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•Jf2? 



Figure 13. — Showing the effect of the propellers in keeping the stern of the icebreaker clear 



of ice while hove to. 



Lay the anchor from the side of the tloe where a patch of open water 

 is formed, or where the surrounding ice is least packed. When riding 

 to an anchor the movement of the ice must be continually observed. 

 If there is a risk of the ice surrounding the ship, weigh anchor and 

 move into a more open region off another floe. Therefore keep the 

 engines ready for immediate action. If a small berg or larger bit 

 drifts down on the ship, it can frequently be avoided and permitted 

 to drift clear by judicious use of the engines while at anchor. 



In selecting an anchorage in a bay or harbor which is open to drift- 

 ing ice, the shallowest depths should be chosen, provided other condi- 

 tions are suitable. A vessel should not select an anchorage too close 

 to a glacier cliff since calving of the barrier may endanger the vessel 

 or set up a hea^'y swell making the position uncomfortable. 



In bays or fiords where fast ice exists, the tidal currents may cause 

 this ice to drift in and out of the harbor, rendering the anchorage un- 

 safe. Fast ice in a harbor usually moves along a tidal crack and, under 

 the force of onshore winds, may acquire violent motion. Vessels 

 should quit moorings at the edge of fast ice whenever onshore winds 

 bloM'. 



52 



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