Another Angry WomanJun 30, 2023
it is with a heavy heart that I regret to inform you that the tech bros have invented sails
Show threadCharlie Stross

@stavvers TBF this is a GOOD idea purely in engineering terms: kites can take advantage of wind speeds and directions that vary at different altitudes, aerofoils bolted to the deck on rigid masts are limited to surface winds. But it's still only a supplement for engine power: modern supply chains can't cope with VLCSs getting becalmed.

The real answer is marine nuclear propulsion. Or teleportation booths. Or sparkly unicorns. Or something.

Jun 30, 2023 at 8:33pmWeb
Show threadChris HopkinsJun 30, 2023
@cstross @stavvers and the kites operate at a higher height where the wings should be faster and more reliable.
I love dunking on tech bros as much as the next mastodoon, but if they can make it reliable and cheap, then let's take every weapon against climate change we can get.
Show threaddr2chaseJun 30, 2023
@cstross @stavvers I read, somewhere, that it takes an implausible amount of kite to equal the power of a ship engine. My brother's been messing with kites for decades, one crucial piece of equipment is the device that lets go of the kite fast, not sure if there needs to be a ship version of that.
Show threadCharlie StrossJun 30, 2023

@dr2chase @stavvers Here's the LARGEST diesel engine in the world, per wikipedia, the Wärtsilä-Sulzer RTA96-C. Two-stroke cycle, 14 cylinders, puts out 80MW (or about 107,000 horsepower), weighs over 2,300 tons. Used for powering 170,000 ton (and up) container ships.

It's hard to see how to replace a medium-sized city's power station with any kind of sail (or to abolish this scale of shipping in a century when climate change will cause frequent local crop failures).

https://en.wikipedia.org/wiki/W%C3%A4rtsil%C3%A4-Sulzer_RTA96-C

Wärtsilä-Sulzer RTA96-C - Wikipedia

Show threadChookMother 🇦🇺🦘Jul 1, 2023
@dr2chase @cstross @stavvers We may have to settle for less speed for the sake of survival.
Show threaddr2chaseJul 1, 2023
@anne_twain @cstross @stavvers Not just shipping.
Show threadGeorge SteelJun 30, 2023

@cstross @stavvers The big advantage of kites is that they're completely retractable and don't affect vertical clearance, which is strictly limited at most cargo ports due to their loading cranes (preventing the use of masts).

Also, even if this doesn't replace engines, it's still quite useful. There are some long-distance ferries in the pacific islands currently using a combination of sails, solar, and diesel generators (running scheduled service between high-clearance ports) that saw an over 90% reduction in fuel consumption compared to their predecessors. Kites could possibly expand this to low-clearance ports as well.