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A Feast of Movable BridgesBy David Clark. Photos by author except as noted.

From simple concrete slabs across culverts, to spectacular spans of steel crossing rivers andstreams, the Mother Road is a feast of bridges of a large variety of styles and types. Every statethrough which the highway runs can boast of their pony trusses and rainbow arches, their buenavistas and devilish elbows, or their canyon-crossers and railroad over-passers. However, if one’staste in road engineering eye-candy can only be satisfied with a feast of movable bridges, thenturn your vehicles towards Illinois and prepare yourself for a hearty triple repast. Route 66 ishome to just three bridges of a movable type, and all three are in the Prairie State: two inChicago, and one in Joliet.

LEFT: Jackson Boulevard Bridge over Chicago River. CENTER: Adams StreetBridge, Photo by Carl Johnson. RIGHT: Joliet’s Ruby Street Bridge, photo by CarlJohnson.

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Appetizer: The notion of motion. Before we dig in to the main courses, perhaps we shouldcleanse our palate with an appetizing tidbit of info as to why some bridges need to move, whileothers can stay put. Surely, if an engineer designs a bridge that will just stay there and allow usto safely get across--that should be enough! In Chicago’s early days, many folks would take aferry across the river rather than trust one of the city’s original spans. Floating pontoon bridgeswere swept away by a flood in 1849. In 1863, the Rush Street Bridge collapsed under the weightof a herd of cattle. According to the Encyclopedia of Chicago, “A narrow river, with low banks,ran through the heart of the city, requiring frequent crossings. Yet the navigable river was one ofthe world's great ports, and the low bridges had to accommodate frequent passage of mastedships.” So when a ship came along, the bridges had to get out of the way.

LEFT: Adams Street Swing Bridge over the Chicago River, built in 1889, replaced in 1927 with currentbridge. This bridge would pivot 90 degrees to allow ships to pass. Stereoview slide image, Author’scollection. RIGHT: The vertical lift bridge in Joliet stays open to river traffic except when needed for theElgin, Joliet & Eastern freight trains. When a train approaches, the bridge is lowered remotely from arailroad office 1.5 miles away.

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Nineteenth century solutions to the movable bridge problem included experiments with severaldifferent designs. The first Chicago drawbridge, at Dearborn Street, was only six feet above thewater and had a narrow channel that interfered with navigation. Swing bridges became thestandard in the second half of the 1800s. These spans pivoted ninety degrees on a pier in thecenter of the river, which allowed ships to pass on either side. Collisions were frequent in thenarrow channels, so it was clear that a solution was needed which would move the entire bridgeout of the ship path. Vertical lift bridges featured tall towers on each bank; counterweights andcables would lift the river span upwards. Although some vertical lifts are still in use, they aregenerally expensive to build and maintain. “Engineer William Scherzer developed a rolling liftbridge that had two leaves that rolled back onto each bank. This bridge was inexpensive andeasy to maintain, but weaknesses emerged over time” (Encyclopedia of Chicago).

McDonough Street in Joliet (US 6 and 52) is served by this Scherzer Rolling Lift Bridge. The curved end ofthe bridge leaf rolls on the horizontal track to open the draw.

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The design recognized as the best solution for safety to both land and river traffic, as well as forreliability and relative inexpense of fabrication and maintenance, has become known as theChicago Trunnion Bascule Bridge. All three of Route 66’s movable bridges are of this design.(Joliet’s history with the movable bridge is a little different, as we will see in the Third Course ofour feast.) A trunnion is a shaft, or pivot-point, and bascule is the French word for see-saw. Theweight of each leaf of the bridge is balanced by a counterweight located below the street level onthe riverbank. A complex of gears and electric motors, operated by a bridge tender, pivots thecounterweight downward and the bridge leaf upward and away from the center of the river. Theengineering details that made this design efficient, economical, and reliable were worked out andpatented by Joseph Strauss, who built the first successful span of this type for Chicago in 1902,at Cortland Street. Mr. Strauss would later become famous as the chief engineer for the GoldenGate Bridge.

Postcard views of the Jack Knife Bridge, which carried the Metropolitan West Side Elevated Railroadacross the Chicago River from the 1880s through the 1900s. This early attempt at a bascule-style bridgeproved unreliable. This bridge was located immediately south of Jackson Boulevard (66). The concretefooting on the west riverbank is all that remains of the bridge and railroad. Left card by V.O. HammonPublishing, right card by Detroit Publishing.

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The First Course: Jackson Boulevard Bridge. Built in 1916, the Jackson Bridge is the onlyChicago River span to carry Route 66 traffic eastbound into Chicago’s Loop for the highway’sentire commissioned life (Route 66 was an official US Highway in Illinois from 1927 through1977). According to the descriptive data compiled by the National Park Service’s HistoricAmerican Engineering Record (HAER), the bridge is “a single-deck, double-leaf, Strausstrunnion bascule bridge [which] measures 202 feet 4 inches from center to center of thetrunnions and has a clear span of 173 feet 6 inches. Superstructure is a steel pony truss withriveted gusset-plate connections. Width measures 64 feet.”

Postcard view of the current Jackson Bridge over the Chicago River, looking north. This view predated thebuilding of the current Adams Bridge and Union Station, therefore circa 1915-1924. The Adams StreetSwing Bridge is visible in the distance, as is the old Union Station, the red-brick building to the left of theAdams Swing Bridge.

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“On each side of lift span is a bridge tender’s house in the Beaux-Arts style. The bridge tenders’houses, rising above lightly scored concrete pylons, are identical in design; each contains apebble aggregate veneer and octagonal plan. A band of single-light windows and ornamentalmolding extend below a decorative cornice line. Each bridge tender’s house is topped by amansard-like metal roof.” The architectural details of the bridge came about with the insistenceof urban planners and the Chicago Art Commission. “Calling attention to the placement of thetruss work below the deck and the use of curved bottom chords, the Commission noted that thisarrangement ‘gives a fine open appearance to the bridge.’”

ABOVE: View looking north at the Jackson Bridge.Maintenance work is underway on the west leaf. In the leftforeground of the image, the footing of the demolishedJack Knife Bridge is visible. RIGHT: Bridge Tender’sHouse on west bank of the river. The mansard roof istypical of the Beaux-Arts architectural style.

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Looking at the sporadic river traffic we see now, it is difficult to imagine that this river was oncethe nation’s busiest commercial port. In 1871, despite being closed to navigation during thewinter months, “more ships arrived here than New York, San Francisco, Philadelphia, Baltimore,Charleston, and Mobile combined.” (Encyclopedia of Chicago). With the transfer of mostcommercial shipping to Calumet Harbor in the early 1900s, the Chicago River is now used bymore tour boats and pleasure craft than cargo barges.

At the height of its glory as a commercial port, the Chicago River’s bridges opened for lake and ocean steamerssuch as the S.S. Roosevelt many time each day during the shipping season. Today, most bridge openings arefor tall-masted pleasure craft. This postcard by Detroit Publishing, date unknown.

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First page of a story in the American Review of Reviews from March 1918, which discusses the importance of Chicago as a transportation center for both rail and water commerce. “It has been, and possesses the possibilities for again becoming, the greatest inland water transportation center in the world.” From the author’s collection.

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During the April 15-November 15 boating season, over 50,000 ships still use the river, requiring30,000 bridge openings each year. The city requested and received restrictions from the Federalgovernment, so now the bridges will only open during non-peak traffic hours, and only with 12-48hours advance request from the ship owner. Bridge tenders do not staff the bridges full-time;rather, the Chicago Department of Transportation uses roving teams that drive from bridge tobridge, opening them in turn.

ABOVE: Chicago’s Straus Trunnion Bascule Jackson Blvd Bridge with the eastern leaf open to allow forpassage of tall-masted sailboats. The trunnions (pivot shafts) and counterweights are located below streetlevel on each riverbank. Photo by Carl Johnson. RIGHT: The Jackson Boulevard Bridge in the openposition. Note the helpful sign on the easel which states “Sidewalk Closed.” Hopefully, would-be daredevilsdetermined to duck under the crossing gate, ignore the “stop” lights and clanging bells, and climb up theinclined walkway, will read this sign and reconsider!

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The Second Course: Adams Street Bridge. In the mid-1950s, the city of Chicago changedJackson Boulevard to a one-way eastbound thoroughfare, and westbound US 66 traffic wasdiverted one block north to Adams Street, parallel to Jackson. Built in 1926, the Adams StreetBridge across the Chicago River is the second-oldest movable bridge along the route. TheHAER narrative indicates that the bridge “measures 199 feet from center to center of thetrunnions and has a clear span of 173 feet. The superstructure is a steel deck truss with rivetedgusset-plate connections. Width measures 64 feet and has four lanes for vehicular traffic andtwo sidewalks.”

Stereoview image showing Chicago’s Union Station. In the left foreground, the footing of the AdamsStreet Bascule Bridge is in place, and the bridge work is in progress. The image is ca. 1926. The swingbridge had just been removed. Keystone View Company, steroeview 146-(29229), author’s collection.

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It is ten years younger than its Jackson Boulevard sibling, and although the bridges look similar,the Adams Bridge was trickier to design and build. Below grade on the west bank of the river, therailroad tracks leading to Union Station veer closer to the river’s edge than at Jackson, whichrequired a reduction in the size of the bridge’s counterweight arms and box. The weight of thewest leaf of the bridge is partially carried on steel girders that extend to piers beyond the railroadtracks.

TOP LEFT: View of Adams Street Bridge, lookingsouth. BOTTOM LEFT: While enjoying our feast ofmovable bridges, you can stop at Potbelly SandwichWorks at the east end of the Adams Bridge andenjoy a feast on a roll. Potbelly’s started in Chicagoand is now in 8 states. ABOVE: Each spring, thecity of Chicago works with area shipyards to arrangefor most boats to travel to their summer harbormoorings on weekend mornings to avoiddisturbance of weekday auto traffic. Photo by CarlJohnson.

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These two bridgetenders are very similarin appearance but if youlook closely, you will seedifferences. Thearchitecture of both theJackson and Adamsbridges is of the Beaux-Arts style. Both featuremansard roofs and anoctagonal shape to thetowers. The façade ofthe older 1915 JacksonBridge (left) is made of apebble-finished dolomiteaggregate, while the1927 Adams Bridge(right) is covered with asmooth-texturedlimestone-basedconcrete.

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An aperitif between courses. Each weekday, I walk the commute from my home on the westside of the river to my workplace on the east side. This walk usually means a crossing on one ofChicago’s Route 66 bridges. I often pause near the middle of the river to contemplate how muchof the history of the United States was shaped in this place. Native Americans of thePotawatomi, Miami, and Illinois nations used the river as a trade route, and French missionaries,explorers, and fur traders used this river as they traveled between the Mississippi River systemand the Great Lakes. This waterway connection led the young United States to recognize thatthis place would one day be a great center for trade between the established east and thewestern frontier.Below grade on the west end of the bridges, the remaining railroad tracks remind me of theyears when Chicago was the railway capital of the continent, a great hub of transportation thatstarted its growth in the days before the Civil War and grew to make this city the pre-eminentGateway to the Great American West.

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Of course, these bridges carried the Mother Road, and since 2001, a new addition to thesymmetry of transit to be seen from this spot is the Chicago headquarters of the BoeingCorporation, visible to the north at the bend in the river near at Washington Boulevard. Foryears, first Midway and then O’Hare has held the title of world’s busiest airport. From here in themiddle of the Adams or Jackson Bridge, I see reminders of the water, rail, auto, and airtransportation that have shaped U.S. history. When I am asked: “why did 66 begin in Chicago?” Ioften reply, “Where else could it have started?”

Boeing Corporation moved their headquarters to thisbuilding in 2001, relocated from Washington State. Not onlydoes this building overlook the Chicago River and 66, thetower is built on the ”‘air rights” bridging Union Stationrailroad tracks.

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The Third Course: Ruby Street Bridge. When Route 66 was born, it entered downtown Joliet fromthe north via a fixed bridge across the Des Plaines River, a steel through-truss structure with threespans supported by stone piers. Unlike the Chicago River, the Des Plaines was too shallow to allowfor commercial shipping, which is exactly why the Illinois and Michigan Canal had been built in 1848.In Joliet, the canal paralleled the Des Plaines on the west side of the river. According to Dr. RobertSterling, author of Joliet Transportation and Industry: A Pictorial History, the last commercialboat to use the canal was the Niagara in October 1914; larger watercraft had rendered the narrow,shallow I & M obsolete. Federation News contributor Carl Johnson has conducted research whichhas shown that in the 1930s, the Illinois Waterway project created a wider and deeper commercial

channel to connect the GreatLakes with the Mississippi Riversystem. Through Joliet, the DesPlaines was dredged, concreteretaining walls were laid on eachside of the channel, and all theexisting stationary bridges in thecity were demolished andreplaced with movable spans.When the US Army Corps of Engin-eers took over the Illinois WaterwayProject from the state, they tore downall of the existing Des Plaines RiverBridges in Joliet.This February 1933photo shows the Ruby Street Bridgewith demolition in progress. From theDr. Robert Sterling Collection.

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The current Ruby Street Bridge opened in 1935, giving Route 66 its second Trunnion BasculeBridge (as already noted, Chicago’s Adams Street Bridge was built in 1926, but did not becomepart of 66 until 1953). It is 395 feet long, with a 256 foot main span and a 44 foot-wide deck.(http://bridges.midwestplaces.com/il/will/ruby-street/). Unlike the Chicago bridges, here the steelpony trusses are above deck, separating the driving lanes from the pedestrian sidewalks. Thebridge tender tower is located on the east bank. Water traffic is sufficiently busy to require 24-

hour staffing;according to FederalRegulation, the draw“shall open on signal,except that they neednot open from 7:30a.m. to 8:30 a.m. andfrom 4:15 p.m. to 5:15p.m. Monday throughSaturday” (CFR Title33 Part 117.393).1936 Curt TeichPostcard of the RubyStreet Bridge. Unlikethe Chicago Bridges,the Ruby Street has itstrusses above deckand has only onebridge tender house.Author’s Collection.

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TOP LEFT: Close-up view of the Ruby Street Bridge’sabove deck steel truss and Art-Deco Bridge Tendertower. ABOVE: Northbound 66 crosses the Ruby StreetBridge from east to west. Barge and ferry traffic iscontinuous, so bridge openings are common. Photo byCarl Johnson. LEFT: View frm inside the bridge tendertower of the Ruby Street Bridge. Unlike the ChicagoBridges, which have bridge tender towers on both sidesof the river, the Ruby Street Bridge has a single tower onthe east bank. Photo by Carl Johnson.

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An After-Dinner Spirit. Joliet was incorporated as a city in 1852, and soon became known asthe City of Stone. Dolomite deposits were discovered during the digging of the I & M Canal.Quarries yielded dimension stone through the 1880s that was used to build Chicago’s WaterTower and St. Patrick’s Church, as well as the bridges of Joliet and other notable structures. Thisstone became popularly known as “Joliet Marble,” or “Joliet Limestone.” As the building-gradestone became depleted, the quarrying operations continued to produce crushed stone that servedas railroad bed, macadam road base, and aggregate for concrete highways.

Joliet shared access to the same transportation network that served Chicago well. The canal andthe subsequent railroads allowed the city to utilize locally mined coal along with imported iron oreto build a metallurgical industry, and the City of Stone soon became known as the City of Steel.As we traverse the Ruby Street Bridge today, following 66 across this span constructed of stoneand steel, we can for a moment capture again the spirit in which this city and this road were built.

If we should encounter one of these bridges when the draw is open, we can join our fellow driversin cursing the delay; or we can savor those precious moments and observe the movement of theship, the craft of the tender, and the passage of history before our eyes.

Photo by Carl Johnson

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Bon a petit!

Photo by Carl Johnson

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Baughn, James. Historic Bridges of the Midwest. http://bridges.midwestplaces.comChicago History Museum. Electronic Encyclopedia of Chicago, The. © 2005.

www.encyclopedia.chicagohistory.orgMaggio, Alice. “Chicago: The Movable Bridge Capital of the World.” www.gapersblock.comNational Park Service, “West Adams Street, Chicago River Bridge,” and “Chicago River Bascule

Bridge, Jackson Boulevard.” Written Historical and Descriptive Data, Historic American Engineering Record (1992). memory.loc.gov/ammem/collections/habs_haer/

Sterling, Robert E. Joliet Transportation and Industry: A Pictorial History. 1997: G. BradleyPublishing Co., St. Louis, MO.

Bibliography

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About the Author...David G. Clark lives on Historic Route 66 in Chicago,Illinois with his wife, Carol Krohn, and their two RoadWarrior Yorkshire Terrier kids, Fred and Ginger. Davehas been researching road history, with an emphasison Chicago and Illinois, since a 66 trip in March 2000began an obsession. He conducts walking and drivingtours of the Mother Road in Chicago by appointment.Dave has published articles about 66 and Chicago inthe Federation News, the publication of the NationalHistoric Route 66 Federation; 66 News, the newsletterof the Route 66 Association of Illinois; and in Route 66Magazine.

In May 2006 Dave released his first book, ExploringRoute 66 in Chicagoland: Journeys throughHistory on the Mother Road in Cook County,Illinois. The book and much more is available on hiswebsite, www.windycityroadwarrior.com