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ships must be limited to one or two. In conducting a large number 

 of ships in such heavy ice, it will be necessary for the icebreaker to 

 keep falling back in order to break the ships out, thus losing more 

 time than if piloting two vessels. 



The arrangement of the convoy should be carefully worked out. 

 The varying ice conditions in the areas along the route and the 

 variety of ships forming the convoy must be taken into considera- 

 tion. The first factor to be considered is the power of the ships. 

 The weakest, as a rule, are placed immediately after the icebreakers, 

 so that they can avoid striking ice obstacles and be able to move in 

 a comparatively clear channel. The most powerful and beamiest 

 ships are so placed in the convoy that less powerful vessels can pro- 

 ceed in their wake. Consideration must also be given to whether a 

 ship is loaded or in ballast. Finally, it is essential that one of the 

 most powerful ships in the convoy be placed in the last position 

 in line. 



A composite convoy consists of two or three simple convoys. The 

 number of ships to each icebreaker and their place in column is deter- 

 mined in the same way as for a simple convoy. The difficult of con- 

 trolling from a position in the front is an important drawback to this 

 type of convoy, which frequently stretches out over a distance of 1^ 

 to 2 miles. The first icebreaker is designated the leader; the others 

 are placed according to orders of the leader's captain, either in column 

 or in line of bearing for breaking out. 



The operating procedure is for the most powerful icebreaker to 

 lead the convoy breaking a channel in the ice without stopping to 

 break out other ships. Following the leader at a distance decided upon 

 by the leader's captain are two or three ships, the weakest and beamiest 

 in the entire convoy. The second icebreaker proceeds astern of the 

 first group followed by two or three ships, and so on. 



The assignment of the second icebreaker is to break out the ships 

 ahead of her so that the leader will not have to return to them and 

 thus detain the convoy. The second icebreaker, on receiving a signal 

 "Stuck" from any of the preceding ships, increases speed, leaves the 

 column and breaks out the ship. When the latter is freed and moving, 

 the icebreaker resumes her previous position in column. The same 



Figure 19. — A composite convoy in column following an icebreaker. 



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