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How to design a sailing ship for the 21st century?

solar.lowtechmagazine.com

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Re: How to design a sailing ship for the 21st century?

#21

Post by counters »

aivisol wrote: post #17

> However, by definition, the sailing ship is not a carbon neutral technology. For most of history, sailing ships were built from wood, but back then whole forests were felled for ships, and those trees often did not grow back. I do not understand this sentence. If I cut down a tree and do not burn it, isn't it a carbon neutral process? It did not release any carbon into atmosphere. By this logic is there any materia…

The thought could be that in "tree form", the material contributes to the net uptake of carbon from the atmosphere, so once it is harvested that negative flux on the balance sheet shifts equilibrium more towards lower or net negative uptake. It's relative.

Re: How to design a sailing ship for the 21st century?

#22

Post by c06n »

tofuahdude wrote: post #19
aivisol wrote: post #17

> However, by definition, the sailing ship is not a carbon neutral technology. For most of history, sailing ships were built from wood, but back then whole forests were felled for ships, and those trees often did not grow back. I do not understand this sentence. If I cut down a tree and do not burn it, isn't it a carbon neutral process? It did not release any carbon into atmosphere. By this logic is there any materia…

The tree is no longer alive to photosynthesize co2.

It only takes up Co2 in its growth phase, not afterwards.

Re: How to design a sailing ship for the 21st century?

#23

Post by faichai »

aivisol wrote: post #17

> However, by definition, the sailing ship is not a carbon neutral technology. For most of history, sailing ships were built from wood, but back then whole forests were felled for ships, and those trees often did not grow back. I do not understand this sentence. If I cut down a tree and do not burn it, isn't it a carbon neutral process? It did not release any carbon into atmosphere. By this logic is there any materia…

It will eventually rot and release its captured carbon.

Re: How to design a sailing ship for the 21st century?

#24

Post by prideout »

minitoar wrote: post #12
vanderZwan wrote: post #7

Earlier quoted context omitted.

Instead of sails we could try other methods, like kites, or that weird turning-metal column effect. To name two serious proposals I've seen

I assume you’re referring to the Coanda effect.

I think rotor sails leverage the Magnus effect, not the Coandă effect.

Re: How to design a sailing ship for the 21st century?

#25

Post by TeMPOraL »

tofuahdude wrote: post #19
aivisol wrote: post #17

> However, by definition, the sailing ship is not a carbon neutral technology. For most of history, sailing ships were built from wood, but back then whole forests were felled for ships, and those trees often did not grow back. I do not understand this sentence. If I cut down a tree and do not burn it, isn't it a carbon neutral process? It did not release any carbon into atmosphere. By this logic is there any materia…

The tree is no longer alive to photosynthesize co2.

Yes, but a tree that isn't growing isn't trapping much carbon dioxide either.

Re: How to design a sailing ship for the 21st century?

#26

Post by aidenn0 »

c06n wrote: post #22
tofuahdude wrote: post #19

Earlier quoted context omitted.

The tree is no longer alive to photosynthesize co2.

It only takes up Co2 in its growth phase, not afterwards.

That seems intuitively true, but apparently it's still debated whether old- or new-growth forests are more carbon-negative.

Re: How to design a sailing ship for the 21st century?

#27

Post by citrin_ru »

tofuahdude wrote: post #19
aivisol wrote: post #17

> However, by definition, the sailing ship is not a carbon neutral technology. For most of history, sailing ships were built from wood, but back then whole forests were felled for ships, and those trees often did not grow back. I do not understand this sentence. If I cut down a tree and do not burn it, isn't it a carbon neutral process? It did not release any carbon into atmosphere. By this logic is there any materia…

The tree is no longer alive to photosynthesize co2.

A tree cannot live forever. Once it is dead all (or almost all) accumulated carbon slowly released back into atmosphere as CO₂ by bacteria. So cutting trees and preserving them from decay is a carbon negative process in a long run.

Re: How to design a sailing ship for the 21st century?

#28

Post by Aperocky »

counters wrote: post #21
aivisol wrote: post #17

> However, by definition, the sailing ship is not a carbon neutral technology. For most of history, sailing ships were built from wood, but back then whole forests were felled for ships, and those trees often did not grow back. I do not understand this sentence. If I cut down a tree and do not burn it, isn't it a carbon neutral process? It did not release any carbon into atmosphere. By this logic is there any materia…

The thought could be that in "tree form", the material contributes to the net uptake of carbon from the atmosphere, so once it is harvested that negative flux on the balance sheet shifts equilibrium more towards lower or net negative uptake. It's relative.

That's not true though, the tree stop growing at a certain point and is really carbon neutral until it dies and decays into the ground and new ones replace it.

By removing trees and planting new ones, this process is sped up and more carbon is removed from atmosphere.

Re: How to design a sailing ship for the 21st century?

#29

Post by naravara »

krisoft wrote: post #14
vanderZwan wrote: post #7

Earlier quoted context omitted.

Instead of sails we could try other methods, like kites, or that weird turning-metal column effect. To name two serious proposals I've seen

Good news on the “weird turning-metal column effect” front: they just installed five tilting rotor sails on a newlybuilt bulk ore carrier. https://gcaptain.com/newbuild-vale-vloc-revealed-as-bulk-car... Why is this important? It shows that the ship owners has seen enough promise in the technology to overcome the potential risks. If it works out well for them we will very likely see wider adoption.

How does this work? The article assumes I should already know the mechanics of it, but googling only seems to turn up a bunch of the same sorts of articles.
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