Features: McLaren Celebrates 30 Years Of Carbon Fibre

MP4-1 chassis tub with 12C monocell and rolling chassis

An event celebrating 30 years of carbon fibre may not sound like this season's hot ticket, but here at PH HQ we'll happily attend the opening of an envelope. Especially if that envelope arrives bearing the Woking postmark and a McLaren logo.

McLaren party planners have much more to offer than tea and (composite?) sandwiches, of course, and their event at Silverstone to mark 30 years since the introduction of the very first carbon fibre chassis F1 car featured guest appearances by McLaren 'hall of fame' legends John Watson and John Barnard. Oh, and a trio of 'over far too quickly' laps of the Stowe circuit at the wheel of the new MP4 12C supercar...

John Barnard - MP4 designer

McLaren's MP4-1 made its racing debut 30 years ago this weekend, and went on to change the world. Speaking at the event the car's designer John Barnard recalled those times:

"It was a gamble, but ground effect was the key to performance. That meant making the tunnels under the car as big as you could, which meant we had to make the chassis as small as we could. To get the stiffness back we needed a new material.

"Up to then carbon fibre had limited uses in racing, typically it was strips used to stiffen wing-ends, but we couldn't use it for aero surfaces or body panels as we didn't have capacity to tool up the moulds.

"Once I'd got the basic MP4 design drawings, Ron Dennis and I approached companies in the UK known to be producing carbon products - helicopter blades, and that sort of thing - but their attitude was always 'that's way too ambitious'. We had a connection to US company Hercules through a racing contact, and their attitude was 180 degrees. They said 'hey, you want to do a racing car, that's interesting!'

"Hercules built rocket parts for NASA, but saw our car as way to move carbon technology forward and ended up building the first chassis for free.

"The very first one was conservative. It was two and a half times stiffer than a similar aluminium chassis, but hadn't saved enough weight - so we took material out for the second one.

"People were sceptical, saying things like 'it will shatter if a mechanic drops a spanner on it', or 'it will turn into a cloud of black dust in an accident'. But it proved itself in a fairly short space of time in a big accident at Monza that year."

John Watson with 1981 MP4

That big accident came courtesy of McLaren F1 team driver John Watson, who took up the story himself:

"I never really thought of myself as a test pilot. I'd seen the construction of the tub, and I'd seen the material used on space shuttle booster rockets, but in racing it had only ever been used as a replacement for metal parts, usually pop-riveted on.

"My team mate Andrea de Cesaris had something like 17 accidents in 1981, and I only had one but people remember it because it was spectacular!

"Coming out of Lesmo at Monza I felt the front running wide and instead of backing off I thought I'd drive through it, but ended up on the kerb and went into what felt like a long looping spin. I went backwards into the tyre barrier where there was a post, and watched what I thought was somebody else's engine slide across the track in front of me. When I got out, I realised that was my engine...

"I just got out and thought: 'Ron's going to have something to say about this, and John (Barnard) is going to be furious'. I had no injuries at all apart from a bit of stiffness in the shoulder, and the tub was completely undamaged apart from the engine mounts being ripped out. Four days later we were back testing at Donington."

A true carbon fibre pioneer

Having 'proved the concept' of a carbon fibre chassis in such spectacular fashion, and proved the car's race-winning potential (not to mention his own) by clinching victory in the 1981 GP at Silverstone, it seemed right that John Watson should give the material another try out in the old firm's new supercar at Silverstone. Having driven the 12C for the first time 'Wattie' appeared impressed:

"It's amazing, I was truly gobsmacked by the acceleration between 80mph and 130mph, which felt as quick as my F1 car. I knew it would be impressive, but not to this level."

Since those early days of carbon fibre in F1, McLaren has led the field with the material in road cars too - the McLaren F1 being the first road car to use a carbon chassis, and the SLR being the most commercially successful carbon-chassis car to date, with 2000 built.

McLaren 12C - 30 years in the making

The new 12C is the latest stage in that story, and brings innovative new production methods to the auto industry that allows the 12C's carbon monocell chassis tub to be produced in 4 hours in a semi-automated process. Compare that to the McLaren F1 chassis build that took 3000 hours, and used a lot of highly skilled labour.

Claudio Santoni is McLaren Automotive's latest carbon fibre 'guru', and he outlined some of the factors affecting the industry today.

"The driving factor, just like in racing, is to use carbon fibre to lose weight. The costs are coming down and there's a supply chain developing that's dedicated to automotive producers."

But with big aerospace firms like Boeing and Airbus getting in on the act, there's also increasing competition for the world's currently limited carbon fibre output - a fact that has led McLaren to sign a 15 year advance contract with its supplier to make sure it has all the material it needs for anticipated production.

Carbon monocells take 4hrs to build...

Claudio also shed a bit more light on the 12C's monocell production process, which involves laying up a 40-tonne, six-part steel mould tool with pre-formed carbon pieces, and then injecting it with resin under pressure prior to 'cooking'.

Two hours later a robot picks the monocell out of the mould and it is transferred to a five axis CNC machine for finishing the suspension pick-ups and frame and engine attachments.

"One of our big concerns was dimensional accuracy," says Claudio, "but having already made 300 monocells we're getting a corner-to-corner tolerance of less than 1mm. One of the seat mounts is two tenths of a millimetre out, but it's consistent every time!" After machining, the monocells are load tested by being subjected to twist forces on a jig to ensure they're fit for purpose.

...a far cry from the 1980s

In future, McLaren says the next big advance for carbon fibre will be automation of the mould lay-up process, essential to get costs down for serious mass production beyond the few thousand cars that can be built annually using the processes introduced for the 12C.

McLaren Automotive is pushing hard to make sure it stays at the leading edge of carbon fibre technology, but as the material becomes more widespread across the industry the company is going to have to fight hard to stay ahead of the game. Having been 'the' carbon fibre pioneer for the material's first 30 years in the automotive industry, if nothing else there's a hard-won reputation at stake.

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