REFRIGERATION OF FISH 567 



Twelve hundred pounds of dry ice was used, contained in wooden 

 fish boxes and distributed in the upper laj^er of boxes of fish. 

 Bunker openings were sealed with building paper nailed on with 

 lath, likewise the doors. The car arrived in good condition. Two 

 more cars followed in June and July. 1926. Numerous shipments 

 then were undertaken from Provincetown. Mass., to St. Louis and 

 Kansas City and from New York to the same points in the hottest 

 summer weather, the time of transit being five to six days. These 

 cars arrived in excellent condition, except when insufficiently in- 

 sulated cars were used. Recording thermometers in two of the cars 

 showed virtually constant temperature of 26° to 28° F. throughout 

 the trips. 



In the three-day shipments 1,200 pounds of boxed ice were included 

 and 200 pounds of granulated ice w T ere scattered over the load just 

 before the car w 7 as sealed to effect rapid cooling of the car. In the 

 five and six day shipments 1,500 pounds boxed and 200 pounds 

 granulated were used at first. All the ice was gone on the arrival of 

 the cars, which Avere tight and well insulated, but the fish were frozen 

 hard. In the later cars of five and six days the amount was increased 

 to 1,800 pounds boxed and 200 pounds granulated, and at the end of 

 five days about 200 pounds remained in the boxes. In other cases 

 2,400 pounds, all in boxes, were used. Where 1,800 pounds were 

 used, the ice was contained in 10 boxes of 180 pounds each. In some 

 of the cars rather serious defrosting had occurred ; in others the fish 

 were held perfectly. In the unsatisfactory 7 instances the trouble ap- 

 parently was caused by insufficient insulation and leaky doors and 

 bunkers. 31 



In the shipments from Provincetown the ice was shipped by ex- 

 press in boxes of sawdust. 



Practical experience in these shipments has yielded information 

 that may be summarized as follows : 



It is practical to ship frozen fish in the hottest summer weather, up 

 to six clays on the road, as the fish remain frozen by the use of dry 

 ice alone. 



A tight car with heavy insulation should be ordered without pre- 

 cooling. Movable floor racks, 4 inches deep, should be on the floor. 

 The bunker openings into the car should be sealed with building paper 

 and lath. Strips of 1-inch wood (or three thicknesses of lath) should 

 be nailed vertically on the sides of the car to prevent any possibility 

 of the boxes coming in direct contact with the walls. The door not 

 used for loading should be similarly sealed inside. The car should 

 be filled as full as possible — up to within 2 to 4 inches of the ceiling — 

 with frozen fish, in boxes, as a full car is more favorable to refrigera- 

 tion with dry ice than a part car. Dry ice, in 8 to 10 wooden boxes, 

 should be distributed in the top layer so as (1) to come next the ends 

 and sides of the car, (2) not to come next to one another, and (3) to 

 be uniformly distributed over the load. There should be no sawdust 

 or insulation around the dry ice, but the boxes may to advantage be 

 lined with heavy paper. 



The dry ice should be delivered to the car w r ith the fish, and 

 loading should be prompt. When the load is in, or during loading, 



31 Solid Carbon Dioxide, or Drv Ice, in the Fish Industry. By Harden F. Taylor. Ice 

 and Refrigeration, vol. 71, 192C, pp. 211-213. Chicago. 



