Pennsy 22nd Street "tower"

As part of the complexity of the railroads in Chicago back before Interstate roads and airlines gutted the railroad business, Pennsy used (but not necessarily owned) three towers within one block: South Branch Bridge, 21st Street and this newly discovered 22nd Street Tower.

Bob Lalich commented on a post that shows the South Branch Bridge interlock tower.
The PRR block operator used to be in another structure near the WB home signal for 21st St. This photo dates from the mid-50s, courtesy of Jack Tomisek.
Bob Poortinga Bob, that is 22nd St which used to control a crossover, a turnout entrance to number 4 track, and a wye to the ATSF. I believe this was totally separate from South Branch Bridge and was a different block operator. There was no interlocking here, just a couple of hand throw turnouts, and trains had to get a highball from the operator to proceed.
Bob Lalich Bob Poortinga - thanks for the clarification. Those were two closely spaced block operators. And there were four PRR tracks east of the crossovers at the time.
Dennis DeBruler The three horizontal (yellow) lights in the top signal head caused me to look up when Pennsy converted to Red Snake Eyes: late-50s.