Truth is in the Details ™

The Case of the Tumbled Tower

Synopsis:
Critical evidence is often perishable and a technical investigator with the dedication and perseverance to collect it can result in coverage decisions made on the basis of documented facts rather than after-the-fact opinions.

Background:
A TV tower fell in western South Dakota during a regional blizzard that was preceded by a long period favorable for the formation of rime ice. The owner’s insurance policy had specific coverages and disclaimers regarding structural defects, wind and ice.

Assignment:
TI was requested to make an immediate site inspection in order to determine the specific cause of the tower falling so that forecasted warming conditions could not destroy evidence of icing, if it was present. Replacement cost of the tower was estimated at $850k.

Analysis:
TI drove over 500 miles through the blizzard to reach the site as the blizzard ended and prior to the warming. The 710’ tall tower was located high on a butte that was the high spot in the region, thus providing for ultra-wide coverage for the TV station. The tower was down in its entirety as was another nearby tower but a third tower had survived and was quite instructive on what had happened.

 

 

 

 

The third tower was almost fully impacted with ice but its guy wires were ice-free. Ice builds up on the guy wires, and when it becomes heavy enough it loses its grip on the steel cable and slides down the guy wire at great speed, often breaking guy wire clamps where they are anchored, leaving a portion of the tower unsupported where it then buckles, dropping the overhead portion of the tower and generally taking down the lower portion as well.

 

 

 

 

It was found that some of the guy wires for the subject tower had an exceptional coating of ice that had not stripped loose when the tower fell. The owner had coverage for icing but as plans were being made to install a new tower the local Native American tribe advised that the butte was sacred ground and demanded that the tower not be replaced. But, that is a story for another day.

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