Intelligent A-pillar

WARNING: Long post!!!

I never thought that I would say that active structures makes sense, as I still don’t think that an active bonnet makes a big difference if a car collides with a young child, but in this case I will make an exception.

Autoliv in cooperation with Saab is developing an expandable A-pillar, so reports the Automotive Engineering International magazine in its printed version. The full article can also be found here.

Folded A-pillar (simulation)

A expandable A-pillar is just a pillar that expands to its full size only if needed, but remains thin for almost its complete life.

Expanded A-pillar (simulation)

Why is this development so interesting?

There is a cynical adage in the motor industry that driver visibility is essential because “people like to see what they are going to hit.”

Or in other words, a thin A-pillar, like in the classic 900, increases the front visibility by a big amount, but it is too fragile to get best notes on the different crash test (EuroNCAP, NHTSA,…). The solution, a thin pillar that gets thick when needed.

Despite huge advances in primary and secondary visibility, there continues to be constraints on further improvement caused by the often conflicting requirements of vehicle design and structural integrity, including the thickness of the A-pillar—a vital aspect of crashworthiness. But now, Autoliv has come up with a potential solution: an expandable pillar.

I’ve heard sometimes that people like this impression of sitting in a tank when they sit or drive a new 9-5, it gives them a certain safety feeling. On the other side when I drive fast on a curvy road, there are too many moments (left curves) were the whole road in front of me is covered by the A-pillar of my OG9-5, impeding me to see any incoming cars, thus making an enjoyable ride too risky, and although my car is capable of more I end driving like an old man.

One solution to solve that could be to use very thick high strength steel for the A-pillar, but this would increase the weight and move the centre of gravity up and to the front, and both things are not good.

Ten years ago Volvo presented the Volvo SCC or Safety Concept Car.

Volvo SCC

It was a proposition to solve this problem, but the final car, the C30, never had this kind of A-pillar.

So Autoliv is now working with Saab for a modern solution using its experience in airbag design and manufacture.

Autoliv is working on the expandable A-pillar solution with Saab. It allows the pillar to be slimmed down to only 23 mm (0.9 in), about three times thinner than a typical pillar, while providing required crash energy-absorbing capability. And it could give a car the sort of chic visual effect that the 1955 Citroën DS 19 achieved with its slimline, set-back A-pillar design.

I think it is enough if it gives the chick visual effect of a Saab 99 or 900. 😉

Autoliv and Saab have presented the results of this research in September 2010 at the ICRASH 2010 (International Crashworthiness Conference) and more recently on June 2011 at the ESV 2011 (Technical Conference on the Enhanced Safety of Vehicles). And looking at the pictures it seems like it is quite production ready.

And how does it work?

Expandable A-pillar (experiment)

The pillar uses high-grade but not high-strength steel. The structure is folded and welded airtight, with a gas generator at one end. In the event of a serious crash, the generator is activated and the steel unfolds and expands, the added cross-section giving the required added strength.

So what is this post all about?

First of all, we are talking here on a very interesting engineering solution to a problem that no car manufacturer has been able to solve. So even if Saab didn’t have anything to do with this, I think it is worth talking about.

Secondly to add some flesh to sentences that we have heard many times in the last months like: Saab can’t go down now, there is too much going on. And there is not only a lot going on, but a lot of interesting and very innovative things.

Thirdly because of a sentence Victor Muller said back in 2010, II might quote him wrong, but the meaning was much like this: Many suppliers may want to work with Saab, because Saab with its small production figures makes it more attractive to test new technologies. For Autolive a Saab car using this technology is a proof of concept, and with that they can go to VW, GM or whoever and sell it out of the shelves.

And last but not least. Autoliv is Autoliv AB a Swedish company, Saab is also a Swedish company, and this shows the engineering potential that exist in Sweden. Sweden should be proud of people and companies like those. To throw this away would be a sin.

I want to congratulate Dr. Bengt Piepkorn from Autoliv Research and Mr. Jesper Lundström from Saab Automobile, and all other people involved in this project for this, imo, great achievement in the automotive industry.

Thank you!!!!

And thank you to A-RO 95 for the hint!!!

46 thoughts on “Intelligent A-pillar”

  1. Very interesting. What this is, essentially, would be an airbag for the car’s frame. I wonder if the idea could be expanded to other parts of the frame, which could be used to not only further enhance safety on a variety of different collisions, but also reduce the chances of costly damage to the vehicles frame in a severe impact. Hence I could see future automobiles be constructed such that there are a number of “joints” made very much like this which could be replaced independently.

  2. .
    Nice article….

    I can remember the 1st 9000 I drove & within the 1st 100m, could not get the thickness of the A pillars in prespective.

    After Opel Monza GSE, they seemed so thick..but we adapt.

    This could be a great jump forward & a ‘new begining’ for Saab if this is built in the new 9-3?.

    As RED J says, this is why the Auto industry needs the likes of Saab…

  3. Nice post Red J. Sorry in advance for going off topic but I have to get this of my chest: The new SU team, and especially you and Tim really stepped up the plate. Off course there are always minor glidges but quality has drastically improved over the last few months and I can almost say you’re getting to ‘Swade quality’ and that’s about as good as compliments get!! Good job guys, and keep it up!

    Griffin up as well of course 😉

  4. Great innovation to a very serious problem. My wife’s Zafira A-pillars have nearly caused several accidents for me, with pedestrians and otehr vehicles – they must be 10-14cm thick each and then there is a further A2 pillar behind, cobined effect is not to be able to see 20% of forward and side vision. The 9-3 is dream by comparison, although the B pillar is quite thick for over-the-shoulder checks at angled junctions.

    Keep it up Saab!

    • I understand completely what you mean. Its not just the thickness of modern A-pillars though but also the angle.

      I drove a C900 for most of my life and last year moved up to a 9-5.
      For a while I didn’t notice anything different but then I had a few close calls with bicyclists. I’ve also driven other modern cars and they’re even worse. I sat in a Suzuki Kazashi last week and I practically got claustrophobic.


      Visibility is a safety feature too.

  5. Interesting piece of engineering. I once drove a new Citroen C5 with a thick and very flat A-pillar, it was really a problem to look out at the left side.

  6. I have saved up some money from a summer job, all in all 20 000kr and after seeing this I am positive that I want to buy some stock in SWAN. Does anybody know how i can buy stock on the Holland exchange when I live in Sweden??

    I think it’s a good way to support SAAB and mabye make a little money.

    • Hey Dejjo,

      The SWAN stock is very volatile and there’s many daytraders trying to earn a quick profit.
      Stock price is € 1,07 atm (9:27 AM CET). If Saab makes it through this rough patch, price might go up to two or three euros over a couple of months. They might go down as well, of course….

      The euronext is a global stock exchange, so I think you can buy stock even if you don’t live in Holland.

  7. I’d argue that the A pillar on the C900 and 99 certainly wasn’t weak. With the curved windscreen and the roof design, Saab used to advertise that the cars could be dropped on their roofs and still protect the occupants. I think Saab just got pushed into the (lazy) GM way of thinking, and A pillars have grown in thickness to resemble Arnold Schwarzenegger’s biceps! Instead with proper design and materials, there really isn’t the need to have very thick A pillars. Visibility is a very important safety factor. Try driving a 9000 and then an NG9-5 to see how visibility standards have suffered. Whilst I don’t think any Saab will ever match a 9000 for visibility again, I would hope future Saabs can at least match the C900?

    • +1
      As far as I remember of a Saab-dealer told me long ago, there is a specially steel or titania in the A-pillar of the C900, enabling it to even withstand a moose-crash leaving enough space for the passengers to survive. Of course a deploying A-pillar would add some kind of crash-zone, but I doubt if this really would increase the stability of the whole structure…
      At least this might be a feature generating some covering in the media, but I hope Saab will stick to their old principle of real-life safety and puts only features in if they really works and increases usability and fun…

      • Great Otto has touched upon a feature of such a design which I also question; that is how much stuctural strength / rigidity would the unactivated pillar provide? Whilst providing increased visibility and addressing the need for strength in crash conditions could this be at the expense of unwanted flexing of the vehicle body outwith extreme conditions?

  8. Markac, the article is suggesting that new A-pillars will be only 23mm thick, so I don’t think that beating 9000’s visibility is much of a problem in future Saabs — hopefully already in the new 9-3 (or is it 93, 900 or Viggen?) 🙂

    • For the 9000, I actually should have said “all round” visibility. Beating that would be very difficult nowadays. I know the 9000 had thicker A pillars than the C900. I drove 99s for about 7 years and then a C900 for ten years. I’d consider my OG9-3’s all round visibility inferior to the older cars.

      • What I hate about modern cars is that from the outside, it might look like the car has reasonable glass area, but once you get inside much of it is masked off. This especially applies to rear windows. At least with the C900 you knew what you were getting.

        • Ah, now I get what you mean, and i agree! Going from my old 9000 to my new 9-3 was like goIng from a scuba mask to the sunglasses they wear in The Matrix ^_^ But with innovations like these new pillars there’s still a chance that Saab might be able to “open up” the glass parts again (if it won’t kill off the aerodynamics, that is).

  9. I drive a 2006 Honda Civic right now (in addition to my trusty old ’99 9-3) and despite having the biggest wind screen I have ever seen in a car, the Civic has horrible blind spots. Its A pillars are very thick but also they are very far forward into the field of view.

    I like the proposed idea a lot, but I wonder how do they repair them after an accident? Or would this only happen in an accident so severe that the car would not be considered reparable? I hope they are also working on doors that blow dents and dings out by themselves too! 🙂

    • I suspect it will take quite an impact before they expand. That said… After an accident, the last thing you will think/worry about is the deployed airbags (quite expensive as well) and structural damage…

      In Sweden, I think it is customary for the insurance company to give you a new car if the damage exceeds 50% of the value and you are still within the first 20000km. Everything that drives up the cost of repair is fine by me… 😛

  10. This is fantastic and very interresting news. By the way, the OG9-5 A-pillars might be quite thick. It did’nt distrub me at all but one thing is for sure. It effectivly stops a moose from hurting you when you hit it and the a-pillar wont bend or break easily. I still feel bad for the moose though. He’s in moose-heaven now. 🙁

  11. The Honda Accord I PX`d against my MY12 9-3SC had very thick A pillars because they apparently had built in airbags. The thickness and steep rake made visibility poor, resulting in constantly moving my head from side to side in order to see around the drivers side pillar, which could easily conceal a motor cyclist. It also resulted in a stiff neck at the end of a long journey. The thinner, less raked pillar in my SAAB is a great improvement, resulting in better visibility and less fatigue.

  12. “Many suppliers may want to work with Saab, because Saab with its small production figures makes it more attractive to test new technologies”

    Does it apply to IAC Group i Skara, Sweden as well? They have a lot of unpaid bills on SAAB.

    I only wonder why not paying in time before there are comments in media? It can´t be unknown
    how much SAAB owes… or?

  13. Interesting concept.

    In addition, lowering the beltline resulting in more glass would improve visibility & reduce that claustrophobic feeling. It would also buck the trend of following the crowd.

    • That would be great. Saab was never one to follow trends anyway. Once upon a time it managed to create it’s own trends. Maybe it’s time again?

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