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Nov 14

Written by: Brett Moss
11/14/2013 1:08 PM 


 Aerial view 1938
Aerial view from the WLS album by Prairie Farmer magazine; click to enlarge

The author is RW gear & technology editor.

If you happen to be passing through the Chicago area in the next few days, especially around White Eagle Drive in La Grange, you might notice a tall tower in the middle of a field. That tower has just celebrated its 75th anniversary.

It belongs to one of radio’s senior faculty, WLS(AM). It was put up in the spring of 1938 by WLS’ then-owner, Prairie Farmer magazine. The area was relatively rural and the 586-foot tower soared over a corn field.

The minds behind this idea are pictured in a 1939 “WLS Family Album.” The builder was Truscon Steel. Warren Shulz, who engineered at WLS for decades, says the tower weighs around 42,000 pounds. And it all comes down to a single point, a ceramic insulator that has never been replaced (see photo, lower right). The rectangular hole that can be seen in a plate above the insulator was thoughtfully placed there so that future generations could replace the insulator by running a steel beam through the hole and then jacking up both ends of the beam.
 Engineering team and site photos
Also from Prairie Farmer. Click to enlarge

Shulz tells Radio World that everyone knows about this but no one has had the nerve to try it.

There has been some refurb work done, however. The tower was reguyed in 2001. Shulz notes that guy wire lifetime is usually figured to be 20 years so at that point the guy wires were well past their replacement time. The guy anchors’ concrete piers run 12 feet below grade. They would not appear to be a failure point.

This stick is a svelte four feet wide. Shulz says it’s built of solid rod, courtesy of Truscon’s railroad bridge-building roots.
 WLS_main_twr_base
The insulator that sits at the base of the tower. Note the rectangular hole in the faceplate. Click to enlarge.

The tower stands out as man’s finger on the northern Illinois plains, so nature has a love-hate relationship with it. Across the decades Zeus’ thunderbolts have failed to fell the tower, wind merely makes the guys sing, ice storms can cause the VSWR to jump but the tower remains.

A hawk once took up residence at the 100-foot side light platform. Climbers and bird tolerated each other. There are five platforms in the triangular tower, each corresponding to a set of side lights. This doesn’t match FAA regs, but as one can imagine, the tower has earned grandfather status.

The official birthday was Nov. 12. See more fun pictures below.

 Conduit being installed on tower
The “platform” and side light system can be seen here during a retrofit of the tower. Click to enlarge.

 WLS-AM Angled Google Earth
This angled Google Earth view allows for a rough comparison to the older view from the late 1930s. Click to enlarge.


 WLS Insulator_pair
Original “cage” insulators, part of the guy system, were replaced in 2001 with the guy wires. Shulz recounts that during a heavy snow, they became caked and began to “flash.”A more modern insulation design has been installed with the new guys. Click to enlarge.

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