the kinzie st. bridge is one of many drawbridges over the chicago river (a railroad bridge next to it is left open). when it was built in 1909 it opened many times a day. it has a control tower where a bridge-tender could see both ends of the bridge when raising and lowering it. now it does not open very often and nobody works there. "pilings" (logs pounded into the ground) were bumpers to stop boats from hitting the bridge.