In 1868, Hammond received a patent for a refrigerator car design. MDT adopted the Wickes Patent into its refrigerator car design. The refrigerator car radically altered the meat business. Two hi-cube boxcars were constructed by St Louis Refrigerator Car Company. At the industry's peak, of ice was produced for refrigerator car use annually. In response to customer demand, REA added a Chicago, Illinois-based refrigerator car line.