Live data from Hacker News

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

solar.lowtechmagazine.com

31–40 of 90 posts

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

#31
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…

Plus, it's my impression (it could be very effective marketing by the lumber industry) that lumber trees are quickly grown and chopped in farms and controlled logging. And the next tree is planted.

I'd guess that construction is probably a pretty good sequester for the wood/carbon in terms of length of service, and likelihood for controlled recycling or burial after its done.

The logging industry is likely incented to maximize the carbon sequestration rate: which is growing trees producing future lumber.

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

#32
post #4

https://www.youtube.com/watch?v=yP1f3Df6SXE Maybe this kind of lifestyle appeals to enthusiasts, but I can't see modern unions allowing some of the dangerous work out on the sails.

aargh - this is a step in the expansion of humanity on a planet divided by vast oceans, a way of life, adventure and the actual elements of air, water and sun.. a union rule book is .. what? boring!

It's a nice case of how anything can be 'just a job' to the people doing it, at which point the people doing the work really want safety at work, even if to outsiders it looks like an adventure.

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

#33

There are types of sails or wind power that have been investigated to reduce carbon output / efficiency of tankers but they never seem to have been deployed at scale in any sense. Basically a kite-surfing tanker. It seems like until we get tiny compact fusion energy we'll always end up running off the cheapest oil products, as they make the most sense economically. Without any actual incentive to switch, not a single…

LFTR: it's almost everything you want from fusion but can do now.

Scales down for the size No meltdown/overload No proliferation risk

But... artificial fuels are probably the (at least) carbon neutral path forward for shipping and aviation.

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

#34

Earlier quoted context omitted.

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.

how is it carbon negative? wouldn't it be neutral? unless the trees were sent underground to prevent release into the atmosphere? or became petrified?

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

#35
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…

Yes, and it is not releasing fossil carbon.

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

#36
post #18
post #8

Earlier quoted context omitted.

Exactly, and these are precisely the vessels that can most handle slower transfer speeds - as you just have more sailboats to make up for slower speeds/smaller sizes. All that matters is how many arrive each day, as the cargo is fungible. In fact, doing such would provide a buffer that could help prevent supply shocks.

At what point does the additional resource of building a lot more ships (which have more crew, eating more food, producing more waste) result in a net negative? Oceangoing ships have a relatively short useful life...salt water is rough on metal.

I suppose the upper limit would be when it’s possible to make an ocean-wide winch system and you can just hook barges to it and pull them across the ocean.

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

#37

Earlier quoted context omitted.

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.

During the age of sail most of those forests were cut down and turned into farms or pasture-land. So there was a net increase in carbon emission just from the expansion in human activity.

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

#38
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…

"by definition" of what? Carbon neutral or sailing ship? Neither term is defined in the article, and neither interpretation makes any sense.

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

#40

I struggle with this whole article. It implies keeping a sailing ship labor intensive just with a few electric winches. Wing Sails seem like a better approach and I assume they are much less labor intensive.

You're spot on. I've followed this topic area for some years out of curiosity. Saildrone style wingsails only require a very small electric actuator to move a control surface. The control surface sets the overall net angle of attack of the assembly. The wing tracks the wind, only needing the control surface changed as the bow crosses the wind.

A system like this can be entirely labor free.

Tall ships on the other hand... I don't care how many electric winches you have, they'll always require massive numbers of people for sail handling.

Post reply on HN