For those who ask are Bullbars really necessary

Agree, a bull bar wouldn't have helped this driver much (if at all), though a bull bar is mounted on the chassis, which is where the actual crumple zones are designed to work (not the body panels), so you don't need to worry about it being too solid - the car will still crumple as intended.

A car without a bull bar is designed to deflect things over the bonnet ie. if you hit a pedestrian, the intention of the car designer is that the pedestrian will be deflected over rather than under the car. A bull bar is generally designed to push the animal downwards so it doesn't come in through the windscreen (hence why bull bars are not so favourable in an urban context).

Having said that, if you hit a buffalo and your bull bar impacts his upper legs, all you do is knock his legs out from under him, and if his centre-of-gravity is higher than the top of your bull bar, he'll still likely roll onto your bonnet/windscreen.

What I was getting at was that the longitudinal strength and crumple zones are designed into the chassis, as that is the level that most vehicle to vehicle impacts will occur.
Cows/buffalo/horses C of G is above this height.

Yep. Car designers probably don't pay a huge amount of attention to such impacts, because they are far in the minority I suspect.

Hit the Brakes ? Swerve ? Instead of a centre hit end up rolling over .....

The "crumple zones" in bull bar brackets are to absorb shock from low-speed impacts that would otherwise trigger the airbags when it is not safe for them to deploy (ie. you bump someone in the carpark and because you've replaced the flexible plastic bumper with a solid bull bar, the air bag sensors measure a far more severe impact). They probably have an impact absorbing distance of less than 10cm so are not going to provide much benefit to vehicle occupants in a severe impact.

The crumple zones that will actually benefit the occupants at high speed impacts are designed into the chassis, not the vehicle panels. These crumple zones are designed to compress in an impact to absorb as much of the impact as possible over the distance between the bumper and the passenger compartment - the passenger compartment is NOT part of the "crumple zone" and should generally not deform (otherwise occupants can be crushed).

As others have said, the pictures show the car behaving as it was designed to do - sacrificing the engine bay to protect the occupants (though they are generally designed/tested primarily with impacts with other vehicles in mind, which will impact lower on the front of the vehicle).

As others have also noted, I'd suggest a bull bar would provide little (if any) additional protection in the above incident, though for a lower speed impact, or smaller animal, it could well be the difference between driving home or being stranded by the side of the road in an incapacitated vehicle.

Would we expect to see skid marks from an ABS-equipped vehicle?

As I understand it, ABS has made it difficult for crash investigators to determine vehicle speed prior to impact because there are no skid marks to measure.

Good point tim_c.

My guess the crash investigators will be having to check for skid marks else where ~ I'm no crash scene investigator so I can't confirm if there were or were not skid marks on the seats, I'll leave that to the professionals.

Safe travels : Joe

Ha! :-)

If the passenger seats have them, they were travelling fast. If the driver's seat has one, they were going really fast.

As I understand it from a few conversations with crash investigators, ABS changes the "skid" marks into a series of smaller "stutters". Obviously, the length of the line of "stutters" would indicate speed, just not quite as easy to determine as when there's a full skid line (or 4).

Its a fair bet that they can download the event data recorder that's hidden away in the ECU and it will tell the truth of what you were doing in the seconds up until the air bags deployed.

Skid marks will just confirm the road position while you were doing it.

This Drive article and Research Paper are a few years old, but gives you some idea of where they are heading with it.

Yep, they can download all the data they require from the airbag computer these days.

So can the insurance companies for that matter

LOL - no grass on the bitumen! :-)

Found this on FB, a couple of years ago. Might have been eating grass on the bitumen too?



Bob

Bob, I believe the driver was charged with rustling and the vehicle was forfeited.

... and they are poorer for it.

They are tested for impacting a solid wall, the problem with low cars and live stock is that the initial impact takes the legs out with negligible loss of momentum and the forward motion of the vehicle sees you with a cow to the face.

Its never going to end well.

Yes Dion, there is a lot of exposed infrastructure on the front of a locomotive.

Macca.

Now, was that a case of a strong bullbar or a weak chassis ??

Maybe some people have a false sense of security with bullbars and basically go too fast in areas with cattle, kangaroos or emus. Even emus can make a mess of a car at speed. And of course it is not just people with bullbars who go too fast for the conditions.
First major outback trip was 65 years ago. I am not a nervous or overly cautious driver but the moment I enter country with cattle and at the first sight of a kangaroo I slow down.

HI
At dawn and dusk most often on dirt access roads I have travelled at 80-90 kmh . But coming around a bend with the sun coming from a bad angle the roos always found the troopy coming flat out from behind scrub . Unavoidable .
Speed is not always a preventative just hopefully lessens the damage . And reduces the chance of a major accident occurring . Reducing speed may even prevent severe mechanical damage thereby avoiding being stranded .

Here's a fine example of a "Wally Bar", Swampy.

By far the best bar for rough work, and light as well.



Bob

hi
Spent many a hour straightening/repairing with oxy and mig welder .

They can take an absolute hammering . So much better than any other bar out there. All the others are just pretenders . Arb Tjm garbage cannot put up with the same abuse period .

Always travelled with a waterbag :-)

I agree, speed is the critical factor in reducing damage. I agree also that speed and weight reduction are critical factors in reducing mechanical mishaps on the car. People travel slower in dangerous country when they don't have a bullbar. Taken to ridiculous extremes, if we all travelled at 20kph there would be no accidents with cars, roos or water buffalos. There is a tipping point speed that allows a reasonable rate of progress with minimal chance of collision and damage making a bullbar a waste of time and money. I try to travel at that speed.

10pm , no moon , 4x4 Ambulance , Reds and Blues ,High beam and Spotlights and all external 'work' lights also 'on' so like a Xmas tree , severe patient needing immediate transfer , 125km of dirt rd done in 54minutes ....not 1 Roo hit .....return trip , 2.30 am, still no moon ,no need for Reds and Blues , just H/beam and spotlights , took 2.5 hrs to do the 125 km back ...17 Roo strikes .....

Well, its obvious - I'll just have to fit a full set of flashing red and blue lights to the ute, dispense with the bullbar, and tell the cops I've fitted those lights for anti-roo-hit protection!

I'm sure the beak will agree with me!! LOL

Cheers, Ron.

Ron N , once again you show your ignorance , 4x4 Ambulances have 'Bullbars' , and since round 2010 they are the plastic fantastic 'SMART BAR' , in order to save weight and the 'rebound' ability without the majority of 'force' being transferred to the chassis .....

You've got about as much humour understanding as a WW2 Gestapo soldier.
I said nothing about ambulance bullbars. As for ignorance - as they say, it takes one to know one.