562 U. S. BUREAU OF FISHERIES 



Shucked oysters in cans and fresh fish in boxes often are stowed 

 in the car and covered with cracked ice. The boxes of fish also 

 contain ice with the fish. 



PREPARATION OF CARS 



In order to prevent the boxes of fish from coming in direct contact 

 with the outside walls, where heat may be conducted directly to 

 them, it is advisable to nail battens along the side walls. Two, or, 

 better, three thicknesses of lath nailed on, vertically or inclined 

 at a slight angle, with eight-penny nails, are sufficient. As an extra 

 precaution the entire cargo is sometimes wrapped by laying build- 

 ing paper on the floor (if the floor battens are removable) and tack- 

 ing it under the lath on the sides. The free ends are tacked 

 temporarily to the ceiling while the car is being loaded. After the 

 load is all in the ends of the paper are freed from the ceiling and 

 brought around over the boxes, entirely surrounding the contents of 

 the car. 



PRECOOLING CARS 



Best results are obtained if refrigerator cars are precooled before 

 they are loaded. A common way to do this is to ice the bunkers 24 

 hours before the car is loaded. Some of the meat-packing houses 

 bring the cars alongside the freezer platform and attach a large 

 canvas duct or " tunnel " to the door leading from a cold room in 

 the freezer. A large fan blows cold air into the car for a number 

 of hours to precool the air and walls of the car. It is advisable tc 

 use a canvas cover over the passageway from freezer to car, in any 

 event, to prevent the circulation of air during the loading. 



Where quick precooling is necessary in an emergency, a 20 per 

 cent ice and salt mixture is used in the bunkers during the loading. 

 This strong mixture thaws more rapidly, reaches a lower temper- 

 ature and chills the car more quickly. When the car is loaded, the 

 bunkers are brought up to capacity with the 10 per cent mixture. 



Where ice and salt are used in the bunkers it is unsafe, especially 

 in warm weather, to pack the car entirely full of fish. Usually the 

 car is packed to within 1 or 2 feet of the top. When the goods are all 

 in, the boxes should be bracked tight to prevent shifting in transit. 



It is highly important that the doors of the refrigerator cars 

 should fit tightly so as to prevent the entrance of warm air into the 

 car. The threshold should be cleaned carefully before the door is 

 closed. 



The cars are reiced in transit as required. This service is per- 

 formed by the carriers at a comparatively low cost for ice and salt, 

 usually plus a switching charge. 



Refrigeration of cars with carbon-dioxide ice will be discussed in 

 connection with the ice. 



REFRIGERATOR-TRUCK TRANSPORTATION 



In cool weather frozen fish may be transported for short distances 

 in an ordinary open truck. Usually a tarpaulin is thrown over the 

 load to cut off the direct sunshine. A closed van is preferable, how- 



