Amtrak's Downeaster ACSES Test Train, with 50th Anniversary P42DC #46, shoves east past the famous Fenway Park on the MBTA Worcester Main Line in Boston, Massachusetts during the afternoon of July 21st, 2021. The train is heading back to Southampton Street Yard after completing a round trip to Portland on the Downeaster route and crossing to the "south side" via the Grand Junction Branch.