



#12 Regazzoni

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Posted 08 September 2019 - 22:10

There is no evidence to be found. There were no T-series with chassis in "true" monocoque construction.

 

The T2, and all the T-series, had the traditional Ferrari construction, panels stiffened by the framework. The 028 wasn't a true monocoque, Lauda survived the quite violent impact also thanks to the chassis construction (and the relatively favourable angle of impact). With a true monocoque he might have had his feet/legs seriously injured too.



#13 ibsenop

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Posted 09 September 2019 - 22:49

Ferrari 126 C chassis by Giorgio Piola
Ferrari-126-C-chassis-by-Giorgio-Piola.j
 
Ferrari 312 T chassis by Giorgio Piola
Ferrari-312-T-chassis-by-Giorgio-Piola.j
 
Fittipaldi F8 honeycomb chassis (designer Harvey Postlethwaite) by Giorgio Piola
Fittipaldi-F8-C-chassis-by-Giorgio-Piola
Ferrari 126 C2 chassis by Giorgio Piola
Ferrari-126-C2-chassis-by-Giorgio-Piola.

Edited by ibsenop, 10 September 2019 - 10:12.


#14 Regazzoni

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Posted 10 September 2019 - 10:14

Those cutaways show very clearly the technical culture of the designer that produced them – a mechanical engineer, I could add “classically educated” (“scienza delle costruzioni”, for those who know what I am talking about), not with an aeronautical structures background and as far away as possible from a self-taught “engineer”. That is Forghieri’s hand and pencil.

 

When they had to change – need for narrow chassis and high stiffness, both requirements result of the ground effect revolution – they called Postlethwaite, who got on famously with Furia, to produce the 126C2 chassis, which was pretty much the same as that Fittipaldi – two honeycombed shells joined along the longitudinal symmetry axis of the car.

EDIT: Missed Ibsen's edit!


Edited by Regazzoni, 10 September 2019 - 10:17.


#15 chr1s

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Posted 10 September 2019 - 20:39

This is from Jenks  Motorsport report on the 1976 British Grand Prix, :- Niki Lauda had a brand new Ferrari, numbered 028 in the 312T series. It did not differ from his previous car, 026 though the monocoque was a fraction lighter, having been constructed in a similar vein to 027" (First used at Monaco)    

 

In his Monaco report Jenks merely says :- Ferrari produced a brand new 312T2 car, 027 in the series and this was given to Regazzoni. His chief mechanic (presumably Borsari?) said  "its a good car, why change it?" The configuration of the T2 remains the same. Note.

 

Jenks goes into no more detail than that, but the fact that he says the monocoque was only a fraction lighter kind of implies that it was not fundamentally different in construction,  if all the steal structure had been deleted, it would surely have been significantly lighter? Also, I like to think Jenks nature was such that a change that significant would not have escaped his notice and would have been reported. So maybe it was Alan Henry who mistaken?



#16 Charlieman

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Posted 13 September 2019 - 11:20

I have been making notes about Ferrari chassis design philosophy since it was raised in a thread several years ago. It is as clear as mud to me, so be gentle in response to my mistakes.

 

The Hans Tanner/Doug Nye Ferrari book and Doug's History of the Grand Prix Car 1966-1985 tell the same story about the Ferrari 312T and T2. The 312T was a logical development of the 312B3 but a clean sheet design, obviously, owing to the transverse gearbox and revised rear suspension. The main difference is at the front where a matrix of tubes on the 312B3 is replaced by a more elegant structure. The front suspension hangs off a magnesium casting with short levers and rockers actuating the springs and anti-rollbar. Development of the 312T began in 1974 and continued into the 1976 season. Chassis numbers overlap with the 312B3, so the first two are #018 and #021.

 

Nye, History of GP Car, describes the inner framework as steel "strip and angle" in the body text. A caption for a Tony Matthews cutaway describes a "square section" inner frame.

 

The 312T2 is less of a clean sheet design but it was intended to address regulation changes in 1976. Sadly it was never fully developed and was unable to maximise that year's Goodyear tyres.

 

Journalists give a consistent record of the first appearances of the 312T2:
#025 -- press display in autumn 1975 with first track event at Race of Champions, 1976.

#026 -- Spanish GP, 1976.

#027 -- Monaco GP, 1976.

#028 -- British GP, 1976.

#029/030/031 -- all raced in 1977 alongside earlier cars.

 

#025 re-introduced the idea of De Dion rear suspension -- in testing at least. The front bulkhead and suspension design was very similar to the 312T but the car dimensions changed. Overall car weight was reduced by 20+ kg. Tanner/Nye Ferrari book states "aluminium U-piece internal framing replaced the steel reinforcement of its Maranello-built predecessors". In the History of GP Car, Nye writes about an aluminium tube frame "while a true monocoque version was on the way".

 

For #026, the Tanner/Nye Ferrari book says that there was no U-piece internal frame. #027 and #028 are also described as pure monocoques.

 

In the Autocar race report for the 1976 Belgian GP,  Peter Windsor describes #026 as a pure monocoque. He explicitly states that the U-pieces of the original chassis are absent. Windsor added that strikes at the factory had delayed build of a third 312T2 chassis. [Nye and Windsor both use the unusual description "U-piece".]

 

#028 was the car in which Lauda crashed at the Nurburgring, which was a pure monocoque according to British descriptions.



#17 chr1s

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Posted 13 September 2019 - 20:20

I have been making notes about Ferrari chassis design philosophy since it was raised in a thread several years ago. It is as clear as mud to me, so be gentle in response to my mistakes.

 

The Hans Tanner/Doug Nye Ferrari book and Doug's History of the Grand Prix Car 1966-1985 tell the same story about the Ferrari 312T and T2. The 312T was a logical development of the 312B3 but a clean sheet design, obviously, owing to the transverse gearbox and revised rear suspension. The main difference is at the front where a matrix of tubes on the 312B3 is replaced by a more elegant structure. The front suspension hangs off a magnesium casting with short levers and rockers actuating the springs and anti-rollbar. Development of the 312T began in 1974 and continued into the 1976 season. Chassis numbers overlap with the 312B3, so the first two are #018 and #021.

 

Nye, History of GP Car, describes the inner framework as steel "strip and angle" in the body text. A caption for a Tony Matthews cutaway describes a "square section" inner frame.

 

The 312T2 is less of a clean sheet design but it was intended to address regulation changes in 1976. Sadly it was never fully developed and was unable to maximise that year's Goodyear tyres.

 

Journalists give a consistent record of the first appearances of the 312T2:
#025 -- press display in autumn 1975 with first track event at Race of Champions, 1976.

#026 -- Spanish GP, 1976.

#027 -- Monaco GP, 1976.

#028 -- British GP, 1976.

#029/030/031 -- all raced in 1977 alongside earlier cars.

 

#025 re-introduced the idea of De Dion rear suspension -- in testing at least. The front bulkhead and suspension design was very similar to the 312T but the car dimensions changed. Overall car weight was reduced by 20+ kg. Tanner/Nye Ferrari book states "aluminium U-piece internal framing replaced the steel reinforcement of its Maranello-built predecessors". In the History of GP Car, Nye writes about an aluminium tube frame "while a true monocoque version was on the way".

 

For #026, the Tanner/Nye Ferrari book says that there was no U-piece internal frame. #027 and #028 are also described as pure monocoques.

 

In the Autocar race report for the 1976 Belgian GP,  Peter Windsor describes #026 as a pure monocoque. He explicitly states that the U-pieces of the original chassis are absent. Windsor added that strikes at the factory had delayed build of a third 312T2 chassis. [Nye and Windsor both use the unusual description "U-piece".]

 

#028 was the car in which Lauda crashed at the Nurburgring, which was a pure monocoque according to British descriptions.

So maybe it was Lauda who was mistaken then?



#18 Ray Bell

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Posted 13 September 2019 - 23:29

How much weight would the tubes (or 'strip and angle') have contributed to overall monocoque weight?

Very little, I'd think, and not a 'significant' amount.

Remember, too, that these are pieces which, in the main, would not have been visible...

#19 Charlieman

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Posted Yesterday, 11:45

How much weight would the tubes (or 'strip and angle') have contributed to overall monocoque weight?

Very little, I'd think, and not a 'significant' amount.

Remember, too, that these are pieces which, in the main, would not have been visible...

It depends on what they were, hence my query on 23 Feb 2018 above. If the inner frame was essentially a jig for the monocoque panels, it could be light and of negligible structural value. 

 

I'll stick just to the 3 litre Ferrari F1 designs. The 1966 Ferrari 312 (V12) is a semi-monocoque and the tubular structure is evident in contemporary cutaway drawings. The concept continues with the 312B series (Flat 12) although with different engine mounting structures. The 312B3 uses the engine as a stressed member, via a magnesium plate (or casting?) forming the rear bulkhead. Chassis #010/011/012 are pure monocoques built at TC Prototypes (John Thompson). Later Maranello-built 312B3s reverted to the traditional tubular structure.

 

As I wrote earlier, the 312T is inspired by the 312B3, but the significance of the inner frame seems to have changed.

 

With 312T2 #025, with inner frame made from aluminium "U-pieces", it sounds like an assembly jig, mostly.



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#20 Regazzoni

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Posted Yesterday, 18:25

The inner frame had a load-carrying function.

 

Instead to rely on journalists' reports who know next to nothing about structures, people should look at the actual chassis, how they were made, shape, outline etc and then try to figure out whether they would have been suitable to be turned into "monocoques", to begin with. Then perhaps also ask why would Forghieri change completely chassis construction - without apparently changing at all the outline - on a car, the 028 in particular, for the championship leader in the middle of the season (British GP). A construction method he's always declined to use. EDIT: for a reason.


Edited by Regazzoni, Yesterday, 18:37.


#21 Regazzoni

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Posted Yesterday, 18:35

As I wrote earlier, the 312T is inspired by the 312B3, but the significance of the inner frame seems to have changed.

How? Where did you get that change of "significance"?



#22 Charlieman

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Posted Yesterday, 19:37

Instead to rely on journalists' reports who know next to nothing about structures...

I studied Mechanical Engineering as a degree. I, too, find it difficult to interpret press racing reports. I try to understand documents from an engineering and historical perspective.

 

My instinct regarding the expression "U-piece" is that it was expressed by a Ferrari person. A British engineer would have said U-section or channel section. 

 

...people should look at the actual chassis, how they were made, shape, outline etc and then try to figure out whether they would have been suitable to be turned into "monocoques", to begin with. Then perhaps also ask why would Forghieri change completely chassis construction - without apparently changing at all the outline - on a car, the 028 in particular...

 

We agree: we need a collection of Ferrari F1 chassis and 3D imaging gear to see how the cars were made.

 

We don't need to think much about how a 312B3 might be built as a pure monocoque; the first three were built in England; job done.

 

So when it is suggested that 312T2 #026 and later were pure monocoques, it is not a ridiculous idea. It is how Ferrari were learning to build chassis.

 

Is it significant that Lauda crashed in #028, the third pure monocoque? 



#23 Charlieman

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Posted Yesterday, 19:47

How? Where did you get that change of "significance"?

The 312T chassis uses a big transverse lump of metal to manage front suspension loads. The load points are into a metal lump rather than a tube matrix.



#24 Bonde

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Posted Today, 18:34

Gents,

 

The evidence that there were or are two styles of 312T2 chassis construction seems to me to be lacking, so I wonder where the notion actually stems from? As far as I can tell, 312B, 312B2, 312T through 312T5, and even the earliest incarnations of 126C, all had the Italian-style chassis with thin, welded steel tubular (or open section) corner members under sheet aluminium panels blind-riveted on. Only 312B3 appears to have been essentially a British (John Thompson) style 'true' monocoque. Having said all that, I have only ever had the opportunity to study 312B up close, so I can be wrong.

 

To my eye, photos of the damaged Nürburgring chassis #028 seem to indicate thin steel framing members under the aluminium sheeting. Off-hand, the damage looks different than what one would expect of an equivalent all-sheet aluminium tub.  In a post on aluminium chassis structures many moons ago I also speculated, like Regazzoni posted here, that Lauda's injuries could have been worse or fatal had he not been protected by those two wide and voluminous structural boxes for the fuel tanks, which, alas failed to protect the fuel bags.

 

On the subject of lateral protection structures, I've noticed that on a lot of different mid-1970s chassis they appear to have been detachable, being bolted on at a few discrete locations. It appears that these add-on deformable structures were torn off in Lauda's accident, whereas on, say a McLaren M23 or a Shadow DN5, they formed an integral part of the tub structure.

 

The regulations stipulated that both the skins of these sandwich  structures had to be of a minimum of 1,5 mm thickness, and at least one of them had to be of aluminium alloy, which makes me wonder why some designers opted not to incorporate the deformable structures in the main chassis structure on new designs. Bolt-on deformable structures (unless the bolts were very closely spaced) would entail a [dead] weight penalty. Even some of those that added deformable structures to existing designs, Lotus T72 and BRM P160 come to mind, attached the deformable structures permanently, with closely-spaced fasteners and let the polyurethane foam form a large surface area bond between the deformable structure aluminium inner skin (the existing tub's outer skin) and the new outer skin, typically of GRP.

 

So - did the 312T2 have double-skinned deformable structures with flat 1,5 alumnium inner skins and those shapely, moulded GRP compound curvature outer skins that were simply bolted on to the chassis proper with a few bolts? What was the wording in the regulations regarding the attachment of the deformable structures?