Scalextrucks

I have stolen one of [daseva]'s Traffic Capacitors (see link) and planted it in a great gash in the red dust of Australia, let's say, six and a half hours' drive outside Koolyanobbing.

Not really, but let me tell you why I would.

As every schoolboy knows*, a laden ore truck weighs about the same as two main battle tanks. I'm told, but haven't checked, that more than half is truck, and less than half, ore.

Night and day, these things scurry back and forth like very very large ants, moving dirt from the latest blasted flitch up to ground level. They burn a *lot* of diesel.

Parts of the ant trails, along the bench tops, are pretty much level, but much the busiest part is the ramp.

The idea is for captive chains or cables running along the ramp, and retractable hooks on the bellies of the trucks (which remind me of those electrical contacts underneath Scalextric cars, hence the name, but which don't actually conduct electricity - at least, not intentionally).

You probably don't need a massively strong free-standing tower, such as would be left over once you'd stripped off and thrown away [daseva]'s helical roadway, but it would surely contribute to the look of the thing. What you do need is some structure up and down which you can move an array of, say, forty-tonne counterweights. The main reason for imagining a free-standing tower is that the side of the pit won't be vertical, and you don't want your counterweights snagging on the country rock as they pass up and down. Maybe an obscenely large gantry would do the trick, but I digress.

Anyway, the chains or cables running the length of the ramp are connected to the counterweights. The dispatchers who, in any case, are already tracking the positions of the trucks using RFID and radio voice contact with the drivers, keep track of which weights are up and which are down and, as each truck approaches the top or bottom of the ramp, may advise the driver to lower his hook, and snag on to one of the chains.

On a downward journey, the hook is used as a regenerative brake, and the potential energy of the empty truck is transferred to the counterweight. At the bottom, the dispatcher remotely locks the counterweight in place at the top of its travel. A little later, when the same truck or a different truck heads back up, with its load, it connects itself to a raised counterweight and gets a helping pull. It still needs to burn diesel as well, because, with its load, it weighs maybe four times as much as the counterweight, but not quite so much diesel.

More daring dispatchers may short-circuit the system and connect the ascending truck directly to a descending truck, cutting out the counterweight entirely. For this, you just need to be sure that your block-and-tackle is OK with a combined weight of several hundred tonnes, and that you have informed the drivers... and their next of kin.

Because of concerns about the friction losses, and the dead weight of the chains themselves, an alternative project is set up in the South Pit, where the ramp is encircled with great loops of copper, and the trucks are magnetized. Even if they don't save much diesel there, it has a marvelous effect on the night shift's flood lighting.

*He doesn't? Tut tut! What are they teaching them these days?