Reefer, Ice, Steel

History: Not all steel reefers contained mechanical refrigeration units. Although today we expect that a modern reefer contain an air conditioning unit to be integral to the car design, this was not always true. There was a period following the second world war when the cost of steel was cheap but the cost of a refrigeration unit was high. Early mechanical refrigeration units were unreliable, noisy, expensive and costly to maintain, and for the early post-war years many railroads continued to use ice for refrigeration even though the technology for mechanical refrigeration was possible.

In the post-WWII period, steel once again became readily available and the railroads rapidly replaced their aging fleets of wood reefers with newly constructed steel cars. Among the more common steel reefers for meat and other perishable commodities were those built by URTX. These cars had a horizontal rivet strip along the middle of each side, improved Dreadnaught ends and diagonal-panel roofs.

From Wikipedia and other sources

Railroad/Company: This set of items is comprised of more than one name. Please look at the component items for details on the specific roadnames and/or manufacturers.