4 ms·

Very little discussion here or in the article on why use these in favor of traditional sails. Looking at America’s Cup, the trend one would expect would be foil

Very little discussion here or in the article on why use these in favor of traditional sails. Looking at America’s Cup, the trend one would expect would be foils supplemented by motor and more traditional sails. I’m sure these are easier to deploy, but consider that an America’s cup boat can do 40 knots in a 12 knot breeze. Sure that’s without cargo and on a highly optimized design with hard working crew, but it does prove the remarkable efficiency of a traditional wing.

dzhiurgis 6y ago
Indeed one is for racing another for cruise. Wonder if you can make inflatable tower for lesser weight and reefing. Maybe there’s some stable design where you start foiling using motors then when you are stable - use excess power to turn rotors. AC75 boats are very unstable without foils and these things are heavy as.
throwaway0a5e 6y ago
Racing has a very different labor cost situation than commercial freight. Commercial freight will likely make use of far less energy efficient but far more labor efficient designs.
nabla9 6y ago
You can just install these rotating wings on the deck and get 5-7% increase in fuel efficiency immediately and lasts 20-30 years with minimal maintenance. The investment pays itself back in 3-8 years. Wing is obviously more efficient. The problem with the wing is the cost and size. You need to design the ship for the wing. https://en.wikipedia.org/wiki/Oceanbird https://en.wikipedia.org/wiki/Oceanbird
walrus01 6y ago
> but consider that an America’s cup boat can do 40 knots in a 12 knot breeze an america's cup boat is to sailboats what an F1 racing car is to a toyota camry. at the very high end of bespoke carbon fiber racing sailboats with crews of 8 or more, we're talking about toys for billionaire status symbols... Look at the ownership and sponsorship of the boats in this for instance: https://en.wikipedia.org/wiki/The_Ocean_Race https://en.wikipedia.org/wiki/The_Ocean_Race
jasonwatkinspdx 6y ago
The newest AC monohulls are amazing devices, but they're not relevant to cargo or merchant vessels. Foils are a form of dynamic lift, where the weight of the vessel is critical. Those AC75s are full carbon, made a great expense. They weigh around 8 tons crewed up. The average container ship today weighs 100,000 tons. That's a whole lotta dynamic lift needed. Additionally the AC75s are only usable in relatively flat seas, and even then face extreme hazards if they fall off the foils. The foiling cats some years ago killed someone due to this. Fully flying hulls on cargo ships are a non starter. However, wing sails may be practical as an assist, and there've been a few startups attempting that in recent years. The best design for cargo ships is a bit different than the AC boats, and uses a fully rotating and self trimming wingsail. See saildrone for an example of that technology at small scale.

dzhiurgis 6y ago

Indeed one is for racing another for cruise. Wonder if you can make inflatable tower for lesser weight and reefing. Maybe there’s some stable design where you start foiling using motors then when you are stable - use excess power to turn rotors. AC75 boats are very unstable without foils and these things are heavy as.

throwaway0a5e 6y ago

Racing has a very different labor cost situation than commercial freight. Commercial freight will likely make use of far less energy efficient but far more labor efficient designs.

nabla9 6y ago

You can just install these rotating wings on the deck and get 5-7% increase in fuel efficiency immediately and lasts 20-30 years with minimal maintenance. The investment pays itself back in 3-8 years. Wing is obviously more efficient. The problem with the wing is the cost and size. You need to design the ship for the wing. https://en.wikipedia.org/wiki/Oceanbird https://en.wikipedia.org/wiki/Oceanbird

walrus01 6y ago

> but consider that an America’s cup boat can do 40 knots in a 12 knot breeze an america's cup boat is to sailboats what an F1 racing car is to a toyota camry. at the very high end of bespoke carbon fiber racing sailboats with crews of 8 or more, we're talking about toys for billionaire status symbols... Look at the ownership and sponsorship of the boats in this for instance: https://en.wikipedia.org/wiki/The_Ocean_Race https://en.wikipedia.org/wiki/The_Ocean_Race

jasonwatkinspdx 6y ago

The newest AC monohulls are amazing devices, but they're not relevant to cargo or merchant vessels. Foils are a form of dynamic lift, where the weight of the vessel is critical. Those AC75s are full carbon, made a great expense. They weigh around 8 tons crewed up. The average container ship today weighs 100,000 tons. That's a whole lotta dynamic lift needed. Additionally the AC75s are only usable in relatively flat seas, and even then face extreme hazards if they fall off the foils. The foiling cats some years ago killed someone due to this. Fully flying hulls on cargo ships are a non starter. However, wing sails may be practical as an assist, and there've been a few startups attempting that in recent years. The best design for cargo ships is a bit different than the AC boats, and uses a fully rotating and self trimming wingsail. See saildrone for an example of that technology at small scale.