Wednesday, May 30, 2012

The Rusting Street Light Poles of Interlocken in Broomfield

A fallen street light pole near where I work has grabbed my attention lately and has me pondering some questions.  It's been down for a few weeks now and looks to have simply rusted out at its base. There are frequent strong winds in this area which probably contributed to its final toppling.  You can tell it took a hard fall because of the crushed street light on half of the top; the other half looks intact.

The poles are in the median of Interlocken Loop in Broomfield, Colorado, between Interlocken and Eldorado Boulevard. Maybe they are 40 feet high.This office park was built-up in the mid-1990s so my rough estimate of the age of these poles is just under twenty years.  Doesn't this seem like a short life span for municipal lighting infrastructure?

Here's a closeup of the thin pole walls at its base, eaten out by rust.  Likely the sprinkler system on the median regularly showered the base throughout the warmer months.  Are such poles engineered to withstand daily spraying?

The fallen pole is laid along the median but I doubt it could have tumbled down that conveniently.  Did it fall like the well-known tree in the forest where nobody was around to hear it crash?  Did it block the road for a while?  Thankfully, I don't think it fell on anyone or caused injury because I would have heard about that.  Maybe it was proactively downed intentionally.

And I see other neighboring poles that also have rusted bases and some that don't appear to be standing straight.  When will others fall?  Will the whole row of poles be replaced soon?

Ok, that's enough pondering by me but if you're a street engineer, municipal planner, or a metallurgy expert, your opinions are welcome!


Sam said...

I frequent the area (as I work in the CTC down the road), and I have noticed those poles leaning several times. I"m glad it's not just my mind playing tricks on me! Hopefully they will replace them soon, as I can't imagine they would last that long with such thin sidewalls.

Peter said...

Another person speculated that the rust damage is from the liquid Magnesium Chloride that they use on the roads in the winter.