4 ms·

-The airship would likely be the bottleneck; a 40ft shipping container may weigh anything up to approx. 30 metric tons. You wouldn't be able to put many of tho

by lb1lf 5y ago

-The airship would likely be the bottleneck; a 40ft shipping container may weigh anything up to approx. 30 metric tons. You wouldn't be able to put many of those under an airship, hence you'd need a lot of rather space-hogging airships.

newsclues 5y ago
But there are ships moored waiting for their turn for the cranes to unload. If you have swarms of these unloading, a few cans, it helps right? I’m sure it would be very handy for edge cases where only a few cans need to be offloaded at a specific port. You can also setup secondary drop off zones that avoid bottlenecks, like straight transfers from ship to train.
- manigandham 5y ago
  Unlikely to help given how big and slow they are. These cargo ships carry thousands of containers.
  - xphos 5y ago
    Airships would probably be much fast than cargo ships though. Ships cut through the water at like maybe 30 mph in good conditions. Airships could easily keep as they are dealing with so much less drag. In the 1930 they moved at like 70 mph aka 2x the speed of container ships. I mean there cargo space would be like 1/40 but with the difference in speed thats only 1/20 in the rate of moving cargo not to mention that you aren't bound by water which is the major issue with ports. They are just very congested and ships are stuck in ship lanes. The air is much more limitless in terms of shipping paths.
    - jsjohnst 5y ago
      > Ships cut through the water at like maybe 30 mph in good conditions. Container ships rarely if ever go that fast. Usually it’s in the 15-18 knots range (aka <20mph) from what I’ve seen.
- lb1lf 5y ago
  -It would help; the question is more whether it would be worth it in the grand scheme of things; seeing as the weight differential between air and hydrogen is approximately 1.15kg/cubic meter at sea level, ignoring any weight in the airship itself, you're going to have to displace on the order of 25,000 cubic meters of air to lift one 20/40ft container (the max gross weight is only a couple of tons larger in a 40ft than in a 20ft unit). This volume of hydrogen is a cube with 30m sides. For one container. Neglecting the weight of the ship itself. The big container ships can carry upwards of 20,000 20ft units - so you're going to need a lot of airships (which will require a lot of airspace) to make an appreciable dent in the cargo unloading time. (The main issue really being that container ships are absurdly large!)
  - vineyardmike 5y ago
    > This volume of hydrogen is a cube with 30m sides. For one container This is actually smaller than i was imagining.
  - FabHK 5y ago
    FWIW, the article contemplates cargo airships with a million m^3, which would carry around 40 containers. That would be a cube with 100m sides, and you'd need 500 of those to replace one big container ship. Seems not a realistic option to replace container ships, but might be realistic for specific use cases.
    - xphos 5y ago
      So like to move a shipping container weighing 40 tons requires what 32x32x32 cubic meter space to be supported that's pretty tiny considering the other advantages. They could travel fast and in basically all weather. Lightening is a worry but if you isolate your hydrogen well it shouldn't be a problem. Not to mention they would be much more fuel efficient. Heck you could probably slap solar on them and get net zero energy discharge for low container ship speeds. The only issue being is I don't know if they would alleviate unloading issues if there was high winds. I don't really know the method for securing an airship but if they just let down a big rope and tie themselves done you can do that anywhere.

by lb1lf 5y ago

newsclues 5y ago

But there are ships moored waiting for their turn for the cranes to unload. If you have swarms of these unloading, a few cans, it helps right? I’m sure it would be very handy for edge cases where only a few cans need to be offloaded at a specific port. You can also setup secondary drop off zones that avoid bottlenecks, like straight transfers from ship to train.

manigandham 5y ago
Unlikely to help given how big and slow they are. These cargo ships carry thousands of containers.
- xphos 5y ago
  Airships would probably be much fast than cargo ships though. Ships cut through the water at like maybe 30 mph in good conditions. Airships could easily keep as they are dealing with so much less drag. In the 1930 they moved at like 70 mph aka 2x the speed of container ships. I mean there cargo space would be like 1/40 but with the difference in speed thats only 1/20 in the rate of moving cargo not to mention that you aren't bound by water which is the major issue with ports. They are just very congested and ships are stuck in ship lanes. The air is much more limitless in terms of shipping paths.
  - jsjohnst 5y ago
    > Ships cut through the water at like maybe 30 mph in good conditions. Container ships rarely if ever go that fast. Usually it’s in the 15-18 knots range (aka <20mph) from what I’ve seen.
lb1lf 5y ago
-It would help; the question is more whether it would be worth it in the grand scheme of things; seeing as the weight differential between air and hydrogen is approximately 1.15kg/cubic meter at sea level, ignoring any weight in the airship itself, you're going to have to displace on the order of 25,000 cubic meters of air to lift one 20/40ft container (the max gross weight is only a couple of tons larger in a 40ft than in a 20ft unit). This volume of hydrogen is a cube with 30m sides. For one container. Neglecting the weight of the ship itself. The big container ships can carry upwards of 20,000 20ft units - so you're going to need a lot of airships (which will require a lot of airspace) to make an appreciable dent in the cargo unloading time. (The main issue really being that container ships are absurdly large!)
- vineyardmike 5y ago
  > This volume of hydrogen is a cube with 30m sides. For one container This is actually smaller than i was imagining.
- FabHK 5y ago
  FWIW, the article contemplates cargo airships with a million m^3, which would carry around 40 containers. That would be a cube with 100m sides, and you'd need 500 of those to replace one big container ship. Seems not a realistic option to replace container ships, but might be realistic for specific use cases.
  - xphos 5y ago
    So like to move a shipping container weighing 40 tons requires what 32x32x32 cubic meter space to be supported that's pretty tiny considering the other advantages. They could travel fast and in basically all weather. Lightening is a worry but if you isolate your hydrogen well it shouldn't be a problem. Not to mention they would be much more fuel efficient. Heck you could probably slap solar on them and get net zero energy discharge for low container ship speeds. The only issue being is I don't know if they would alleviate unloading issues if there was high winds. I don't really know the method for securing an airship but if they just let down a big rope and tie themselves done you can do that anywhere.