
Maersk installed 100-foot-tall rotating sails on one of its tankers - petethomas
https://www.wsj.com/articles/maersk-tankers-turns-to-wind-power-to-cut-soaring-fuel-costs-1535641239
======
abtinf
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 maintenance) trumps every
other value. A pioneering containerized shipping company went bankrupt
pursuing a high-speed shipping strategy that cost marginally more than low-
speed competition.

Edit: Oh, there is a second edition! Updated link.

Edit: replaced unhelpful snark.

[https://www.amazon.com/gp/aw/d/0691170819/](https://www.amazon.com/gp/aw/d/0691170819/)

~~~
jessewmc
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?

~~~
mabbo
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 there are very good reasons this would never work, but I still
love the idea.

~~~
fasteddie
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.

~~~
acrooks
Maybe a little bit picky, but the average size of a crew on a, say, 9000 TEU
container ship is actually closer to two dozen. 20-24 most of the time.

The number can rise further with more complex cargo.

------
fmsf
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](https://en.wikipedia.org/wiki/Magnus_effect)
and
[https://en.wikipedia.org/wiki/Rotor_ship](https://en.wikipedia.org/wiki/Rotor_ship)

I'm curious of what will be the results.

~~~
robfitz
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.

~~~
taneq
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.

~~~
IronWolve
Too true. Like the new dodge ram etorque, using its electric motor to replace
the alternator, it can launch the truck and let the combustion motor take over
at highway speeds. 1-2 mpg is a large improvement for a truck. 1500 dollar
option that pays for itself, and a good step towards getting battery tech into
trucks.

I've seen it mentioned boats/ships using electric assist will also be another
catalyst for battery tech integration, fuel costs on those large ships are
always a topic.

Bolt on solutions that are affordable with quick turn around on investment.

------
factsaresacred
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 for propellers -
> perhaps it seems with modern materials, wind monitoring and computer
> assisted controls this has been tilted to the favor of Flettner rotors.
> Flettner also invented trim tabs which any large power boat operator knows
> very well._

> _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._

~~~
eanzenberg
>> 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.

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

~~~
eanzenberg
Great for his fam, bad for the other 8M jews (my grandparents’ families
included)

~~~
robbiep
... so Flettner’s a bad guy? (I’ve ancestors who perished there too, you can’t
lump everyone, including those involuntarially held, as this situation seems,
in the same bag)

------
nabla9
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
speed and connecting to electric grid while in harbor the CO2 emissions are
down significantly.

The best way to reduce energy consumption for a ship is to reduce the speed
and make thinner ships. This is the new trend in shipbuilding. New cargo ships
optimized for slow speed don't have the bulbous bow because it does not
increase efficiency in lower speeds.

~~~
jabl
> Viking Line installed similar 80-foot rotor sail on a LNG powered Cruise
> Ferry on the route between Helsinki-Stockholm.

Turku - Stockholm, actually.

> The best way to reduce energy consumption for a ship is to reduce the speed
> and make thinner ships.

Do you mean thinner as in narrower, or thinner materials to save weight? If
you mean narrower, I've understood bigger ships tend to have a length/width
ratio of about 6:1, as a rule of thumb compromise between seakeeping ability,
fuel consumption, cargo space etc. Do you have some more information about
design tradeoffs going into such narrower ships?

> New cargo ships optimized for slow speed don't have the bulbous bow because
> it does not increase efficiency in lower speeds.

Oh, interesting! Any links for further reading on this topic?

~~~
nabla9
Ah yes. you are correct on both counts: Turku and narrower (I had brainfarts).

reading:

[https://gcaptain.com/cma-cgms-22000-teu-ships-to-feature-
bul...](https://gcaptain.com/cma-cgms-22000-teu-ships-to-feature-bulbless-bow-
made-for-slow-steaming/)

------
IB885588
Another option is skysails (giant kites that drag the ship forward):

[https://en.wikipedia.org/wiki/SkySails](https://en.wikipedia.org/wiki/SkySails)

Hopefully someday almost all ships have a mix of these things + maybe run on
algae-based advanced biofuels or something like that.

~~~
alex_duf
Edit: I'm wrong, see responses bellow for correction

Original message: I seem to remember (if I'm wrong please correct me) that the
Magnus effect works regardless of the direction of the wind, whereas the sky
sail needs the wind to be roughly in the same direction of travel.

They could be combined but as far as I understand these spinning columns are
more generic

~~~
LeifCarrotson
You are, unfortunately, incorrect. The Magnus effect doesn't gain you anything
other than the helpful drag of a tall cylinder when going in the same
direction as the wind. Rotating it only pulls you sideways, which doesn't
help.

However, it can pull you forward when the wind is coming from the side. You
change the direction of rotation based on which side the wind is coming from.

Without tacking, no (edit: solely) wind power systems will help when going
straight upwind.

~~~
jacquesm
> You are, unfortunately, incorrect.

No, you are, unfortunately, incorrect.

> Without tacking, no wind power systems will help when going straight upwind.

[https://en.wikipedia.org/wiki/Windmill_ship](https://en.wikipedia.org/wiki/Windmill_ship)

~~~
danaos
He was right that "The Magnus effect doesn't gain you anything other than the
helpful drag of a tall cylinder when going in the same direction as the wind."

In fact, the Magnus rotors will not provide any usefull thrust is both upwind
and downwind scenarios.

[https://en.wikipedia.org/wiki/Rotor_ship#/media/File:Points_...](https://en.wikipedia.org/wiki/Rotor_ship#/media/File:Points_of_sail_for_rotorships.svg)

~~~
ars
> In fact, the Magnus rotors will not provide any usefull thrust is both
> upwind and downwind scenarios.

If the wind is coming from behind won't it simply push the stationary
cylinder, adding some thrust?

------
ValleyOfTheMtns
I've been wondering why shipping companies haven't been doing this for years
now. Whenever I brought it up with friends they would say it's probably not
worth the effort, but I can't see how it wouldn't be worth it. It's
essentially free energy to help move the ship around. Got to say, I feel
vindicated by this story.

~~~
tomtimtall
Essentially free energy... except the cost to install, the cost to operate,
maintainable and of cause the cost when one of them breaks and causes damage.

For a lot of these “why don’t they just” the answer is simply that they did
the math and saw too small an upside for too big a risk.

They are trying this out to see if the overall concept works in practice or if
it falls short.

~~~
ant6n
Or they never did the math, assuming it wouldn't work out because of cost to
operate, maintain and insure.

------
carapace
Magnus Effect.

As sled runners are to wheels, so the wing is to the Magnus effect rotor.

Lift goes up with the square of the radius. Think about that.

I'm in the process of ramping up a toy company that builds and sells kits for
Magnus Effect drones.

I plan to just keep making them bigger, first for cargo then for mass
transport. It will be necessary to move people efficiently by the million in
the decades to come. Already floods and wildfire have begun to increase, soon
enough the waters will rise and it will be needful to move our asses.

By using a simple recursive-fractal infrastructure there's pretty much no
upper limit. Cf. "Tensarity"[1] and Alexander G. Bell's cellular kites[2].
Also Bucky Fuller's Cloud Nine[3]. Self-powered[4][5].

I imagine huge aerial machines, more like gauzy flying buildings than
aircraft, that carry a million or more people at a time. Cities in the sky.

[1]
[https://en.wikipedia.org/wiki/Tensairity](https://en.wikipedia.org/wiki/Tensairity)

[2]
[https://duckduckgo.com/?q=Alexander+G.+Bell%27s+cellular+kit...](https://duckduckgo.com/?q=Alexander+G.+Bell%27s+cellular+kites&t=hj&atb=v110-1_b&iax=images&ia=images)

[3]
[https://en.wikipedia.org/wiki/Cloud_Nine_%28tensegrity_spher...](https://en.wikipedia.org/wiki/Cloud_Nine_%28tensegrity_sphere%29)

[4] Tethered power generators, "Magenn" company, defunct?
[https://en.wikipedia.org/wiki/Airborne_wind_turbine](https://en.wikipedia.org/wiki/Airborne_wind_turbine)

[5]
[https://en.wikipedia.org/wiki/Vaneless_ion_wind_generator](https://en.wikipedia.org/wiki/Vaneless_ion_wind_generator)

------
adam
This should be a big deal for combatting CO2 emissions as well. I believe it
was never refuted after it came out a few years ago that ~15 of these ships
emit the same CO2 as all cars in the world? [https://inews.co.uk/news/long-
reads/cargo-container-shipping...](https://inews.co.uk/news/long-reads/cargo-
container-shipping-carbon-pollution/)

~~~
slapshot
The article says "pollution" not CO2. Given that they burn bunker fuel (very
dirty oil left over after things like gasoline are refined away), it's likely
the article means particulate or sulfur emissions.

The CO2 emissions are easily estimated and not even close. A container ship
can burn 225 tons of bunker fuel per day at normal cruising speed.[1] At a
generous 300 days in transit per year (they spend time in port loading /
unloading / waiting), that's 67,500 tons of fuel per year. It's a massive
number, but a drop in the bucket relative to the 913 million tons of oil
consumed by Americans every year, the majority of which is spent on motor
vehicle fuels.[2]

Even assigning just 50% of US oil consumption to cars, you're comparing about
450 million tons consumed by American drivers versus about 1 million tons for
15 large cargo ships.

[1]
[https://transportgeography.org/?page_id=5955](https://transportgeography.org/?page_id=5955)
[2] [https://www.statista.com/statistics/264825/oil-
consumption-i...](https://www.statista.com/statistics/264825/oil-consumption-
in-the-united-states/)

------
lgats
[https://www.fullwsj.com/articles/maersk-tankers-turns-to-
win...](https://www.fullwsj.com/articles/maersk-tankers-turns-to-wind-power-
to-cut-soaring-fuel-costs-1535641239)

------
komali2
> Fuel makes up approximately 60% of our total cost and this technology has a
> significant potential to cut fuel consumption by 7% to 10% on the ships that
> it will be installed."

Jesus, I'm surprised we haven't seen all sorts of crazy ideas coming out of
Maersk to reduce this overhead given that it's the bulk of their cost. Wind
pillar things seem kinda tame compared to the shit I'd try to pull to save
that level of money... Across all vessels no less!!

------
mvpu
Wonder why ships aren't trying solar panels and electric motors and auto-
pilot... they're out in clear Sun, have a large surface area, and no
traffic...

~~~
ethagknight
Two problems with boats and solar propulsion: 1) they need 24/7 power. 2)
Using a random LG 330 W panel on top of the Edith Maersk, it would take an
array 1/3 of a mile by 1/2 of a mile in area to match Edith's 80,000 kW engine
power output. Edith is 1/4 mile long and 3/100ths of a mile wide.

Quite a gap, and thats before you start factoring in batteries for the night,
structure to support the array, storms...

~~~
Steko
> 2) Using a random LG 330 W panel on top of the Edith Maersk, it would take
> an array 1/3 of a mile by 1/2 of a mile in area to match Edith's 80,000 kW
> engine power output. Edith is 1/4 mile long and 3/100ths of a mile wide.

Back of the envelope math says we're short by a factor of ~108. We can get
savings in a few places:

(1) We don't have to match the full engine output with solar. Many container
ships use super slow shipping at a fraction of the power, [1] says 10% engine
load. With batteries you can still increase throughput substantially when
needed.

(2) Panels can exceed current ship dimensions, perhaps greatly (tow a long
tail of solar panels on floats?). Let's just go for double width and length
for now.

(3) Efficiency gains. We're at 20% in back of envelope above but I can get
that for my house. Let's say Maersk ponies up for 30% cells.

Still some ground to make up but at least we're in bullshitting distance of
claiming it's viable.

[1]
[http://articles.maritimepropulsion.com/article/Turbocharger-...](http://articles.maritimepropulsion.com/article/Turbocharger-
Retrofit-Aids-Slow-Steaming41703.aspx)

> thats before you start factoring in batteries for the night, structure to
> support the array

Presumably there's some space/weight savings in not having an 80MW engine.

~~~
flyingfences
> Panels can exceed current ship dimensions

They really can't, though. Sure, there's plenty of space when the ship is out
on the high seas, but any time the ship needs to go into port (kind of the
point of a ship) or navigate tight waters such as straits or canals, then the
footprint of the panels really has to not exceed the footprint of the ship.

~~~
manquer
it is not a b/w choice between 100% solar or 100% oil, hybrid solutions could
work and address the gaps solar/electric cannot handle,even 10-20% emission
savings could mean a lot .

Also it doesn't have to be solar directly, an electric propulsion system which
can use hydrogen or high density battery/ storage which plugs into the grid
eventually is good enough.

You don't need to drag the cells with the ship, they could be perhaps
stationary middle of the ocean and charge the replacement batteries and you
could line few such charging stations near the major shipping lines.

------
JamesCoyne
This led me to wonder how important height was a restriction on ships. Turns
out "air draft" is reported for major ports.

Some interesting findings: The Panama Canal has an air draft of 201 ft imposed
by the Bridge of the Americas; the Port of Oakland has an air draft of 220 ft
imposed by the Golden Gate Bridge.

Height from waterline does not appear to be typically listed for ships, but I
would guess that most cargo vessels do not have 100 ft of clearance to spare.
I think this means these sails would only be fitted to vessels which generally
don't care about height restrictions (e.g. ships larger than Panamax) or ships
running predictable routes.

[https://en.wikipedia.org/wiki/Air_draft](https://en.wikipedia.org/wiki/Air_draft)

~~~
nattaylor
I believe the unloaded freeboard of a typical containership is 80-100' The
bridge (navigation deck) is higher, but the "sails" would be mounted from the
deck, so I expect most ships would be OK.

~~~
JamesCoyne
Right, but container ships are stacked with containers higher than the top
deck. So maybe this only makes sense for tankers and bulk carriers, or any
large cargo vessel that is _not_ a container ship.

------
newnewpdro
Calling these sails is a stretch, and IMHO just an attempt to market them as
more "green" than they really are.

They may as well be propellers. It's great to improve the fuel efficiency of
these vessels, but the word sail evokes a mental image profitably inconsistent
with reality.

------
joering2
What these ships are mostly surrounded by are waterfields that go as far as
you can see. Can they come up with some sort of rolled flexible solar panels
that once ship goes into full sail they release their “solar tail” behind that
floats on the water surface and captures sun and turns it into electricity for
ships’ engines?

I mean 300 meters square of solar panel should be sufficient to push the ship
at its nominal speed. For free!

~~~
a_c_s
I think you're vastly overestimating the power output of solar cells.

Using 20% efficiency panels gives us 0.2KW/m^2/hr.

According to this Quora answer [1] a small container ship uses 15,000kW: for
one 24 hour day that means it needs 360,000KWH in energy.

If we assume 10 hours a day of full sunlight then we need 180,000m^2
(equivalent to 18 hectares or 44.48 acres or 33.7 football fields) of solar
panels.

This of course overly optimistic as it assumes no drag nor increase in power
needed to haul these solar panels (and batteries for use overnight, etc.).

[1] [https://www.quora.com/How-much-does-it-cost-to-fuel-a-
cargo-...](https://www.quora.com/How-much-does-it-cost-to-fuel-a-cargo-ship)

~~~
telchar
Nitpick, but 0.2KW/m^2/hr would be an acceleration, not a constant rate. You
mean 0.2KW/m^2 - this is constant power output. W already includes a per-unit-
time component. I'm nitpicky on this topic because of how many professionally-
written articles I've seen make similar mistakes.

------
qume
My small 12 meter long boat has a sail area of 900sqft. When sailing
perpendicular to the wind it captures pretty much all of that.

The sail on that ship is 100' high, and looking at the aspect is around 15'
wide, or 1500sqft. That type of sail I think only harneses half of that area,
so half of 1500' or 750' best case.

I can say with complete confidence that if all the energy from two of my boats
were towing one of those ships, even in a hurricane, it's going to increase
fuel efficiency by approximately 0.0%

EDIT: I just did a random sample of wind speed [1] of points on the globe on
international shipping routes [2] and it looks like they are generally around
10-15km/h. Thats barely enough to get my boat up to speed. There is a reason
sailboats take very particular routes and don't just go from point A to B

[1] [https://earthjustice.org/sites/default/files/world-cargo-
shi...](https://earthjustice.org/sites/default/files/world-cargo-shipping-
lanes_957b.png)

[2]
[https://earth.nullschool.net/#current/wind/surface/level/ort...](https://earth.nullschool.net/#current/wind/surface/level/orthographic=-157.21,10.45,671/loc=-131.119,24.791)

~~~
craftyguy
These use rotor sails, which are different than what you have on your boat.
Unless of course you also have rotor sails?

------
paulsutter
Noting the use of the plural, How many are installed on the ship? We see
two(?) in the photo? What’s the practical limit?

> has installed 100-foot-tall rotating cylinders on one of its product tankers

------
billconan
found this video explaining it
[https://www.youtube.com/watch?v=2OSrvzNW9FE](https://www.youtube.com/watch?v=2OSrvzNW9FE)

------
tunnuz
[https://en.wikipedia.org/wiki/Magnus_effect](https://en.wikipedia.org/wiki/Magnus_effect)

------
poorman
I hear this is what Nautilus Labs is trying to solve
[https://nautiluslabs.co](https://nautiluslabs.co)

------
ourmandave
In a different related article I learned that Ro-Ro vessels are Roll-on Roll-
off cargo vs Lo-Lo vessels which are Lift on - Lift off.

And I thought IT loved acronyms.

------
joeborza
Amazing, new, disruptive technology for shipping...

Now who has the patent on SAILS!

This kind of reminds me of constant remakes of Spiderman ;0)

------
chooseaname
Was hoping to see more than 10% reduction. Seems fuel prices could easily
absorb that quickly.

------
Jsharm
A little embarrassed to ask but why would normal sails not work?

~~~
interdocken
maintenance. the materials used for actual sails stretches eventually and is
less effective. presumably these towers have very little to replace.

~~~
jhayward
They have a very expensive, hard to replace, and high maintenance bearing at
the base of the tower that carries the full force of the sail leveraged by a
long moment arm. This bearing (along with lack of height = low wind) has been
the reason that Flettner sails and wind turbines haven't been economical in
the past.

------
krupan
How loud are these when they are rotating?

------
lucidguppy
Think of the PR we could harness with this alternative energy source!!!

------
singularity2001
wouldn't it help to add little shovels for friction?

------
korbonits
SAILING FOR THE WIN

------
Timmah
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.

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

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

~~~
superkuh
After manned narco subs and towed sub capsules were mitigated by new police
efforts drug traffickers experimented with magnetically attached parasite
containers on the side of large shipping boats. But they didn't have to move.

~~~
Timmah
How do they mitigate narco subs? Sonar patrols I presume?

------
DannyB2
From TFA...

> Maersk Line spent around $3.4 billion on fuel last year for its fleet of
> around 800 vessels.

Wouldn't savings from wind power be bad for the petroleum industry? And
therefore by lobbyist extension bad for everyone?

~~~
macmac
That's Maersk Line, which is the container shipping division of Maersk. The
rotor sails are being installed on a tanker vessel from Maersk Tankers. Deck
space is a valuable commodity on a container vessel, so not as obvious where
to place the rotors.

~~~
DannyB2
I quoted that line exactly from TFA. (the friendly article)

~~~
macmac
I am sure you did. That doesn't make it any less misleading.

