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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?
[pertinax, Aug 13 2010]
[pertinax, Aug 13 2010]
"Place of Large Rocks" [pertinax, Aug 13 2010]
" .... and can sometimes be seen in the mainstream British press ..." [8th of 7, Aug 13 2010]
They're not saying how much this one weighs...
... but it could carry three Abrams and two T-80s, if you found a way to load them into the bucket. Just think of that gravitational potential energy, being discarded via the brake pads. [pertinax, Aug 16 2010]
Ah, here it is:
The biggest one weighs, empty, 576 metric tonnes. [pertinax, Aug 16 2010]
Similar enough to allow a little auto-congradulation, methinks [Alterother, Mar 17 2012]
||// As every schoolboy knows* //
||I like this idea, [pertinax].
||It reminds me of the way cars are nudged through an automatic car wash, except instead of cars they are monstrous dump trucks, and instead of a nice flat even run they have a steep grade they have to traverse, and...
||Dang it, no, I guess that's not it.
||I won't bother with my aircraft carrier snag line reference, because I don't want to have dreams tonight about a 100,000 ton ore truck touching down on an aircraft carrier.
||Ore truck roadways are inherently temporary constructions thus infrastructure based solutions would be difficult to justify.
||Well, how about that? My ideas made ideas. The
'traffic capacitors', btw, are large towers that take
up the area of an intersection for cars to travel
inside up and down to relieve traffic. The key was
that they could be ferried in and out of the
intersection with a giant helicopter, but
apparently we can't get one big enough. In this
idea, he's taken one and dropped it in an ore
mine, another temporary need for traffic control.
That's why it may be justified, [jhomrighaus],
Because the structure is temporary
it could very well be cheaper to use this then
spending all the gas on the current trans. tech.
used, which is nothing more than how the
Egyptians built the Pyramids, opposite and inverse
of course.. and with engines.
||Anyways, are you just needing one of my portable
structures (without the helix) to do
counterweight driven elevation of trucks on
platforms? Or will they be ferried up and down the
helices? I think the former would be more cost
||So if the "down truck" carries loose industrial waste down while the "up truck" is carrying fresh loose iron ore, the diesel would be much lower.
||Although there is the problem that the loose rubble (extracted byproduct of iron ore for example) would be much lighter by cubic volume than the more massive iron ore (forgive my terminology which is probably shot with holes). None the less this must be more efficient, than what we are currently doing.
||Is an all-mechanical regenerative system really the
best way to do it? Mightn't electric motors, run in
reverse as generators, as the trucks rolled downhill
be more efficient? Of course, you wouldn't put
batteries on the trucks: you'd have overhead cables
and pantographs. You could reduce rolling
resistance by using metal wheels on metal rails, but
that would be optional.
||What [mouseposture] said; those trucks tend to be diesel-electric anyway, so you're already halfway there.
||But please see Lem's 'Cyberiad' for a dire warning about the perils of such socialisation of electricity.
||I can't find the reference quickly but the electrical system
for dieselectric haul trucks using pantographs and
regenerative braking is well baked. There are more and
more AC powered truck systems showing up also.
doesn't six and a half hours' drive outside Koolyanobbing
just bring you back to Perth?
||Depends if you get lost, [AusCan531].