> Swedish and Russian railways pack 6 to a compartment; Amtrak struggles with 2.
But there are two roommettes side by side. Both European and Amtrak cars have a length of ~26m. An Amtrak Superliner sleeping car can sleep up to 44 people. A sleeper as used by Austria’s ÖBB can sleep 12*3=36 people. A 3rd class Russian sleeping car holds 54 [https://www.vagonweb.cz/razeni/vlak.php?zeme=%D0%91%D0%A7&ka...]. Comparable.
I used an older generation of that third class Russian carriage design last year. Biggest problem is the length of the benches and the noise. It's not like it was _great_ but for a dirt-cheap cross-country train ticket in Ukraine I expected a whole lot worse.
54 sleeper car actually can be full. Basically no way to fill the Amtrak car, as people don't like to share the bedrooms.
Russian trains used to have 3 bunks, which improved the economics.
But there are two roommettes side by side. Both European and Amtrak cars have a length of ~26m. An Amtrak Superliner sleeping car can sleep up to 44 people. A sleeper as used by Austria’s ÖBB can sleep 12*3=36 people. A 3rd class Russian sleeping car holds 54 [https://www.vagonweb.cz/razeni/vlak.php?zeme=%D0%91%D0%A7&ka...]. Comparable.