SNCF and Amtrak operation compared
Two trains are pictured here: A non-tilting, standard TGV of the French SNCF, and the tilting train Amtrak Cascades.
Question: If both trains run through the same tight curve, which one is faster?
|curve radius||superelevation||speed limit 1
|Cascades Talgo, tilting||1000 feet||4 inches||48 mph
|TGV, non-tilting||1000 feet||4 inches||53 mph
Reason: Not the tilting mechanism sets the curve speed, but the allowed amount of unbalanced superelevation.