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conning, it was continually necessary for him to ask the helmsman for 

 the ship's heading in the absence of bergs or landmarks. In order to 

 comply, the helmsman, who was wearing dark glasses, then had to 

 look down and with diflficulty read the heading from the gyro at one 

 side of the wheel. He then had to readjust his eyes to the ice pack, 

 impart the heading to the O. O. D., and get his mind once more on his 

 steering. Helmsmen are rotated every 30 minutes. 



Sometimes it is very difficult to decide whether to strike a floe 

 squarely to enable the ship to penetrate the ice and keep closely to 

 the present course, or hit it a glancing blow in order to help make a 

 turn in following a lead. 



Have the helmsman stand on a stool so he can look down on the 

 point where the bow enters the ice. Keep your headway if possible. 

 Take advantage of open water. Frequently the longest way is the 

 shortest, all factors being considered. Steer toward the point where 

 the dark "water sky" is highest in the heavens, provided, of course, 

 it is not too far from your base course. 



Ability to break ice is dependent on (1) degi-ee of surface water 

 between floes, (2) ice thickness, (3) ship's weight, (4) ship's power, 

 (5) thickness of ship's plates, (6) ship's shape, and (7) snow cover 

 of ice. 



Remain clear of bergs in heavy pack. Especially avoid passing 

 between two adjacent bergs in heavy pack as the ice you break has no 

 place to go except to clog up the ship's wake. Also, the ice pack resists 

 advance because of side pressure from the bergs. 



In ballasting down Wind class icebreakers before entering the pack, 

 a drag of about 6 inches is the best trim for a general situation, par- 

 ticularly in ice escort where maneuverability is an all-important factor. 

 The peak tank arrangement of the Wind class permits altering the 

 trim in a few minutes. 



ANCHORING 



During all of the operation in the Antarctic in 1948 there were 

 only about three points at which the Edisto stopped that the water 

 was shallow enough to anchor in. This problem was taken care of 

 elsewhere by merely wedging the bow of the ship into the pack at 

 full power until she became stuck and held fast, or by mooring to 

 the ice shelf with regular mooring lines to "dead men" sunk in the 

 ice. The more successful and easier method was lying to with the bow 

 wedged in the ice. This, however, would apply only to the icebreaker 

 class of vessels because others would not be able to force themselves 



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