"The logical goal of inspections is to spot potential issues and schedule appropriate fixes before they cause serious problems."

 By R. Bruce Wright, CPCU

Many, perhaps most, members of this program have one or more towers in order to facilitate communications and control among their employees and business partners. Tower installations exist at main office sites, at district or field offices, at other facilities, or on land maintained solely for the purpose of serving as an antenna tower site. As we visit utilities in our program, we find that these towers often are taken for granted rather than treated as a special class of structure needing regular, special attention.

Towers come in a variety of styles. Some may be freestanding or guyed, tall or short, ground mounted or on buildings. Regardless of the type of tower your cooperative may own, there are several basic issues your cooperative should address routinely. These issues range from security and maintenance through regulatory requirements. Some of these issues, such as FAA licensing and tower marking requirements, are beyond the scope of this brief article but are important in their own right. If your company has a tower, or is planning to erect a tower, that is 200' or more in height, you are into a special class of tower and should have a local specialist advise you of your responsibilities for obtaining a license and meeting the lighting and painting color codes that apply to these taller towers. Most utilities have towers shorter than 200' but these, too, require some regular attention.

For starters, all towers, guyed or freestanding, should have a security barrier of some type to limit public access. The goal is to at least discourage both vandals and thrill-seekers that might find the tower an irresistible temptation. Typically, a chain link type fence at least 6' in height should surround the tower base and any guy anchors. Many cooperatives have sited their towers inside their perimeter fence that secures their entire property in order to avoid the need for a special fence just for the tower.

You should regularly inspect any towers. If you have towers that are located remotely from your staffed locations, someone should visit them at least once a month to visually inspect them in much the same way as they might inspect substations. Even the towers at your office locations could be reviewed in this fashion since people become complacent with their common, everyday surroundings and may not notice specific items that need attention. The logical goal of these visual inspections is to spot potential issues and schedule appropriate fixes before they cause serious problems.

In addition to monthly visual inspections done by your own people, all towers should be inspected on a periodic basis by a competent inspector. The frequency of these professional inspections, as recommended by experts, varies from doing them annually to doing them for guyed towers at least every 3 years and at least every 5 years for self-supporting towers. A major factor in determining the appropriate frequency is the prevailing climate and soil conditions. In areas where severe winter weather is common, damage from ice freezing and thawing can quickly split supporting structures, making annual inspections very important. In areas where soil conditions promote settling or shifting, off plumb towers and sagging guys can be a common problem and may require annual inspections also.

Of course, there may be times when a professional inspection would be appropriate earlier than the routine schedule calls for. Any problems your own people spot while doing their monthly inspections might require an immediate professional inspection to assess how severe the problem is. For those of you in coastal areas that have the unfortunate combination of generally sandy soil and exposure to high winds and hurricanes probably should have your tower(s) professionally inspected as soon as possible after a major storm.

Jay Nelson of Nelson Communications Services, Inc. points out that regular clearing of weep holes is critical to tower longevity. His company recently replaced a tower built in 1991, just 10 years old, that had a structural leg failure due to water retention and freezing caused by plugged weep holes. It had never been inspected. Jay reports that “Insects, leaves and other debris often prevent the weep holes from draining properly, and retained water can freeze and expand with tremendous force. Poor drainage can also promote rapid corrosion.”

Unlike your monthly general inspections, the more detailed technical inspection process is not simply a quick once over, or an “eyeballing” of the tower. Senior managers should carefully consider whether to attempt inspections with their own employees or to hire a local expert. It is important that only trained personnel who are experienced in climbing, inspections, and tower adjustments should perform this work. As an example of the issues to be reviewed in an inspection, here is an excerpt from the outline of the inspection points as recommended by the Telecommunications Industries Association (TIA):

1. Tower Conditions (both guyed and self-supporting)
   1. Members
      1. Bent members (legs and lacing)
      2. Loose members
      3. Missing members
      4. Climbing facilities, platforms, catwalks -- all secure
      5. Loose and/or missing bolts
   2. Finish
      1. Paint and/or galvanizing condition
      2. Rust and/or corrosion conditions
      3. FAA or ICAO color marking conditions
      4. Water collection in members (to be remedied, e.g., unplug drain holes, etc.)
   3. Lighting
      1. Conduit, junction boxes, and fasteners weather tight and secure
      2. Drains and vents open
      3. Wiring condition
      4. Controllers functioning
         1. Flasher
         2. Photo control
         3. Alarms
      5. Light lenses
      6. Bulb condition (Option: change all bulbs at one time)
   4. Grounding
      1. Connections checked and secure
      2. Corrosion observed and remedied
      3. Lightning protection secure (as required)
   5. Tower Base Foundation
      1. Ground Conditions
         1. Settlements or movements
         2. Erosion
         3. Site condition (standing water, drainage, trees, etc.)
      2. Base condition
         1. Nuts and lock nuts tight
         2. Grout condition
      3. Concrete Condition
         1. Cracking, spalling, or splitting
         2. Chipped or broken concrete
         3. Honeycombing
         4. Low spots to collect moisture
         5. Anchor-bolt corrosion
   6. Tower Assembly Profile
      Antennas and feed-lines (each)
      1. Frequency
      2. Elevation
      3. Type
      4. Size
      5. Manufacturer
      6. Connectors and hangers
      1. Optional appurtenances (walkways, platforms, sensors, floodlights, etc.)
         1. Elevation
         2. Arrangement
         3. Drawings or sketches
      2. Foundation and anchors
         1. Plan
         2. Elevations
         3. Size
         4. Depths
         5. Soil type (if known or necessary)
   7. Tower Alignment, Tower Plumb and Twist (See 6.1.2.1 and 6.1.2.2)
   8. Insulators (As Required)
      1. Insulator Condition
         1. Cracking and chipping
         2. Cleanliness of insulators
         3. Spark gaps set properly
         4. Isolation transformer condition
         5. Bolts and connections secure
         6. Manufacturer type and part numbers for future replacements
2. Guyed Towers
   1. Anchors
      1. Settlement, movement or earth cracks
      2. Backfill heaped over concrete for water shedding
      3. Anchor rod condition below earth (Maintain required structural capacity of anchor during exploration, inspection and maintenance. Attachment to temporary anchorage may be required.)
      4. Corrosion control measures (galvanizing, coatings, concrete encasement, cathodic protection systems, etc., refer to Annex J.)
      5. Grounding
      6. Anchor head clear of earth
   2. Tower Guys
      1. Strand
         1. Type (lx7 EHS, lx19 bridge Strand, etc.)
         2. Size
         3. Breaking strength
         4. Elevation
         5. Condition (corrosion, breaks, nicks, kinks, etc.)
      2. Guy Hardware
      3. Elements
         1. Bent, broken, cracked or bullet damaged
         2. Loose
         3. Missing
         4. Loose and/or missing fasteners
      4. Corrosion condition
      5. Radomes and/or cover conditions
   3. Feed Lines (waveguide, coax, etc.)
      1. Hangers and supports
         1. Condition
         2. Quality
         3. Corrosion condition
      2. Flanges and seals (check integrity)
      3. Line Condition
         1. Dents
         2. Abrasions
         3. Holes
         4. Leaks
         5. Jacket condition
      4. Grounds
         1. Top ground strap bonded both ends
         2. Bottom ground strap bonded both ends
      5. Feed-line support (ice shields)
         1. Properly attached
         2. Loose and/or missing bolts
         3. Members straight and undamaged

TOWER LEG VERTICAL ALIGNMENT

1. Check with transit. Two transit setups are required. Line transit parallel to one face and center on leg. Second setup should be at 90° on same leg. Show on sketch below the locations used for transit setup. Indicate North.

Approximate wind speed during measurements mph.

Note: This procedure is not sufficient to determine both twist and out of plumb.

Measure Guy Initial Tensions.



As you can see, the inspection outlined above is not a “walk-by” procedure! Nor does this outline even begin to address the fall protection precautions that the inspectors must take ensure to ensure their own safety and to meet regulatory requirements, since that is an entire other story on its own.

Only you can decide if you need to hire an outside expert to do this work, or if you have a staff member who is qualified to perform for it, but however you decide to do it, a through inspection of this type this should be regularly performed on any tower(s) you own in order to ensure that these structures will not present you with an unexpected reason to call your claims adjuster.