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Re: Train Physics Problem

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On Tue, 03 Nov 2015 08:38:49 -0600, Odd Bodkin wrote:

> 
> Not insignificant, but not huge either.
> 

Yes, that is correct.

This factor becomes even less significant in the everyday operating
conditions of track gradients where the gravitational forces on
a heavy train dwarf everything else.  A slight 2% grade can bring many
trains to a complete halt.

Trains also must dissipate all that huge energy as heat whenever they
slow to a stop.  Most locomotives can use "regenerative" braking where
the traction motors are run in reverse, using the magnetic field to
produce current.  The current is then directed to resistive elements to
produce waste heat.  Although it could be desirable, I doubt that it
would be possible to use batteries to store that energy, much like
in some automobiles.  AFAIK, no battery could absorb so much power
so quickly.

I wonder why no one else jumped on this question?  It is, after all,
pure physics.  Most would rather rabidly bark at global warming issues
which are not at all appropriate to this group.

But trains are the most efficient way to move stuff on land.  They
can beat trucks on all counts (except for expeditious point-to-point
delivery).  Any society that does not embrace trains is a losing society,
yet currently railroad trackage is being abandoned at a rapid rate.
Before too long, the US will possess only a few "backbone" rail corridors
with all other transport being inefficient and extravagant trucks and planes.

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Train Physics Problem Fabian Russell <root@localhost.localdomain> - 2015-11-03 02:05 +0000
  Re: Train Physics Problem Fabian Russell <root@localhost.localdomain> - 2015-11-03 02:31 +0000
    Re: Train Physics Problem Fabian Russell <root@localhost.localdomain> - 2015-11-03 02:38 +0000
    Re: Train Physics Problem gillyshin <spectrum8@sincity.info> - 2015-11-03 04:38 +0000
      Re: Train Physics Problem gilber34 <fafa@invalid.com> - 2015-11-02 22:58 -0600
        Re: Train Physics Problem Fabian Russell <root@localhost.localdomain> - 2015-11-03 05:22 +0000
  Re: Train Physics Problem Odd Bodkin <bodkinodd@gmail.com> - 2015-11-03 08:38 -0600
    Re: Train Physics Problem Fabian Russell <root@localhost.localdomain> - 2015-11-03 18:19 +0000
      Re: Train Physics Problem Odd Bodkin <bodkinodd@gmail.com> - 2015-11-03 15:00 -0600
        Re: Train Physics Problem Fabian Russell <root@localhost.localdomain> - 2015-11-03 21:22 +0000
          Re: Train Physics Problem Odd Bodkin <bodkinodd@gmail.com> - 2015-11-03 16:55 -0600
            Re: Train Physics Problem Fabian Russell <root@localhost.localdomain> - 2015-11-03 23:19 +0000
        Re: Train Physics Problem Fabian Russell <root@localhost.localdomain> - 2015-11-03 21:31 +0000
          Re: Train Physics Problem Odd Bodkin <bodkinodd@gmail.com> - 2015-11-03 17:17 -0600
    Re: Train Physics Problem benj <none@gmail.com> - 2015-11-03 13:41 -0500
      Re: Train Physics Problem Fabian Russell <root@localhost.localdomain> - 2015-11-03 18:53 +0000
        Re: Train Physics Problem benj <none@gmail.com> - 2015-11-04 18:08 -0500
          Re: Train Physics Problem Fabian Russell <root@localhost.localdomain> - 2015-11-04 23:33 +0000
      Re: Train Physics Problem Odd Bodkin <bodkinodd@gmail.com> - 2015-11-03 15:10 -0600
        Re: Train Physics Problem Fabian Russell <root@localhost.localdomain> - 2015-11-03 21:48 +0000
          Re: Train Physics Problem benj <nobody@gmail.com> - 2015-11-04 02:45 -0500
  Re: Train Physics Problem "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-03 09:19 -0800
    Re: Train Physics Problem "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-04 15:15 -0800

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