Looks like they could totally fit a bike rack on these things too!

  • BoscoBear@lemmy.sdf.org
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    6 months ago

    I think you make some good points.

    Most importantly, the hard part of these projects is the right of way. I agree that it should be used to its greatest advantage. I suspect you could rip these rails up, lay down kiddie train rails and a bike path for the same price.

    The biggest reason for standard monorails is grade separation.

    The burden of air resistance is negligible at these speeds. The rolling resistance, lifespan, and pollution of rubber tires is a disadvantage, but at these speeds it is probably the best use of rubber tires.

    You only need two lanes for pods at passing tracks. The need for continuous two way traffic probably means the capacity has outgrown this solution.

    • litchralee@sh.itjust.works
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      6 months ago

      You also have good points. As it happens, near my metro area is a park which does indeed have a children’s railroad that both crosses and then parallels a major bike trail. And it’s absolutely adorable.

      The point re: rubber rolling resistance and pollution is well taken. But I don’t think the air resistance is negligible here. I realized now that the linked article doesn’t describe the speed of this monorail, so I had assumed it was something like a sauntering 30 kph (18 mph), which if available 24/7/365 from rural areas into the urban core and had consistent on-time performance, that’d be excellent.

      But this other article lists the speed for these pods as 60 kph (37 mph). That’s kinda terrifying for a pod, where just the gyro components weigh 650 kg (1433 lbs), and definitely implicates air resistance. At that speed, the gyro had better be robust enough to counter sudden winds that would threaten to tilt one pod into the path of an oncoming pod.

      Now that I think of it some more, on a horizontal curve, roads will widen the lanes so that vehicles won’t side-swipe each other. And tracks are set farther apart than on straightaways, for the same reason. But the pair of rails? They’re always 1435 mm (4 ft 8.5 in) apart, so will the pods be designed for a maximum curve speed and angle, or will passing be disallowed on curves?

      Finally, I will concede that requiring two way pod lanes would definitely be a success story. But seeing as they’re planning to use abandoned trackage, even a single-track railroad will already provide two “lanes” for their pods for free. If they had right-of-way that doesn’t have existing track, it’s not clear if their plan is to install a single rail.

      EDIT: I forgot the other article’s link: https://update.phoenixcontact.com/en/balancing-act-on-the-rail/

      • BoscoBear@lemmy.sdf.org
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        6 months ago

        I would say 30kph would be plenty especially for nonstop on-demand service. 60kph sounds unrealistic.

        The reason I think you could lay new track is that kiddie train track is really cheap and used railroad rail is pretty valuable.

        The value of a scrap railroad track varies by material and its condition. Depending on its dimensions and shape, a ton can range from $300 to $750. For example, an R50 track will fetch a price of between $200 and $750, while an R65 way will cost more than twice that.

        It would be simple to make self driving golf carts that followed a magnetic or inductive guideway or even used a virtually guideway with gps. There are a few of these available off the shelf right now. One I remember is dutch and there was another produced in Great Britain.

        • litchralee@sh.itjust.works
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          6 months ago

          The reason I think you could lay new track is that kiddie train track is really cheap and used railroad rail is pretty valuable.

          Railroad track is certainly valuable, although its removal and rehabilitating the rail bed can add up. Here in the USA, a number of disused railroads are simply left in place, usually only removing the points which connect to the mainline. I’m informed that part of the reason is due to regulations that make it hard to re-establish a rail segment if the rails are fully dismantled. I also have to imagine that if the rails are too valuable, unscrupulous scrap dealers would have made off with them already.

          I certainly agree that any track used in service of a self-balancing pod has better of good or excellent quality, since we absolutely do not want pods coming off due to a rail issue.

          I do like that all these ideas are essentially recreating the lazy river experience, but with no inflatable donuts lol

          P.S. I added the right link to my last post; I forgot to paste it earlier

          • BoscoBear@lemmy.sdf.org
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            6 months ago

            Rail is hard to steal because it is hard and heavy. Look at the price of small sections used for anvils. It was a shock for me.

            I participated in a exploration of PRT that was done by someone at University of Washington a few decades ago. One of the things discussed was the comparison of travel times between slow PRT and fast light rail. It doesn’t take many 60-90 second stops to really slow your average speed.

            It’s kinda like that brain teaser: If a race car does the first lap at 60 miles an hour how fast does he have to go on the second lap to average 120.