Today’s well cars go by many names (double-stack cars, for instance) but their primary purpose has not changed over the past twenty years or so; to haul international containers in loads of one or two (typically two if railroad tunnel and bridge clearances will allow) from port to market and vice-versa. While the car has been embraced by railroads for its efficiency it is actually little more than a glorified flat car. The well car was also just another step in the evolution of COFC service (said "Cof-cee"), or "Container On Flat Car." You might be surprised to learn that while the movement of intermodal freight in such large quantities is a relatively recent phenomenon, its history and experimentation within the industry can be traced back decades to around the time of World War II! It slowly grew from the 1950s to become a major source of traffic for roads like Conrail and the Sante Fe during the 1980s. Today, most Class Is now derive a substantial source of annual revenue from the movement of intermodal.
Reference: American-Rails.com
