THE TITANIC-50 YEARS LATER 



using strategically placed thermite explosive charges on grounded 

 icebergs off Newfoundland. Large bergs were literally shattered by 

 a series of explosions and reactions. The thermite theory involves 

 the high temperature of combustion when thermite, an intimate 

 mixture of powdered aluminum and iron oxide, reacts to produce 

 molten iron. The high temperature gradient, though from a relatively 

 small heat source, may set up shock waves within the berg and 

 fracture it along planes of internal stress. Boarding an iceberg in the 

 open sea to plant the charges is not only very hazardous and fool- 

 hardy but frequently impossible. 



INTRODUCTION OF ELECTRONIC AIDS 



Throughout the war years of 1941 thru 1945 the Ice Patrol 

 was suspended as it had been between 1916 and 1918. However, 

 during the Second War many scientific advances were made, and 

 their application greatly increased the efficiency of the post war 

 International Ice Patrol. During the absence of a surface patrol, 

 aerial observation flights of the ice area were successfully flown. 

 After the resumption of the regular ice patrol in 1946, aircraft contin- 

 ued to play an ever increasing role. Equipped with radar for probing 

 areas of reduced visibility and Loran for a system of precise position- 

 ing, aircraft were able to systematically search the ice areas quickly 

 and fairly thoroughly. Patrol planes flying set patterns at an alti- 

 tude of 500 to 1,000 feet, cross and recross the ice area on parallel 

 courses about 25 miles apart, while obtaining Loran fixes at 3 to 5 

 minute intervals. These ice observation flights have been so effective 

 that during light ice years continuous surface patrols are unnecessary. 

 Normally preseason ice observation flights begin in January and 

 continue until the commencement of a continuous surface patrol. 

 Flights are resumed after the surface patrol is terminated. 



Yearly the number of vessels equipped with radar increases. 

 Consequently, since 1945, the Ice Patrol has conducted continuing 



research programs in iceberg detection by Radar. These experiments 

 prove radar is useful in detecting ice, but the atmospheric conditions 

 over the Grand Banks that create a need for radar often cause sub- 

 normal propagation of radar waves. The research indicates there is 

 no preference to the frequency of the equipment as ice is not fre- 

 quency sensitive and the response of ice to S- and X- bands is the 

 same. The effect of fog on either band is negligible, but rain can 



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Boarding party preparing iceberg for thermite charge, 



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41 



