Hybrid trains, cheap partial electrification, momentum~

cycleops612

10 kW
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Sydney Australia, Me: 70kg/154lb. 350w, 22kg ex ba
Its half baked, but what do u guys think?

The forgotten infrastructure cost free propulsion method for trains it seems is gravity.

Electrification is good it seems,but woo, the capital costs mean it never happens - in america anyway.

But does every mile of track really need messy and problematic catenary wires overhead?

Not really. Get it up a hill on electric, and the trains moment for many miles after that means a small ice motor & gravity suffices to maintain decent speed.

i.e. - use the trains mass as a "storage battery" for a hybrid locomotive.

On a hill on a 2 track line, one direction is uphill, and the other down. So, electrifying that track need only be done for the uphill side. The single side electrification swaps tracks at the top of the hill.

Secondly, if a trainsets are standardised at say 1km long, and the trainset forms an electrical bus bar, then if only every second km is wired, some point of the train is in contact with the power supply, and thus the whole train (multiple engine cars) via the trains loom. So for example, the ohead power could end .5km from the top of the hill, but the front engine is still powered for .5km into its descent from the crest.

Added together, these factors could result in a much reduced cost for the benefits of electrification.

Given the mass of trains, i quite believe 20% electrification would work well.

e.g. Coast to coast - electrify the mountainous bits and likely halts, and have a liesurely (ice) motor across the vast flat great plains.

I notice the TGV for the chunnell provides for using the modern norm of 25kv AC ohead wires, AND archaic 3rd rail ~700v DC, presumably to avoid the tunnel space hungry ohead wires. Tunnels are not cheap or easy, so that has merit too.
 
Trains in our steep mountain slopes use the motors as generators to de-accelerate. The generated el. current is fed via the overhead line to the train on the other side of the mountain to do the climb (see). r
 
rolf_w said:
Trains in our steep mountain slopes use the motors as generators to de-accelerate. The generated el. current is fed via the overhead line to the train on the other side of the mountain to do the climb (see). r

Pretty normal i think, but lossy, and as discussed, often doesnt justify the cost of electrification on the down hill run.

On a gradual descent, a gravity powered train is no cost energy recovery, unless excessive braking. On sections where this occurs, then electrification on both sides of the hill may be justified.

In the big picture, whats important is to minimise use of dirty and increasingly scarce liquid fuels (ie diesel). wasted (by braking) nuclear or green electric, is at least not simply burning carbon to convert 20%~ of its heat into usable power via an ice, or 90%? if a modern coal power station.

an interesting factor in the US is the high incidence of double stacking containers - i.e., very high trains.

the fuel US rail freight uses is insane - huge.

An imperfect improvement thats cost justifiable beats a perfect one that never happens as it needs subsidies.
 
Electrification of rail is very expensive so there must be a good reason your ideas haven't already been implemented.
 
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