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Incandescent Bulb Tower Beacons

R

RadioFan2J3

I've been away from tower lighting issues for years and I was following a discussion where a poster had claimed with those two-bulb beacons, that sometimes they were set up for single bulb operation, with the idea that when that bulb failed, the second bulb came into operation.

I know incandescent light systems are rapidly disappearing, so this thread is more academic than practical.

It has been decades since I've changed tower lights and I do not ever recall changing the beacon lamps in a system where there was any wiring which would power one socket or the other, but that both bulbs were powered on when the system was on.

Has anyone on the forum ever have a tower where only one of the two bulbs in a beacon would be used at a time and the second bulb switched on, in the event the first bulb fails?

Just trying to fill an old memory cell.
 
All the Hughey Philips beacons I have seen have both bulbs wired in parallel. Something else to consider is the angles in the glass shape the light pattern. The upper and lower halfs have different patterns.

Make sure to bring some needle nose pliers with you up the tower so when the bulb breaks in the socket, you can twist the base out. HiHi!
 
Technically, I believe BOTH lamps of a L-864 code beacon are supposed to be operational.

There are setups where two L-810 fixtures (the ones that use traffic-signal bulbs) are set up with a transfer relay. Most often seen marking the edges of buildings or other low-height obstructions.
 
grich said:
Technically, I believe BOTH lamps of a L-864 code beacon are supposed to be operational.
Click to expand...

That is also what I thought. My tower climbing days are long gone and not that many towers, but I never found a code beacon wired other than parallel, both lamps would light.

grich said:
There are setups where two L-810 fixtures (the ones that use traffic-signal bulbs) are set up with a transfer relay. Most often seen marking the edges of buildings or other low-height obstructions.
Click to expand...


I don't think that would have been legal for FAA/FCC purposes for towers.

Thanks.
 
The old FCC Form 715 specified the lighting requirements for towers. Although no longer published, licenses usually specified the particular paragraphs of Form 715 that would apply to the station’s tower(s). Paragraph 3 gave the information about the top beacon. The 2 - 620 or 700 watt lamps inside the code beacon were to burn simultaneously.
Courtesy of Cavell Mertz & Associates:

FCC Form 715
 
Unless it's grandfathered in? Any changes to the lighting structure would probably trigger updating to current standards.
The FAA has in the past ordered changes to existing lighting, such as requiring all the multi-level beacons flash at the same time instead of alternately.
This from personal experience so YMMV.
 
boiseengineer said:
Unless it's grandfathered in? Any changes to the lighting structure would probably trigger updating to current standards.
The FAA has in the past ordered changes to existing lighting, such as requiring all the multi-level beacons flash at the same time instead of alternately.
This from personal experience so YMMV.
Click to expand...

Long ago and far away, somewhere on the west side of I-81, south of the I-66 interchange in Virginia, there was a tower with two levels of beacons, two levels of side lights.

That was the only tower I ever saw which had alternately flashing beacons. It was that way for years. I've been on that stretch of I-81 in decades, so I don't it that tower is still lit that way.

But that was different than the earlier premise that a standard two bulb beacon could meet FAA/FCC requirements with only one bulb operating at a time.

thanks.
 


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