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?"

Comments

economics and variability

[jollyreaper]

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.

Re:economics and variability

[Jamey]

The other story of the 20th Century was "Just-In-Time", which meant reserves and stockpiles have been kept as low as feasible. That would be another factor limiting acceptance of sail - we'd need larger stockpiles to ride out any delays. Honestly though, with satellite imaging, and computer control - there's no real reason sail travel should be any less controllable and predictable than using fossil fuels. And at the speeds involved, there wouldn't even need to be any major code to do image processing and interpretation on the ship itself (though with the computer needed to handle the rigging, and the need to monitor against potential collisions, should be enough to actually do the planning on ship... but coordination would be better from a central site and general directions relayed via satellite.)

Re:economics and variability

[PPalmgren]

Its not just about fixed scheduling, its about weight and economies of scale. Sails are no longer viable with the size of the ships transporting cargo. The smallest ship I've dealth with holds 300 20ft containers with an avg weight of ~30,000 lbs. Some can be loaded with over 200 million pounds of cargo. I don't even think we have the materials developed to make sails for those physically possible.

The only practical application of sails for cargo ships is augmenting the engine, which we've seen before here on slashdot (too lazy to find the link).

Re:economics and variability

[linzeal]

Why not just go nuclear? We could eliminate CO2 and increase the speed by 2x over diesel.

Re:economics and variability

[ixl]

Dependable schedules are one reason, the other big reason is that sails interfere with loading and unloading the boat.

Modern shipping extensively uses cargo containers that are rapidly loaded and unloaded using cranes. This advance has drastically lowered the per-unit costs of shipping freight in the last half-century (check out the book "The Box" for more details).

If adding sails makes it difficult to use a crane to unload containers from the deck of a boat (likely, imo), then it would make the per-unit cost of shipping skyrocket.

Re:economics and variability

[LiquidCoooled]

i would prefer to have nuclear used in the ocean where a limitless supply of plasma coolant is available and has the option to "eject the warp core" when things go tits up.

Re:economics and variability

[sgt scrub]

It isn't just cheaper because of fossil fuels. Bigger always meant better in the shipping industry. The average lifetime of a cargo ship is 30 years. Small boats last, on average, half that. Large cargo ships are easily recycled. They are 80% steel. Small cargo ships are fiberglass or wood. Cargo ships very rarely sink. If they do, they make excellent reefs. It takes very little hull damage, and smaller storms, to sink small boats. Fiberglass sucks for reefs and wood decays to quickly.

Re:Windmill != Ship

[Neil Watson]

Neither computers nor crews pilot vessels into harbours. Harbour pilots do.

Re:Weight

[Anonymous Coward]

Speed from Sail power is proportional to drag, not weight.

Re:USV

[kpainter]

"Dear mister pirate. This ship is equipped with 'ROMG'. This stands for remote operatable machine guns.

Way too messy. If the computer had the ability to control the ventilation system and hatch locks, the computer could lock them inside. That is when the nerve agent would be released. Post the video of those bastard's slow, agonizing death on YouTube. That would make them think twice about jacking ships.

Re:In a way, it's already hapenning

[Xemu]

For large ships, there's also software than can plan the optimal passage by simulating and optimizing routes for given arrival times while minimizing fuel consumption and avoiding weather damage.

Re:it's not perpetual motion- energy is being adde

[pi_rules]

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.

Financial fail ...

[oneiros27]

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.)

Re:Security?

[Petronius Arbiter]

The ship did have a safe room according to news reports. That's why the pirates took only the captain.

150 years ago, British Foreign Secretary Palmerston observed that "Taking a wasps' nest... is more effective than catching the wasps one by one". - http://news.bbc.co.uk/2/hi/africa/7991512.stm

Also consider Julius Caesar's experience being taken by pirates. There was a politician who carried out his promise.

Comment removed

[account_deleted]

Comment removed based on user account deletion

Wingsails, not traditional sails

[knarf]

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...