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Re: [carfree_cities] Re: Fuel-Sipping Trains

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  • Joel Siegel
    I m hoping this is on-topic (certainly follows the subject line). It concerns the fuel/energy requirements for _high-speed_ rail. George Monbiot has an
    Message 1 of 18 , Jun 13, 2007
      I'm hoping this is on-topic (certainly follows the subject line). It concerns the fuel/energy requirements for _high-speed_ rail.

      George Monbiot has an article in the 7-May-2007 issue of The Nation. Titled "Flying Into Trouble", it mostly covers the environmental damage (particularly greenhouse emissions) resulting from air travel.

      http://www.thenation.com/doc/20070507/monbiot (subscription required)

      A paragraph from the article on that topic: "Carbon dioxide emissions per passenger mile from a standard airliner are very similar to those from cars. But you can cover nearly 15,000 miles in one day by plane. The CO2 produced by planes is augmented by the other greenhouse gases they release, magnifying its effect by 270 percent. This means that flying is one of the most destructive things we can do."

      Monbiot also observes that "new [aviation] fuels are the stuff of fantasy[]", that "[t]he standard jet engine has more or less reached the limits of efficiency, and there is no replacement anywhere near production[]", and that new aircraft designs which might cut fuel consumption by 30% or so are barely in the "concept" stage, with unproven workability or stability.

      High-speed rail does not escape criticism, however.

      "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."

      In general, the last sentence is the important one: Monbiot contends that high speed is incompatible with environmental stewardship, particularly with preventing runaway climate change, at least with today's technologies or those whose viability becomes reasonably foreseeable in the near future.

      Thoughts?

      Regards,

      Joel (Siegel)
    • J.H. Crawford
      ... That s physics at work: resistance increases with the square of the speed. There are ways around it, to a degree. If the trains are light, energy
      Message 2 of 18 , Jun 13, 2007
        Joel Siegel said:

        >High-speed rail does not escape criticism, however.
        >
        >"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."

        That's physics at work: resistance increases with the
        square of the speed. There are ways around it, to a degree.
        If the trains are light, energy requirements are much
        reduced. If the streamlining is good, resistances is
        also reduced. I have heard (no substantiation) that the
        double-decker TGVs running from Lyon to Paris use about
        the same amount of seat-mile energy as conventional
        trains despite running at 300 km/hr or so. They are
        very light weight, have low frontal area for the number
        of seats, and the streamlining is good. That's about
        the limit of the technology, IMHO. I also think that
        it probably doesn't make sense to run trains much above
        300 km/hr. The newest TGVs are 360, but the cost is
        large and the actual reduction in travel time is not
        great. Not worth the cost?

        It is NOT all that hard to store electricity, although
        there are losses. Pump storage is proven and can be
        used, essentially, to store electricity. Pump water
        up hill when there's plenty of electricity. Let it
        flow back down hill to turn generators when there's
        not enough. Losses are about 30% IIRC.

        But, in general, things are probably going to have to
        slow down, unless you go with the nuke option.

        Regards,

        Joel




        ----- ### -----
        J.H. Crawford Carfree Cities
        mailbox@... http://www.carfree.com
      • 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 3 of 18 , Jun 14, 2007
          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 4 of 18 , Jun 14, 2007
            > 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 5 of 18 , Jun 14, 2007
              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 6 of 18 , Jun 14, 2007
                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 7 of 18 , Jun 17, 2007
                  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 8 of 18 , Jun 17, 2007
                    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 9 of 18 , Jun 18, 2007
                      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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