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You've got to be kidding. Using a fully sail powered cargo vessel is a PR stunt, not the way of the future. Regular motorized cargo vessels will probably use so

by nradov 1y ago

You've got to be kidding. Using a fully sail powered cargo vessel is a PR stunt, not the way of the future. Regular motorized cargo vessels will probably use some form of sails to slightly reduce fuel burn on downwind legs but it's physically impossible to move huge volumes of cargo purely by sail power in an economical way. There just isn't enough energy in the wind.

jacquesm 1y ago
That's both wrong and right at the same time. There is plenty of energy in the wind, but when it isn't blowing in a favorable direction for your journey it will cause you to have to considerably lengthen your trip or end up in places where you don't want to go. It also isn't as constant and/or reliable as a motor. But until a few hundred years ago wind was all we had, and there is no reason why you could not make a containership that is wind powered just like it used to be. It's going to be interesting to see what kind of hull that would be. When the wind is blowing, favorable direction or not and it exceeds your expectations you're going to find out that there is more energy in the wind than you are prepared to deal with. If you've ever been on a sailboat in a storm that is the last thing you would write.
- nradov 1y ago
  Nonsense. Even if the wind is blowing the right direction it doesn't have enough energy to move a huge merchant vessel at economically viable speeds. Do you have any clue about the mass and drag involved with something like a 20000 TEU container ship? There is no magic hull shape which can ever make sail propulsion alone make sense. This is basic physics.
  - skylurk 1y ago
    Those same 20000 TEU container ships are famously susceptible to being blown about by winds when they loose power. The stronger argument is that wind is not consistent or reliable enough for logistics. At least, not without doing a lot of extra math. So I agree that sail propulsion alone won't happen at large, but it's an interesting question of how far in that direction commercial shipping can go with modern technology.
_yb2s 1y ago
There’s more than enough energy in the wind, and modern sailing technology has come a long ways. Some modern recreational sailboats can cross an ocean as fast as a cargo ship on just wind power, and speed isn’t even much of a factor for a lot of shipping. With the right tech I think fuel free shipping can disrupt fossil fuel shipping just by being cheaper. Back when engines first replaced sailing fuel was nearly free, and sailboats were incredibly slow, dangerous, unreliable, and didn’t sail upwind well, and all that has changed- time to take another look.
- nradov 1y ago
  Bullshit. We're not talking about recreational yachts here. There is not enough energy in wind alone to move huge merchant vessels at economically viable speeds across oceans.
  - fgfarben 1y ago
    ...how do you think trans-oceanic trade was done before steam or diesel powered ships? Plenty of customers don't care about latency, just cost. No fuel = no fuel cost.
    - nradov 1y ago
      You're really missing the point. The volume of cargo carried by sailing vessels in the old days was orders of magnitude lower. Not even remotely comparable to the current global trading system. Customers care about total cost, not just fuel. There is also crew wages, maintenance, insurance, capital depreciation, etc. Sailing vessels that carry useful amounts of cargo are much slower than equivalent motor vessels so all other costs go up. Fuel is cheap.
      - solresol 1y ago
        > The volume of cargo carried by sailing vessels in the old days was orders of magnitude lower. Surprisingly, no, it wasn't. I'll slightly fudge the numbers and talk in terms of proportion of world trade that was carried by ocean-going vessels (because if you double the population then it's reasonable to talk about doubling the number of ships). The world economy was very globalised in 1913. That level of globalisation in trade wasn't matched again until the 1990s. We're only a little more global now than we were in the age of sail. The British navy and merchant fleet was a wonder of its era.
mlhpdx 1y ago
Modern sailing technology is amazing, and you may want to check it out. Speeds are, literally, 10 times faster (or more) today than the recent past. It’s absolutely astonishing. The even better news is that the technology is becoming available to the general population and also commercially viable for projects like this.
- nradov 1y ago
  I am familiar with modern sailing technology. Very little of it is applicable to huge merchant vessels. This project is a cute little stunt but it's never going to be economical for moving bulk cargo. Sails will be a minor supplement at best. Seriously, do the math.
  - bloudermilk 1y ago
    Sincere question: have you done the math? If so, this conversation would be a lot more interesting if you shared it.
    - nradov 1y ago
      How much sail area would it take to move a 20000 TEU ship at, let's say, even 12 kts? How tall would the masts have to be? Would they fit under bridges? You guys are talking about total fantasies here.
      - mlhpdx 1y ago
        The power required would be the same as that provided by the bunker fuel engines in common use. Modern, computer controlled sails are efficient and very powerful. It’s obviously working for this ship, which is a conservative build.
        throw-qqqqq 1y ago
        I think nradov has a point about the physics. > The power required would be the same as that provided by the bunker fuel engines in common use And that is a lot of power! Emma Mærsk has an engine output around 80-90MW. The largest off shore wind turbine today is 26MW with a rotor diameter north of 300m/1000ft(!!). Common (modern) offshore wind turbines today are about 10-15MW with rotor diameters of ~220m/720ft. I will not conclude it is impossible at this end of the scale, but you need a huge foil area to match such engine output. IIUC, the physics work against us as we scale up in size, because of the square/cube-law https://en.wikipedia.org/wiki/Square%E2%80%93cube_law https://en.wikipedia.org/wiki/Square%E2%80%93cube_law (weight of the foil/sail + mast is cubed when the area is squared).
SoftTalker 1y ago
Absolutely. There's a reason steam replaced sail immediately when the technology was invented.

by nradov 1y ago

jacquesm 1y ago

That's both wrong and right at the same time. There is plenty of energy in the wind, but when it isn't blowing in a favorable direction for your journey it will cause you to have to considerably lengthen your trip or end up in places where you don't want to go. It also isn't as constant and/or reliable as a motor. But until a few hundred years ago wind was all we had, and there is no reason why you could not make a containership that is wind powered just like it used to be. It's going to be interesting to see what kind of hull that would be. When the wind is blowing, favorable direction or not and it exceeds your expectations you're going to find out that there is more energy in the wind than you are prepared to deal with. If you've ever been on a sailboat in a storm that is the last thing you would write.

nradov 1y ago
Nonsense. Even if the wind is blowing the right direction it doesn't have enough energy to move a huge merchant vessel at economically viable speeds. Do you have any clue about the mass and drag involved with something like a 20000 TEU container ship? There is no magic hull shape which can ever make sail propulsion alone make sense. This is basic physics.
- skylurk 1y ago
  Those same 20000 TEU container ships are famously susceptible to being blown about by winds when they loose power. The stronger argument is that wind is not consistent or reliable enough for logistics. At least, not without doing a lot of extra math. So I agree that sail propulsion alone won't happen at large, but it's an interesting question of how far in that direction commercial shipping can go with modern technology.

_yb2s 1y ago

There’s more than enough energy in the wind, and modern sailing technology has come a long ways. Some modern recreational sailboats can cross an ocean as fast as a cargo ship on just wind power, and speed isn’t even much of a factor for a lot of shipping. With the right tech I think fuel free shipping can disrupt fossil fuel shipping just by being cheaper. Back when engines first replaced sailing fuel was nearly free, and sailboats were incredibly slow, dangerous, unreliable, and didn’t sail upwind well, and all that has changed- time to take another look.

nradov 1y ago
Bullshit. We're not talking about recreational yachts here. There is not enough energy in wind alone to move huge merchant vessels at economically viable speeds across oceans.
- fgfarben 1y ago
  ...how do you think trans-oceanic trade was done before steam or diesel powered ships? Plenty of customers don't care about latency, just cost. No fuel = no fuel cost.
  - nradov 1y ago
    You're really missing the point. The volume of cargo carried by sailing vessels in the old days was orders of magnitude lower. Not even remotely comparable to the current global trading system. Customers care about total cost, not just fuel. There is also crew wages, maintenance, insurance, capital depreciation, etc. Sailing vessels that carry useful amounts of cargo are much slower than equivalent motor vessels so all other costs go up. Fuel is cheap.
    - solresol 1y ago
      > The volume of cargo carried by sailing vessels in the old days was orders of magnitude lower. Surprisingly, no, it wasn't. I'll slightly fudge the numbers and talk in terms of proportion of world trade that was carried by ocean-going vessels (because if you double the population then it's reasonable to talk about doubling the number of ships). The world economy was very globalised in 1913. That level of globalisation in trade wasn't matched again until the 1990s. We're only a little more global now than we were in the age of sail. The British navy and merchant fleet was a wonder of its era.

mlhpdx 1y ago

Modern sailing technology is amazing, and you may want to check it out. Speeds are, literally, 10 times faster (or more) today than the recent past. It’s absolutely astonishing. The even better news is that the technology is becoming available to the general population and also commercially viable for projects like this.

nradov 1y ago
I am familiar with modern sailing technology. Very little of it is applicable to huge merchant vessels. This project is a cute little stunt but it's never going to be economical for moving bulk cargo. Sails will be a minor supplement at best. Seriously, do the math.
- bloudermilk 1y ago
  Sincere question: have you done the math? If so, this conversation would be a lot more interesting if you shared it.
  - nradov 1y ago
    How much sail area would it take to move a 20000 TEU ship at, let's say, even 12 kts? How tall would the masts have to be? Would they fit under bridges? You guys are talking about total fantasies here.
    - mlhpdx 1y ago
      The power required would be the same as that provided by the bunker fuel engines in common use. Modern, computer controlled sails are efficient and very powerful. It’s obviously working for this ship, which is a conservative build.
      - throw-qqqqq 1y ago
        I think nradov has a point about the physics. > The power required would be the same as that provided by the bunker fuel engines in common use And that is a lot of power! Emma Mærsk has an engine output around 80-90MW. The largest off shore wind turbine today is 26MW with a rotor diameter north of 300m/1000ft(!!). Common (modern) offshore wind turbines today are about 10-15MW with rotor diameters of ~220m/720ft. I will not conclude it is impossible at this end of the scale, but you need a huge foil area to match such engine output. IIUC, the physics work against us as we scale up in size, because of the square/cube-law https://en.wikipedia.org/wiki/Square%E2%80%93cube_law https://en.wikipedia.org/wiki/Square%E2%80%93cube_law (weight of the foil/sail + mast is cubed when the area is squared).

SoftTalker 1y ago

Absolutely. There's a reason steam replaced sail immediately when the technology was invented.