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  • Rooftop Antenna Safety

    Hello all! I was wondering if anyone had a powerpoint or some other type of presentation put together for safety when working around rooftop mounted antennas (cell included) while doing fire operations.

  • #2
    The first biggest thing,

    DO NOT GET NEAR THEM

    While you cannot see the radio waves, the frequencies that are used in microwave / cellular communications can very well "cook you". Microwave just happens to go after your eyes, and the two little sperm factories hanging you know where. The average firefighter will not be knowledgeable enough to distinguish a cell site from their own departments repeater. The best thing you can do is pre-plan the hell out of these places, just like any other hazard in your community.

    One of the biggest issues with any radio site is how power is distributed. Coming in to the building you'll find your typical AC line. Granted, it may not be 110, but 220, 3-phase, whatever. USUALLY this is then broken down to a set of battery chargers and reconditioners after going through a panel box that allows automatic switching from the HUGE generators you'll find at these sites. We're not talking a 12volt 30 amp setup like you might find for a department base radio, but 120 volts and 250+ amps of SUSTAINED DC current coming off the batteries. If you get zapped by these batteries, you are TOAST. The chargers will just think you're another battery... Which brings me to my next point...

    In your pre-plan of any radio site, you need to look at where all the power disconnects are. If you disconnect just the feed from the power grid, you haven't taken the equipment off line. You'll hear a generator come on, or depending on the system the batteries will maintain the operation until they reach a certain point. Have the representative of the cell/radio/whatever company come and show you how to safely disable power to the equipment. This includes disabling the primary and backup power supply with a PHYSICAL disconnection. Shutting equipment off does not solve these problems. Even once you have disconnected the equipment, you are still not totally safe...

    Around the top of the room (in most cases) you will find a very large gauge multi-stranded copper wire with many more wires connected into it. This is the "Halo", or how equipment is grounded. This is typically connected to very long, thick, copper spikes that are driven in to the ground. You do NOT want to get between the Halo and the equipment. It WILL use you as a path of least resistance.

    While power is still on or equipment is still in operation you need to take actions to protect what is around the site. If you try to use water in a place like this, expect to get really FUBAR'd. You'll be lucky if you life. The same needs to apply when operating around exposed coax and antennas. If you touch an antenna that is being transmitted with, you WILL receive burns. I've gotten burned, and had to deal with the side effects. It's not fun at all. I made the mistake of touching a VHF antenna that was putting out 110 watts. I now do not have feeling on the left side of my left hand. The lack of feeling goes partially up my arm. It feels like it's asleep, but can also be very painful depending on other stimuli.

    You don't have to touch an antenna to feel it's effects. The wavelength of any radio signal can have adverse affects on your body. Microwave communications equipment (what cell phones fall into) can cause parts of your body like your eyes, testicles ( ) to heat up and cause cell degradation at a rapid rate.

    If there is a fire in one of these facilities, do NOT attack using a handline. Chances are that if the incident requires fire department intervention, the insurance company will write it off and everything will be replaced with brand new gear. If you NEED to attack a fire in these facilities, a CO2 or Dry Chemical extinguisher is the preferred method. If it's larger then what you can handle with extinguishers protect and confine the fire. It's already a total loss. Not to mention, your crew isn't worth losing for a couple hundred thousand dollars of electronics.

    Many buildings have towers, masts, or other radio antenna gear mounted on top. If you're at one of these buildings with a fire in the cockloft, you're really gonna be screwed. "Heavy Duty" antenna masts and towers are made to withstand heavy winds, ice buildup, and all the outside factors such as the extra weight of all your antennas and the coax cable. These towers require tremendous support not only from the support wires, but from the building itself.

    If you think that there may be any structural collapse, shift in the building, significant weakening of the structure, or see any change in the position of the tower due to the situation at hand you need to increase your collapse zone, and go to defensive operations. This probably isn't going to be a popular statement, especially since we're supposed to be the ones protecting lives and property... But we need to protect ourselves first. Treat the tower as part of the building. The building's height needs to include how far the tower sticks above it. Use the total heigh t when calculating your collapse zone. These towers can tip over, or come straight down through the building.

    I could go on and on... Emergencies in these places aren't your run of the mill incidents. Don't even think about bringing a metal halligan into the picture. Non conductive tools, ONLY. Perhaps the FDNY guys can post their procedure on these facilities. I've seen it before but I can't recall where. There's quite a few on Firehouse, so I'm sure someone can help us.

    Also, what I've posted here comes from being a firefighter, and working around this equipment in various roles. I got burns from an antenna VERY easily, just by touching the wrong thing. Now add in to the equation someone who is completely unaware of what's in these places, and doesn't know what things are.. You have a recipe for disaster.
    Originally posted by ThNozzleMan
    Why? Because we are firemen. We are decent human beings. We would be compelled by the overwhelming impulse to save an innocent child from a tragic, painful death because in the end, we are MEN.

    I A C O J
    FTM-PTB


    Honorary Disclaimer: While I am a manufacturer representative, I am not here to sell my product. Any advice or knowledge shared is for informational purposes only. I do not use Firehouse.Com for promotional purposes.

    Comment


    • #3
      Best advice, coming from someone with a run of sea time with the navy: ensure that the power distribution is OFF.

      Thats the simple answer. Beyond that, all what Res343cue said above is 100% valid.
      If you don't do it RIGHT today, when will you have time to do it over? (Hall of Fame basketball player/coach John Wooden)

      "I may be slow, but my work is poor." Chief Dave Balding, MVFD

      "Its not Rocket Science. Just use a LITTLE imagination." (Me)

      Get it up. Get it on. Get it done!

      impossible solved cotidie. miracles postulo viginti - quattuor hora animadverto

      IACOJ member: Cheers, Play safe y'all.

      Comment


      • #4
        Thanks for your responses. I'm actually looking for specifics for an awarness presentation I'm trying to put together. For example, cell antennas radiate xyz watts in an xyz pattern from the antenna, so therefore you don't want to get within xyz feet from the antenna. We have some structures in our city that have cell antennas on the corner of the building and occasionally we need to gain roof access inorder to control an elevator. Thanks again for your responses.

        Comment


        • #5
          Any antenna at close range has radiation all around it.

          The radiation pattern only matters on a macro scale, not the micro one you're talking about. If they are up their with the antennas, they are going to be exposed to the radiation that they put out.

          The problem with looking at just the "watts" they put out is that cell sites vary the power they put out depending on what is needed, just like your mobile phone does.

          Get up there, do what you need, and get off. You're not able to do anything short of shutting the site down.
          Originally posted by ThNozzleMan
          Why? Because we are firemen. We are decent human beings. We would be compelled by the overwhelming impulse to save an innocent child from a tragic, painful death because in the end, we are MEN.

          I A C O J
          FTM-PTB


          Honorary Disclaimer: While I am a manufacturer representative, I am not here to sell my product. Any advice or knowledge shared is for informational purposes only. I do not use Firehouse.Com for promotional purposes.

          Comment


          • #6
            There isnt much that can be added that 343 didnt already cover. That radiation is the real deal.....What do you think kills Cancer??
            Buck
            Assistant Chief/EMT-B

            Comment


            • #7
              RF Safety

              Call the people who own the antennae. They MUST have a document that calculates the RF exposure especially in the "near field" This is an FCC and I believe a Canadian DOC requirement.
              I am a Ham Radio instructor and my speciality is RF Exposure & Safety and even our stations (small potatoes power-wise) should have these surveys performed if nothing else to cover our ***es if one of our neighbors decides to complain that I fried her pet goldfish!

              I can find the actual reg for you, if needed.

              BTW: 343 You Rock, Pal!


              Keep Safe Y'all.

              Jimmy Mc Carthy
              FF/EMT, Ham radio call WN4GMT/0
              Cum catapultae proscriptae erunt tum soli proscripti catapultas habebunt. (When catapults are outlawed, only outlaws will have catapults!)

              Comment


              • #8
                Jim brings up a good point, but it applies to the "radio" and not antenna.

                Station documentation is required at ALL sites for each transmitter, not antenna. This is because you can "Combine" transmitters to use the same antenna, or "combine" receivers to use one also. A little bit of small-bean clarification but it's yet another avenue you can go down to protect your crew.

                The documentation on site is supposed to include what frequencies each specific radio uses for TX and RX, station call sign, owner, what band, TX output, ERP (antenna output), names of the technicians that work on the site, as well as how to contact them in case of emergency. This is considered "public information" and must be given if asked. Some places are very good about this, others won't even attempt to have it. The FCC doesn't care until something screws up and they will get money for it.

                PS: Jim, once I get my ticket I'll have to see if I can reach you from Vermont (without Echolink, that's too easy ).... We've got a 10m repeater up on top of a mountain that clears all the other ones in the area.
                Originally posted by ThNozzleMan
                Why? Because we are firemen. We are decent human beings. We would be compelled by the overwhelming impulse to save an innocent child from a tragic, painful death because in the end, we are MEN.

                I A C O J
                FTM-PTB


                Honorary Disclaimer: While I am a manufacturer representative, I am not here to sell my product. Any advice or knowledge shared is for informational purposes only. I do not use Firehouse.Com for promotional purposes.

                Comment


                • #9
                  To think if I kept on my career path, I'd be working on these systems, and higher power ones. Glad I'm "just" running into fires and treating sick and injured people now...
                  The comments made by me are my opinions only, not of the Fire and EMS services I am affiliated with.

                  I have lost my mind..has anyone seen it? it's not worth much..but it's mine

                  Comment


                  • #10
                    Originally posted by MalahatTwo7
                    Best advice, coming from someone with a run of sea time with the navy: ensure that the power distribution is OFF.
                    We have something like this in our local:


                    Realistically you don't want to be within 100 yards of it while energized.
                    So you call this your free country
                    Tell me why it costs so much to live
                    -3dd

                    Comment


                    • #11
                      Here's an interesting rooftop antenna setup I came across the other day.


                      You not only have to remember the antennas, but the equipment and cables that come with them, as well as the load they place on the roof.

                      This was a Type III tenement in Queens, NY.
                      http://www.x635photos.com/displayima...album=41&pos=2
                      My Fire Apparatus Photos: x635Photos.com

                      Seth G., Round Rock Texas

                      Comment


                      • #12
                        Go to Rfsafety.com

                        Comment

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