Excerpts from the report: This study is part of a broad program of research to improve the design and performance of transportation equipment used in the movement of agricultural products, as a means of improving and expanding the marketing of farm products. Little precise information has been available heretofore regarding the efficiency of refrigerated railroad cars in terms of their heat transfer performance. This study has produced comparative information on certain types of cars and their refrigerating units to assist in the improvement of design and to reduce deterioration and spoilage of perishable foods in transit to market. This study indicates that an industrywide standard method of rating refrigerator car performance would provide better means for analyzing experimental structural innovations and for exchange of information within the industry. This should lead to better quality control in refrigerator car construction and, in turn, to increased efficiency of operation and better control in the protection of perishable foods during movement to market.