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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

#161

Post by lostlogin »

eanzenberg wrote: post #123
factsaresacred wrote: post #34

Copying the first comment from WSJ 'cause it's interesting: > These are known as Flettner rotors after the German engineer Anton Flettner who invented them and made the first rotor sailing ship in 1924, with one sailing one across the Atlantic in 1926 - and they are not turbo sails. They have generally been in disuse as it has been deemed that the energy expended in propulsion by Flettner rotors was higher than that…

>> An interesting note, Flettner was considered so valuable to the Germans in WW2 that Heinrich Himmler, the head of the Gestapo saw to it that Flettner's Jewish wife was escorted to Sweden for her safety for the duration of the war. That's nice and all but he still helped the nazis with military research while many of his colleagues fled, Einstein included.

It’s hard to understand, as that’s more or less moving her so he doesn’t kill her.

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

#162

Post by adrianN »

nattaylor wrote: post #153
Timmah wrote: post #138

Would be excited to see this technology combined with the "underbelly bubbles" technology that I heard about a few years ago where they reduce drag by releasing air bubbles under the hull. Yeah it takes energy to do it but the decreased resistance is supposedly a net gain. Two 10% gains would be awesome.

Some fleets have implemented special bottom paint to reduce drag by reducing algae growth.

I wonder how long a magnetic cleaning robot could survive on the hull of such a ship.

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

#163

Post by baddox »

jessewmc wrote: post #64
abtinf wrote: post #18

Some years ago I read The Box by Marc Levinson, a history of containerized shipping. Highly recommend it. If you live in SF and have wondered about the numerous barely used piers, this book explains their history as well - and why the major container terminal ended up in Oakland instead. One of the painful early lessons for the industry was the discovery that minimizing operational costs (particularly fuel and mainte…

Ignorant question: if operational costs trump all, especially fuel (Maersk says in the article 60% of operational cost) why not pure sail power? Is there some other maintenance cost or infeasability there? Or is there another hidden variable that is not satisfied?

I read an article about the potential of drone ships that claimed one reason ships don't go even slower is the logistics around having a crew on the ship for the entire voyage.

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

#164

Post by cwmoore »

PeterisP wrote: post #124
cwmoore wrote: post #107

Earlier quoted context omitted.

It wasn't my idea. My idea was that it shouldn't be dismissed for the reason you presented without a citation.

What can be asserted without evidence can also be dismissed without evidence. As there's a well known consensus that some factor (e.g. saltwater caused maintenance issues in this particular case) tends to be a game-breaker, then it's perfectly reasonable to dismiss 'without a citation' ideas that encounter this factor if the idea has no mention/citation of how they're going to fix, avoid or tolerate this. If there's…

Point taken regarding your first line, though that sword would cut both ways I think. See https://news.ycombinator.com/reply?id=17886400 regarding the second and third.

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

#165

Post by unwind »

nabla9 wrote: post #75

Viking Line installed similar 80-foot rotor sail on a LNG powered Cruise Ferry on the route between Helsinki-Stockholm. It reduces power usage roughly 20 percent (900 tonnes CO2 annually). Compared to tankers ferries don't carry significant amount of weight even when they are full. They are basically full of air and 60-100 cars or trucks. Together with using LNG, periodically cleaning the bottom of the ship, slower s…

Just for completeness' sake, the ship is the MS Viking Grace[1]. It's fun seeing the LNG supply vessel AGA Seagas [2] in the early mornings, required since the city of Stockholm did not allow the refueling to happen by tanker truck for safety reasons.

[1] https://en.wikipedia.org/wiki/MS_Viking_Grace [2] http://www.aga.ee/en/products_ren/liquefied_natural_gas/mari...

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

#166

Post by travisjungroth »

fasteddie wrote: post #126
mabbo wrote: post #103

Earlier quoted context omitted.

I've long imagined some fun possibilities for this. I picture a small-ish shipping ship, say something moving 20 or 30 containers only, fully autonomous (100% crewless) with sails and solar only powering it. Solar electric motors handling the near-land operations and "not enough wind" conditions, sails otherwise. If you had autonomous loading and unloading, you would have zero variable/operational cost. I am certain…

The reason autonomous/crewless isn't really feasible or worth investing in is that most container ships only have a crew of about a dozen, and they are generally from low-wage countries so that their salary costs are far out-weighted by the fuel.

I think this is a good example where automation doesn’t mean getting rid of all jobs, just 99% (which has nearly the same effect). I mean, we still have blacksmiths hand forging swords ffs.

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

#167

Post by jotm »

jseutter wrote: post #77
jessewmc wrote: post #64

Earlier quoted context omitted.

Ignorant question: if operational costs trump all, especially fuel (Maersk says in the article 60% of operational cost) why not pure sail power? Is there some other maintenance cost or infeasability there? Or is there another hidden variable that is not satisfied?

This is a good question, and almost pure sail power may become a thing in the future. It looks like Maersk is trying to get ahead of the switch to cleaner fuel coming in 2020, which will increase their fuel costs by about 60%. This idea of putting sails on a large ship was at best only marginally cost-effective before now. Some practical considerations come into play - while saving money is good, being able to reach…

Why not use electrical propulsion and charge batteries from wind and solar? At first, as a fuel saving measure in optimal conditions (rely on internal combustion engines most of the time). Seems better than pure sail power, even though that is more efficient (due to direct wind to motion conversion).

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

#168

Post by eigenvector »

fmsf wrote: 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.

Notably, wind turbine OEM Enercon already used it on one of its transport ships.

https://en.wikipedia.org/wiki/E-Ship_1

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

#169

Post by [deleted] »

lostlogin wrote: post #161
eanzenberg wrote: post #123

Earlier quoted context omitted.

>> An interesting note, Flettner was considered so valuable to the Germans in WW2 that Heinrich Himmler, the head of the Gestapo saw to it that Flettner's Jewish wife was escorted to Sweden for her safety for the duration of the war. That's nice and all but he still helped the nazis with military research while many of his colleagues fled, Einstein included.

It’s hard to understand, as that’s more or less moving her so he doesn’t kill her.

[deleted]

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

#170

Post by uryga »

taneq wrote: post #48
robfitz wrote: post #9

Earlier quoted context omitted.

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 "avera…

I think that's something we lose sight of in software sometimes, where we're used to some token effort improving performance by 10x or more. In the real world, if you can make something 10% more efficient, that's a game changing, industry conquering advantage.

I'd guess (no real evidence) it could be because a lot (most?) software runs on timescales where 10% isn't that significant. Also, maybe something to do with Amdahl's law, where speeding up one part by 10% rarely speeds up the whole thing by the same amount?
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