No. 4 (I921) BRINE-FREEZING 49 



The median line of tanks is for equalizing the temperature of 

 brine from the different cooling tanks before it flows to the freezing 

 pits. All these sets of chambers connect by high level piping in 

 the following way : — each set of six fish-freezing tanks connect 

 with one equalizing tank and each of these with two cooling tanks, 

 A loiv-level pipe connexion also exists between the cooling tanks 

 and the freezing tanks; in each of these pipes a propeller is fitted, 

 drawing partially warmed brine from the freezing tanks to take the 

 place of the cooled brine that flows out by the high level con- 

 nexion first into the equalizing reservoirs and thence into the 

 fish-freezing pits. 



When the temperature in all the tanks is reduced sufficiently, 

 i.e., to — l4/^° C, operations may be started by filling fish baskets in 

 clutches of seven into the freezing pits after a final souse in fresh 

 water in a small tank at the fore end of the line of freezing pits. 

 An instruction board is hung at one end of the room on which is 

 chalked the time' at which the fish in each particular pit should be 

 removed. This is necessary as the tanks are not all filled at 

 the same time, and again one tank may contain small fish which 

 require only one hour's immersion, while another lot of larger fish 

 may require two hours to freeze. 



A small overhead travelling electric crane is used for carrying 

 the units to the pits and for lowering in and taking out. After 

 freezing, the crane takes a clutch of baskets to a pit filled with 

 fresh water and rinses them rapidly in it, partly to remove any dirt 

 adherent and also to give a coating of frozen fresh water — 

 " glazing " as it is technically termed. 



From this point the baskets are carried to the packing tables, 

 where the fish are rapidly transferred to wooden boxes lined with 

 waterproof paper, and nailed down, the weight of e;ich being 

 marked legibly on the outside. After that they go to the cold 

 storage rooms to await despatch. When more fish is received than 

 can be dealt with in one day, it is stored with ice in an insulated 

 store adjoining the receiving room. Here the fish can be kept 

 absolutely good (in summer time in Denmark) for several days at 

 an expenditure of 8 lb. ice to 20 lb. fish. The insulating material 

 used throughout is tarred cork particles pressed into blocks. 



To keep the fish fully frozen as long as possible when sending 

 by rail in ordinary covered railway vans, the boxes are insulated 

 roughly by surrounding the whole mass either with dried seagrass 

 7 



