Dynamic Hopper System An interesting cargo item on CSX M403-02 on October 2, 2023 was the Delta Railroad Services/SRT "Dynamic Hopper System", seen passing over Doodletown Bight with the Bear Mountain Bridge in the background on the Hudson River in New York. SRT explains that this piece of equipment is used for "load/transport/unload materials of different sizes and granulometry and, in particular, waste material from ballast cleaning", and this type of equipment is in use on work projects across the United States.