Smoke Stack Restrictions

A telephone call to the local authority's planning office would determine this.

An F word comes to mind: FCC

• FCC Form 854

In this link you will find: "antennas at the 60' elevation on the building smokestack." See if it will relate to your situation.

PROPOSED SRINT NETWORK VISION UPGRADE FOR A - Granicus

FCC 854 Main Form This one is for, 'Antenna Structure Registration'

If there are lightning rods now atop the smoke stack I would be inclined to not put something else up there. The lightning rod is intended and designed to take a jolt of lightning, an antenna is not. The potential risk to equipment ($) and personnel isn't worth the risk.

What I would consider would be to install multiple antennas around the stack with the top of them just below the top of the stack and not interfering with the lighting rods. One option would be to put 4 antennas up spread 90 deg. apart. Coupling of the antenna would have to be more sophisticated than merely connecting there leads together to the feed wire but certainly not a major project to do it right.

This arrangement would not exceed any of the current limitations if that is important. This method is commonly used in the cell phone industry. They use directional antennas mounted around the tower. Yours doesn't have to have directional units but they would give you a greater signal strength.

Good Luck, Old Salt

Misconception about lightning rods. They are NOT designed to take a "jolt of lightning" to ground. That is not how they work. The lightning rod dissipates electrons. The reason for the wires touching the structure are to absorb electons from a positive charged structure, carry them to the arrester [misnamed] at the top of the structure and release them into the atmosphere surrounding the structure. The more the rods, the more the efficiency. Over time, this actually charges an aurora around the structure. If lighning were to discharge in the immediate area, this invisible "umbrella" effect [if you will], reduces the concentration of the strike over an area thousands of times larger than if there were no lightning rods present.

If lightning were to actually strick an arrester, the arrester and / or the ground wire would melt or a portion of it / them vaporize.

Sir,

The misconception is on your end.

While the low resistance path to ground supplied by a lightning rod array will bleed a small portion of charge from a cloud, it will not prevent a direct lightning strike on the structure. It offers a lower resistance path for the energy to take than the structure does.

Since clouds are not highly conductive, the charged particles IN CLOSE proximity to the rods may be scavenged to ground but they don't work very well to bleed the energy from a cloud that is two miles wide and 3,000 feet thick.

Cheers.

Nope! I am correct. Corona discharge [ion discipation] is what the lightning rod does to lower the potential, thus making a lightning strike less likely on the structure.

No misconception involved with the my original post. My statement was that a lightning rod is designed to be and intended to be struck by lightning and an antenna is not. I stated it as that since I had no desire to have to brush up and review my lighting rod knowledge for a reply to this forum. It is very apparent that a lighting rod is not designed to be an antenna and a antenna is not designed to be a lightning rod. There are many cases where antenna are designed to accommodate lightning strikes such as the Empire State Building and the old North Tower of the World Trade Center but at a sacrifice to their potential operation as an antenna.

No matter how a lightning rod is designed to work it is designed to be more of a lighting rod than an antenna and functions that way.

The sole purpose of my post was to offer another potential solution for the original posters stated problem as I interpreted the post, mount several antennas below the uppermost part of the stack. This works in some situations but by far not all situations. It doesn't interfere with the function of the lightning rods and doesn't place the antennas in a location where they are less likely to act as lighting rods.

I made no statement that the design of a lightning rod is to take a jolt of lightning to ground.

Good Luck, Old Salt

A FCC study 2C or 1A would have to be done on the structure. If the FCC determines that the structure interferes with flight lines, then anything from painting/lighting/combo may be required. The carries will bear the cost of doing the study. Other than that, the local Zoning ordinance/laws apply...however, within reason the FCC can over rule local Zoning. I've done quite a few of these installations.

Lightning Rods are at the 155' level

Antennas, if installed would probably not be more than 100'

Hope this quiets the fued...

Please refer to post #4. The situation you describe is what this type of solution was developed for.

I have personally been involved in the installation of antennas 85' high up on a 120' brick masonry stack. Never had any problems with the system fortunately since it was difficult to find people who were willing to work up there if needed. Another was antennas 75' high on a 100' steel stack. Only problem with this system was that the stack deteriorated at the top and crane operator clipped one antenna off with the removed top portion while repairs were being made.

Again this is the system used by cell phone towers. Someone else has already done most of the development work for you!

Good Luck, Old Salt