The circuits upon the steel "crossarms" bolted to these rather heavy-duty poles probably were for trolley and/or electric utility service.

Also note the street lamp on the left. The lightbulb within its globe illuminated the translucent glass street signs immediately beneath.

Mac's (or the equivalent) Industrial Strength Road Salt eroded (corroded) the cast iron bases of many poles like these. Owing to their eventual and subsequent lack of physical integrity, newer street lighting sources and the need for more utility lines, most steel pole lines in this city were replaced during the 1950s and 60s.