h a l f b a k e r yA riddle wrapped in a mystery inside a rich, flaky crust
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Spiral escalator used as a replacement
for lifts in the London Underground (re-
using the vertical shafts). |
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Read the idea again, and you'll find a different form and technology. |
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wow, this was a tough idea to visualize. I had issues with the platforms recycling until I saw [hippo]'s first link. That is taken care of, but now I too have an issue with the "down" part. Escalators work so well because they have a leisurely travel rate which allows the average person to transition from standing to walking without too much trippng involved. Here in the states, by law, that speed can be no more than .45 meters per second. Assuming this speed on the way up, geometry tells us that passengers coming down would be traveling at roughly 1.82 meters per second in order to both counteract the screws upward force, as well as make enough progress downward to not cause a log-jam of people waiting to go down. That's leg breaking speed for even a healthy adult. Even presupposing a braking system to slow down passengers upon their eventual exit, the distance between platforms on the down screw would have to be almost 3 times as far apart as on the upside, and that would mean a que of passengers trying to get back down. I think [FarmerJohn] may have foreseen this, so I withold my vote till he gives us some more details. |
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[eyeguy] If we say an up rider is moving 0.45 mps relative to the screw (and 0 mps relative to an external observer), then a down rider could move 0.45 mps relative to the screw in the other direction (0.9 mps relative to an observer) to make similar vertical progress. |
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An observer on the turning screw would see up riders and down riders passing at the same speed in opposite directions. This tells me that the need for platforms on both threads is the same per meter, meaning no queues. Of course some sort of top acceleration and bottom deceleration zones would be needed for down passengers. |
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This would be fun to build. Perchance a quick sketch? |
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so on the down screw (giggles childishly), how do you manage the platforms? They have to be going .90 mps relative to the passenger so they can get on, accelerate to 1.35 mps to make headway against the up-going screw (giggles again), then decelerate to .90 mps so the passenger can get off again. Inevitably there would be imbalance in the amount of people it could bring up vs. the amount it could bring down, not to mention the complexity of keeping the passanger platform behind the currently exiting one from slamming into the one ahead it. Hey! can it have three blades? Two for going down and 1 going up? Wait, one more thing... "downward screw" (giggles with maniacal childish laughter yet again). |
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[eyeguy] I still see a start acceleration zone 0.45 to 0.9 mps only and an end deceleration zone to 0.45 as sufficient, and the platforms only near each other at start and end. |
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in that case I think I have no further issues with this idea, seems complicated, but workable. And who wouldn't want to ride a pyramidal turning thingy in the mall. For free no less. + |
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This would be really kewl. ++ |
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