Lalon SanderOct 18
"Humans aren’t very efficient movers—until you put us on a bicycle, when we become some of the most energy-efficient land travelers in the animal kingdom.": https://www.scientificamerican.com/article/a-human-on-a-bicycle-is-among-the-most-efficient-forms-of-travel-in-the/
Show threadSchrottkatze (-> treehouse.systems)
@lalonsander
i'd be interested in where trains are in that.
Oct 18 at 9:17amWeb
Show threadviqOct 18
@schrottkatze @lalonsander I've seen once table or graph with numbers, and trains are still much worse in that respect than bikes.
Show threadWesDymOct 19
@viq True. But for motorized transport of more than a bike or trike could carry, trains easily beat out every other common surface motor transport. That's why I almost always mention them when discussing transit. Over any distance longer than you'd comfortably commute by bike, a train wins every time, and if your goal is an energy-efficient society, rail must be a major component.
Show threadviqOct 19
@wesdym you'd need a hell of a lot of bikes to carry what a train can. But it still takes more energy to move it than this amount of bikes would have used.
Show threadWesDymOct 19

@viq I made exactly the qualification you're offering here in the comment you responded to.

I don't understand why some people seem to feel a need to argue just for the sake of arguing. Especially when the point they raise was already made by the person they're raising it too.

Show threadviqOct 19
@wesdym I guess I misunderstood or missed it, sorry.
Show threadlis  Oct 18
@schrottkatze @lalonsander considering a diesel locomotive which uses 6-20 g diesel per t·km; let's assume 10 for simplicity's sake. diesel has an energy density of 43 kJ/g, or about 10 kcal/g.

that would work out to 100 kcal/t·km, or 0.1 cal/g·km. so about the same order of magnitude as a human on a bike. possibly even lower. electric locomotives may be even more efficient.

that is, if you count energy per total mass moved. a bike typically has less than a quarter of the mass of the human riding it, but a train can weigh many times more than what it's transporting, especially if what it's transporting is humans. for instance, a crowded twindexx carriage might transport something like 250 people. assuming an average human+luggage weighs 100 kg, that's 25 t of payload in a >50 t carriage, plus maybe 75 t of locomotive…
Diesellokomotive – Wikipedia

Show threadWesDymOct 19

@lis Yep! Even 'inefficient' locomotives end up with a very high overall efficiency compared to any other motorized surface transport bigger than a bike or trike. Rail trainsport is just inherently very efficient, for the energy needed to move mass along a rail.

If you want a high-density, high-efficiency MASS-transit system, always consider what role rail could have in it.

Show threadDerPumu (he/him)Oct 18
@schrottkatze @lalonsander they might be near that unmarked yellow dot in the 100kt area