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    Franklin Piloting Technique
    From: Byron Franklin
    Date: 2009 Aug 2, 14:03 -0700

                                                    Compass Error Licked,
    Byron Franklin, page 1.
                                                            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 World 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 north to our 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 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 buss
    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 a 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 could 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. Once underway, 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 to correct the
    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.�
    By the book and classroom teaching, when a triangle is plotted, pick
    the center as the fix. This rule leads to failure. When three Navaid
    are plotted within 180 degree you are not in the triangle. You are
    outside, the two closer is the fix and the farther is your indicator,
    accuracy and compass error for a correction. Publishers don�t try new
    ideas they just repeat what has already been in other books.
                                                       Compass Error
    Licked, Byron Franklin, page 2.
                                                        Mechanics to Cross
                                                        Geometry of
    The chart plotter and navigator should have a complete knowledge of
    plotting geometry to insure accurate fixes. Plotting geometry is
    predictable, uncomplicated and easy to use once understood.
    Special knowledge.
     A. single line of position (LOP) has two (two) dependable predicable
    traits (1) direction (2) offset
        1 Direction. When facing each NAVAID.
             a. When compass error is present, each line of position (LOP)
    will miss the observer to the left hand when the error is WEST and to
    the Right when the error is EAST.  See figure1
         2. Offset. When facing each Navaid, the line of position (LOP)
    will offset distance of the closest point of approach (CPA.)at the
    observer                                                        See
            a. When compass error is present, the (offset) CPA distance
    will depend on the distance to each Navaid and the amount of gyro/
    compass error in degrees.
             b. Close Navaids will have a closer (offset) LOP to the
    observer, far Navaids will have a farther CPA. The offset can be, but
    not needed) computed by using the rule of sixty (Radian rule)
    B. LOP�s will have either (1) systematic error or (2) a random error
           1. Systematic error is, the true angle between the LOP�s is
    correct, but the true north ailment is off the meridian. This may be a
    gyro, bad repeater alignment or seeking the meridian.
            2. Random error is, the true angle between the LOP�s is not
    correct and may be caused by bad observation, ship movement between
    observations or compass card not centered.
    The magnetic compass with the problems of ship movement is normally
             3. Any two Navaid LOP�s that are systematic will cross
    somewhere on a circle that includes the observer position. If a third
    Navaid on the circle and its LOP are added, all LOP�s will cross at
    the observers position on the circle, but the three, if in systematic
    error will fall on the circle to the west (left hand) or to the east
    (right hand)of the observer the greater the error the greater the
    distance.    -Still intersecting on the
    circle-.                                        See figure
    3.                         4. Navaids LOP�s that are random will work
    in the same manner but will be not be as accurate. The Franklin
    Piloting technique will improve fixes with Random error such as the
    magnetic compass. (with or without variation or deviation.)
    See Franklin piloting Technique.
              5. Any combination of Navaids will work with the Franklin
    technique except the case where all three Navaids are on a circle with
    the observer. This is easy to recognize on the chart and a rare
    happening. In this case the center Navaid would be the
    farthest            revisit Figure 3.
    The far Navaid can give near 100% total compass error when not between
    the fixing navaids
    it will give less than total. When the far Navaid is opposite the
    fixing Navaids the far Navaid will give more than total
    error.                       See figure 4.
    I will have to send figures later.
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