• blazera@kbin.social
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    1 year ago

    Anyone who doesnt think its a good idea doesnt know what it is or how air drag works

    • NeonWoofGenesis@l.henlo.fi
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      1 year ago

      There’s so many flaws with a system like this, I can’t imagine how you could make it economical. I’m just gonna list a few that have popped up in my mind over the years

      1. Thermal expansion. Steel contracts and expands a lot depending on the temperature, railroads have regular expansion joints to account for this. But having expansion joints which withstand a vacuum in a 500+ km tube in a reliable way would be amazing. Imagine the maintenance cost just for those. Expanding, contracting, shifting left, right, up and down.
      2. Maintaining a vacuum. Maintaining a continuous vacuum over 500+ kilometers. There’s gotta be a lot of pumps using a lot of energy, considering it would be impossible to prevent leaks over such a humongous distance.
      3. Vacuum failure. With such a large distance, there’s bound to be failures along the hyperloop. The train can probably slow down along these sections, but they would need to be prepared. Reparation means many hours of downtime, for people who chose a vacuum train presumably to save travel time.
      4. Capacity. A regular long-distance train can take on hundreds of people, which makes the costs tolerable. All of the concepts show very short vehicles, with maybe a couple seats side-by-side. That’d make the cost/person very high.
      5. Embarking/Disembarking. The people have to enter the train somehow, either through pressurizing a very long section, or having very precise door section which the train mounts to.
        • In the case of pressurizing, it would take a long time for pressurize -> passengers move -> depressurize, adding long wait times at the station.
        • In the case of entrance doors, this hampers flexibility. There can’t be longer trains than what the station is designed for, the train design and length must always be the same, and any wear&tear on the train could potentially prohibit making a proper seal with the exit door.
      6. Related to the above point, long-distance railroads have many sub-destinations. Imagine having to pressurize->depressurize at every station, when a regular train just has to stop and open the doors.

      I believe all of the above points would make a vacuum train economically stupid and impossible.

      Just to escape the friction of air?

    • Ado@lemmy.ml
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      1 year ago

      I don’t think I need to know how air drag works, I just need to know that busses and trains exist. Build up those systems and you’ll have better efficiency than anything requiring cars.

        • bluGill@kbin.social
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          1 year ago

          A lot of hyperloop proposals are pods not trains. Never mind that a little thought proves the concept is only viable with large trains.

      • blazera@kbin.social
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        1 year ago

        yeah I think you’ve got that vegas loop in mind, that’s not what a hyperloop is. a hyperloop is a train, a maglev train inside a vacuum tube.

        • Atemu@lemmy.ml
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          1 year ago

          Have you seen how hard it is to convince governments to invest the most efficient and cost-effective medium to long distance mean of transport we have today that has proven itself over hundreds of years?

          Now imagine trying to convince them to invest in pretty much the same thing but with a tiny fraction of the throughput and many times the cost.

          It’s not much of a technical issue. They can be built and will be feasibly buildable in the not too distant future. The problem is economical.

          (Though I must admit that I could absolutely see the US investing in Hyperloops to transport aristocrats instead of high-speed rail for the peasants. I was more thinking of countries here that are republics with half-decent democracies.)

    • magic_lobster_party@kbin.social
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      1 year ago

      Maintaining ordinary railroads is challenging enough. Hyperloop is like a heavily scaled up version of the vacuum tubes found in CERN, which is already one of the biggest engineering achievements of all time. I can’t imagine how hyperloop is going to operate safely at all.

      • blazera@kbin.social
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        1 year ago

        Hyperloop is like a heavily scaled up version of the vacuum tubes found in CERN

        Where are you getting this from? I havent seen anyone propose hyperloop vacuums be that extreme.

      • blazera@kbin.social
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        1 year ago

        Traveling through a vacuum gives crazy efficiency gains, especially at high speeds as air drag goes up exponentially with speed. So you can travel faster and with less energy needed.