4 ms·

> it is the greenest method of moving freight. Water transport, where available, is far greener than trains for moving freight.

rektide 4y ago
Anything you can cite here? I think of water as extremely fantasically high drag. I know that scales inversely down proportional to size, but I still think of rail as the ultra-efficient best option. Would love to read more detailed review/analysis.
- CompelTechnic 4y ago
  https://truecostblog.com/2010/05/27/fuel-efficiency-modes-of-transportation-ranked-by-mpg/#:~:text=Freight%20trains%20consume%20328%20BTU%20to%20move%20a,achieve%203262%20BTU%20per%20passenger-mile%2C%20or%2038.3%20pmpg https://truecostblog.com/2010/05/27/fuel-efficiency-modes-of....
  - candiodari 4y ago
    The TLDR is, on the surface of the earth the slower you're going, the more efficient it tends to be. That even holds for, for example, making trains or cars move slowly: they'll be most efficient at a pretty slow speed. Even planes are most efficient flying 0.0001% above stall speed, the slowest they can possibly go. Most energy in transport goes into moving the atmosphere out of the way. Planes fly high, but that really only makes them comparable to a car. Surprisingly that also means that for really long-range transports even rockets aren't as inefficient as you'd initially think.
- zmgsabst 4y ago
  This thread made me curious, so I looked up engine sizes between trains and boats. A transport ship[1] can carry 9500 TEU with 53,000hp. That’s 190,000 feet of containers, or 36 miles. A train can be 1.5 miles with 4000hp per engine. (According to Google “facts”.) That’s 24 trains to move the same containers, with at least 96,000hp between them. (And that’s ignoring a 1.5mi train will have more than a single engine.) That trains use more horsepower to move the same freight suggests that they’re less efficient. [1] https://en.m.wikipedia.org/wiki/COSCO_Guangzhou https://en.m.wikipedia.org/wiki/COSCO_Guangzhou
  - klyrs 4y ago
    Don't they usually stack containers two high on trains?
    - ElectricalUnion 4y ago
      If you have old infrastructure with low overhead (old tunnels and bridges for example) you can't run that and you need to use rail yards to assemble/disassemble container stacks. It gets expensive fast.
      - klyrs 4y ago
        Hah, fair, I've only lived in the western half of North America, where infrastructure was almost all built after heavy rail lines were laid down.
  - fswd 4y ago
    ... obviously then a floating canal train, would beat both of them. The best of both worlds!
  - repiret 4y ago
    My Toyota Sequoia has close to twice the horsepower than my Cessna 182 did, but the Cessna burnt easily twice as much fuel per mile than the Toyota. The Cessna cruised at 65% power. The Toyota cruises at closer to 10% power, but needs the excess power available when a hill comes along. I suspect a similar dynamic exists with trains and ships - trains need to have power available to go up a hill, while ships probably cruise at closer to full power.
    - rektide 4y ago
      Thanks. To dogpile on what a bad measure that was, I'd add another example: A Tesla Plaid S is 1020HP. Is it less efficient because the engine is oversized? Seemingly the opposite. It's 33kWh/mi compared to the nearby Performance S (with similar 21 inch wheelsizes). If we assessed miles*capacity/hp though, things would look incredibly dire & dark for the Plaid; the worst EV in production perhaps? In general, engine output capacity doesnt really tell us much.
quickthrower2 4y ago
Doesn’t the need for locks make it incredibly slow?
- moring 4y ago
  That would be latency vs. throughput, i.e. good for things that need a steady supply like food, and bad for one-off low-latency things like mail.
na85 4y ago
I'm pretty sure that I read somewhere there are like 100 freighters that produce as much emissions as all cars on the roads globally.
- SmooL 4y ago
  It's far greener per ton of cargo, not absolutely.
- sp332 4y ago
  That was talking about sulfur and nitrous oxides, not CO2. And that's because once they're out away from ports, they burn cheap bunker fuel which is ridiculously dirty. This can be easily addressed by switching to other fuels, and some places have already banned bunker fuel since that report.

rektide 4y ago

Anything you can cite here? I think of water as extremely fantasically high drag. I know that scales inversely down proportional to size, but I still think of rail as the ultra-efficient best option. Would love to read more detailed review/analysis.

CompelTechnic 4y ago
https://truecostblog.com/2010/05/27/fuel-efficiency-modes-of-transportation-ranked-by-mpg/#:~:text=Freight%20trains%20consume%20328%20BTU%20to%20move%20a,achieve%203262%20BTU%20per%20passenger-mile%2C%20or%2038.3%20pmpg https://truecostblog.com/2010/05/27/fuel-efficiency-modes-of....
- candiodari 4y ago
  The TLDR is, on the surface of the earth the slower you're going, the more efficient it tends to be. That even holds for, for example, making trains or cars move slowly: they'll be most efficient at a pretty slow speed. Even planes are most efficient flying 0.0001% above stall speed, the slowest they can possibly go. Most energy in transport goes into moving the atmosphere out of the way. Planes fly high, but that really only makes them comparable to a car. Surprisingly that also means that for really long-range transports even rockets aren't as inefficient as you'd initially think.
zmgsabst 4y ago
This thread made me curious, so I looked up engine sizes between trains and boats. A transport ship[1] can carry 9500 TEU with 53,000hp. That’s 190,000 feet of containers, or 36 miles. A train can be 1.5 miles with 4000hp per engine. (According to Google “facts”.) That’s 24 trains to move the same containers, with at least 96,000hp between them. (And that’s ignoring a 1.5mi train will have more than a single engine.) That trains use more horsepower to move the same freight suggests that they’re less efficient. [1] https://en.m.wikipedia.org/wiki/COSCO_Guangzhou https://en.m.wikipedia.org/wiki/COSCO_Guangzhou
- klyrs 4y ago
  Don't they usually stack containers two high on trains?
  - ElectricalUnion 4y ago
    If you have old infrastructure with low overhead (old tunnels and bridges for example) you can't run that and you need to use rail yards to assemble/disassemble container stacks. It gets expensive fast.
    - klyrs 4y ago
      Hah, fair, I've only lived in the western half of North America, where infrastructure was almost all built after heavy rail lines were laid down.
- fswd 4y ago
  ... obviously then a floating canal train, would beat both of them. The best of both worlds!
- repiret 4y ago
  My Toyota Sequoia has close to twice the horsepower than my Cessna 182 did, but the Cessna burnt easily twice as much fuel per mile than the Toyota. The Cessna cruised at 65% power. The Toyota cruises at closer to 10% power, but needs the excess power available when a hill comes along. I suspect a similar dynamic exists with trains and ships - trains need to have power available to go up a hill, while ships probably cruise at closer to full power.
  - rektide 4y ago
    Thanks. To dogpile on what a bad measure that was, I'd add another example: A Tesla Plaid S is 1020HP. Is it less efficient because the engine is oversized? Seemingly the opposite. It's 33kWh/mi compared to the nearby Performance S (with similar 21 inch wheelsizes). If we assessed miles*capacity/hp though, things would look incredibly dire & dark for the Plaid; the worst EV in production perhaps? In general, engine output capacity doesnt really tell us much.

quickthrower2 4y ago

Doesn’t the need for locks make it incredibly slow?

moring 4y ago
That would be latency vs. throughput, i.e. good for things that need a steady supply like food, and bad for one-off low-latency things like mail.

na85 4y ago

I'm pretty sure that I read somewhere there are like 100 freighters that produce as much emissions as all cars on the roads globally.

SmooL 4y ago
It's far greener per ton of cargo, not absolutely.
sp332 4y ago
That was talking about sulfur and nitrous oxides, not CO2. And that's because once they're out away from ports, they burn cheap bunker fuel which is ridiculously dirty. This can be easily addressed by switching to other fuels, and some places have already banned bunker fuel since that report.