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 CHAPTER XI 



CONVOYING IN ICE 



An ice convoy consists of one or more ordinary ships, whether or 

 not strengthened for ice navigation, accompanied by one or more ice- 

 breakers. Either the icebreakers or the escorted vessels may be naval 

 craft. When naval icebreakers are escorting merchant vessels, most 

 of the problems that accompany ordinary ocean convoy o})erations will 

 be present in an accentuated degree, although they fall out of the scope 

 of the present discussion. 



It is highly desirable that a convoy while in ice be under the direc- 

 tion of the commanding officer of the leading icebreaker. If circum- 

 stances require that the senior officer of a naval force be embarked 

 in a vessel without ice-breaking qualities, it is recommended that he 

 delegate tactical control within the ice zone to the icebreaker. 



Most of this chapter is based on Russian accounts of ice convoy oper- 

 ations. Beginning 50 years ago in the Baltic, later operating in the 

 AVhite Sea, and finally opening the Northern Sea Route, the Russians 

 have accumulated a large body of experience in operating icebreakers 

 jointly with merchant vessels. 



TYPES OF CONVOY 



There are three possible types of ice convoy : 



(1) Single ship convoy. 



(2) Simple convoy: one icebreaker escorting a group of ships. 



(3) Composite convoy: two or more icebreakers escorting sev- 

 eral ships. 



A simple convoy consists of several transports or other vessels and 

 one leading icebreaker. The captain of the leading icebreaker 

 decides upon the number of vessels he can take through. His deci- 

 sion de]:>ends on the type of ships which are to follow the icebreaker 

 and the condition of the ice en route. If the ships to be convoyed 

 are reinforced for ice navigation and have sufficiently powerful 

 engines, an icebreaker can take an average of four of them through 

 an ice coverage of TO to 80 percent. If the condition is favorable, 

 only 50 to 60 percent ice, the number of ships can be increased. 

 If there is close pack with over 80 percent coverage, the number of 



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