Tally's Phenomenal Response to Hermine

Hundreds of downed power lines fixed per day!

written by Jeremiah W. Murphy on 2016-09-12

A quick calculation suggests that work crews fixed hundreds of, maybe even a thousand, power lines per day, and brought power back to the city in less than a week. By any measure this was an amazing feat of emergency response and management.

Tallahassee is a beautiful lush city that embraces and loves its many majestic trees. In fact, as one flies to or from Tallahassee, it is difficult to see the city. Rather, your eye is greeted with a sea of green canopy with a few of the tallest buildings poking through. It's no wonder Tallahassee's new tagline is "City in the Trees".

OK, I made up that tag line, and I'm probably the only one using it, but you get the point. We have lots of trees, they're pretty, and we love them. It's no wonder then, that in the aftermath of Hermine, 80% of Tally was without power.

In the morning after Hermine, I walked around my neighborhood and quickly realized that the city must be thrashed. In my beautifully quaint neighborhood, Glendale, there were at least 5 trees across power lines, and if there were 5 in my small neighborhood, then Tallahassee must be a mess. In fact, I estimate that there were roughly 14,000 trees across power lines in Tallahassee. The calculation is simple. Glendale is about 1,000 feet by 1,000 feet.

Tallahassee, like any modestly sized city is of order 10 miles across. Since a mile is 5280 feet, the area of Tally is roughly 2,800 times greater than my neighborhood. If my neighborhood is a fair sample of the areal density of downed trees, then the total number of trees across power lines is 2,800 x 5, which is 14,000.

If the city hoped to restore power to the city in a week, then the work crews would have to make 2,000 repairs each day. Even if I've overestimated the areal density of downed trees by a factor of 4, then that would still be 500 repairs per day. I estimate that it would take a crew anywhere from 2 to 4 hours to repair each break, which for a 12-hour work day means that one work crew can fix 3 to 6 breaks. To have any hope of making all of those repairs in one week, there must have been hundreds of work crews. The logistics must have been complicated, to say the least.

Indeed, cleaning up Tally was a monumental task, yet power was restored to 90% of Tally customers within 5 days of Hermine and 97% within six days.

Aside: These are rough estimates based upon observations in my neighborhood and a rough extrapolation. If you have the actual numbers, please contact me, and we'll test this calculation.