EAST OF S CANAL STREET, SOUTH OF 18TH STREET

PENNSYLVANIA RAILROAD VERTICAL LIFT BRIDGE

ORIGINALLY CONSTRUCTED FOR THE PENNSYLVANIA RAILROAD IN 1915, THIS VERTICAL LIFT BRIDGE IS USED TODAY BY AMTRAK. DESIGNED BY WADDELL AND HARRINGTON, AN ENGINEERING FIRM SPECIALIZING IN VERTICAL LIFT SPANS, IT USES 2 195 FT TOWERS TO ELEVATE ITS 1500 TON, 272 FT 10 IN SPAN AS MUCH AS 130 FT ABOVE THE WATER. UPON COMPLETION THIS SPAN WAS THE HEAVIEST OF ITS KIND IN AMERICA, AND IS TODAY THE ONLY VERTICAL LIFT SPAN ON THE CHICAGO RIVER. THE BRIDGE TENDER'S CORRUGATED METAL CABIN, NOW DEFUNCT, STILL SITS ON THE UPPER CHORD OF THE PRATT TRUSS.

THE ENORMOUS SCALE OF THIS ENGINEERING TRIUMPH IS STILL IMPRESSIVE TODAY. BEFORE THE SPAN IS RAISED, AN AIR-RAID SIREN IS SOUNDED. SOON THE MASSIVE COUNTERWEIGHTS DESCEND, LIFTING THE SPAN AMIDST A CHORUS OF CREAKING STEEL THAT ECHOES THROUGH CHINATOWN (SEE VIDEO BELOW).

SOURCE:

LIBRARY OF CONGRESS: HISTORIC AMERICAN ENGINEERING RECORD: "PENNSYLVANIA RAILROAD, SOUTH BRANCH CHICAGO RIVER BRIDGE"
HAER No. IL-112