Amtrak's 60 Hz traction power system
Amtrak’s 60 Hz traction power system operates along the Northeast Corridor between New Haven, Connecticut, and Boston, Massachusetts. This system was built by Amtrak in the late 1990s and supplies locomotives with power from an overhead catenary system at 25 kV alternating current at 60 Hz, the standard frequency in North America.
Source: Wikipedia — Amtrak's 60 Hz traction power system (CC BY-SA 4.0)