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ice against the ship's sides with great force while passing close aboard 

 her. The speed of the icebreaker must therefore be regulated with 

 great care. 



CONVOY SIGNALS 



Some system of signals must be agreed upon in ice convoy work. 

 The following one-letter whistle signals have been arbitrarily chosen 

 and are actually being used by the U. S. S. R. : 



The signals (siren or steam whistle) used when vessels are scat- 

 tered in the ice are the same as in Eules for Preventing Collisions 

 at Sea. 



One short blast "Am going to starboard." 



Two short blasts "Am going to port." 



Three short blasts "The engines are going astern." 



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