The massive fish belly under frame was the backbone of cars built between 1910 and 1930. Supporting 80 foot long cars, it weighed almost a quarter of the total weight of the car. After the first year of building steel cars, Pullman began to shave off the excessive weight and over designed of the under frame, but was forced to add extensive end crash reinforcement to the upper structure. By 1915, a standard sill, bolster, and upper structure had been established.
Steel had proven itself, and by 1912, the Pullman Company was the largest manufacturer of steel products in the world. (two years before Henry Ford produced the Model T automobile). However, it should be noted that many of these improvements were forced upon the company to keep the competitors out of the arena. Pullman owned many of the gas producing plants that supplied fuel for the old gas light fixtures. They had developed the wood constructed to a science, and owned many of the saw mills, but not a single steel mill. Pullman was selling the beauty and elegance of wood inside and out. A steel car could never muster the awe of its' patrons. The longer lasting steel cars would reduce replacement business. For these reasons, the Pullman Company was the last major builder of railcars to convert to the modern construction. But as king of the railcar business, few noticed the competitors steel cars until the Pullman Company changed. When they did convert to steel construction, Pullman changed to the new technology so fast that the competition was left derailed, never to challenge the giant again.
The Pullman Company published an employee flyer called The Standard which in March of 1955 highlighted the companies history as it concerns the car construction business. It details the shrewd financing and mergers of the company through its first 75 years. In 1947 the passenger cars and their operation was sold to each of the 47 operating railroads. The remaining Pullman Standard Car Manufacturing Company was consolidated into Pullman Incorporated and remained until 1970 when it ceased operation. The time and come and gone for a man and company like Pullman. But during those 80 years, the total number of overnight guests Pullman's porters ticked into bed equaled ten-times the 1947 population of the United States.