The History of Chicago's Freight Tunnels
This picture shows a 1-inch scale model of Chicago Tunnel Company ash car number 715 as it appeared in the 1930's in a typical loop building boiler room. This museum quality diorama was built by Phil O'Keefe using measurements taken on an abandoned rail car in the tunnel system.
The History of Chicago's Freight Tunnels
Construction on Chicago's unique freight tunnel network began in 1899 in the basement of a tavern in the heart of the Loop near LaSalle and Madison Streets. Workers dug a small access tunnel from the basement down to the center of the intersection forty feet below grade. There, they continued to carve tunnels by hand out of the blue clay under nearly every street in downtown Chicago. Excavations were quietly removed through the tavern and other small access tunnels during the night. Forms were put in place and the tunnels were lined with non-reinforced concrete about one foot thick. The finished tunnels were roughly six feet wide by seven and a half feet high.
Left: A tunnel under construction showing the knife marks in the blue clay and the wooden forms in place. About one foot of concrete was forced behind the form. Right: Some of the first visitors to the tunnel are standing on a section of third rail (cog) trackage used by the first two locomotives on the system.
Although the tunnels were officially constructed to house only telephone cables, the Illinois Tunnel Company also secretly installed two foot gauge railroad tracks in them. The company was interested in running miniature freight trains in the tunnels, using small electric mine locomotives and pony sized freight cars. Trains would enter Loop building basements to pick up and deliver packages and mail. Also, the trains would deliver coal to, and remove cinders from, building boiler rooms.
This 1910 postcard photo shows the intersection of Dearborn and Randolph Streets. Downtown Chicago was once much busier than it is today and streets were typically clogged with streetcars, automobiles, horse drawn wagons, horses, and pedestrians. Few of the people in this picture knew about the little narrow gauge electric railroad that was being constructed forty feet under this chaos. It is interesting to note that the green Chicago Railways streetcar on the left ran until the early 1950's.
A few years after construction began, test trains were run in a few sections of tunnel with two locomotives and a hand full of freight cars. The four wheeled locomotives received power from a "third rail" cog which was situated in a slot between the two running rails. The test operation proved to be feasible, however, it was decided to eliminate the third rail in favor of overhead trolley wire.
This photo shows a typical grand union (a crossing with switch tracks going between each leg of the cross). The Chicago Tunnel Company had grand unions under almost evey street intersection in the Loop. Note the overhead trolley wire which was energized at 250VDC. The conduits on the ceiling may have been for telephone cables or trolley feeders from a substation.
By 1906, freight service was officially established. The tunnel system was expanded over the next twenty four years to include approximately 60 miles of track. Click here to see a map of the system. Service was provided with 149 four wheeled electric locomotives of various capacities, and over 3000 double truck freight cars including flat cars, merchandise cars, coal cars, and ash cars. Click here to learn more about the cars that ran in the tunnels. Tunnel freight cars were delivered to railroad freight stations, warehouses, office buildings, and store buildings via elevators or direct access.
This 1920's photograph shows a locomotive, a merchandise car and some visitors at the intersection of State and Madison. This location was completely obliterated during construction of the State Street Subway in the late 1930's. The subway helped ruin the company.
The Illinois Tunnel Company never did very well financially, and it was troubled by political and legal problems through it's parent the Illinois Telephone and Telegraph Company. In 1912 the Illinois Tunnel Company was reorganized and renamed the Chicago Tunnel Company. Eventually, the telephone cables were removed, and the tunnels were used exclusively for freight train movements.
A happy motorman switches ash cars in Marshall Field & Company's basement with a locomotive from the 525-534 Series built for the Chicago Tunnel Company by Baldwin Locomotive Works in 1913. These were the largest locomotives to run in the tunnels.
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Chicago Tunnel Company Site Map
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If you have any comments about this site, or if you would like to share information about the tunnels, you can e-mail Phil O'Keefe at: chicagotunnel@ameritech.net
