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a new boat be operated in ice for a few hours, and then be sheathed 

 only on the portions that exhibit signs of wear. 



Boat engines should be cooled by fresh-water circulating systems or 

 by air, A salt-water cooling system is likely to become clogged from 

 slush drawn into the injection line, resulting in overheating the engine. 

 Use a series-parallel circuit with four batteries instead of the usual 

 two for starting boats. If temperatures below 20° F. are expected to 

 be encountered, engine heaters should be provided for all boats to 

 eliminate starting failures. 



A water breaker filled to 75 percent capacity will not crack when 

 frozen solid. 



The paper by Commander Ryder cited in the bibliography describes 

 a light boat specially built for use in polar regions. This paper should 

 be consulted if it is planned to use small boats extensively around a 

 base camp. 



PREPARATIONS EN ROUTE TO POLAR REGIONS 



The following check-off list covers items of maintenance and prep- 

 aration that should be carried out before entering the ice zones. 



1. Painting and hihrication. — Paint topsides and decks ; regrease the 

 rigging with a light coating; put winter grade lubricants in all the 

 deck machinery. 



2. Antifreeze. — Put ethylene glycol or alcohol in the cooling systems 

 of motor boats and any other exposed internal-combustion engines. 



3. Batteries. — Fill all storage batteries in boats with 1.280 specific 

 gravity electrolyte. Keep batteries as near full charge as is possible 

 at all times. 



4. Water tanks. — See that no water tanks are over 90 percent full. 

 Owing to the risk of contamination with sea Mater from leaks caused 

 by contact with ice, use the potable water (if any) in the fore peak 

 tank first. All water tanks adjacent to the outer skin of the ship 

 should be equipped with heating coils, 



5. Tounng gear. — Rig towing bridle forward for immediate use 

 in the event of necessity of being towed by the icebreaker. Break out 

 towing gear and keep it available on the fantail for possible use in 

 towing another ship. 



6. Mooring lines. — Manila has a tendency to freeze or dry-rot in the 

 center if exposed to cold for long periods. A line permitted to drag 

 through snow and water becomes ice-coated immediately and is hard 

 to handle, slipping in gloved hands and on winch drums and capstans. 



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