Chicago River Bascule Bridge, West Cortland Street, Spanning North Branch of Chicago River at West Cor, Chicago, Cook County, IL
Photo Caption Pages
Spanning North Branch of Chicago River at West Cor, Chicago, IL
Find maps of Chicago, IL
Documentation compiled after 1968.
Survey number HAER IL-138
Building/structure dates: 1901 initial construction
Significance: Designated a landmark by the American Society of Civil Engineers, the Cortland Street Bridge is a double-leaf bascule span that became in the early twentieth century the standard for movable bridges designed by the city engineer of Chicago. The Cortland Street bridge was the first of this type and featured electric motors that drove pinion gears which engaged a rack attached to the end of each truss. Counterweights on the shore sides of the bridge counterbalanced the roadway and superstructure that spanned the river and thus little power was required to raise or lower the bridge. When raised, each leaf assumed a nearly vertical position providing a wide clearance for vessels plying the river. City engineers designed the machinery so that the bridge could open within one minute during calm weather and under three minutes during windy conditions.
Chicago Department Of Transportation
Lowe, Jet, Photographer
Fitzsimons, Gray, Historian
Historic American Engineering Record (Library of Congress)
1. VIEW OF EASTERN BRIDGE PORTAL, LOOKING WEST
2. VIEW OF WESTERN BRIDGE PORTAL, LOOKING EAST
3. VIEW OF WESTERN BRIDGE PORTAL FROM NORTH SIDE OF BRIDGE, LOOKING SOUTHEAST
4. DETAIL OF BUILDER'S PLATES: '1901, CARTER H. HARRISON, COMMISSIONER OF PUBLIC WORKS, MAYOR F.W. BLOCKI, JOHN ERICSON, CITY ENGINEER'; 'FITZSIMONS AND CONNELL CO. SUBSTRUCTURE'; 'AMERICAN BRIDGE COMPANY, LASSIG PLANT, CONTRACTOR FOR SUPERSTRUCTURE'
5. VIEW OF BRIDGETENDER'S HOUSE, LOOKING EAST
6. DETAIL OF LIFTING MACHINERY HOUSED UNDER THE APPROACH ROADWAY; 38 HORSEPOWER ELECTRIC MOTOR IN RIGHT-CENTER, RACK AND PINION GEAR TO THE LEFT
7. DETAIL OF LIFTING MACHINERY HOUSED UNDER THE APPROACH ROADWAY; 38 HORSEPOWER ELECTRIC MOTOR IN LEFT-CENTER, RACK AND PINION GEAR TO THE RIGHT
8. DETAIL OF LIFTING MACHINERY HOUSED UNDER THE APPROACH ROADWAY, SHOWING SHAFT WHEEL EQUIPPED WITH HANDBRAKE THAT IS OPERATED FROM THE BRIDGETENDER'S HOUSE
9. LOOKING SOUTHWEST, CORTLAND STREET BRIDGE
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