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 CHAPTER VII 



PREPARING A VESSEL FOR ICE OPERATIONS 



In the preceding chapter the design features which render a vessel 

 suitable for operating independently in ice were discussed. The lim- 

 ited number of such vessels in existence generally makes it necessary 

 to conduct operations in ice using vessels of ordinary type convoyed 

 by icebreakers. Although in such cases it is impossible to make the 

 structural modifications just described, proper care in preparing a 

 vessel for work in ice will add greatly to the safety of the operation 

 and the comfort and efficiency of the personnel. 



When navigating in ice a vessel runs the risk of being damaged in 

 various ways, so that both prevention and remedy depend largely on 

 the extent to which she has been prepared for the voyage. The pri- 

 mary phase of preparation consists of the measures taken while in port 

 and en route to the area of operations, since both facilities and time 

 are limited in the frozen areas. The second phase comprises the pre- 

 cautions taken while in the operating area. Needless damage, delay, 

 and work can be eliminated by a taut ship with an alert and energetic 

 crew. However, regardless of all preventive measures taken, damage 

 to the vessel is not always avoidable, so that the third phase of main- 

 tenance, that of making repairs to the vessel after it has been dam- 

 aged, may be and usually is necessary. Remedial measures, anticipated 

 or improvised, skillfully made, will in many cases be the salvation of 

 the ship. 



FITTING-OUT SHIP 



The following check-off list of items to be attended to before leaving 

 the home port for polar waters has been compiled from the combined 

 experience of naval combatant types, naval auxiliaries, and merchant 

 ships. Not every item, therefore, will be found applicable in indi- 

 vidual cases, but careful consideration should be given to all. 



1. Screws. — Equip the ship with steel propellers. Provide a spare 

 propeller for each shaft. If propellers have removable blades, see 

 that all blades are interchangeable. Test the spare bosses in drydock 

 to see that they fit the shaft. Provide wrenches for boss and propeller 

 nuts. Since the propellers are especially vulnerable when operating 

 through ice, consideration should be given to fitting the ship with some 



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