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

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

#21

Post by klondike_ »

why_only_15 wrote: post #10

Does anybody have a good book or good resources for nuclear powered merchant marine? Naively it makes sense that nuclear power could support much larger ships and go much faster than diesel, but i don't know how true that actually is.

The US tried this concept at one point with the nuclear powered NS Savannah, which was a cargo/passenger ship. Unfortunately it was already outdated by the time it was built, unable to accommodate the modular containers taking over the shipping industry. It was mostly a novelty at the time and was expensive to run.

Still though it seems nuclear would be a good fit for shipping. Most large ships use electric motors for their propellers anyways, and the US Navy has extensive experience deploying reactors in submarines. Theoretically you would only need to refuel such a ship every 10 years or so. Fears about terrorism or contamination will probably prevent such a ship from being made any time soon, not to mention the lack of infrastructure.

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

#22

Post by nradov »

krasin wrote: post #5

I hope we get rid of cargo ships that burn matter. But sails are too high maintenance to be scalable. Last year, as an experiment I've launched a tiny solar-powered boat ([1]). Ultimately, it was too small and underpowered only making ~900km ([2]) before dying. I hope to build a bigger drone boat next, hopefully with an ability to move up to 1 tonne of cargo. Apparently, it's possible, but (unfortunately) requires ve…

Nuclear may be part of our energy future, but security concerns and operating costs make it impractical to put reactors onboard civilian merchant ships. They can't afford to pay multiple armed security guards and trained reactor operators. Plus some countries don't even allow nuclear vessels into their ports.

A more realistic solution would be to use land based reactors to manufacture carbon neutral synthetic liquid hydrocarbon fuel. Then burn that fuel in the ships as an alternative to fossil fuels.

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

#23

Post by jasonwatkinspdx »

hinkley wrote: post #14
jasonwatkinspdx wrote: post #7

Earlier quoted context omitted.

This. Anachronism is not the answer. These newly built tall ships will never be anything more than in essence a vanity project for brands that want to highlight their environmentalism. If you want an efficient modern cargo sail ship, you should start with freestanding self trimming wingsails. These have roughly 3x more lift vs drag at the same sail area. But far more importantly: they can be controlled entirely by de…

We are going to have to think of a different way of accessing the cargo. Cargo ships as currently built cede the entire middle section of the boat to cranes. Cranes they won't see until the end of their voyage, or the beginning of the next. The whole rest of the time you can't use the vertical axis for anything else. Things that slide around tend to break loose in heavy weather, and boats don't stay afloat if the cen…

Depends on the ship. Container ships are just one type. Bulk cargo and stuff like car transporters remain relevant too.

But in the case of container ships, they have frames every so often to stabilize and secure the load. Those are the natural tie in point for wing sails. This is a relatively straightforward naval engineering problem. CG vs Center of Lift has been well understood since the 1800s.

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

#24

Post by krasin »

patrickyeon wrote: post #17
krasin wrote: post #5

I hope we get rid of cargo ships that burn matter. But sails are too high maintenance to be scalable. Last year, as an experiment I've launched a tiny solar-powered boat ([1]). Ultimately, it was too small and underpowered only making ~900km ([2]) before dying. I hope to build a bigger drone boat next, hopefully with an ability to move up to 1 tonne of cargo. Apparently, it's possible, but (unfortunately) requires ve…

That's really cool! It looks like you're in the SFBA (or at least launched your boat from nearby), so are you familiar with Sofar and Saildrone? Do you have a way for people to follow what you're doing, or pitch in? I'd be interested in this (contact info in my profile).

Thanks for the kind words!

Yes, I am in SFBA; I know about Saildrone; Sailbuoy, Liquid Robotics and a few other similar companies pursuing small data-collection drone boats. I didn't hear about Sofar yet - thanks for the link.

As a full disclosure, the boat I launched was made under collaboration with Blue Trail Engineering ([1]) known for SeaCharger ([2]). All cool parts on the photo are from them; my parts were camera / extra satellite modem / some cloud autopilot. I am way less cool than Damon from Blue Trail Engineering.

As for my solar drone boats hobby, it's so slow moving that there's nothing to follow at the moment. If I get the second boat out of the CAD stage, I would probably get something on my low-profile youtube channel ([3]). But I would not expect anything too soon: bigger boat requires very careful engineering, and with my limited hobby budget it will take time.

Anyway, thank you for the words of encouragement. :)

1. https://www.bluetrailengineering.com/ 2. http://www.seacharger.com/ 3. https://www.youtube.com/channel/UCXLwwf3muIhUs7zYIbRTHNw

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

#25

Post by nradov »

hinkley wrote: post #14
jasonwatkinspdx wrote: post #7

Earlier quoted context omitted.

This. Anachronism is not the answer. These newly built tall ships will never be anything more than in essence a vanity project for brands that want to highlight their environmentalism. If you want an efficient modern cargo sail ship, you should start with freestanding self trimming wingsails. These have roughly 3x more lift vs drag at the same sail area. But far more importantly: they can be controlled entirely by de…

We are going to have to think of a different way of accessing the cargo. Cargo ships as currently built cede the entire middle section of the boat to cranes. Cranes they won't see until the end of their voyage, or the beginning of the next. The whole rest of the time you can't use the vertical axis for anything else. Things that slide around tend to break loose in heavy weather, and boats don't stay afloat if the cen…

Fixed sails won't be viable for container and bulk cargo ships due to the need for unobstructed access. They might be able to make limited use of kite type sails for running downwind.

Sails could be more viable for tankers and car carriers. Those don't rely on cranes for loading and have more free space on deck.

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

#26

Post by nradov »

carapace wrote: post #4

Make it big , get it up out of the water. The larger your ship is the more efficient it can be, and the less of it in the water the less energy is needed to push it. So make big big ships with really really big sails. You want the ships to fly with just the keel in the water to steer against the wind. You might think I'm joking or talking nonsense, but look up Alexander Bell's cellular geodesic kites, and Bucky Fulle…

I think you're joking and talking nonsense. There are practical limits to the size of a planing or foiling vessel. This is just basic physics. Adding more sail area isn't helpful; at some point it's counterproductive and actually slows the vessel down.

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

#27

Post by kortilla »

patrickyeon wrote: post #20

Two of the last paragraphs: > All of this is technically possible, and as we have seen, it would produce less in emissions than the present alternatives. However, it’s more likely that a switch to sailing ships is accompanied by a decrease in cargo and passenger traffic, and this has everything to do with scale and speed. A lot of freight and passengers would not be travelling if it were not for the high speeds and l…

Because the latter isn’t a sustainable solution to the problems we are facing. The environment can’t support all of the current population at any kind of modern lifestyle.

Unless “changing lifestyles” is “give up all daily transportation, heating, cooling, meat, and 99 percent of electricity”, it’s not gonna cut it.

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

#28

Post by nradov »

klondike_ wrote: post #21
why_only_15 wrote: post #10

Does anybody have a good book or good resources for nuclear powered merchant marine? Naively it makes sense that nuclear power could support much larger ships and go much faster than diesel, but i don't know how true that actually is.

The US tried this concept at one point with the nuclear powered NS Savannah, which was a cargo/passenger ship. Unfortunately it was already outdated by the time it was built, unable to accommodate the modular containers taking over the shipping industry. It was mostly a novelty at the time and was expensive to run. Still though it seems nuclear would be a good fit for shipping. Most large ships use electric motors fo…

Large merchant ships don't use electric motors. The propeller is directly driven by a large diesel engine through a mechanical transmission because that is the cheapest and most efficient design.

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

#29

Post by exporectomy »

patrickyeon wrote: post #20

Two of the last paragraphs: > All of this is technically possible, and as we have seen, it would produce less in emissions than the present alternatives. However, it’s more likely that a switch to sailing ships is accompanied by a decrease in cargo and passenger traffic, and this has everything to do with scale and speed. A lot of freight and passengers would not be travelling if it were not for the high speeds and l…

It's also complete nonsense. Invent a worse technology so people will use it less. If you can compel people not to use the faster ships, then just compel them to use those less instead!
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