Modern cargo ships are so huge traditional sails wouldn’t provide enough force to push them around. Neither will these kites, mind you. But, supplemental energy will still be a bonus, and a kite can reach higher and sit in faster, more stable winds.
Modern cargo ships are so huge traditional sails wouldn’t provide enough force to push them around.
Believe it or not, “proportionality” is a thing. You make the ship bigger, you make the sails bigger to match. Simple! Granted, previously, making sails bigger was limited by the weight of the things when hoisted by men operating manual winches, but now we’ve got motors now to solve that, and higher strength-to-weight ratio materials, too.
Point is: I maintain that, in principle, you could make a post-Panamax sailing ship – even a traditional fully-rigged one – if you really wanted to, and it would be capable of sailing at hull speed on wind power alone. It’s just that they don’t want to for reasons unrelated to technical feasibility.
You’re assuming everything scales linearly, which is not necessarily accurate. The square-cube law rains on many people’s parades.
I can see how you’d think that, but I’m really just asserting that these specific things scale well enough to still work at post-Panamax size.
It would be really interesting to see a fully rigged ship with dozens of sails where the rigging was pulled by motors and controlled by computers rather than humans. It would also be interesting to see what they could do with modern materials. Nylon sails, carbon fibre masts, steel lines, etc.
Having said that, I would bet that a real modern cargo ship would probably use fancy solid wing-style sails.
You underestimate the force of wetted surface area resistance. The sail area needed to move a modern cargo ship at the snail’s pace of old sailing ships would be unmanageably large. You simply couldn’t hold enough sail area to get them near their current speeds. These hybrid sail concepts are nice, but all they do is save some fuel.
The longer the ship, the more masts you can add, so the length doesn’t really matter. What would matter is the width, but I don’t see why the sail surface area couldn’t scale with the ship’s surface area. Sure, it would be a huge amount of sail, but it’s a huge amount of steel.
So, I got that information from a different Lemmy comment, and on the spur of your contradiction I went looking myself. My search results are flooded with mostly useless news articles (they went to tell stories, not relay technical information). Regardless, the most ambitious claim I’ve seen is to reduce emissions by up to 90% for a ship design that can’t handle shipping containers and is about 1/4 the size of the largest ships being produced today.
Don’t get me wrong, I want this to happen. In fact, I would ban carbon-fuel shipping today, if I could make it happen. That being said, I don’t think we’ll ever get back to 100% wind power.
The sail kite project has had claims of up to 10% fuel savings for about 20 years, now.
It’s all moot when we should just be focusing on figuring out practical nuclear shipping. It’s the only way to meet or exceed our current standard and be carbon-free. The NS Savannah proved it could be profitable ages ago, and that without any economy of scale to reduce costs.
Hmm i feel like there it was a case of working against the ocean whereas here I think it is working with the wind so it shouldn’t be THAT bad… but who knows…
