>>1055613This chart is for fixed voltage fixed frequency, which hasn't been regularly used since the 3 phase systems in Italy were closed in the 60s, and weren't used for any new builds since the 30s.
Modern locos use variable voltage variable frequency drives, which ends up with a speed vs torque curve like this, flat top constant torque, limited by current causing stator heating, then 1/x curve once limited by available power or voltage rating.
