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. These boxcars were built beginning in 1947 and share the same basic design, with certain elements such as door size, door style or roof type varying among the different railroads and production years. When production of these cars ceased in 1963, over 100,000 had been produced. Features include body-mounted Accumate(R) couplers, Barber S-2A 50-ton trucks with metal wheels, separately applied ladders, etched-metal roof walk, 12-stiffener roof, Ajax and Miner brake wheels and appropriate door style.