INTRODUCTION TO SONAR 



standard surface displacement (ssd) of 3180 

 tons, and is designed for traveling faster under 

 the water than on the surface. 



An intensive building program for nuclear 

 submarines has been in effect for several years, 

 and many new ships have joined the fleet. The 

 USS George Washington (SSB(N) 598) was the 

 first submarine designed to launch, while sub- 

 merged, the Polaris missile. The USS Mariano 

 Vallejo (SSB(N) 658), shown in figure 2-3, is 

 the 40th, out of a programed 41, fleet ballistic 

 missile submarine to be commissioned. Her 

 speed is in excess of 20 knots, and she can 

 dive below 400 feet. 



One of our fastest submarines is the USS 

 Skipjack (SS(N) 585) (fig. 2-4), whose hull is a 

 radical departure from the conventional idea 

 of submarine hulls. Her diving planes are on 

 the sail, resulting in increased maneuverability. 



SUBMARINES IN GENERAL 



A submarine ranges in length from about 

 50 feet to more than 400 feet. Diving is ac- 

 complished by controlled flooding of ballast 



tanks. To surface the submarine, compressed 

 air expels the water from the tanks. 



Probably the smallest submarines in the 

 world belong to the ex-German Seahound class 

 (now in Russian possession). They are 49 feet 

 long and displace only 15 tons. Somewhat heavier, 

 but still in the midget submarine class, are the 

 U. S. Navy's X-1 and the British Shrimp class. 

 The X-1 is less than 50 feet long and displaces 

 25 tons. Boats of the Shrimp class are slightly 

 longer and displace 30 to 35 tons. 



At the other extreme are the bulk of the 

 U. S. Navy's submarines. Included are the latest 

 nuclear-powered submarines. Some of these ships 

 are over 400 feet long and displace more than 

 7000 tons (ssd). Others, designed for speed and 

 maneuverability, are not quite as long, and dis- 

 place less tonnage. 



Some submarines can cruise in excess of 20 

 knots submerged. A type of diesel submarine 

 used by the Germans in World War II, and now 

 a part of the Russian fleet, can dive at a rate 

 of 1 1/2 feet per second, and can turn 90° in 

 a little over 1 minute, using full rudder and 5 

 knots of speed. 



71.1 

 Figure 2-4. — USS Skipjack (SSN 585). 



12 



