[HN Gopher] London's Victorian Hyperloop: a pneumatic railway be...
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London's Victorian Hyperloop: a pneumatic railway beneath the
capital (2013)
Author : frontrowseat
Score : 47 points
Date : 2022-07-18 15:28 UTC (7 hours ago)
(HTM) web link (www.newstatesman.com)
(TXT) w3m dump (www.newstatesman.com)
| helsinkiandrew wrote:
| The images don't appear for me but do on the original New
| Statesman article:
|
| https://www.newstatesman.com/politics/2013/12/londons-victor...
| lambic wrote:
| Seems like a bad cert
| dang wrote:
| OK, changed from https://citymonitor.ai/transport/victorian-
| hyperloop-forgott.... Thanks!
| neonate wrote:
| https://web.archive.org/web/20210929030913/https://www.newst...
| rob_c wrote:
| dang wrote:
| " _Please don 't fulminate._"
|
| " _Eschew flamebait. Avoid unrelated controversies and generic
| tangents._ "
|
| https://news.ycombinator.com/newsguidelines.html
| ballenf wrote:
| All the problems from the hyper loop involve the energy of a
| vacuum. Why not accelerate the air in the tube in an actual loop?
| You reduce air pressure in front and increase it behind the car?
| Train cards could have baffles to allow for stops (let the air
| pass by the car).
| addicted wrote:
| The problem with the hyper loop is that it's not clear it
| solves any real problems.
|
| For subway style intra city transit the rapid speeds and
| acceleration are hardly useful since you have many short travel
| segments. It's a non starter there.
|
| For inter city travel, the biggest challenge is getting right
| of way and building infrastructure between the 2 cities. This
| is hard enough to do for regular HSR, which has far more
| tolerance than the hyperloop vacuum tube would. It's not clear
| how one would solve that for the hyperloop.
| gamblor956 wrote:
| Damn you for going beyond first principles and actually
| thinking about why something that seems so simple hasn't
| actually been done before! /s
| zdragnar wrote:
| Air is removed to reduce drag / pressure on the car. If,
| instead of removing it, it were accelerated, you would need one
| of two things:
|
| 1) Move the air at the maximum speed of the cars. This
| optimizes for that speed, but increases wear on the brakes and
| total braking distance by putting forward pressure on the train
| as it slows down.
|
| 2) Move the air at some average speed. Now you increase overall
| energy consumption having to fight (some) drag, while also
| having (slightly) increased brake wear and stopping distance.
| Nobody wins here, and you'd need to do a lot of fancy maths to
| figure out the right balance between energy consumption of the
| train and air-moving fans versus energy consumption of creating
| and maintaining a vacuum.
|
| Alternatively, you could get crazy complex by having something
| like blast doors sitting between different zones (acceleration,
| top speed, deceleration) that automatically open and close, and
| try to create loops of air at different speeds and directions
| in each of the sections. I'm not even going to bother guessing
| how difficult to safely operate or how efficient such a system
| would be.
| cosmodisk wrote:
| If you are ever in London, this place is amazing:
| https://www.postalmuseum.org/visit-us/what-to-expect/mail-ra...
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(page generated 2022-07-18 23:01 UTC)