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8125Re: [carfree_cities] McLanes vs. Train Lanes

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  • J.H. Crawford
    Feb 27, 2005
      Hi All,

      Todd said:

      >Aside from things I simply didnt know, I think my only mistake was the
      >suggestion of the necessit of tilting trains.

      >The fact that the tracks would
      >already be tilted would make that unnecessary it seems (unless tilted tracks
      >are much more expensive than non-tilted ones).

      I never suggested tilt-body trains. They don't help much. The real
      issue in curve negotiation is wheel climb--the flange of the outer
      wheel climbs up over the rail and you're in big trouble. I've never
      seen how tilt-body trains are any better in this regard than regular.
      They ARE more comfortable for the passengers, but the degree of
      lateral acceleration is already not high. Unlimited superelevation
      can allow fast running in a "balanced" condition, where there is
      NO lateral force on the rails (unless the train comes to a stop
      between stations, a circumstance that must be considered from the
      outset).

      >Then again Joel mentions that
      >the tilts of tracks are limited so we dont have oranges and copies of his
      >new book etc.

      This is not treated at all in the next book. Superelevation is
      only limited in conventional practice because of the limitations
      of conventional freight trains, which would not be allowed on
      this system (overhead clearances are too low to permit it anyway).

      >Also, I mentioned that the ICE3 trains have more power to go up steeper
      >grades, this is because they are in fact EMUs (Electric multiple units) and
      >have propulsion units spread throughout the train.

      This is interesting. Do you have any statistics on this, Todd?

      >I suppose the only caveat in all this if people actually want to tear down
      >the freeways. That is unlikely but I would hate to see a so-called freeway
      >being preserved - with all of its negative effects aside from traffic -
      >because the railway lobby wants it.

      No, this is not such a sad thing. If there are ever no cars to
      run on the freeways, we'll probably need at least four lanes
      to handle the rail traffic. Remember that really heavily used
      rail lines, like the Pennsy in northern NJ, need to be SIX tracks
      wide. This is fairly rare, but it does arise.

      Regards,



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      J.H. Crawford Carfree Cities
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