392 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1962 



and she also proved the existence of these leads throughout the Arctic 

 pack during summer months. In March 1959, less than 7 months later, 

 Skate proceeded to the Pole a second time. During this severest of all 

 seasons in the Arctic, Shate developed a procedure for surfacing blind 

 through the ice which completely covers the Arctic Ocean during the 

 winter darkness. 



In February 1960 Sargo became the third of the "ice boats" to under- 

 take what many consider was the most hazardous task of all. Build- 

 ing on knowledge gained from Nautilus and Skate, and utilizing 

 prototype equipment to guide her around shoals and deep ice, Sargo 

 operated for many days in shallow waters under the unfavorable cir- 

 cumstances of complete ice coverage and round-the-clock darkness. 



Several questions remained after Sargo successes. Could nuclear 

 submarines operate under ice in proximity to icebergs without fear of 

 colliding with this deep draft ice ? Could nuclear submarines operate 

 under the ice in the restricted waters between land masses? If a 

 nuclear submarine could operate in narrow, shallow passages under the 

 ice and in the vicinity of icebergs, it seemed likely that there were 

 usable passages in the islands of northern Canada that should be 

 sought out and used. Several ice-blocked straits crossed this area, but 

 wliether they were passable by submarine was not known. 



Much had been learned about icebergs since the establishment of the 

 International Ice Patrol in 1913 after the tragic sinking of Titanic. 

 Icebergs are the droppings of glaciers which exist on many of the 

 Arctic islands. The weight of centuries of snowfall shoves the glacier 

 down the island slopes toward the sea where huge pieces break off, be- 

 coming icebergs. Time and pressure and temperature have converted 

 snow to very hard ice by the time it reaches the sea. Once afloat, it 

 may wander in Arctic waters under the effects of current and — to a 

 lesser extent, wind — for years while a slow erosion occurs, "Whenever 

 curi'ents take it into warmer waters, disintegration occurs within a 

 few days. 



Most of the world's icebergs occur in Baffin Bay. Greenland is by 

 far the most important source; here 12 large glaciers alone have been 

 recorded as calving 2,300 bergs in 1 year. Icebergs do not normally 

 occur in the Arctic Ocean so that previous nuclear submarme 

 expeditions have not confronted them. 



A new nuclear submarine, U.S. S. /iSeac^ra^on (SSN-584:) was having 

 her post-shakedown sliipyard availability at Portsmouth, N.H., at 

 this time. Seadragon was scheduled for transfer to the Pacific Fleet 

 at an opportune moment, and so it was decided to fit her with ice 

 equipment and send her to Pearl Harbor by way of a Northwest 

 Passage, if one could be found. On August 1, 1960, Seadragon sailed 

 northward. 



