Maglev hyper tunnels

[farmerben]

 

Maglev trains with electo-magnetic coils along the track are super expensive, and a maintenance problem.

 What if we reverse the model.  The track is superconductor, and the vehicle must supply all the power, or get it from an overhead cable like buses.  Electric vehicles could use it with a simple modification.  Ferro shoes inside the wheel base, that switch on and off.  

The track and tunnel company simplifies its responsibilities but not assuming responsibility for rapidly switching power systems.  Instead their pledge is to continuously supply liquid nitrogen and oxygen.  They guarantee pure breathable air in a positive pressure tube.  Thus ventilation solves itself.  

The track company would need to rescue broken down vehicles.  But the major thing that would solve this is 1/4 mile entrance ramps on sidetracks.  The track system would test each vehicle arriving for that first 1/4 mile.  If it passes the test it shoots onto the mainline at full speed.  If it fails the test, or if traffic requirements dictate, then the vehicle sidetracks off near the original entrance station.  

[Shpaget]

You propose to chill the tracks to cryo temps to get achieve superconduction? Thousands of miles of not thermally insulated superconductor magnets? That would not only waste huge amounts of power, but ice buildup would derail any train that tries to drive there. Keeping the air perfectly dry is going to be pretty unpleasant for the passengers, so you need to seal off the cabin, which again is not trivial.

Why all this? So you can go faster? But in a pressurized tube that actually makes it harder to go faster than open air? High speed train lines need to take into account special tunnel designs to prevent the train from acting as a plug that forces a huge amount of air through the tunnel. 

The speed of conventional trains is limited by several factors, but air resistance is one of the primary. You don't solve it (and driving in vacuum tubes brings a whole lot of new problems). Another important factor is power pickup from overhead wires. Even simple things like that get complicated once you get to 300+ km/h. A levitating train needs two of those.

Until we figure out room temp superconductors (that are also superconducting at standard pressure), I don't see this happening.

[Nuke]

do you even need to cool/power the track? because the dumber you make the tracks, the cheaper the installation per a given distance. or even using high temp super conductors in the track, of course htcs are rather expensive at present. or just use dumb aluminium plate.

an htc arctic loop running around 65 degrees north latitude use the naturally cold conditions there to keep the htc plates superconducting. the scandinavia -> russia -> alaska -> canada -> greenland -> iceland loop is mostly over land but would require some of the longest ocean bridges ever built (something like 1500 miles of it in various places). though the line could work without the larger ocean sections, it would just take the long way around going form say canada to norway. you would only need a 50 mile bridge through the bering strait.  

evacuated tube with pressurized train would keep the passengers warm and also keep ice from forming in the tubes. htc plates could be passive sinked to the outside environment through the tube walls. installation would be above ground similar to the construction used in the trans alaskan pipeline. 

using huge battery packs and then have automated battery swap stations at regular intervals could provide the power and tank up your liquid nitrogen. you probably aren't using this for freight and so lighter weight trains can be used. or perhaps use non contact inductive power transfer from hvac lines which would enable heavy freight (would be useful if the tube was wide enough to accommodate standard shipping containers).

Edited April 23, 2020 by Nuke