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:
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!
TECHNIQUES FOR TIMING LIGHTS
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 KMartŪ, WalMartŪ, Radio ShackŪ, 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:
CHECKING A LIGHT'S FOCUS
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.
REPORTING THE RESULTS
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.
SUMMARY: ACCURATE AND THOROUGH REPORTING REQUIRED
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.
Introduction and Background