Les groupes frigorifiques pour le transport routier à longue distance. Historique et évolutionRefrigeration units for long distance road transport. History and development

The big truck or trailer fitted with a refrigeration unit is a familiar feature of the highway traffic. But 50 years ago the transport of perishable food-stuffs over long distances by road was almost unknown. The development of the truck and trailer industry and the efforts of refrigeration engineers created rapid progress mostly using standard commercial refrigeration units fitted with petrol-driven engines and special controls suited to road traffic. Though there were some early European patents it was in the USA that the first practical units were produced on an industrial basis.The second world war brought a rapid development of mechanically refrigerated road transport since many railroads were destroyed and supplies had to go by road. After the war European industry started building its own models and by the 60's several manufacturers offered refrigeration appliances more or less comparable to US models. Most were still powered by gasoline engines but diesel powered units appeared soon, owning to the important price advantage of diesel fuel. US manufacturers also switched to diesel powered units, due mainly to the new piggy-back transportation mode combining rail and road transport.The increasing size of trucks and trailers, together with the need for lower temperatures by the frozen food industry, and the recent development of paletizing of the load are responsible for the steady increase of refrigeration road transport.