When apparent leaning (or visible camber) is present in a monopole tower, there is a high likelihood that it is caused by the “Sunflower Effect” due to thermal expansion of the steel.

This PAN explains how the sun’s position, cloud cover, and ambient temperatures can all influence a monopole’s camber throughout the day, along with affecting other tower components such as safety climb systems and coax. Other topics discussed:

  • Thermal expansion in monopoles vs. other supporting structures
  • Effects on safety climb wire tension
  • Risk mitigation solutions caused by the “Sunflower Effect”
  • Antenna tilt effects on performance
  • Safety Equipment Manufacturers Consensus (SEMC) Document
  • Determining if a ‘leaning’ monopole is due to the “sunflower effect”
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