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Maersk installed 100-foot-tall rotating sails on one of its tankers

wsj.com

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Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#2
It's called the Flettner rotor, it uses the Magnus Effect. Cool stuff but not exactly new tech. It gives a nice read, here's some links to wikipedia on the topic: https://en.wikipedia.org/wiki/Magnus_effect and https://en.wikipedia.org/wiki/Rotor_ship

I'm curious of what will be the results.

Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#5
post #4

Not a single word about flettner in that article. Do they hate Germans or does it not fit the ____GROUNDBREAKING____NEVER_DONE_BEFORE____ narrative of today's newspaper articles?

I don’t think WSJ “hates Germans”. Probably just poorly researched

Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#6
post #4

Not a single word about flettner in that article. Do they hate Germans or does it not fit the ____GROUNDBREAKING____NEVER_DONE_BEFORE____ narrative of today's newspaper articles?

"Shipping executives said previous efforts didn’t catch on with operators because either the costs of such technologies were too high or tests didn’t yield the expected fuel savings. But modern, lightweight and relatively cheap rotating sails show more promise, they said."

That seems less revolutionary than evolutionary.

Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#7
post #2

It's called the Flettner rotor, it uses the Magnus Effect. Cool stuff but not exactly new tech. It gives a nice read, here's some links to wikipedia on the topic: https://en.wikipedia.org/wiki/Magnus_effect and https://en.wikipedia.org/wiki/Rotor_ship I'm curious of what will be the results.

Apparently this is a turbo sail and not the same as the Flettner rotor. The Wikipedia article you linked to mentions the same. Ones powered by electricity and one by air? Both seem to take advantage of the Magnus effect though

Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#9
post #2

It's called the Flettner rotor, it uses the Magnus Effect. Cool stuff but not exactly new tech. It gives a nice read, here's some links to wikipedia on the topic: https://en.wikipedia.org/wiki/Magnus_effect and https://en.wikipedia.org/wiki/Rotor_ship I'm curious of what will be the results.

They claim 7-10% reduction in fuel usage, with fuel making up 60% of their total costs.

Given that they soon expect to be spending $5 billion/year on fuel for 800 ships, fuel spend is a bit north of $6 million/year for an "average" ship. But size seems to vary widely (they note that only the 80 of their largest ships are being considered for these sails).

At an installation cost of $2 million, saving 10% of an "average" ship would return 600k per year, or a 3.5 year paypack, which seems well worth doing where possible. And they'll obviously get better than that on their 80 largest.

Not a magic bullet by any means, but certainly seems worth using.

Re: Maersk installed 100-foot-tall rotating sails on one of its tankers

#10
post #2

It's called the Flettner rotor, it uses the Magnus Effect. Cool stuff but not exactly new tech. It gives a nice read, here's some links to wikipedia on the topic: https://en.wikipedia.org/wiki/Magnus_effect and https://en.wikipedia.org/wiki/Rotor_ship I'm curious of what will be the results.

> Rotor ships take advantage of this same effect by spinning a large vertical cylinder, typically using an electric motor, and using the resulting force for propulsion.

I always thought sails were partially defined by being passive. I wonder why these aren't called "rotor fans" if they're electrically driven?

Is there anywhere it's discussed when rotors are expected to outperform normal fans? They seem to be used only on large ships, but I can't see a first-principles explanation for that.

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