no 4WDs near schools? that’s bull!

18 May 2005 at 23:55 (General)

Greenie idiots. banning 4WD’s from going near schools is nearly as ridiculous as banning bull-bars in the city. 4WDs are, in fact safer because they give you elevated confidence…

okay, seriously, The idea was suggested by coroner Jaqueline Milledge who was investigating the events surrounding the death of Bethany, a 5 year old who was run over by a Nissan Patrol in 2002. Joan Maclennan, who was driving the 4WD said she’d never drive a 4WD again and has urged her friends to buy something smaller. “It ruined my life” she said yesterday. (source: the Australian)

It’s interesting, the media (today tonight, ABC radio and the start of the Australian article) have been reporting it as a suggested ban on 4WDs from going within 200 metres of a school. That is impractical. It would stop people who live next to schools from being able to drive near their property. In actual fact, the coroner is recommending that they ban 4WDs from school property and from PARKING within 200 metres. This makes a lot more sense. I wouldn’t want to regularly drive a vehicle where I can’t see kids running about in an area where kids run about.

As for bull-bars, Dad says there’s an organisation of engineers who are dedicated to getting them banned in cities. Bull bars are stupid, they decrease everyone’s safety. I think it’s fairly straight forward to see how they decrease the safety for everyone else, if you hit a person or car with a bull bar you’re going to leave a bigger imprint because bull-bars don’t bend and they don’t crumple, they stay put.

However, I assume that many people don’t understand the added personal danger of being behind a wheel attached to a bull bar because many people keep adding them to their gas guzzlers. Modern vehicles are designed to crumple on impact, this slows the time for the deceleration. So instead of slowing down really fast, your vehicle absorbs some of the impact. It’s like falling on bark chips compared with falling on concrete. The bark chips still slow you down the same amount, just over a longer period so you don’t get the jarring smack felt with sudden deceleration.

A bull bar partially defeats this system of crumple zones because bull bars are really hard. they don’t bend and crumple much, they’re designed not to. So when you hit something they stay put and the impact is absorbed by whatever the bull bar is attached to. However, because the bull bar is so rigid it converts what may have been a localised crash into an impact that is fairly well distributed across the entire front of the car. The crash is absorbed a lot faster and you get a faster deceleration. I think it’s like the same principle that makes a belly-flop more uncomfortable than a pin-drop; the more surface area for absorption the faster the deceleration is. This means the occupants are going to experience a rougher impact, they will typically suffer worse whip lash and they will be relying on their seat belts even more so than normal.

Dad goes as far to say that he doesn’t think he’d ever equip a car with a bull bar. Even if he lived with bulls, or travelled through roo country he’d rather have the crumple zone. I don’t know, I’m not an engineer (like dad) so I’m not going to try to give that sort of advice and dad was sort of just making an off hand statement…. but I’ve been reading a bit about g-forces in accidents and maximising crumple zones doesn’t seem like a bad idea to me.

I seem to notice a pattern, I blog a lot about transportation, mainly about cars which hate to love and I love to hate. But don’t get the wrong idea, there’s more to life.

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10 Comments

  1. Deirdre said,

    No, there isn’t more to life – cars are everything.

    :)

    I’ve never thought about that bull bar problem before (the fact that it transmits the impact, rather than absorbing it). So what’s the point of them, then? Are they only useful against soft bodies (kangaroos, pedestrians, etc)?

  2. Kent said,

    man, I love physics.

  3. toto said,

    Even against a soft body they aren’t as good as a crumple zone. So I don’t really know what their point is. The whole logic is rather backwards.

    Perhaps people get them because they look big and aggressive and help to keep bits of cyclist from getting caught in your grill. They add a bit of weight to help decrease your fuel economy (an important requirement when selecting a 4WD) and the shiny ones are also good at reflecting light from the headlights back at the driver so that they can’t see as well.

  4. Kent said,

    well, their point on a big vehicle is to prevent damage to the vehicle, obviously. pretty useful for trucks in the bush, I suppose. as for city use, well, they must just get smeared with wankerjuice in the factory and the wankers are attracted to them like flies to meat. ? best idea I can come up with.

  5. Kent said,

    PS ban 4WDs from picking up kids? sign the death warrant of eastern suburbs primary education!

  6. toto said,

    I used to have negative vibes when building the holden 4wd’s (or any car really), perhaps without realising it I’ve helped to embed arseholness into those cars.

    and I didn’t see your physics comment.. Yes, nothing better than some decent physics talk. :)

  7. Teddy said,

    Yes, Physics just never gets old. ;)

    The Bull bar is simply designed so that the crumple zone is only used in larger collisions, as a bull bar is cheaper and easier to replace (and takes less damage as it doesn’t crumple). Out in roo country where “minor” collisions are common this is a definite advantage, but in the city you don’t have to worry about wrecking the front of you car on a cute furry animal.

  8. Ian Finney said,

    As a manufacturer of safety protection bars in the UK which have proven to offer grater predestrian protection in line with new European Legislation voted May 2005 than the base vehicle there was no logical reason to ban the bar just offer a safer alternative with a proven track record, any one wanting to know more details please contact info@conceptmouldings.co.uk your analogy of crumple zones is almost correct but head and leg impact zones as covered within the directive are the beanchmark to greater vehicle safety.

  9. matty said,

    I can’t believe you tried to write that in one sentence.

    and I almost fail to believe you have roo bars in the UK. I mean you don’t have roos and you don’t have bulls. Why do you need to strap chunks of metal to the front of your cars? maybe you’re talking about safety-cells/cages such as these? Quite different from these. Safety cells serve a valuable purpose because they stop people from being crushed/pinned inside their cars. Bull bars just protect the engine and increase trauma.

  10. An obese badger said,

    “Why do you need to strap chunks of metal to the front of your cars?”

    To slaughter us, that’s why!

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