Internet Training for Aid Verifiers
Verifying a Light's Characteristics

Last updated: 08 JUL 2005

Index (Jump) to Topics: Introduction and Background Light Rhythms as Described / Defined in the Light List Verifying a Light's Characteristics Techniques for Timing Lights Checking a Light's Focus When is a Light Considered to be "Watching Properly"? Reporting the Results Using the Private Aid Verification Worksheets Summary: Accurate and Thorough Reporting Required   Back to Aid Verifier Internet Training Menu Information extracted from the Light List, Volume V, Mississippi River System, COMDTPUB P16502.5, and enhanced for the Eighth Western Rivers Auxiliary AORs.

Practice timing flashing lamps - click on a characteristic below to open a separate window: Fl (2) R 6s Fl G 6s Fl (2) R 5s Fl G 4s

INTRODUCTION AND BACKGROUND

Most lighted aids to navigation are equipped with a Daylight Control which automatically causes the light to operate during darkness and to be extinguished during daylight. Aid Verifiers should understand that each light is under its own control and therefore all lights do not come on or go off at the same time. At periods of twilight, Aid Verifiers must assure there is sufficient darkness to where a light should be operating before reporting the light as "extinguished".

Many private aids are shore powered (versus battery powered) and may not use a Daylight Control to turn the light off during daylight hours. While the light may be ON 24 hours a day, this is not a discrepancy.

A light's characteristics is described using the following three factors:

For example:

A light with published characteristics of Fl G 6s would have a FLASHING light rhythm, GREEN lens color and a period of SIX SECONDS.

A light with published characteristics of Fl (2) R 6s would have a GROUP-FLASHING light rhythm, RED lens color and a period of SIX SECONDS.

The following table shows the light rhythms typical on the inland rivers.

Verification of a light's characteristics is done by timing the light for the number of flashes expected in one minute. Remember: A light's PERIOD is the length of time in seconds during which the characteristics are repeated in regular sequence.

The Number of Flashes Expected in One Minute is Calculated by:

The following table is for light characteristics for Coast Guard aids and private aids commonly found on the inland rivers. The first entry is for the examples used above.

Click on the characteristics in the table below to view a lantern showing the characteristics!

Timing a lighted aid requires a timing device that will give elapsed time. Many wrist watches have this capability but experience has determined that a sports watch (inexpensive, available at K­Mart®, Wal­Mart®, Radio Shack®, etc.) is an easier device to use because of the large buttons and easy-to-read display. And, because it is easier to use, it will tend to give more accurate results. However, the less expensive devices don't have an illuminated display so a flashlight with red lens (to protect night vision) would be needed.

Each Aid Verifier will develop their own techniques for doing the actual timing of flashing lights. The following is suggested as a "starting point" technique for someone who is new to aid verification.

• Always start and stop timing at the end of the last flash in the period. This eliminates the "anticipation" factor that is created when timing repeated sequences.
• Some people are in the habit of counting "one" on the stroke when they start the watch. Of course this throws off the count of the number of flashes. To break this habit, count "zero" when you push the start button on the stopwatch.
• Timing lighted aids must be performed at night. The person doing the timing should be dedicated to that task and should not be interrupted nor should they be expected to be manning any watch positions. Positions should be rotated during the mission.

The following diagrams represent the statements made above:

Note: The following applies to all lights -- on Coast Guard aids, on private aids and on bridges.

In order for a light to be visible as expected, the light must be level so as to show within the viewing range of the mariner. The mounting of dayboards and / or the lantern assembly of a lighted aid is considered to be in focus if they are within plus or minus 15-degrees from the horizontal.

Sometimes it has been observed that the structure (pilings, cells, concrete piers, etc.) is listing as much as 35- to 45-degrees. Often these structures cannot be repaired without totally rebuilding the aid. However, the tower mountings and leveling plate for the light assembly do allow the horizontal position of the aid (light, dayboards, mile board, ...) to be adjusted so as to be in focus (e.g., within the +/- 15-degree tolerance). In this case, as long as the aid can be seen within the viewing range of the mariner, it would be considered as "Watching Properly" assuming that all the other characteristics are operationally correct.

If the aid (light, dayboard, etc.) is not in focus, then specifics regarding the problem should be noted. The structure may show signs of damage. Problems with bridge lighting have been observed because the light fixture was installed facing the wrong direction.

Flashing lights are considered to be "watching properly" when the actual (timed) number of seconds for the expected number of flashes falls within plus or minus three seconds (57.0- to 63.0-seconds inclusive). Example:

If a light with published characteristics of Fl (2) R 6s actually showed twenty flashes in 58.4-seconds, the light would be considered as "watching properly" AS FAR AS THE TIMING CHARACTERISTICS ARE CONCERNED.

Referring to the example above, the Aid Verifier should enter the timing results on the aid verification worksheet as:

"   20   flashes in   58.4   seconds"

Many private aid facilities have more than one light. Unless ALL lights are "Extinguished", the Aid Verifier must identify the specific light for each of the timing results. The table below shows some conventional ways of doing this. It may also be easier to habitually always list the lights starting with most upstream light.

If the location of the lights is identified by ATONIS in the "Remarks" Section of the worksheet, you might be able to list the lights by number starting with the MOST U/S light as #1, then #2, etc.

As an example, for a private aid appearing in the Light List as:

Light List Number	Name / Location	Mile	Bank	Characteristics
7710	MEREDOSIA TERMINAL DOCK LIGHTS (5)	71.7	RIGHT	Fl G 6s

Examples of entries might include:

For the most upstream light:
"MOST U/S = 10 FLASHES IN 59.4 SECONDS" or
"#1 = 10 FLASHES IN 59.4 SECONDS"
Followed by:
"U/S = 10 FLASHES IN 61.3 SECONDS" or
"#2 = 10 FLASHES IN 61.3 SECONDS"
Then:
"Middle = 10 FLASHES IN 56.4 SECONDS" or
"#3 = 10 FLASHES IN 56.4 SECONDS"
And:
"D/S = EXTINGUISHED" or
"#4 = EXTINGUISHED"
Finally:
"MOST D/S = 10 FLASHES IN 60.1 SECONDS, LAMP DIM, LENS CRACKED" or
"#5 = 10 FLASHES IN 60.1 SECONDS, LAMP DIM, LENS CRACKED"

Which of the above sample entries would be considered as "watching properly"?

Answer: #1 and #2

Referring to the preprinted Class I Private Aid Annual Night Verification Forms published in the Aid Verifier Website:

• The date and time entries recorded at the top of the form are always the actual date and time of the visit. If both daylight and night visits are made, both times may be recorded separated by a slash ("/").

 
• If any timings are outside the tolerance (57.0- to 63.0-seconds, for example), circle "N" after the entry

  Timing of Lamp(s) Correct? Y / N ______________________
  Otherwise, if correct, circle the "Y"

• If a light is extinguished, check " Lamp: (   ) Extinguished " on the form and indicate if a fixture is visible

  If a light is good, check: " Lamp: (   ) Good " on the form.

• If the verification of an aid shows that there are no discrepancies, then check:

  " (   ) WATCHING PROPERLY " under "Remarks" at the bottom of the form.

• If any discrepancies, such as extinguished lights, are considered critical they should be reported via VHF marine radio to the AOR Group. Urgent discrepancies should be reported via phone to the Group or the AOR cutter. Record the fact on the worksheet that such communication was made:

  Critical/Urgent Disc. Reported Via: (   ) VHF Radio (   ) Phone To:                           at           Hours on       /       /      

• The Aid Verifier (and only the Aid Verifier) should print their name and member number and sign the report form.

Remember that the people receiving your Bridge and PATON reports are expected to follow up by contacting the owner of the private aid or bridge and get the discrepancies corrected.

As you describe the discrepancy and identify which light you are referring to, make sure the information is accurate and complete. (Some Aid Verifiers even attach pictures!)

Consideration should be given to the poor soul who is thousands of miles from the aid in question and has to deal with the owner over the telephone! Put yourself in their place when you review your work.