First was the tall towers along the trail by the I-355 Des Plaines Valley River Bridge. Note that the bridge itself is 80-100 feet in the air. So those towers are probably around 200 feet.
Note that the ladder has the pegs at a 90 degree angle instead of 180 degrees. I wonder if the workers can unlock something and turn both rows of pegs 45 degrees toward the tower. And, as I expected, the permanent ladder does not go all the way down to the ground. Since the workers would have a key to the access gate, it would be easy for them to truck in a ladder to the site to start the climb.
The base of those towers are over 6 feet in diameter.
An overview shot shows the towers that transition the line up to the tallest towers. And the shot below shows the steel truss towers that were used before they built the bridge.
I spent some time trying to figure out why they went over the bridge instead of under it. I've seen special low towers used tow lines cross each other so that one line can go under the other. Did the forest preserve insist that they stay in their old footprint and the bridge designers could not move the pier a little bit one way or another? And then I remembered that the bridge had to be raised 10-15 feet to clear the flight range of the Emerald Dragonfly. Those wires are carrying a high enough voltage that the dragonflies probably need not fly directly into a wire to have a bad day. Thus the wires went over the bridge instead of under to avoid impacting the dragonflys.
Update: a view of the towers from a bluff.
I've been down by the bridge several times. In fact, it is the first place I went when I retired and started this blog. I'm embarrassed that I never noticed this tower before. I looked around to see if I could find more towers. There is another one upstream from here. I got up on the approach for the old Lemont Road Bridge and found the following view that includes both towers. You can see from the bridge and the tops of the barges that these towers are located close to the Chicago Sanitary and Ship Canal.
Later, when I was on Canal Bank Road between Harlem Avenue and a Santa Fe Railroad Bridge, I spotted another old tower in the tree line between the road and the canal. So I drove the whole distance looking for more. I found just three. And they were adjacent. This shot was looking upstream.
|Allison Hirsch Fore shared|
Historical photo of the week: A brave man stands at the top of an electric cable pole near the Romeo Road Bridge in Lockport on August 30, 1907. Power generated at the MWRD's Lockport Powerhouse was transferred through cables along the Chicago Sanitary and Ship Canal to a control station in Pilsen.This confirms my theory that these towers were part of the CS&SC project.