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NAVIGATIONAL SYSTEMS

Navigation systems include the gyrocompass and repeaters, the dead reckoning system, underwater log, LORAN, magnetic compass, and sextant.

The gyrocompass receives its directive from a high speed spinning gyroscope driven by electric motors. Its directive action is based on the mechanical laws governing the dynamics of rotating bodies. When any object is spinning rapidly it tends to keep its axis pointed in the same direction. The gyrocompass consists of a spinning gyroscope, made north seeking by placing a weight below the axis, which is mounted in gimbals so that the movements of the submarine do not effect its position. A dial mechanically connected to the gyrocompass has the points of the mariner's compass marked on it and indicates the submarine's true course. Repeaters are located throughout the submarine.

The Log system consists of a pit sword and master unit in the forward torpedo room.  These determine the boats speed through the water.

The dead reckoning system consists of a dead reckoning analyzer indicator in the control room and two dead reckoning tracers, one in the control room and one in the conning tower. The system, when properly set at the starting point, indicates at all time the latitude and longitude of the submarine on dials in the analyzer and traces the ship's movements on a chart placed on the tracer. The analyzer indicator is an instrument for converting the ship's course and distance into direct readings of latitude, longitude and miles traveled. It receives the course from the gyrocompass and the distance from the underwater log, a device that measures the apparent distance traveled by determining the difference between the static pressure and the dynamic pressure as the submarine moves through the water.

LORAN is a navigational system for determining position by means of radio. The word is derived from the first letters of the words "LOng RAnge Navigation." The principal of operation is based on the difference in travel time (in millionths of a second) to the point of observation, of radio signals from two transmitting stations located several hundred miles apart. The DAS-3 LORAN unit aboard Pampanito is a combined radio receiver and indicator and is capable of determining the differences in the arrival times of the signals within a microsecond. This measurement determines the line of position as indicated on carefully prepared charts. Similar measurements made on a second pair of LORAN stations provides a second line of position. The intersection of two or more of these lines determines a "fix" in the conventional manner.

For more traditional means of navigation the submarine carries a magnetic compasses in the conning tower and control rooms, chronometers and a sextant for celestial navigation.

The ships radars, sonars and depth sounder all where helpful in navigating the boat and determining its position when near shore.

 

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Version 2.00, 11 Sep 2006