Slashdot Mirror
Computer-Controlled Cargo Sailing Vessels Go Slow, Frugal
An anonymous reader writes "Big container ships are taking it very slow these days, cruising at 10 knots instead of their usual 26 knots, to save fuel. This is actually slower than sailing freighters traveled a hundred years ago. The 1902 German Preussen, the largest sailing ship ever built, traveled between Hamburg (Germany) and Iquique (Chile): the best average speed over a one way trip was 13.7 knots. Sailing boats need a large and costly crew, but they can also be controlled by computers. Automated sail handling was introduced already one century ago. In 2006 it was taken to the extreme by the Maltese Falcon, which can be operated by one man at the touch of a button. We have computer-controlled windmills, why not computer-controlled sailing cargo vessels?"
The bean-counters decided it was better to operate off a relatively fixed cost like fuel and have a dependable schedule. The whole story of the 20th century has been "Yeah, you could do this or that but it's just simpler and cheaper to use fossil fuels." Environmentalism won't drive alternative fuels, economics will. If it becomes cheaper to use sail, we'll go back to sail. The cost of fuel will only rise from this point, peak oil is here, so the economics we need for sail should be here now.
Kwisatz Haderach
Sell the spice to CHOAM
This Mahdi took Shaddam's Throne
Why have a crew at all? Think of the surprise that the Somali pirates would get if they got on board and found no one. Just a sailboat with a locked server room.
I'm sure the pirates would love to see computer controlled, slow moving ships. Unless you have robots/zombies guarding them? Or sharks with frickin lasers on their heads?
INAM (I'm Not A Miller) and I'm not up-to-date with the tech, but as far as I'm aware windmills can't plough into harbours destroying themselves and their cargo, potentially killing lots of people at the same time.
http://twitter.com/onion2k
There's already some good ideas about putting sails on container ships (that don't get in the way of loading, like masts would do)
See slashdot from 2007:
http://hardware.slashdot.org/article.pl?sid=07/11/26/1925210
Yeah... Let's send robot ships out there to travel to a port and then wonder WTF happened when it doesn't arrive... Did the scurvy pirates get it or did it drift off course or did it sink?
Im guessing a modern container ship weighs just a lil bit more than even the Preussen. You would need some pretty serious sails to move a container ship.
I've often wondered if we converted all our power generation to wind, whether we'd replace global warming with rapid global cooling? After all, wind is really just presure differentials caused by asymmetric heating.
Is there a chance that by trying to save the planet, we replace a disaster that turns half the world in to a desert with a disaster that places northern Europe under a kilometer of ice?
Simon
As someone with experience building/outfitting a sailboat I can say that the main issue is cost.
The fact is that sailboats are built quite differently from motorboats, hull shape, ballast, draft, etc.
In addition to that the rig (sails/spars/blocks/cordage) are quite expensive, roughly 10 times more expensive than an engine that can perform the same job.
will it cause us problems reading each other's e-medical records, & banking inf.?
put some turbines on them cargo ships
SkySail: using the a computer controlled parasail to improve fuel efficiency. Article http://www.popularmechanics.com/outdoors/boating/4235055.html
can it be a big mother mounted windmill and an electric motor???
bonus being- no tacking into the wind-- rotate the damn windmill and head on into it...
every day http://en.wikipedia.org/wiki/Special:Random
I think the more immediate concern would be the potential impact on wildlife from having massive wind farms. Would large arrays of wind turbines potentially have any adverse affects on bird migrations, or even just birds in general? Or bats? What sort of injury/death risk do wind turbines pose for birds and bats?
It seems like nothing man can do can have zero impact on the environment, ultimately.
This is a great idea, assuming that the reduced costs equate to reduced shipping rates that equal or exceed the depreciation of the goods being shipped . . .
I mean, having your goods sitting on a ship 2.6 times as long as necessary isn't exactly a money-making idea.
-Peter
...why not computer controlled sailing cargo vessels?"
They are computer controlled to a degree but the reason they aren't unmanned has to do with the fact that navigating a boat is a remarkably difficult endeavor and our technology available to the task is both extremely expensive and insufficiently flexible to the wide variety of sea conditions and probably unreliable in such a hostile operating environment. That of course presumes it is possible at all to do it safely which is highly unlikely. Add in the fact that unmanned vessels would be remarkably attractive target for piracy and that should pretty much seal the deal.
It is 200 hundred somali men doing "the helicopter" standing nude on the ship. That would generate sufficient horizontal force to power the ship.
No, since perpetual motion machines haven't been invented yet and it would have to be even better than that. Since if you want the ship to move in any other direction than the wind is blowing, the windmill would have to generate more energy to move the ship in the desired direction than the wind direction and that is impossible. If it worked, the ship wouldn't need wind at all because drag would obviously rotate the windmill when the ship is moving and then we'd have more than a perpetual motion machine.
Everyone's talking about pirates. Seems to me that storms are more likely... the longer you are at sea.
Modern cargo vessels keep a crew of trained mechanics (more than one per vessel) and a machine shop on board.
If your mechanic cannot repair or fabricate a replacement for a component that goes out during a voyage, you are SOL until a replacement arrives - which requires a small delivery ship to get out to you, fast. Which requires fossil fuels.
The sail that would get a modern cargo vessel up to thirteen knots -- for an appreciable portion of the voyage -- is some seriously highly engineered stuff. And pretty large to boot. You're not repairing or replacing that without skilled mechanics/engineers and a well-equipped and specialised machine shop.
Maintaining the speed of a modern cargo vessel already underway through the use of a sail is far more feasible - and there are versions in use.
A modern cargo vessel can be operated and maintained while under way by a relatively common skillset and materials. The more exotic you require the skillset and materials to be, the higher the cost of operating and maintaining the vessel.
Cargo ship speeds go up and down with the costs of ship charter and fuel, and with the demands of customers. Read "The Box", a history of shipping containers and the ships that move them.
Right now, the Baltic Dry Index is down to where it was around 2000, after a huge 5x spike last year. So there's a huge glut of available container ship capacity, charters are cheap, and freight rates are way down. So operators have to optimize for low cost at the expense of speed and throughput.
There's also no big demand for speed from the customers. Much of what's being shipped is going into storage anyway. Unsold cars are piling up near ports, filling up storage and spilling over into rented parking lots. That's presumably happening with containerized commodities too, in cases where the buyer can't just cancel the order.
It's one of those things that happens in a depression.
the wind is adding energy to the situation
if you had a very efficient windmill, and a very aerodynamic & hydrodynamic boat-- why is it impossible?
picture a pulley mounted on the sea floor, through which a rope connects two boats, both 100 miles downwind from the pulley
BOTH are of equal mass.
one boat has a large sail and is angled to go with the wind-away from the pulley,
the other boat is very aerodynamic and pointed into the wind
you are suggesting the aerodynamic boat won't move into the wind?
imagine the aerodynamic boat has a windmill mounted on it.
yes- it will be far more efficient to have the boat going in the same direction as the wind
but is it absolutely required? there is no tipping point where windpower can generate enough electricity to move a ship against the wind?
this blade http://www.gepower.com/prod_serv/products/wind_turbines/en/downloads/ge_15_brochure.pdf produces 1500 KW
this story
http://solarfeeds.com/index.php?option=com_content&view=article&id=5404:cargo-ship-powered-by-solar-panels&catid=129:ggs&Itemid=249 says that a 40kw solar setup supplies 2%
40 going into 1500 37.5 times gives us 75% (37.5*2) of the energy needed for the ship
if one of the GE turbines could supply 75% of the energy needed, two of them would supply 150% of the energy needed-- as I readily accept we are going into the wind- the ship is providing one hell of a lot of counterforce- but it could not be overcome with a third?
every day http://en.wikipedia.org/wiki/Special:Random
Well, you're right and wrong. Actually, it's entirely possible to put a VAWT on top of a ship and move it. However, it's somewhat unlikely that you could get efficiency over just having a sail, meaning that the amount of energy you'd get from the wind would be less, which in turn would mean that you would not be able to sail as many points from the wind as a real sailing ship. Basically, you would pretty much always have to follow the winds. It's not impossible to construct a route like that, though.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
You can not move forward by capturing energy being used to push you backwards. To move forward would require more than 100% of the energy that you're capturing. It doesn't work.
Heh heh heh... just wait until those grappling hooks are on your hull and desperate armed pirate robots are scurrying up the rope ladders.
Most seagoing sailboats are motor sailers already. Sailing cargo ships will need generators for refrigeration etc., so there is no point in NOT providing either a gearbox and prop shaft or an electric drive for emergency power and manouevering.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
It isn't quite as simple as that because the sail supports increase in weight as rather more than the cube of the length, so the superstructure does get heavier in proportion as the ship gets bigger. The design has to be optimised considerably. But there is no reason why sail power should not scale, using modern CAD to do the design work.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
You can not move forward by capturing energy being used to push you backwards.
Except that you're not capturing the energy pushing you back, you're capturing the energy spinning the blades of the windmill. Some portion of that wind is pushing you backwards (at 45 degrees, you can approximate 50% of the wind's force pushing backwards and 50% turning the blade), along with the portion of wind pushing back on the masts, the hull, the people standing on deck, etc. If the energy transferred from the wind pushing you backwards is greater than the amount of energy transferred by the windmill to the engines to the water, you go backwards.
I think it's unlikely that turbine and engine efficiency is high enough to motor directly into the wind with such a setup.
Those numbers only work when your personal interest rate is 0, which is rarely the case.
Realistically, you need to adjust for the time value of money. ($100 now is worth more than $100 27 years from now, as I could make interest off of it)
So, if we assume that the savings are every month, with a 3% interest rate compounded monthly, we'd have (12x27) payments of about $49,617 each with 0.25% interest per period:
PV(A) = (49_617 / 0.0025) * ( 1 - (1 / 1.0025**(12*27) ) )
Which works out to just over $11 million. The install cost would have to be less than this, to deal with the reoccurring costs of maintenance of the new system.
Oh ... and if the interest rate were 6%? That $11mil estimate would be cut to under $8mil, or about 1/2 of your estimate. In a good market where we might be able to make 18% return, over 27 years, it's worth less than $3.3M.
Now, I don't know how much container ships cost, but if I can add another ship and move more containers, that may give me a better benefit for the same cost.
(and, I know you later said that the actual savings were higher -- but the point is, you should _never_ just multiply reoccurring costs or savings by the number of periods to get the equivalent present value, especially for periods of years.)
Build it, and they will come^Hplain.
I wouldn't want that if, for no other reason, due to the piracy off of Somalia. It would be far too easy for them to simply steal the nuclear fuel if they were nuclear powered.
Heck, there's concern about even arming the crews because they're afraid this would just encourage pirates to steal the weapons.
Some moron did the article. A moron who has never been to sea, obviously.
I challenge any weekend warrior to find me any cargo ships that make 26 knots, anywhere, today, last year, or last decade. In an emergency, a FEW of them might make that kind of speed, but they can't sustain it day after day, like naval ships can. A blown boiler is sure to ruin anyone's day.
Warships didn't even make a habit of running that fast, 30 years ago, when fuel was cheap. The first time I crossed the Atlantic, I asked "How long?" like any kid in the back seat of a car, on a long trip.
The answer: "We can be in Portugal in 5 days, if we burn x gallons per minute, or we can be there in 11 days, if we burn y gallons per minute. So, we'll be there in 11 days."
The destroyer I served on was capable of doing about 35 knots (officialy 30+) and we could catch ANY commercial freighter, tanker, container ship, or whatever.
IF, and I say IF, cargo ships were capable of 26 knots as the article says, THEN, they would be transiting the hi danger piracy zones at that speed, and the pirates wouldn't be catching them.
Many 19th century sailing ships could routinely take most commercial traffic in a race, even BEFORE companies started slowing down to conserve fuel. Revisit the sailing times for ships such as the Cutty Sark, then look at the sailing times for today's tankers and container ships. Real sailing times, not "best case scenario with favorable winds" sailing times. ;)
"Windows is like the faint smell of piss in a subway: it's there, and there's nothing you can do about it." - Charlie Br
http://news.bbc.co.uk/2/hi/europe/7201887.stm
http://www.kiteship.com/
What you state is true, but, as the other guy said, it doesn't apply in this situation because you're not capturing the energy being used to push you backwards. Remember, the velocity of the water need not be the velocity of the wind; in fact, it almost never is. Also remember the difference between apparent wind and true wind. The apparent wind is what determines the force on the blades or the sail, not the true wind, except where the true wind = apparent wind which would be the case for a wind turbine securely fastened to the ground as for most wind turbines, but not true for one on a moving boat.
I think by your line of thinking, you would think that a sailboat (powered only by the sails) could never go faster than the wind which powers it does. Or even that a sailboat could never travel closer to the wind than a beam reach. Of course both of those false; you just need a properly designed sailboat. That's because the apparent wind can be greater than the true wind. The same idea applies to the wind turbine on the boat; there's no reason it could not travel directly into the wind if the boat was aero- and hyrdodynamic enough.
'And don't give me any of that 'first directive' nonsense, this ship is Designed For Windows 7 (tm)"
if this is supposed to be a new economy, how come they still want my old fashioned money?
You capture much more energy than is pushing your windmill blades backward; most of the energy you capture is spinning your blades around in a circle.
You can certainly move forward using the energy that is pushing your working surface sideways. A sailboat on a tack moves upwind, because the sail is pushed downwind (which is counterproductive), but it is pushed even harder sideways across the wind. Windmill blades move sideways across the wind at all times; think of the blades as seperate sails, on an eternal upwind tack.
Designing a windmill-driving-a-turbine contraption to make headway upwind poses no impossible hurdle. Whether enough efficiency can be obtained in practice is a different matter. Carts with windmill powered wheels that move directly upwind have been constructed by countless physics students, including me.
Except that in order to capture energy from the spinning of the blades you must prevent the windmill from moving backwards, which means that the engines must have enough energy to prevent the ship from moving backwards. Conservation of energy simply dictates that it cannot be done because if you make the windmill more efficient, it will mean more wind resistance and consequently the ship will be pushed backwards even harder and then the engines will need even more energy.
Now, your approximation of 50 % at 45 degrees fails to take into account the ship's movement, which makes the real angle different. Only if the wind is from behind the ship, does it become possible to use windmills to capture energy without the need for additional energy because the movement of the windmill isn't in an undesired direction and thus it isn't necessary to prevent it but any energy captured is still only converted to heat and friction in the windmills and engines. Capturing energy from the windmills cannot result in enough energy to make the ship move faster than the wind since then the wind would no longer be from behind relative to the windmills and consequently there's no benefit in doing so compared to simply letting the wind push the ship.
Sailboats do all sorts of nonintuitive things that are in fact quite compatible with physics... like sailing downwind faster than the wind, and sailing upwind. There's no reason a boat powered by a wind turbine can't go directly upwind.
This is false, you can not sail upwind using traditionals sails but using wind turbines it is certainly feasible. And why would moving forward require more then 100% of the energy captured? As long as the wind is pushing hard enough, it will move forward. The energy provided by the wind just has to exceed the resistance of the boat to move (friction). And then, the energy needed to move the boat against the wind does not increase linearly with the wind speed.
Imagine a boat with a windmill on it. Imagine the windmill being sideways to the boat (at 90%). Now, we both agree that if the wind makes the turbine turn sufficiently fast, the boat will move forward, right? Now, turn the turbine so it faces the bow. The same wind force, a bit more if we account for wind resistance, will be needed to turn the turbine blades and move the boat forward in the wind direction. The turbine does not care at all what direction the boat is going, it only care about apparent wind speed.
And wind speed on a boat is all about apparent wind speed. This is also how boats and vehicle can sail much faster then the wind itself. They create their own wind! Look up the Greenbird land yacht that recently reached 126.1 mph with winds only between 30 mph and 40 mph.
I'd rather be sailing...
They have crew on board to provide vital maintenence to both engine and navigational system. This entire discussion is stupid beyond belief!
We're not talking about unmanned ships, just ships with sails which are adjusted by machines instead of dozens of sailors.
is. The captain turns the steering wheel and a bunch of motors do the furling/unfurling.
No sig today...
why not add solar panels, wind turbines, and the ability to burn ocean crud as fuel? Its the cost of fuel, not the lack of automization that makes them slow moving.
Any modern sailboat can sail up to around 45 degrees upwind.
If you zig zag you can reach an upwind destination on sail power alone.
You can not move forward by capturing energy being used to push you backwards. To move forward would require more than 100% of the energy that you're capturing. It doesn't work.
This is correct, if you mean sailing *directly* upwind. However, the physics of sailing is not always obvious. Intuitively, it would seem that you can't sail upwind at all, but of course we know that if you do it an an angle, you certainly can sail upwind.
In an even more counterintuitive example, it is possible to use the wind to sail downwind faster than windspeed, though it's dramatically easier on land (with a wheeled sailing vehicle) than on water. Google dwfttw (Down Wind Faster Than The Wind) for discussion of the physics involved, and videos of it in practice.
Some people whose physics is weak still argue that it's impossible, even though the analysis bears it out and it's been demonstrated in practice. The result makes for great flamewars, if you have popcorn available.
I stole this sig from someone cleverer than me.
A sail wouldn't do nearly what it did for the ships back then.
What we lack is not resources or money but imagination. Money is just a number on human social value. If we decide that we value something all of a sudden it can go from having no value to having huge value.
It's actually not simpler to use fossil fuels than it is to use the wind around you... or at least from the perspective of someone thinking in longer range terms.
My great grandfather was a sailing ship captain. Of the last European commercial sailing vessels. They would get towed out from London all the way to the spot where the Ocean wind was steady and left from there. Across the Atlantic to South America. They went all around the world that way and carried heavy cargo like tin and coal. I'm not a real buff on the history but my impression was that the sailing ships were used for the cheaper materials (low density per dollar) were sent by said whereas only the higher value cargo would be on fuel transport --- this was because fuel was so much more costly than sail.
With all of our technological advances it isn't hard to imagine a more efficient huge sailboat. But we are creatures of habit and change is adobted slowly even if it is superior technology. We could do sailing, the question is do we want to?
Stupidity is its own reward.
Comment removed based on user account deletion
Comment removed based on user account deletion
Sails, whether made of traditional textile material or something more newfangled will probably not power those container ships moving all that crap from far-east to west. Wingsails on the other hand could be used for generating a sizeable portion of the needed thrust. They also have the advantage of being much easier to automate, give more thrust per surface unit and give better handling. Rigid wingsails can be covered with photovoltaics giving even more 'free' power in the right circumstances.
Point your favourite search engine to 'wingsails' for more info on this subject...
--frank[at]unternet.org
http://xkcd.com/556/
.
It has good steaks and a fun Margarita night.
I'm not sure if this is a joke.
The very force that makes the windmill spin is also pushing the boat backwards. If the boat has 0 wind resistance and the windmill is 100% efficient, the boat will remain stationary. This arrangement will never result in a positive net force.
If the boat is moving at an angle to the wind, then yes; the windmill will make the boat move faster, but no more than a simple sail would.
reminds me of Escher
in your world, energy is directional?
Considering how much freight is moved around the world by burning oil. A fleet of nuclear powered ships could avoid a lot of pollution and run decades on reactors.
already in use, automatic deployment, can harness the jetstream, more power than any wingsail