CDOT Bridge Crews on Deck for Safety. Bridge Lift and Boat Run. July 11, 2020.

CDOT bridge inspection and monitoring crews take center stage during every bridge lift along the South and Main Branches of the Chicago River. Here are the best photos from the event of July 11, 2020.

Roosevelt Road/ 12th Street Bridge Features include…
… the east leaf and signal systems…
… the monumental bridge tender’s house and its historic plaque
… and this view of the Union Station Powerhouse.
Here, a CTA #18 Bus waits east of the bridge.
Jackson Boulevard Bridge features include:
…this precise reflection of the east leaf and the signal systems, and a bridge tender’s house.
Jackson Boulevard Bridge descends, showing east and west leaves.
Adams Street Bridge and SE bridge tender’s house and signal systems.
Monroe Street Bridge east leaf and a bridge inspector.
Monroe Street Bridge east leaf and bridge tender’s house.
Monroe Street Bridge Leaves and Boats Crossing North.
Madison Street/Lyric Opera Bridge opening leaves.
Madison Street Riverside Spans: Best Seats in the South Loop.
Madison Street Bridge and inspector.
Madison Street Bridge east leaf and part of SE bridge tender’s house.
Bridge inspector watching descent of Madison Street Bridge, and a view of tender’s house.

Bascule bridge features include single or double leaves, single or double decks, warning lights and barricade arms, bridge tender’s houses and chimes warning of when a bridge is about to lift. The term ‘bascule’ is from the French meaning “see-saw”. It is a principle of balance and strength based on the triangle, a shape you will see in every aspect of a bridge from its roadway deck to its truss web.

Washington Boulevard Bridge East Leaf and Inspection Crews.
Randolph Street Bridge East Leaf and modern Bridge Tender’s House
Railings along sidewalks are features of bascule bridges approaching and along the clear span of the bridge’s leaves. You can tell the decades a bridge was built in by the design of its bridge tender’s house and its truss styles. Look for steel mill brands as well– they make a great research project.

The next article features the second part of Saturday’s bridge lift, going from Lake Street to DuSable Bridge at Michigan Avenue.

Divi Logan. Chicago. July 16, 2020.