Are they? I vaguely recollect freight trains' weight being in the vicinity of 6-8 thousand tons, not in the twenty thousands. How long would such a train be, 200 boxcars or something? Seems a bit unwieldy.

This link [1] says the median US train is 5,400 feet, and this link [2] quotes an intermodal railcar for 53-foot containers at 67 feet, 9 inches; although 40 foot containers are the most common size; let's use 60 feet as a round number car length; that would put the median train at 90 cars; the 90%ile train is 9,800 feet or 163 cars by my length estimate, and 99%ile was 14,000 feet or 233 cars.

Probably depends on the specific route, but 200 cars doesn't seem unrealistic.

[1] https://www.aar.org/article/freight-train-length/ [2] https://www.mrc-rail.com/railcar-results/intermodal/

They are unwieldy and because of their length they're now too long for the sidings constructed to allow trains to pass each other causing scheduling issues. The whole rail industry in the US is slowly choking itself to death on it's own short term profit motives.

Many of them even float... Referring to ships that are next size up.

And 25 years earlier in 1905, 6000 ton Calvin Hall was moved on the Iowa campus in a similar way. It was a well-understood technique by 1930.

Probably had a bunch of domain knowledge left over from https://en.wikipedia.org/wiki/Raising_of_Chicago

For further reading, I found this [0]. 20000T happens, but seems to be on the top end and not a typical train.

[0] https://www.trainconductorhq.com/how-much-does-a-train-weigh...

Capital T is tesla, a unit of magnetic flux density.

very important comment /s

Old habits die hard. I still occasionally see some engineering veterans who use the capital letter "S" for seconds (and they would write "nS" instead of "ns" for nanoseconds) - even in chip datasheets. And when I was reading a textbook one day, I also noticed that the author, an expert with a life career at Bell Labs, just couldn't write MHz properly, and instead wrote "Mhz".

In their time, Siemens and Hertz had not even been added to the SI system yet, I imagine they would speak in terms of mhos and megacycles back then.

At least mhos and megacycles are unambiguous, unlike S or T.

Another commenter mentioned T is teslas, seems like the abbreviation for a ton depends on which ton you are talking about (wikipedia lists several and not all of them are mass/weight!).

From a conversion the article uses I believe they are using the metric ton (aka megagram) which abbreviates to the lower case t. The article you reference does not seem to ever abbreviate 'ton' and I suspect that may have been done intentionally to avoid running into this issue? Its what I would have done, anyway.

I don't think this impacts the readability of your comment I just thought it was a shame that the other comment didnt go all the way and attempt to describe correct useage.

For comparison, the Ever Given that got stuck in the Suez a couple years back has a capacity just short of 200,000 tons.

https://en.wikipedia.org/wiki/Ever_Given

Kinda blows my mind that it floats on water.

It's basically thanks to the fact that the water under the ship is ~870 times more dense than the air inside the ship.