The 40’ Boxcar is widely known as one of the most popular freight cars used by railroads as they transitioned from steam to diesel. In particular the Pullman Standard or PS-1 design was one of the most popular and was widely used by North American railroads. Pullman had been making freight cars for more than half a century when it hit a home run with the PS-1. Introduced in 1947, it set the standard for postwar American freight cars.
What made the PS-1 a landmark was its welded construction — an area in which Pullman led the industry. In addition to lighter weight, welding offered superior strength and better resistance to weather and corrosion than contemporary riveted cars.
Like the EMD diesels that became ubiquitous on American railroads, the PS-1 was part of the postwar shift away from customized, railroad-specific locos and cars toward standardized designs produced in large quantities on efficient assembly lines. No wonder the PS-1 was soon followed by the highly successful PS-2 covered hopper, PS-3 open hopper, PS-4 flatcar, and PS-5 gondola.