If you were to line these up end to end it would be 96 miles long.
The Panama Canal is only 50 miles long.
You could do it but the entire length of the track would be completely full of containers twice over.
I somehow feel it would not be cost effective in the long run.
Panamax ships carry up to 5,000 TEUs; Neo-Panamax, introduced after the canal's expansion, 14,000.
Beyond that, I think OP was referring to a hypothetical piece of infrastructure that would dwarf anything we've ever built on this planet: drydocking the entire loaded ship and moving it across Panama on a massive rail system capable of moving entire ships across the land.
TBH, I have no idea how a rail compares to a canal in terms of terrain pressure and building viability. Without further information, it's a promising alternative that is very obviously limited by the (area) density of those ships, but obviously a major investment. Somehow, the ship is able to sustain its weight, so it's not an absurd idea, but they can just barely sustain it, so it's only a just barely not absurd of an idea.
One coupd use starship so, sub-orbital or even orbital would be so much faster! /s
https://en.wikipedia.org/wiki/List_of_largest_machines
The ships look like they're over an order of magnitude heavier than anything on land.
By my calculation, "The Captain" is just under 5 tons per square meter. Contrast that to the neopanamax, almost 6.5 tons per square meter (some uncertainty here -- I'm going by DWT which apparently doesn't contain the ship itself). So yeah, it's certainly heavier, but the areal density isn't an order of magnitude greater.
Serious question, surely it's expensive to unload but so is waiting for the canal. For some loads it seems like it'd make sense to bridge the oceans using rail.
This does mean that you would like to work with the same shipping line at both ends, to address the matching of ship capacities.
Such a rail canal was suggested for the Isthmus of Tehuantepec, though (the narrow waist of Mexico): https://en.wikipedia.org/wiki/Isthmus_of_Tehuantepec#/media/...
And rivers still flow from that downstream, likely entering the water table of a much larger area than the lake itself. Despite it being "artificial", the water still passes through it to downstream ecosystems, as it did before any dam construction. While they may be lower volume due to the drought and limited releases from the lake, replacing that with "Salt water or nothing" would still be a massive change.
If you don't think that would have much impact, start advocating to alleviate western US water concerns by pumping from the Great Lakes and reversing the course of the St Lawrence River to flow from the Atlantic into the lakes. I'm sure people will be very receptive.
200,000 tons of water per ship, 26 metres above sea level, about 200MWh, so call it 500MWh. With 20,000 ships a year that's 50 a day, or 25GWh. A 2GW solar plant
A large solar farm would can reach that capacity (you don't need to run the pumps 24/7, so Solar is perfect)
How much more to desalinate the water?
Ecology problems aside, you need water at the higher elevations to operate the locks, and the lacks have to retain enough water to remain navigable. It's not practical to pump that much water up hill, so we're at nature's mercy for the water supply.
If there isn't enough water in the system to operating the existing locks, there's no point adding a parallel set to draw from the same limited water supply.