Testing ACS-64 locomotive No. 601, 2013.

The first Amtrak Cities Sprinter (ACS-64) electric locomotives were sent to the U.S. DOT Transportation Technology Center near Pueblo, Colo. in summer 2013 for a series of tests, including maximum speed runs, acceleration and braking, operating with Amtrak passenger coach cars attached and testing the overall performance capabilities of the locomotive. Engineers also validated the on-board computer system and software, and evaluated ride quality by using instruments to measure things such as noise and wheel vibrations. A variety of additional tests and validation exercises were also conducted as part of the commissioning process to ensure the locomotives were operating and performing as designed.

The ACS-64s entered revenue service in February 2014. Designed by Siemens, the dual-cab Cities Sprinters have a peak 8600 horsepower and run at speeds up to 125 mph. A regenerative braking system can feed up to 100 percent of the energy generated during braking back to the power grid. Safety is paramount with enhanced crash energy management components such as crumple zones, while a microprocessor system allows for self-diagnosis of technical issues.

Photographer: Chuck Gomez for Amtrak.