316 MARINE PRODUCTS OF COMMERCE 



succeeding section. A car of this type is being investigated by the Fruit Growers 

 Express Company in collaboration with the U. S. Thermo Control Company of 

 Minneapolis, Minnesota. 



In Canada. Several new ideas relating to the mechanical cooling of railway cars 

 are being investigated by the Fisheries Research Board of Canada in collaboration 

 with the Canadian National and Canadian Paciiic Railway Companies. The 

 work started in 1948 when the Fisheries Research Board reconditioned an old 

 overhead tank car loaned by the Canadian National Railways. 



The Canadians were the first to apply the "packaged system" to a railway car. 

 The experimental car is equipped with two identical packaged units, each one 

 being capable of supplying the maximum cooling or heating load. These units are 

 fitted into metal compartments on each side of one end of the car. Each com- 

 partment is fitted with a cradle in which the unit rests and a track which permits 

 the unit to be pulled out of the compartment for inspection or other purposes. 

 The units are secured in place by means of a clamping device which permits a 

 quick exchange in case of failure or for repair purposes. They are located against 

 an insulated bulkhead through which the evaporator and evaporator fan project 

 into a plenum chamber. A new or reconditioned unit can thus be installed in a 

 matter of minutes. 



The units are powered by 4-cylinder gasoline engines which are entirely 

 automatic in both cooling and heating operations. Heating is accomplished by 

 reversing the refrigeration cycle or, by what is popularly called, the "heat- 

 pump" principle. 



The insulated body of the car is completely jacketed, and the course of the air 

 circulated through the jacket is from floor to ceiling. Should a portion of the 

 circulating air be required to pass through the loaded portion to take up heat 

 of respiration from fruit or vegetables, then grills in the walls at the floor and in 

 the ceiling can be provided to permit the desired amount of air to pass through 

 the load. Thus the car can be used for the shipment of any perishable commodity 

 that requires a constant temperature, within the range of the thermostats — 10 to 

 60° F (— 23.3 to 15.6° C), and the shipment can be carried through any weather 

 conditions with only the manual adjustments made at the beginning of the trip. 

 Fuel sufficient for 10 days of normal operation is provided and oil reservoirs with 

 capacities of 5 gallons obviate the changing of lubricating oil, except at the end 

 of a trip. 



A mean temperature of — 2° F (— 18.9° C) was maintained in the experi- 

 mental car as 2 carloads of frozen fish were carried across the Dominion in June 

 and July of 1949. One carload of apples was also shipped in January, and no 

 difficulty was experienced in maintaining a mean temperature of 33° F (0.6° C). 



The results of the Canadian experiments indicate that the system employed is 

 quite capable of supplying the temperatures required for the shipment of fresh 

 fish, fruit and vegetables, and frozen fish and other commodities under any 

 weather conditions encountered in Canada. However, further tests will be neces- 

 sary to supply data for studies of its economic feasibility. 



Packing Fresh Fish for Shipment 



Fresh (unfrozen) fish, as has been indicated already, are shipped in express 

 refrigerator cars in both carload and less than carload lots. In the carload lots the 



