LaSalle Street Tunnel

The LaSalle Street Tunnel was Chicago's second traffic tunnel under the Chicago River. It was started November 3, 1869, and completed July 4, 1871. It was designed by William Bryson who was the resident engineer for the Washington Street Tunnel. It was 1,890 feet (576m) long, from Randolph Street north to Hubbard (then Michigan) Street, and cost $566,000.

LaSalle St. Tunnel

South portal before 1888
Overview
Status	Closed and covered
Start	Michigan (Hubbard) St.
End	Dearborn St.
Operation
Opened	1871 (public), 1888 (cable) 1912 (after lowering)
Closed	1939
Owner	City of Chicago
Operator	North Chicago Street Ry. Chicago Union Transit Chicago Surface Lines
Technical
Length	1,887 ft (575.16 m) (as built)
No. of lanes	3
Highest elevation	594 ft (181.05 m)
Lowest elevation	534 ft (162.76 m) (after lowering)
Tunnel clearance	15 feet 9 inches (4.80 m)
Width	30 ft (9.14 m)

History

As built

Originally built with one lane for pedestrians and 2 lanes for horse-drawn traffic, by the 1880s it was in poor condition. On March 23, 1888, the North Chicago Street Railroad leased the tunnel. If they repaired it and made other local improvements they could use the tunnel exclusively for cable car service.^[1][2][3]

The reversing of the Chicago River in 1900 exposed the roof of the tunnel in the new riverbed and in 1904 the Federal government declared it a hazard to navigation. The tunnel was closed to cable cars on October 21, 1906. ^[1][2][3]

Reconstruction

The approaches were deepened to a new lower tunnel level. The grades were aligned for the cars to enter from a shallow subway just below street level. The subway was not built, concrete ramps raised the tracks up to street grade.^[3]

The tunnel section under the river was removed and a two tube steel plate replacement built in a drydock on Goose Island was lowered into a trench in the riverbed. The tunnels connecting the approaches and the tubes were dug through and under the original tunnels.^[3][4]

After lowering

The deepened tunnel was opened to electric streetcar service on July 21, 1912. It was in use until November 27, 1939, when it was closed during the construction of the Milwaukee-Lake-Dearborn-Congress subway, the Lake & LaSalle (now Clark & Lake) station of which intersected the tunnel's south ramp under Lake Street. By 1950 the south approach had been covered, the tunnel and the north approach were filled and covered by 1953.^[1][2][3][5]

See also

Washington St. Tunnel