Heavy Loading of Northwestern Apples 



HANDLING HEAVY LOADS UNDER VENTILATION 



Under standard ventilation the car ventilators are left open both 

 day and night, unless the outside temperatures become dangerously 

 low, regardless of how warm it becomes during the day. Under 

 controlled ventilation, the ventilators are closed when the outside 

 temperatures become higher than those of the fruit. When shipped 

 under ventilation there is no great difference in temperature between 

 cars heavily loaded and those with normal loads. This is illustrated 

 in figure 2. Under ventilation the range in temperature between the 

 top and bottom layers is less than under refrigeration, but the tempera- 

 ture of the load as a whole is not likely to be as low as when it is 

 shipped under refrigeration unless the ventilated shipment passes 

 through outside temperatures ranging below 40. This is illustrated 

 in figure 3, wherein comparision is made between the average fruit 

 temperatures in heavy loads under standard refrigeration, standard 

 ventilation and controlled ventilation. Great advantage is found in 

 controlled ventilation over standard ventilation, since lower and more 

 uniform temperatures are maintained where cars have ventilators 

 closed when the outside temperatures are high. 



FLUCTUATING TEMPERATURES IN BOX CARS 



Temperature records of fruit shipped in box cars offered very con- 

 clusive evidence of the unsuitability of this type of equipment for 

 apple shipments from the Northwest. Figure 4 shows the striking 

 fluctuation in fruit temperatures under the influence of the changes 

 in the outside air temperature. This chart also shows how little one 

 or two ply of building paper protects the fruit from outside tempera- 

 ture changes. The box car has no provision for ventilation and offers 

 neither protection from heat during the warm fall weather nor from 

 freezing during a cold period, and is not suitable for long-distance 

 shipments of apples. 



Various methods of temporary insulation and heating were provided 

 for box cars by shippers during the latter part of the shipping season. 

 Figure 6 shows three methods of providing temporary insulation. 

 Car B with an inner wall space 6 inches from the car wall filled with 

 shavings gave the best results. The inner wall held the shavings in 

 place, whereas in the car where the shavings were separated from 

 the fruit load by building paper only the shavings settled somewhat 

 and part of the top became uncovered. The eel-grass quilt offered a 

 protection approximating that of the shavings for short periods of 

 cold weather owing to the very efficient manner in which it was 

 applied. These cars were subjected to a temperature of 13 below 

 zero for a few hours with but slight frost damage on the floor. 



