A northbound Southern Railway freight winds its way under the Duke Street Bridge in Alexandria as it nears Potomac Yard. The three locomotives are all high-nosed SD35s (3019, 3013, 3055), part of a fleet of 100 delivered between Sept 1965 and Jan 1966. If you look closely the fireman has opened the door to get a breeze in the stifling DC heat and humidity. Based on the time, this is the 158-manifest train between the old flat Spencer Yard in Spencer, NC and Potomac Yard.