Strong Poles Factory Installed
Vibration Suppression Systems
Strong Poles is constantly looking for ways to make our SteadyMax Security Camera Poles more rigid and more steady in any wind condition. Normally when you think of a pole shaking in the wind, it is from very high winds. However, most destructive pole vibration actually happens in much slower winds (10-30 mph). As the wind frequency nears certain speeds and directions, or interacts with the local topography or nearby structures, this causes a vortex as it passes by the pole. As this vortex reaches a frequency that resonates with the pole, vibrations can occur that causes the pole to shake – either at the top of the pole, or mostly in the middle of the pole.
These vibrations, which are a natural phenomenon, and are usually site specific, are not due to any fault in the pole design, material or workmanship, can be described like this:
- First Mode Vibration:
This is when you see the top of a pole shaking back & forth, similar to a diving board.
- Second Mode Vibration:
Occurs around the mid point of a pole, and acts more like a guitar string.
Strong Poles installs two separate Vibration Dampener Systems (in our SteadyMax Poles), that work to stop both modes of vibration in their infancy. The Dampener at the top of the pole is an impact style design that essentially introduces an impact opposite of the vibration oscillations that interrupt the vibration and shuts it down. The second Dampener is mounted closer to the mid point of the pole and counterrqacts the higher frequencies found in Second Mode vibration, in much the same way as the First Mode Dampener. Together, these two systems go after any sway and vibrations that may happen, and returns the pole to the stable camera platform it is intended to be.
Strong Poles SteadyMax poles are designed based on AASHTO (American Association of State Highway and Transportation Officials) criteria. The standards and codes take into account direct wind pressures on the pole and typical cameras, sensors and antennas that may be mounted on the pole, as well as the associated bending, shear, axial and torsional stresses on the pole, and secondary moment effects (the pole and fixture being off center of the pole base when the wind deflects the pole).