TRANSPORTATION OF FISHERY PRODUCTS 315 



ammonia solution from which anhydrous ammonia must be recovered or 

 the solution otherwise utilized, are distinct disadvantages to this system. Should 

 it be applied generally by railway companies, recovery plants would have to be 

 spaced throughout all railway systems so that cars could be serviced at 24-hour 

 intervals. The plants would require, in addition to recovery equipment, adequate 

 storage and pumping facilities, not only for the liquid ammonia, but also for the 

 strong ammonia solution transferred, so that a number of cars could be serviced in 

 a short time. 



Mechanical Refrigerator Cars 



Europe (the Altek System). The necessity for sub-zero temperatures for the 

 holding and transport of all frozen foods, coupled with the inability of ice and 

 salt mixtures to hold such temperatures in the standard refrigerator cars, has led 

 to investigations with compression systems. In Europe a fairly satisfactory com- 

 pression system was developed about 1937 and called the Altek system. 



The essential components of this system, as used in Belgium, consisted of an 

 11-h.p. water-cooled Diesel engine, a two-stage air-condensing direct expansion 

 ammonia system, a 110-volt d.c. generator, electric fans for engine cooling and 

 air circulation through the evaporator, fuel tanks with a capacity sufficient for 

 7 days of operation, thermostats and control mechanism for automatic temperature 

 control within the range 5 to 50° F (— 15 to 10° C), and electric heaters for heat- 

 ing the car to the required interior temperature. 



It was reported that the railway cars in Europe equipped with this system 

 were given extensive tests in 1937 and the following year; as a result negotiations 

 were under way in 1939 to have a unit tried out in Canada, but World War II 

 intervened. 



The fate of the manufacturing company is not known; but, as evidenced by the 

 equipment which fell into Allied hands dviring and at the end of hostilities, some 

 of the principles applied in the Altek system were used by the Germans in both 

 railway cars and trucks during the latter part of the war. 



United States. A truly mechanical type of car was introduced in 1930 and 

 tested in 1931. This car was cooled with a 1-ton compressor driven by a Diesel 

 engine, and its operation was described as satisfactory. At that time, however, a 

 temperature of 10° F ( — 12.8° C) was considered satisfactory for frozen foods. 



In the past few years the increased use of mechanical cooling of road trucks 

 and trailers has given support to the view that similar mechanical systems are at 

 least technically feasible in railway cars. Studies are now being conducted in 

 both the United States and Canada to determine the economics of the various 

 mechanical systems adaptable to railway cars. 



At present in the United States two types of equipment are being studied. One 

 is somewhat similar to the Altek system, already described, and employs a Diesel 

 engine. This may be called a 'T)uilt-in" type, for the various elements of the 

 system (engine, generator, compressor, and evaporator) are built into the body 

 of the car. A car of this type is being investigated jointly by the Atcheson, Topeka, 

 and Santa Fe Railway and the Trane Company of La Crosse, Wisconsin. The 

 other type is known as the "packaged system," in which a unit with all its ele- 

 ments forms a single "package" or parcel. The power for such a unit is supplied 

 by a gasoline engine. A brief description of the parcel type will be found in the 



