Do the Road Rules Apply on Private Property?

Brace yourself for a shock. The law doesn't differentiate between public and private property when it comes to where the road rules apply. This can have startling, and sobering, consequences. Just below is an example that relates to being on a camping trip in a 4X4, but the same principle applies in the car park of a major shopping centre.

Let’s say you’re in the bush. Let’s say you’re camped on an outback station, on private property that’s open to the public. Legally. A place where recreational camping is allowed. Encouraged, even, as a source of revenue for the grazier. The sun’s setting. You’re on the bank of a choice creek. It’s been a textbook day. Half a dozen fresh fish on the barbecue plate (bad day for them; a good one for you), and you’re swapping lies with mates, with a few beers to chase them down.

A light chill is creeping in as the sun sets. You decide that maybe there isn’t enough firewood at hand

Read More
safety, driving, LegalJohn Cadoganroad rules, private property, road laws, rules Comments
The Vehicular Obesity Epidemic: Cars & SUVs are getting overweight

You can’t open a newspaper or a magazine these days without staring at a headline about the obesity epidemic. But it’s not just waistlines that are rapidly expanding – vehicles are, too.

It’s a worry because, as good as those vehicles are, the basic physics can’t be overlooked – hauling around more mass means consuming more fuel. And burning more fuel means emitting more CO2, if you care about that sort of thing. As a nation, we probably can’t afford to burn more than the 30 billion-odd litres that are currently going up in smoke annually.

Stuffed if I know about the environment. I’m no expert on that, and there seems to be robust dispute between opposing ‘expert’ camps. But the one thing I do know is, Australia has

Read More
John CadoganComment
Energy Density & How Some Fuels Offer More Bang Per Litre

Filling one’s tank is so utterly mundane an experience that few spare a passing thought for the staggering volume of energy routinely transferred in the process. Occasionally some fool makes a Molotov of himself at the bowser with an unwitting static electricity discharge into the air-fuel vapour mix around the filler neck. Captured on CCTV, it’s the merest blip on the popular radar that petrol is anything other than a benign, unremarkable liquid.

The truth, however, is rather different.

Petrol and its more viscous sibling, diesel, are almost perfect energy storage mediums. They cram so much energy into such a small volume, and they weigh and cost so little, that other fuels – especially alternatives – have real trouble measuring up.

Say you fill up on unleaded. The nozzle might click off automatically at 58 litres. You’re ready for another 600km of driving. For a mere $77 you have just tipped 43kg of stored energy into your tank. It doesn’t sound like a big deal until you actually measure the energy, which in this case is a mammoth two billion joules.

Read More
fuelJohn CadoganComment
Things You Probably Don't Know About Engines
  • The big difference between petrol and diesel engines is where the fuel and air mix 
    In the majority of petrol engines liquid petrol is injected into the inlet airstream before it enters the cylinders. A mixture of fuel vapour (droplets of liquid) and air enters the cylinders, where it is compressed and ignited by a spark. A diesel engine ingests only air. This is compressed well beyond the point where a fuel/air mixture would spontaneously burn. At precise points near the peak of each compression event, measured doses of fuel are injected, which ignite spontaneously. The diesel process is more efficient.
  • The piston doesn’t really push spent gasses out past the exhaust valve
    Engines aren’t pumps, but they do experience what engineers call ‘pumping losses’. When the fuel/air mixture burns, it expands rapidly, and this expansion is the harbinger of motive power. It shoves the piston down. Before the piston gets right to the bottom of its stroke the exhaust valve opens. The mixture, still expanding rapidly, is expelled through the aperture of the open exhaust valve. In a very real sense, its expansion pushes it out the chamber. Which leads us to…
  • The piston doesn’t really
    • Read More
    techJohn CadoganComment
    Greenhouse, Carbon Dioxide & You

    Let’s talk about you. You live in Australia. You consume energy, which pumps CO2 into the atmosphere. You’re part of the global warming problem. Feeling guilty yet?

    How big a part of this problem is your driving? Passenger vehicles yield just 7.4 per cent of Australia’s CO2 emissions, and our national emissions are just 1.4 per cent of the world’s total. Crunch those numbers, and Australia’s cars total just over one one-thousandth of global CO2 emissions.

    According to the Australian Bureau of Statistics Australia has 11 million passenger vehicles. So your car represents one one-thousandth of global emissions, divided by 11 million. Conclusion: Your car isn’t

    Read More
    fuelJohn CadoganComment