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    Re: Gyro Error
    From: Byron Franklin
    Date: 2012 Aug 17, 17:04 -0700

    This is now I found and invented the Franklin ploting Technique.
    .

    The Franklin Piloting Technique
    Compass Error Licked.

    In 1958 I reported aboard the USS Outpost AGR 10. The AGR was a radar picket ship modified from a Wold War II Liberty Hull. She was very top heavy with high radar antennas and the same gyro she was originally built with. Her mission was to track any thing heading toward the United States and report anything that was unscheduled. A jet fighter plane from the main land would investigate the intruder. Accurate navigation was important to ensure we were on station, using the gyro, Loran A and the sextant. The old gyro was good enough to run the open sea, but was always slow moving about the meridian, so that visual cross bearings in restricted water were difficult. As the quartermaster chart plotter I could give good navigation recommendations to Officer of the deck (OOD), but I was not happy with the charted fixes that my recommendations were based on. I had noticed that when coming into the last leg and heading 000 north to the pier, there were two charted well-spread Navigation Aids (Navaids) close by to port-side. Also, the ship was visually in the middle of a north/south channel with buoys on both sides. IT WAS EASY TO SEE THAT WE WERE IN THE CENTER OF THE CHANNEL. The third and only other Navaid was to the south and very far away. The line of position (LOP) from the well spread close by (>2000yds) Navaids always crossed in the center of the channel where we were visually between the buoys. The only other Navaid was far to the south (> 6000yds), This Navaid’s LOP was always outside of the 100 yards wide channel.
    The AGR moored, I was tired after the two months at sea and piloting the AGR for about the two-hour transit to pier-side. I boarded a bus to go home, Newport RI. The compass error problem would not let me rest, so I went over in my mind, the two close-by charted fixes always in the channel and the far Navaid falling outside of the channel.
    It became apparent! An idea that I could use the close by well-spread Navaids to get my fix.
    I needed the third LOP to make the fix legal (according to the book, three LOP’s) so I can correct each of the LOP’s by using the bearing of the far Navaid as true from the center of the buoyed channel “FIX”, the observe sighted bearing difference was error, I can use the same correction for all three, collapsing the triangle. I found that I could use this technique anytime to find and maintain a fix, while monitoring the movement of the compass. I no longer needed the buoyed channel as a guild and I could use the far LOP to give me both direction and amount, any time or place or placement of NAVAIDS to correct the compass.
    With this idea I tamed the monster of compass error. It became a pussy cat to me.
    My complete mechanics to Cross Bearings “ The Franklin piloting Technique.” I willl write more, about the history of it.correct Sea Stories
    should be interesting to NAVLIST.

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