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may carry the vessel upon a grounded mass, or heavy floes ; there is 

 also the danger of their overturning and calving. Unceasing watch- 

 fulness is necessary for eddies and currents, if fast to a floe, and a 

 weather eye must be kept on any bergs or heavy ice that may be near, 

 lest they approach without noise or perceptible motion. 



The movement of a berg through a wind-compacted belt of ice 

 creates a fair lead which may remain open for an indefinite period, 

 depending on the size of the berg and the force and direction of the 

 wind. In traversing pack, advantage may be taken of the leads so 

 created by following the berg through the ice belt. In 1943, the 

 Northeast Greenland Task Unit Cutter North Star^ beset in close pack 

 storis, managed to plant her ice anchor on a large berg which drifted 

 close aboard. Because of the rapid relative drift of sea ice, as com- 

 pared with that of the current-propelled berg, she was towed to open 

 water. In order to save time and fuel, the Eastwind in 1944 resorted 

 to the same tactics in working through a consolidated field of polar ice. 

 It should be noted that both of the aforesaid operations occurred in 

 northeast Greenland where low water temperatures insure the stability 

 of bergs. 



If entering a narrow strait or bay into which the winds blow directly, 

 keep an alert watch on drifting ice, since the gi-eatest danger from ice 

 exists in an enclosed space. 



If operating in an area to windward of a prominent point in the 

 coast line, exercise caution : a sudden increase in the wind may bring 

 the pack down upon the vessel which, if set toward a lee shore, may 

 become quickly beset and subjected to pressure. 



Care should be taken when operating in the vicinity of ice tongues 

 which project seaward from the coast line without reference to the 

 trend of the coast line. An ice jam along an otherwise clear coast 

 may indicate the existence to leeward of such a tongue. Stranded 

 bergs, shoals, islands, and seaward extensions of land may produce 

 ice jams, and vessels finding themselves to windward of such features 

 must be prepared to quit the vicinity upon the appearance of pack ice. 



In slewing through pack ice there are two effective ways in which 

 progress can be made through areas in which there are only cracks 

 and narrow lanes between floes. In the first method the vessel charges 

 the openings between the floes and, upon impact, puts the rudder hard 

 over. When the forward motion of the ship ceases, the rudder is re- 

 versed and the engines placed on half-speed ahead. The effect is 

 to widen the opening and let the ship gain easier entrance. This oper- 

 ation is repeated until the floes yield, forming a lead wide enough to 

 allow the vessel to proceed ahead. 



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