They were invented decades ago.

They have fewer moving parts than wheelbois.

They require less maintenance.

There’s obviously some bottleneck in expanding maglev technology, but what is it?

  • @Candelestine
    link
    English
    91 year ago

    They’re very expensive to build. That’s it, really.

    • Semi-Hemi-Demigod
      link
      fedilink
      91 year ago

      If it had a significant advantage the expense would be worth it, but steel wheels on steel rails already have a coefficient of friction 10x lower than rubber tires on asphalt, so it’s not worth it.

      • @Candelestine
        link
        English
        21 year ago

        You do save money on them in the long-run. I just assume it takes decades to get all that return on investment back out, thus any entity interested mainly in quarterly profits has little incentive to make the investment, which would be disruptive to their finances in the near-term.

          • @Candelestine
            link
            English
            21 year ago

            Fewer major repairs is the way they save you money. Fewer moving parts, less friction, less wear and tear. All the energy savings gets tossed out the window in the interest of going faster, in the ones we’ve made so far anyway.

            • lol3droflxp
              link
              fedilink
              41 year ago

              There may be fewer moving parts but that does not necessarily mean cheaper/less repairs. Current railway parts (especially wheels) are fairly low tech and easily fixed. What if the cooling of a superconducting magnet fails? That’s expensive.

              • @Candelestine
                link
                English
                01 year ago

                Sure, I didn’t say they never require maintenance or anything. Simply that over a long period of time they become cheaper to operate, after taking into account repair and replacement costs.

                If you don’t take repair and replacement costs into account, they become more expensive. This is probably another reason there are not many of them. Repair is where they save you the money though, due to how infrequently they require it.

      • @[email protected]
        link
        fedilink
        -2
        edit-2
        1 year ago

        If we somehow remove the friction of air on train body. Then maglev would be zero friction transport.

        Edit : Oh my. My little joke comment has ballooned into a full on debate. And I’m not even aware of any of these things they’re all saying.

        I just made a comment guys, I’m not serious or not in any agenda.

        • @[email protected]
          link
          fedilink
          English
          21 year ago

          Atmospheric Railway and Hyperloop bullshit all over again. Unless you’re in space, this isn’t feasible.

            • @[email protected]
              link
              fedilink
              English
              21 year ago

              Sure on a small test track. As soon as it was meant to be scaled up, every attempt has been whittled down. Either it fails completely (Look up Brunel’s Atmospheric Railway) or has been so expensive and impractical that it gets reduced to cars in tunnels.

              If you are most concerned with efficiency, then building the cheaper HSR infrastructure to get freight off of roads and passengers off of planes as fast as possible should be the first priority. Holding even a partial vacuum in tubes hundreds of miles long just to eke out a little more energy efficiency is laughable. Everything leaks. Maintaining cabin pressure in a 73-meter plane is a completely different beast from maintaining vacuum in miles of tube. It’s likely that maintaining the tubes will end up costing so much that any efficiency gains acquired from the vacuum will evaporate.

              • blazera
                link
                fedilink
                -11 year ago

                The vegas loop is its own dumb thing, its not relevant.

                For the leak thing, dont just assume whatever wild claim that benefits your side. Heres a DoE study, if you search leak youll find an estimated power usage profile, with large spikes for acceleration, and a sliver of an orange bar across the profile as the baseline load for maintaining vacuum against leaks https://www.energy.gov/eere/vehicles/articles/effect-hyperloop-technologies-electric-grid-and-transportation-energy

                • @[email protected]
                  link
                  fedilink
                  English
                  2
                  edit-2
                  1 year ago

                  When I’m talking about leaks, I’m not talking about the extra energy required to constantly run vacuum pumps. I’m saying that HSR infrastructure needs inspection and occasional repair, but not nearly to the extent that a vacuum tube based solution would. Any savings made via efficiency are pissed away by having to pay more maintenance crews and material cost to maintain the infrastructure. The tubes are also much less likely to be able to be automatically inspected like rails can be using inspection cars because any train moving through the tube can only inspect the interior walls. Besides, rail already exists across much of the US for use as freight infrastructure. These same rails, if inspected and tested properly, can be used for high speed rail much more immediately than waiting for tubes to be built. Besides all of this, more aerodynamic trains can and have been built, but are not in use in the US. Instead, we send bricks down the rails. The “immense” efficiency gain from 0.5 atmospheres of air pressure is likely significantly less impressive when compared against well designed trains with regards to aerodynamics.

                  All of this is also completely ignoring how dangerous tunnels are for fires. Even with proper safety precautions, fires in tunnels are exceptionally dangerous. By venting out the smoke that kills people, you increase the intensity of the fire that also kills people.

                  • blazera
                    link
                    fedilink
                    -11 year ago

                    Oh man yeah welded joints are just falling apart every week, it takes a fortune to upkeep some stationary metal.

                    I dont think you understand air’s role in aerodynamics. At half atmosphere…you’ve plainly removed half the friction, there is half the air molecules to collide with the train. To give some perspective, all of the fastest manmade vehicles, by crazy high magnitudes of difference, are space vehicles. The ISS is whizzing around at nearly 5 miles a second in low earth orbit. Air is the limiting factor in speed. Its the only reason any additional fuel needs burning to maintain speed.

                    Finally…youre not gonna have a fire in a vacuum tube

          • lol3droflxp
            link
            fedilink
            21 year ago

            You mean that hyper idiotic Hyperloop idea that’s just a warmed up remix of the vacuum train idea from the 1920s and will efficiently kill all passengers if a little thing goes wrong (if you can get a hundreds of kilometres long vacuum chamber airtight anyway)?

            • blazera
              link
              fedilink
              -11 year ago

              its a big topic, just be aware that “vacuum” in the real world is a sliding scale of air pressure. vacuum tube doesnt automatically mean conditions on a spacecraft in sci-fi when a hole is shot through a window. You can cut air pressure to half of atmospheric, and have an extremely weak vacuum, and still get amazing efficiency gains. We already have routine transit of pressurized cabins in the form of planes.

              • lol3droflxp
                link
                fedilink
                2
                edit-2
                1 year ago

                Still means 0.5 bar overpressure if something breaks, which is deadly. Also the proposed pressure for the Hyperloop was 0.1 atmospheres iirc. If there is a weakness in the tube it will fail catastrophically and a pressure wave kills anyone in it. Watch the video where the mythbusters implode that huge tank.

                You basically bring a lot of the problems with space travel down to earth.

                • blazera
                  link
                  fedilink
                  -11 year ago

                  "vacuum tube doesnt automatically mean conditions on a spacecraft in sci-fi "

                  Half atmosphere is less pressure difference than normal passenger planes.