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heeling system in operation, she always backed clear." It is believed 

 that tlie heeling system should not be used continuously while under- 

 way except in heavy pack that is rotten enough to give a mushroom 

 effect. That is, the ice is unmoved except in the direct path of the 

 ship and the ship acts as a wedge which is driven in but does not break 

 its way through. If the ship is heeling under these ice conditions, 

 every roll she makes has the effect of extra, small wedges assisting in 

 relieving her for another strike at the ice. Another situation in which 

 heeling would be necessary is where large bergs or land on either side 

 will not permit the heavy floes to move out of the ship's way, causing 

 the ship to become wedged in. 



The necessity and importance of the heeling system cannot be over- 

 emphasized. It should be used only when it is necessary to keep the 

 ship moving ahead or to break her out in the event she is beset. 



During the heeling of the icebreaker, when beset and attempting to 

 free her, keep a careful lookout for the results, so as not to miss the 

 moment when the icebreaker falls through the ice. At this moment, 

 all engines must be backed, since during the listing of the icebreaker 

 the engines are stopped. The desired effect cannot be secured if they 

 are left running. If they are not stopped they create a peculiar equi- 

 librium between the holding force of the ice and tlie pulling force of 

 the propellers, whereas a sudden jerk is needed to get the icebreaker 

 off. This is accomplished by starting all engines simultaneously and 

 operating them at full speed at the exact moment the icebreaker falls 

 through the ice. If the heeling method does not achieve the desired 

 results it can be supplemented by changing the draft forward and aft. 

 For this purpose the fore peak tanks are filled and the after tanks are 

 emptied ; this process is then reversed, causing the stern to submerge 

 and the bow to emerge. While operating the trimming and heeling 

 tanks, the space in which the icebreaker is stuck is somewhat increased, 

 enabling the ship to back up and run ahead. 



It sometimes happens that an icebreaker wedges in so solidly that 

 both these methods are insufficient. Additional help can then be given 

 by Avorking the engines in different directions. The ship may then 

 swing a little and sometimes loosen herself out of the wedge. If all 

 these methods used either separately or together do not produce re- 

 sults, ice anchors are used. The ice anchor is led out on the ice and 

 placed about halfway between the bow and stern of the ship. The 

 fluke of the ice anchor is put into a hole or crack in the ice and the line 

 from it led through a bow chock to the drum of the windlass. When 

 everything is ready, all engines are worked full astern. The ice- 

 breaker must at the same time be heeled to one side. The windlass 



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