Panama Canal’s Continuing Draft Reductions Pose Threat to Trade
Buried lede: it's due to a drought reducing water availability for the locks. Cause is climate change. https://maritime-executive.com/article/panama-canal-s-continuing-draft-reductions-pose-threat-to-trade
@cstross @dnavinci I too hadn't realized it crossed fresh water until now! But from what I'm reading, "crossing a mountain" seems a bit misleading. The inland waterways are 85' above sea level.
That said, I think these are natural waterways and pumping salt water into them would probably be ecologically horrific.
@cstross @dnavinci Wait, sorry! Reading further (https://en.wikipedia.org/wiki/Gatun_Lake), it appears these waterways were created as part of the panama canal project. They aren't natural.
If I had to guess, they don't fill it with seawater because, while the height isn't that extreme, the VOLUME of water is so large that it would still be intensely expensive.
@cifram @dnavinci A quick back of the envelope calculation shows that pumping the volume of water displaced by the ships using the canal to the height of Gatun Lake would, at 100% efficiency, use roughly 100% of Panama's electricity production (which is mostly from hydropower). Meanwhile it takes *more* water than that to move the ships through the locks, and pumps aren't 100% energy efficient, so that's a minimum.
Also the ecological damage of flooding a tropical rain forest with seawater ...
@dnavinci @cstross There were two competing canal plans; the one we have, using fresh water and going over the mountains in Panama, and a sea level canal through Nicaragua.
There is a Chinese businessman with forty-plus years left of fifty year rights to built and operate such a canal from the Nicaraguan government; the project is considered defunct but could wake up.
Lake Nicaragua is part of that route; "ecological disaster" is a mild term for salting it up.
@dnavinci @cstross Probably the least awful option is massively upgrading the Isthmus of Tehuantepec railway connection, but that still involves loading and unloading ships.
The deeply crazed option would be various PANAMAX+ bathtubs and the world's largest funicular railway. (On the plus side, presumably you could use the braking energy from descending bathtubs to provide most of the energy requirements to lift ascending bathtubs.)
@cstross @dnavinci Would that use less water? I suppose you could build elevated canals and fill them with sea water, so it's "up, across, down", probably by stages.
A CVN will fit in the New PANAMAX locks, at least at the waterline. It'd be something to see photos off the flight deck edge at the top of either the funicular or the wheel. ("we can fly!")
Charlie Stross
DNAvinci
Tormod Halvorsen
Aubrey Powell
Ed Davies
Graydon