florida everglades: non-penetrating roof-mounts sustain 150 Mph gust

As hurricane Wilma sped across the Everglades, the storm increased to a category 3 hurricane and wind gust exceeded 150 Mph across a wide area.

For many years MCIS has been engineering and installing 15’ and 20’ non-penetrating roof mounts designed to withstand sustained winds of 125 Mph. These mounts sit on rubber mats and are usually anchored by cinder block ballast with the weight distributed to just several pounds per square inch.

MCIS clients with these mounting systems will be interested to know that gust of 150 Mph blew off all the roofing material, including tar paper, at one of our customer sites, but their 15’ tripod remained standing. So intense were the winds, the 6’ antenna on the tripod was damaged by airborne roofing debris.

MCIS designs microwave communication systems for 3 conditions: Standard, Extreme and Survivability. Our Standard conditions are 50 mph winds and heavy rains (tropical storm). Reliabilities quoted by MCIS (99.999% for example) are always under those standard conditions (under normal weather conditions reliabilities are typically much higher).

Extreme conditions are very low probability events where system degradation is acceptable but system failure is not (e.g. a reduction in throughput is expected but the link is maintained). These are typically 90 mph winds and heavy rains.

Survivability is typically defined by the local building code or 120 mph, whichever is greater. All of these conditions are customer defined and cost-performance trades are developed to help the customer make informed decisions.