Refrigerated railroad cars are known as reefers. They are insulated boxcars that keep the cargo at a regulated temperature, often around 40 degrees Fahrenheit. The first reefers relied on ice to cool the load. Diesel-powered refrigeration units displaced the ice as a more efficient coolant.
A Mr. Wilder is credited with designing the first refrigerated railroad car to ship butter along the Northern Railroad of New York around 1851, but he did not patent his design. His reefer was a 36-foot-long wooden boxcar. The sides were lined with bunkers to hold ice. Roof hatches opened to allow the ice. The first patents for refrigerated railroad cars were filed in the 1860s by W.A. Chandler of the Union Star Line and by J.B. Sutherland and D.W. Davis of Detroit. Wooden reefers were built until the 1940s when the industry switched to steel reefers. The early steel reefers still had roof hatches that opened at the ice refilling stations so that the area between the exterior wall and the load could be filled with fresh ice about every 400 miles. By 1958, reefers began to be cooled using diesel-powered refrigerator units. The most recent improvement to refrigerated railroad cars came in the 1960s. This was the invention of the plug door, which allowed a tighter seal, allowing the car to remain cooler longer.
Beginning with Gustaves Franklin Swift's purchase of 10 refrigerated railroad cars in 1857, the meat-packing industry became dependent on the railroad to carry meat to the nation's eastern cities. Philip D. Armour used reefers to deliver his meats after 1875. In fact, the development of reefers eliminated the need to drive large herds of cattle from the grazing lands in the west to the butchering plants in the Midwest.
Refrigerated railroad cars also affected the breweries. The then St. Louis-based Anheuser Co. bought 40 reefers in 1877. The company still owned the St. Louis Refrigerator Car Co. in 2008. The company starts with used 40-foot boxcars. Then it adds one and one-half feet of height and five feet of length to build new insulated boxcars that can keep a load cool from coast to coast.
Another company that produces reefers is the American Refrigerator Transit Co. It began as a partnership between the Missouri Pacific Railroad and the Wabash Railroad and builds diesel-powered reefers that are 50 feet long. The cars can carry 140,000 lbs. each, keeping the freight at an even temperature in a sealed environment.