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How do trains stay on track? (2009) [pdf]

139 pointsby scrrrabout 10 years ago

13 comments

userbinatorabout 10 years ago
It&#x27;s similar to the principle that keeps flat belts from slipping off their pulleys...<p><a href="http:&#x2F;&#x2F;woodgears.ca&#x2F;bandsaw&#x2F;crowned_pulleys.html" rel="nofollow">http:&#x2F;&#x2F;woodgears.ca&#x2F;bandsaw&#x2F;crowned_pulleys.html</a><p>...even in extreme situations such as this:<p><a href="http:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;File:Transmissionsriemen.jpg" rel="nofollow">http:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;File:Transmissionsriemen.jpg</a>
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derrasterpunktabout 10 years ago
additionally, here is Richard Feynman explaining it: <a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=y7h4OtFDnYE&amp;index=7&amp;list=PL04B3F5636096478C&amp;spfreload=10" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=y7h4OtFDnYE&amp;index=7&amp;list=PL0...</a>
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kpsabout 10 years ago
I wondered, how would this work with an axle-less low-floor bogie? The answer I found here[1] is — it doesn&#x27;t. “<i>… there is only a single series of trams that have these bogies, later versions returned to the traditional type with axles. … The wear problem is because those bogies don&#x27;t seem to track as well, they go from left to right in the track</i>”. The implication is that there were people designing rail vehicles who didn&#x27;t know how they stay on the track.<p>[1] <a href="http:&#x2F;&#x2F;modeleng.proboards.com&#x2F;thread&#x2F;4521&#x2F;chilled-iron-tram-wheels#ixzz3Y3IbKD3i" rel="nofollow">http:&#x2F;&#x2F;modeleng.proboards.com&#x2F;thread&#x2F;4521&#x2F;chilled-iron-tram-...</a>
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guardiangodabout 10 years ago
Here&#x27;s a video demonstration by Richard Hammond of Top Gear.<p><a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=OEo-hQbyy30" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=OEo-hQbyy30</a>
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msraviabout 10 years ago
Also, a great video explaining the working of a differential:<p><a href="https:&#x2F;&#x2F;youtu.be&#x2F;K4JhruinbWc?t=110" rel="nofollow">https:&#x2F;&#x2F;youtu.be&#x2F;K4JhruinbWc?t=110</a>
anentropicabout 10 years ago
anyone know if this was an intentional part of wheel&#x2F;rail design from the start... or they originally intended it to work how we naïvely imagine and by accident it worked this way and was subsequently refined ?
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ChuckMcMabout 10 years ago
In a similar note I wondered what the patent on the railroad ties on the Caltrain bed were (#5104039) and found this: <a href="https:&#x2F;&#x2F;www.google.com&#x2F;patents&#x2F;US5104039?dq=5104039&amp;hl=en&amp;sa=X&amp;ei=s-Y3VevVL5O4oQSvk4HgAw&amp;ved=0CB0Q6AEwAA" rel="nofollow">https:&#x2F;&#x2F;www.google.com&#x2F;patents&#x2F;US5104039?dq=5104039&amp;hl=en&amp;sa...</a> which has an interesting discussion about how the tracks manage to stay underneath the trains.
RockyMcNutsabout 10 years ago
Does the rail have some flexibility to twist and meet the wheel cone at the right angle, and&#x2F;or is it pitched to match the angle of the wheel surface? When I look at the tracks and this wheel shape, I see the wheel riding on a corner of the rail, which is obviously not the case.
anonuabout 10 years ago
The portion on the structural properties of wood a bit further down the PDF are just as interesting.
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a-dubabout 10 years ago
<a href="http:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Hunting_oscillation" rel="nofollow">http:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Hunting_oscillation</a>
noir_lordabout 10 years ago
Edit <a href="https:&#x2F;&#x2F;cmnewsletter.wordpress.com&#x2F;" rel="nofollow">https:&#x2F;&#x2F;cmnewsletter.wordpress.com&#x2F;</a> typical, find the answer just after asking the question below.<p>This was brilliant but I&#x27;m really struggling to find an index page with the rest of them, I can find some of them via google directly.<p>Anyone figure it out?
fishanzabout 10 years ago
I&#x27;ve been on and around many trains and yet I never quite understood the concept of the wheel flange and how track junctions worked until very recently, thanks to a kids show: chuggington.
exDM69about 10 years ago
I would love to try to simulate this with a computer program some day.<p>I really enjoy playing train simulator games, but as far as I understand, none of them actually simulate the physics of cone wheels and flanges.