REFRIGERATION OF FISH 



625 



but the heads are removed when the vessel lands. Smaller and 

 medium-sized fish, such as croakers, spot, butterfish, shad, small 

 weakfish, mackerel, mullet, and flounders usually are round. Gut- 

 ting removes the focus from which infection ma}- spread — the in- 

 testine — but exposes the belly cavity to the effect of water and 

 infection of a different kind. In large fish, such as salmon and hali- 

 but, it is customary to fill the belly cavity with the crushed ice. For 

 obvious reasons this hastens the thorough chilline; of the whole fish. 



ICING PACKAGES FOR TRANSPORTATION 



For this purpose boxes or barrels are used. Where boxes are 

 used a layer of ice is put on the bottom, then a layer of fish, then 

 ice, and so on. There is no standard size of box, but shippers have 

 their own shapes and sizes, usually designed to contain 100, 150, of 

 200 pounds net. of fish. One size 

 of box. rated at 150 pounds, is 

 33 by 19 by 15 inches deep, inside 

 dimensions, and is used in the 

 Gulf of Mexico snapper fishery. 

 A Great Lakes box measures 2G 

 by 17 by 12 inches deep. On 

 these boxes a board on each side is 

 about 8 inches longer than the 

 box proper, extending 4 inches on 

 each end. to form handles and to 

 prevent the boxes from being stood 

 on end. A halibut box used on 

 the west coast, rated at 200 pounds 

 net. is oiy 2 by 25 by l§y 2 inches 

 deep, inside measurements. This 

 box has no end extensions for 

 handles, but some of them have 

 rope handles. Another box. used in California, is 34i/ 2 by 18 by 9% 

 inches deep. This is rated at 150 pounds net. 



The common practice is to crush the ice used for fish. The smaller 

 sizes of lumps are preferred— from y 2 to 1 inch. Sailer 93 sum- 

 marizes the answer given by 40 fish dealers to a questionnaire on the 

 use of ice for packing fish. There is shown a general preference for 

 boxes rather than barrels. The ice and fish layers are alternated, 

 with a heavy layer of ice at the top. The amount of ice required for 

 100 pounds of fish varies from 50 to 100 pounds, according to the 

 weather and the opinions of the packers. Ice that has been used 

 once for packing fish rarely is used again for that purpose. There is 

 also a strong concurrence of opinion among fish packers that fish 

 should be thoroughly precooled in ice and repacked for shipment. 



Every plant that uses much ice has a mechanical ice breaker. This 

 is a revolving drum provided with steel spikes, inclosed in an iron 

 casing, with a hopper for feeding in the cakes of ice. Such a ma- 

 chine (see figs. 48 and 49) will crush a ton of ice in three minutes. 



Fig. 48. — Ice breaker. Courtesy, 

 Cochrane Corporation. 



*-^. Sailer. "Broken Ice for packing shipments of fish." Paper read before the 

 annual convention of the United States Fisheries Association, at Atlantic City. N. J.. 

 kept. 2 to 5, 1925. Published by the Cochrane Corporation, Creasy Ice Breakers 

 Department, publication No. 1360. Philadelphia, 1925. 



