KHR said:
Right. But then you don't need to build a tunnel to reduce air resistance. As
far as I can see, reducing air resistance is the main advantage of the
proposed tunnel scheme.
[Tomb] On a vaccuum plantoid like our moon, it might offer dust
protection for the mechanism.
You didn't mention two factors:
* the speed of the transport. Basically, you can move stuff cheaply
and slowly or fast and expensively. Conventional rail is very slow -
slower than trucks over almost any distance. Depending on your specific goods
and the costs of delays in delivery, it can be more profitable to move stuff
by air.
[Tomb] Really? I'd say that depends a lot on your situation. Take the
early Canadian Prairies. Trucks didn't really have too many roads and the
train could get going a fair clip.
[Tomb] Some goods have time-to-deliver issues that make air viable.
For things that do not, sea or rail transport over long distances are cheaper.
[Tomb] The majority of goods in the world are moved by sea. It is by
far the largest total tonnage. I think you'll find rail is #2.
* the cost of investment, which has to be offset by the income from the
transports. If the tunneling is so expensive that 90% of the transport price
goes for servicing the debt from the original investment, it won't help if
actually operating the train costs next to nothing.
[Tomb] What about an external tube structure? Not necessary to incur
tunneling expenses. What if I can tunnel very much more cheaply than current
tech?
A specific example of this is the Transrapid Maglev train project in Germany.
Nifty technology, but the cost of building the track was such that it could
not be operated profitably even under very optimistic assumptions.
[Tomb] Given current tech. Given some advances, maybe that
changes.....
OO said:
Sure, they are. But they only move at two-three *hundred* mph,
whereas the long-distance ETT capsules are supposed to move at four
*thousand* mph... from a kinetic-energy point of view that's a rather
significant difference.
[Tomb] True. A concern if you have it moving through cities. If not,
then it isn't such a big deal (in that, at 300 mph, you can easily kill
everyone on the train, so doing 4000 kph isn't going to be any worse in that
regard, so the only extra danger is to the surroundings).
> 4. It has traditionally been far more efficient to move mass by rail
In addition to KHR's comments, you forgot one very important factor: rail is
"far more" efficient *iff* it goes *all the way to the final destination*.
[Tomb] This I think is more a character of the type of cargo than
even of the destination issue. After all, at worst, your truck leg is no worse
than a part of an overall truck transport route. (Counting the transfer cost
separately). So if the train part is much cheaper, and transport costs
reasonable, then you are still better off.
OO: If you need to use a truck even a short way of the distance (ie., to and
from the railway terminals), the efficiency of the
combined rail-truck system drops very fast - which is one of the
major reasons why long-distance trucking is common even on routes
where there's a railway line available.
[Tomb] I think you'll find a lot of these exist for a number of
reasons including the distribution of rail transported cargos to areas not
directly serviced by rail. And containerization, where feasible, goes a long
long way to speeding up transfers and reducing the expense associated
therewith.
In spite of the gains from container systems, the transfers from truck to
train and from train to truck often cost you more than
you gain by using railway for the vast majority of the distance :-(
[Tomb] I guess that depends where you are. I believe in Canada, when
I last heard, the difference was pronounced. If you're moving something from
Toronto or Ottawa to Vancouver or Edmonton, you are best off with a train. And
trains can carry cargos that trucks can't attempt due to load restrictions.