Railroads started to develop refrigerator cars in the late 1800s. By 1870, shippers, scientists, and the railroad companies were working to find a way to transport various products by rail that needed to stay cool. This included meat, fruits, vegetables, and various other commodities. Special cars were constructed with insulated sides and a variety of cooling methods were tried. The predominant method was using ice – either crushed or in blocks.
Ice reefers, built of wood, typically had 4 rooftop hatches at each end. There, ice was loaded into bunkers, usually at specially built structures called icing platforms. Cool air circulated over the ice and throughout the car, keeping the contents cool. Depending on the shipments, cars might have been “pre-cooled” before loading to keep the products from being loaded into an already warm car. This helped keep the product cool for longer periods of time while using fewer ice.
Typically, ice reefers needed to be topped-off with fresh ice at least once a day. Because of this, icing stations were erected along mainlines around the country, usually located at or near water tanks (for fueling steam locomotives). If a shipment did not need refrigeration, the car could be used for a dry shipment just like a standard boxcar.
Initial cars were built entirely of wood. By the early 1900s, reefer cars were typically constructed with wood bodies while being reinforced by steel at the ends and roofs. This strengthened the overall structural integrity of the cars. While all-steel cars started appearing in 1936, wood cars could still be seen through the 1950s and 60s.
The initial development of mechanical reefers commenced in the 1950s, but their widespread adoption occurred in the 1960s due to their superior efficiency, cost-effectiveness, and reduced maintenance requirements for transporting refrigerated goods. For instance, the Pacific Fruit Express fleet expanded significantly during the mid-1960s and early 1970s with the construction of the 57' reefers, although shorter mechanical reefers existed prior to this period.
Mechanical reefers took over the transportation of produce like lettuce and tomatoes by the early 1970s. As a result of the proven technology, almost every Class I Railroad had dismantled their icing platforms by 1974. Some ice reefers did persist in limited non-produce carrying roles throughout the 1970s, serving in trackside meat packing operations.
