Paris to London on Eurostar.

The impact the Chunnel has had on commerce–all kinds, but primarily tourism, I would guess–between the UK and the Continent must be really amazing . . . even astronomical. I mean, Londoners can now run over to Paris for lunch and be back here in time for their blooming’ tea!
Consider: Eurostar trains, literally dozens every day, operate in both directions between London and several European cities, but primarily Paris and Brussels. The one-way trip to Paris takes about two-and-a-half hours; it’s a bit less to Brussels. The typical Eurostar trainset has a power unit at each end, 18 coaches, and can transport as many as 800 people.
Yeah–(dramatic pause)–Holy Crap!!
 My train, number 9029 (above), left Paris this afternoon at 12:43 and arrived in London at 2:10, UK time.  The SpeedBox app on my phone showed us running at 135 to 140 miles-per-hour for most of the first hour out of Paris, then stepping up to a pretty consistent 180 to 185 for most of the rest of the way. The speed fluctuates because the driver runs it up to whatever is the maximum speed allowed for any given section of track, then coasts for a minute or so, allowing the train to gradually slow before accelerating again. It works wonderfully because the weight of the train is so massive and there is so little friction with the steel wheels on the steel rails.
Three of four times during the trip, we passed another Eurostar train heading in the opposite direction on the adjacent track: WHOOM! You can literally feel the concussion and no wonder: the combined speeds could be as much as 360 miles an hour and the distance between the two trains is only about four feet.
And that reminds me of the time back when equipment–coaches, actually–were being designed and built to run at 100 to 120 miles per hour on the Northeast Corridor between Washington, New York and Boston. The concern at the time was that two trains passing each other at such speeds could potentially suck the windows out of the coaches … I guess the concern being for any that could have been improperly installed in any little way.
Of course Amtrak had to come up with some kind of explanation for what appeared to be undersized windows, especially because their advertising was busily selling the scenery passing by outside their trains. And so I’ve been told by people who were around at the time that the official reason for the smaller-than-expected windows was that the trains were going to travel up and down the NEC at such high speeds, the small windows would evoke comparisons with the even smaller windows you get in a jet liner.
I dunno. Sounds kind of far-fetched to me. If that was their story, I doubt that anyone bought it.