fixing...

[gtroza] fixing my mom's glasses

...my mom's...

[gtroza] fixing my mom's glasses

...glasses

[gtroza] fixing my mom's glasses

open sesame!

under the bridge at w.chicago street, at the lowel level of chicago's infrastructure you can see these gears. i am not so sure which of the movable types this mechanism comes from. there are several: trunnion bascule [using a counterweight], scherzer rolling lift [rolling like a rocking chair], swing bridge [rotating parallel to the water around a central point] or vertical lift bridge.
must be bascule or a similar version...

photos by life universe.

underneath

i am reading on this article that chicago has more movable bridges than any other city in the world! 37-43! ~20 downtown!