h a l f b a k e r yA few slices short of a loaf.
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One of the problems of cities is lack of real estate to
build additional roads.
However, engineers at BorgCo, after a large lunch
and a pleasant afternoon in a pub, have developed
an almost foolproof solution.
Existing roads carry traffic only on their single
planar upper surface.
However,
if the space occupied by a conventional
roadway was used to accomodate a cylinder, the
interior of the cylinder would have an area of pi x
the width of the cylinder; over three times bigger.
Therefore, for space-constrained limited access
urban thruways, the road is replaced with a
sucession of sturdy frames supporting long
cylindrical sections, which are spun such that the
centripetal force at the top of the cycle is about
0.8g, giving about 1.8g at the bottom.
This allows the entire inner surface of the cylinder
to be used for traffic.
Occupants will experience nothing more than a"
gravity" field that that averages out at 1.4g, not a
problem when seated.
To the occupants of the tunnel, there is no
sensation of rotation as the entire environment is
rotating.
O'Neill cylinder
http://en.wikipedia.../O%27neil_cylinders [CraigD, Aug 19 2012]
Round Up amusement park ride
http://en.wikipedia...Round_Up_%28ride%29 [CraigD, Aug 19 2012]
Wall of death
http://www.youtube....watch?v=mjxa2Lklugs This? [tatterdemalion, Aug 20 2012]
[link]
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Nicely halfbaked idea, [8th of 7] kinda an O'Neill cylinder on Earth but youve dropped a term in your calculations.
If the cylinders centripetal acceleration is 1.8 g, the feels like gravity acceleration at its top is 0.8 g (1.8 - 1), but at the bottom not 1.8, but 2.8 g (1.8 + 1). |
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As a thrill ride, the sight of vehicles (or pedestrians) above, below, and all sides would be worth it to me, but Im pretty sure the ralph factor would be about the same as on a Round Up amusement park ride, and more than the commuting public would be willing to tolerate. |
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"I don't understand it, officer. I just made a quick
lane change and suddenly I was upside-down on top
of this caravan." |
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(Which prompts the comment that the tunnel need
not rotate; simply have helical lanes and a
recommended minimum speed. Congestion would
be self-clearing.) |
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Damned minus signs
yes, correct, but even
so the average g is still only 1.8, quite
tolerable by a healthy victim, sorry user. |
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Neglecting coriolis force, the chunder
coefficient should be within limits, as on the
fairground rides the patrons have external
fixed references - in the tube, everything
moves together. |
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Can't picture it, can you elaborate a bit on the orientation of the cylinder to the roadway it replaces? And a bit about how it interfaces with non-cylindrical parts of the world, that is to say, how does one become "on" the cylinder from a state of previously being "not on" it? Or not. |
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Bicycles work better in high velocity. Meaning they can
accelerate with gravity and follow a curved path. |
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Unless the vehicles are all wedge shaped, this is
going to have a very sharp height limit. |
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Getting on is simple. You drive at high speed onto a very wide moving sidewalk that is going the same direction you are going. Restart you car since it stalled when the wheels came to a sudden stop. Start driving forward at the designated speed, then make a left turn when instructed and floor the accelerator. |
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The "moving sidewalk" you are on is going at the same speed as the surface of the rotating cylinder, so if you get the timing right, you enter the tube just as you go off the edge of the moving sidewalk and don't have any laterall acceleration, you just feel the force of gravity increase (plus some sudden rotational acceleration). If you get to the edge of the sidewalk too early, you drive off the edge before the tunnel, but because of your sideway momentum you slamm into the outside of the tunnel which is suitably reinfoced. If you are late, you miss the entrance and spin out in the gravel deceleration area. If you are just a tiny bit late, the front of the car gets into the tube and the front gets lifted, but the back doesn't so the car goes spinning and tumbling through the air. |
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Excellent. This idea is quite clearly the safest and easiest way of making best use of our road capacity. |
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//an almost foolproof solution.//
[marked-for-tagline] |
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// how does one become "on" the cylinder
from a state of previously being "not on" it // |
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You've seen The Italian Job, haven't you?
Well, just like that. |
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I'd like to see a race track that spins around the stadium pinning the cars to the vertical surface making them go much faster relative to the audience. They'd also be easier to view since they'd all be racing on a vertical wall. It would be like watching the cars from overhead on a conventional racetrack. |
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But back to your idea, could you have a non-spinning version of this where the cars just have 3 spiral lanes where they all supply their own centripetal force? They might get a bit dizzy but other than that it should work. |
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One problem with this is that it wont really solve traffic
congestion because the tunnel can only be entered and
exited flat on the ground. So enhanced traffic flow in the
tunnel will result in back ups particularly when exiting. |
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I saw a real "wall of death" at a travelling fair recently - they had two motorbikes riding round inside a 5 metre high vertical wall, with the riders riding sidesaddle with no hands. They would zoom up the top of the wall (where the spectators were, leaning over) and then change direction at the last second. Terrifying stuff. |
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//could you have a non-spinning version of this
where the cars just have 3 spiral lanes// |
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May I refer the good Doctor to the annotation of my
esteemed colleague, [MaxwellBuchanan] toward the
northern pole of this page? |
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//May I refer the good Doctor to the annotation of my esteemed colleague, [MaxwellBuchanan] toward the northern pole of this page?// |
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Oopsie doodle, missed it. Credit (or blame) for that idea goes to you. |
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// add some more horizontal levels within the
square tunnel. // |
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Two words: "Cypress Structure". |
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//Two words: "Cypress Structure"//
Perhaps Im not cut of the same bold stuff as a well-liquored BorgCo engineer, but Id be reluctant to bring up earthquakes and our proposed giant wall of death spinning tunnels in the same conversation. |
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Some example numbers seem in order:
Lets use a US standard 10 3.7 m wide lane roadway, with a 2 slightly less wide median strips, for a total circumference of 44 m, radius 7 m;
Rather than 1.8 g cent accel, use 1.22 (12 m/s/s);
This gives rim/roadbed speed of 9.17 m/s (20.5 MPH), period of rotation 4.8 s. |
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Not too bad numbers for the necessary entering/exiting machinery. Moving sidewalks could manage it, as could a well-steered pedal bike or automobile, or a run and jump. Moving too fast (0.89 m/s (2 MPH)) anti-spinward could drop you from the topside, so as [MaxwellBuchanan] notes, lane changes need be made with care. |
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Im thinking a burner (or similarly culturally inclined folk) project of record-setting scale could actually prototype this as a sort of black market amusement ride. Harness everybody into chairs for the entering/exiting, and this could be a commercial park ride. |
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On a test scale, it could be demonstrated as
follows: |
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Place a car in the tube, facing
circumferentially. |
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The tube starts to rotate, increasing to the
"ooperating" speed. At the same time, the car
accelerates in the opposite direction,
remaining at the lowest point of the tube,
matching velocity. |
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When the tube reaches operating speed, the
driver gets a signal, which is their cue to turn
sharply along the axis of the tube, and at the
same time braking sharply. |
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The vehicle should come to rest facing along
the primary axis, and "stuck" tto the inner
wall. |
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Yes, but where does the driver come to rest? |
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Their first stop will be a mortuary van
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//Perhaps Im not cut of the same bold stuff as a well-liquored BorgCo engineer// |
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