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Re: Fuel-Sipping Trains

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  • dawie_coetzee
    There are secondary effects that are not reflected in any of these comparisons. For instance, a railway station within easy reach of pedestrians will both be
    Message 1 of 18 , Jun 14, 2007
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      There are secondary effects that are not reflected in any of these
      comparisons. For instance, a railway station within easy reach of
      pedestrians will both be symptomatic of and increase the viability of
      pedestrian-accessible destinations in general. Compared with car travel
      there is therefore at worst a lesser tendency to generate a need to
      travel. In practice there might well be a tendency to reduce the need
      to travel.

      We all know how car-dominated environments create dependence on cars,
      requiring that we take longer trips more often. A truer comparison
      might be 1km by train to perhaps 8km by car, 7km of the latter
      contributed solely by the sort of environment associated with that mode
      of transport. Has anyone actually quantified this?

      -Dawie

      --- In carfree_cities@yahoogroups.com, Richard Risemberg <rickrise@...>
      wrote:
      >
      > > Fuel-sipping trains
      > > June 11, 2007
      > >
      > >
      ...
    • Jym Dyer
      ... =v= In the U.S. cars are rarely filled to seating capacity. The average ridership is slightly over 1 person per car. So it s hard to take numbers like that
      Message 2 of 18 , Jun 14, 2007
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        > A 26 MPG Honda Civic fully loaded with five passengers?
        > 130 passenger miles per gallon.

        =v= In the U.S. cars are rarely filled to seating capacity.
        The average ridership is slightly over 1 person per car.
        So it's hard to take numbers like that seriously.

        =v= Also, wow, Honda Civics are way down to 26 MPG now?

        =v= One complication in these comparisons is that passenger
        rail in the U.S. has very little dedicated track. For the
        most part Amtrak runs on track owned by freight companies.

        =v= Another complication is that Amtrak is subject to a dogmatic
        "business model" that competing modes are not. The ideology is
        that Amtrak should turn a profit, and there's a budget fight for
        its small subsidy every year. So service keeps getting hurt and
        the trains do such things as haul freight along with passengers
        (preventing a switchover to lighter trains).

        =v= Meanwhile, of course, cars and planes enjoy a staggeringly
        high and rarely-mentioned subsidy.
        <_Jym_>
      • Greg Steele
        There is an accountant joke I once heard where three accountants are applying for an executive position. The CEO of the company asks each of the candidates
        Message 3 of 18 , Jun 14, 2007
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          There is an accountant joke I once heard where three accountants are
          applying for an executive position. The CEO of the company asks
          each of the candidates what is 2+2. Two of the applicants says 4
          and don't get the job. The third, who gets the job, asks the
          CEO, "What do you want it to be?"

          I am not aware of any studies that would answer some important
          questions raised in this discussion and in the larger discussion
          about funding for rail.

          The laws of physics say that the faster an object moves through
          space the more resistance it will encounter, therefore, more energy
          is required to achieve higher speeds. I am sure that the field of
          aero-dynamics has can provide formulas to quantify this in terms of
          frontal area and speed. What is lacking is a quantified functional
          relationship of increased weight and drag from adding one additional
          coach car to a train-set. Intuitively, it seems that adding cars
          (therefore, more passengers) would add a very small increase in
          energy usage while greatly improving the passenger- miles/gallon
          ratio. Therefore, one could state the passenger- miles/gallon to be
          anything they wanted to by adding or subtracting the number of
          coaches/passengers per train. There are of course practical limits
          to how long a passenger train can be in terms of station platforms
          and crews. In addition, at some point the weight of the train will
          require an additional locomotive which alters the equation.

          I have heard passenger – miles/gallon figures that are all over the
          map. Until someone does some hard science on this that deduces the
          issue to friction of steel wheels on steel rails vs. rubber wheels
          on assault. I suggest that we look at any calculation of passenger –
          miles/gallon will a great deal of skepticism.
        • J.H. Crawford
          This is all pretty tangential. The basic physics are: It takes lots of energy to accelerate a train, and the total amount of that energy increases with the
          Message 4 of 18 , Jun 14, 2007
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            This is all pretty tangential. The basic physics are:

            It takes lots of energy to accelerate a train, and the
            total amount of that energy increases with the SQUARE
            of the speed.

            It takes lots of energy to drag trains up hills; this
            is related to weight and elevation, not to speed.

            Long, thin objects have high "Reynolds Numbers" which
            means that the amount of air drag is considerably lower
            than for short, fat objects.

            Mass of a train has no effect whatever on the amount
            of aerodynamic drag.

            Light, long, streamlined trains are the most efficient.
            Slower trains are more efficient than faster ones, all
            other things being equal.

            Again, the TGV double-decker gets good efficiency despite
            its very high speed.

            Regards,


            ----- ### -----
            J.H. Crawford Carfree Cities
            mailbox@... http://www.carfree.com
          • Matt Hohmeister
            Actually, this brings up a question I ve been wondering for some time. In an era of dwindling oil supplies, are we better off with jets or ships? 747 or QM2?
            Message 5 of 18 , Jun 17, 2007
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              Actually, this brings up a question I've been wondering for some time. In an era of dwindling
              oil supplies, are we better off with jets or ships? 747 or QM2? Or is there another solution?
              Anybody?

              > "The obvious replacements for planes are scarcely better. Fast passenger ships appear to
              be even worse for the environment than jets. ... [Paragraph] Nor are ultra-high-speed trains
              the answer. Though trains traveling at normal speeds have much lower carbon emissions
              than airplanes, Professor Roger Kemp of Lancaster University shows that energy consumption
              rises dramatically at speeds above 125 miles per hour. Increasing the speed from 140 to 220
              mph almost doubles the amount of fuel burned. If the trains are powered by electricity, and if
              that electricity is produced by plants burning fossil fuels, they cause more CO2 emissions
              than planes. Running trains on renewable electricity is certainly possible, but this faces
              problems: Trains must run on time, and that means there is little room for 'demand
              management,' which means reducing the electricity load in response to fluctuations in
              supply. In all transport systems, high performance is incompatible with low consumption.
              The faster you go, the more energy you need."
            • Richard Risemberg
              ... Ships do not have to be powered by oil or coal. Highly refined sailing vessels with solar auxiliary power for days of calms and for harbor maneuvering can
              Message 6 of 18 , Jun 17, 2007
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                On Jun 17, 2007, at 8:40 PM, Matt Hohmeister wrote:

                > Actually, this brings up a question I've been wondering for some
                > time. In an era of dwindling
                > oil supplies, are we better off with jets or ships? 747 or QM2? Or
                > is there another solution?
                > Anybody?
                >
                Ships do not have to be powered by oil or coal. Highly refined
                sailing vessels with solar auxiliary power for days of calms and for
                harbor maneuvering can move considerable tonnage and numbers of
                passengers. However, it is obvious that if we are serious about
                sustainability, we will have to accept that international trade and
                travel will be slower and more expensive. (Although someone, upon my
                telling them this, suggested that sail transport labor costs could be
                lowered by using crews of slaves...I hope they were kidding.)

                And no, I don't think nuclear-powered ships are the answer!

                http://tinyurl.com/25u5bt

                Rick
                --
                Richard Risemberg
                http://www.bicyclefixation.com
                http://www.newcolonist.com
                http://www.rickrise.com
              • dawie_coetzee
                Localization. ...it is obvious that if we are serious about sustainability, we will have to accept that international trade and travel will be slower and more
                Message 7 of 18 , Jun 18, 2007
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                  Localization.

                  "...it is obvious that if we are serious about sustainability, we
                  will have to accept that international trade and travel will be
                  slower and more expensive."

                  Precisely. I know Joel Crawford takes a somewhat contrary position in
                  his book, but I'm a firm localist. Pedestrian cities and localized
                  economies are perfect for each other. Indeed, the one only comes to
                  full fruition in the context of the other.

                  -Dawie



                  --- In carfree_cities@yahoogroups.com, Richard Risemberg
                  <rickrise@...> wrote:
                  >
                  > On Jun 17, 2007, at 8:40 PM, Matt Hohmeister wrote:
                  >
                  > > Actually, this brings up a question I've been wondering for some
                  > > time. In an era of dwindling
                  > > oil supplies, are we better off with jets or ships? 747 or QM2?
                  Or
                  > > is there another solution?
                  > > Anybody?
                  > >
                  > Ships do not have to be powered by oil or coal. Highly refined
                  > sailing vessels with solar auxiliary power for days of calms and
                  for
                  > harbor maneuvering can move considerable tonnage and numbers of
                  > passengers. However, it is obvious that if we are serious about
                  > sustainability, we will have to accept that international trade
                  and
                  > travel will be slower and more expensive. (Although someone, upon
                  my
                  > telling them this, suggested that sail transport labor costs could
                  be
                  > lowered by using crews of slaves...I hope they were kidding.)
                  >
                  > And no, I don't think nuclear-powered ships are the answer!
                  >
                  > http://tinyurl.com/25u5bt
                  >
                  > Rick
                  > --
                  > Richard Risemberg
                  > http://www.bicyclefixation.com
                  > http://www.newcolonist.com
                  > http://www.rickrise.com
                  >
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