- 17 - 



The AMS boxes were especially constructed to test certain variations in 

 design which were not available with the ARS and commercial pallet boxes. 

 AMS-1 had removable gates to permit easy filling, solid sides, and a spaced 

 bottom. This box, with an overall height of 40 inches, was constructed to test 

 the effect of deeper boxes on fruit bruising. AMS-2 was built on a smaller 

 pallet base to provide comparison with operations using standard apple boxes 

 on 36- by 40-inch pallets. AMS-3 was designed without stringers underneath and 

 was intended to be handled with a clamp-type industrial lift truck. AMS-4 was 

 designed with removable sides and inside dimensions of such size that it could 

 be used either for storing apples in bulk or for storing packed fiberboard 

 shipping containers of apples. 



COOLING STUDIES 



Earlier studies on the storage life of apples indicate that the sooner 

 field heat can be removed from apples, the longer the fruit will keep in 

 storage. With this in mind, it was determined that studies should be made of 

 the rate that apples cooled in the different types of pallet boxes. These 

 results were compared with the cooling rates of fruit held loose in field or 

 standard boxes stacked on pallets. The types of pallet boxes were so selected 

 that as many variables as possible were studied to determine their effect on 

 the cooling of fruit. 



The cooling studies were essentially an investigation of the, effects of 

 box dimensions and ventilation on cooling performance. 



The cooling characteristics of 9 different types of pallet boxes 

 containing unpacked apples were studied in tests conducted in 2 commercial 

 apple storage plants in the vicinity of Yakima, Wash. At each test location 

 the cooling performance of pallet loads of standard apple boxes filled with 

 unpacked fruit served as a check to adjust for the differences between the 

 two storages. 



The characteristics of the various boxes studied are shown in table 2. 

 In all pallet boxes, except AMS-3, air could pass above and below each box, so 

 the minimum dimension from center to exposed face of the body of fruit is 

 one-half the depth. For 6 of the pallet boxes, this distance (D/2) ranges 

 from 12 to l2& inches. For the 35-inch deep box with solid sides and spaced 

 bottom, D/2 equals 17J£ inches and for the 32-inch deep box with fiberboard 

 liner it is 16 inches. For the box without a pallet, the minimum center to 

 side face distance is 20 inches. Pallet box, Comm.-2M, is the same type of 

 box as Coram. -2 but the interior was completely lined with paper to give the 

 effect of solid sides and solid bottom with no vent at all. Only the top of 

 the box was open to permit entrance of air. 



Both convection and conduction play a part in the cooling of fruit in 

 these containers; however, the relative importance of each in the total per- 

 formance is unknown. Cooling accomplished by conduction is influenced by a 

 number of variables. The most important, in these tests, was the distance 



