Problem illustration:
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?

TGV travels along the Cote 
d'Azur   Cascades Talgo travels along the coast at Richmond Beach.
TGV at La Napoule (Cote d'Azur), Cascades Talgo at Richmond Beach


  curve radius superelevation speed limit 1
Cascades Talgo, tilting 1000 feet 4 inches 48 mph
TGV, non-tilting 1000 feet 4 inches 53 mph
1 Other increments than 1 mph are ignored for speed restrictions. The reason is explained here.

Reason: Not the tilting mechanism sets the curve speed, but the allowed amount of unbalanced superelevation.

Unit conversion for text on this page.
1000 feet radius 305 m radius 5 degrees 44 minutes 50 seconds of curvature
4 inches 102 mm  
48 mph 77 km/h  
53 mph 85 km/h  

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Last modified: 2003-10-21