The Liberty Bridge, spanning the Monongahela River, shown here on April 30, 1937.

The opening of the Liberty Tunnels in January 1924 was a major transportation development, linking the growing South Hills neighborhoods with the downtown area. However, once arriving on the other side of Mount Washington, motorists were routed to Arlington Avenue, then on to Carson Street and the Smithfield Bridge to cross the Monongahela River in order to reach the city center.

The need for an accompanying bridge was always a part of the master plan. It was vital to the continuing development of the entire South Hills region. Construction of the Liberty Bridge began in 1925 and it was ready for a grand opening in the Spring of 1928.

Now approaching 100 years of service, the venerable bridge has stood the test of time, and continues to be a key part of the Pittsburgh transportation network. For many who live or work in the South Hills, it's part of our daily life.

History of the Liberty Bridge

♦ History of the Liberty Tunnels ♦

The Liberty Bridge in 2012, eighty-four years after the grand opening in March 1928.

New Bridge is Needed

Although the tunnels made a huge difference in travel time from the South Hills to the North Face of Mount Washington, getting to the downtown city center still required a right turn onto a ramp to Arlington Avenue (called Brownsville Road at the time), then heading downhill to Carson Street and across the Smithfield Street Bridge. The resulting congestion was relieved by the construction of the Liberty Bridge.

From the time talk began of a tunnel through Mount Washington began there was discussion regarding a bridge across the Monongahela River to link the tunnel directly with downtown Pittsburgh.

Original plans for the Liberty Bridge, made public in May 1919.

When work began on the tunnel in 1919 plans were made public showing the proposed new bridge. The plans above show a completely different configuration for the northern approaches, with a different path for the proposed Boulevard of the Allies along with a Fourth Avenue Viaduct and Sixth Avenue extension to Second Avenue.

Varying Design Proposals

Expectations were that work on this span would begin shortly after the Liberty Tunnels were complete in January 1924, but that did not happen. Further designs were put forth, with varying proposals put forth for northern and southern approaches.

Early artist's conception of the proposed north and south end bridge design.

Another competing version had the northern ramps joining Shingiss Street and a Sixth Avenue Viaduct along with the current Boulevard of the Allies design.

Additional studies were initiated, causing delays. Further postponements came when the city was delayed in getting approval for the bond issue necessary to fund the project.

A later artist's conception showing the actual off ramp configuration on both northern and southern ends.

A $30 million bond issue was approved to cover several large improvement projects. In addition to the Liberty Bridge, the bond covered the construction of Mount Washington (McArdle) Roadway, the Armstrong Tunnels, construction of the County Office Building and numerous road improvements.

Bridge Piers

Work began in August 1925 with the construction of the bridge piers. A huge caisson was launched from Neville Island, built by the Dravo Contracting Company. The caisson was towed upriver and positioned to begin the pier construction.

The caisson was sunk below the river bottom until it reached bedrock, twenty feet below the river bed. Way down below the river, crews of fifteen men, working eight hours a day at double normal atmosphere, worked to clear away mud from under the caisson to reach bedrock.

The launching and towing of the caisson for the Liberty Bridge on August 18, 1925. On hand for the occasion were
F.C. Beinhauer, Daniel Winters, presidentof City Council, E.T. Whiter, regional vice president of the Pennsylvania
Railroad, County Commissioners Joseph G. Armstrong and E.V. Babcock, M.W. Clement, general manager of the
Pennsylvania Railroad, Judge Charles H. Kline, R.M. Dravo, vice president of the Dravo Contracting Company,
County Commissioner James Houlahen, Judge J. Carpenter and County Controller John P. Moore.

Clearing mud and taking a rock sounding in the south river caisson on September 25, 1925.

Working at the caisson for the southern pier of the Liberty Bridge in August 1925.

Construction of the piers that would support the Liberty Bridge as it crosses the Monongahela River.

Once the piers were in place, the steel frame was erected from both shores extending towards the middle. On June 15, 1927, both ends were joined. Another nine months would pass before construction was finished.

Liberty Bridge Construction Photos

Work begins on southern approaches to the Liberty Bridge in December 1925.

Work begins on southern approaches to the Liberty Bridge in December 1925.

Progress of the bridge construction as of October 24, 1926.

  
The bridge span extends from the approaches at the southern (left) and northern ends on February 4, 1927.

The northern end of the bridge extending over the Baltimore and Ohio Railroad yards on March 16, 1927.

  
The bridge span extends a bit further and is now over the banks of the Monongahela River
at the southern (left) and northern ends on March 16, 1927.

Work proceeds along the southern section of the bridge deck as the cranes move steadily forward along tracks.

  
The southern end of the bridge extends further over the Monongahela River, braced by falseworks, on April 8, 1927.

  
The northern end of the bridge continues to extend over the Monongahela River on April 8, 1927.

  
Work beginning on the Boulevard of the Allies ramps (left) and the two bridge sections nearing on June 6, 1927.

The Liberty Bridge under construction on June 15, 1927.

  
The two bridge sections were joined in the middle on June 15, 1927.

Ironworkers attaching the beams that connected the southern and northern ends of the bridge.

Looking south at the joining of the two sections of the Bridge on June 15, 1927.

A view of bridge construction from the Boulevard of the Allies in July 1927.

A view of bridge construction from the Boulevard of the Allies on August 12, 1927.

Greater Pittsburgh - The New Liberty Bridge - March 10, 1928.

The Liberty Bridge on March 12, 1928, two weeks before the grand opening.

Work proceeds on the traffic circle at the southern end of the bridge on March 12, 1928.

A view of the completed bridge on the day before the dedication on March 26, 1928.

Retaining Wall Construction on North Approach

The bridge design called for construction of three retaining walls along the northern approaches. Two smaller walls, one along the upper Bluff and another along the Pennsylvania Railroad car yard were needed, in addition to a massive wall along the mass of the hillside. A large cut into the Bluff was necessary to clear the path for the lower ramps to connect to Forbes Avenue.

The large retaining wall along the north approach under construction on October 28, 1927.

Booth and Flinn began work on the walls in March 1927. The main sloping wall was one of the highest of its type in the world, rising ninety feet from ground level, with long anchor beams embedded in the rock and attached to the concrete, making it an integral part of the hillside. Over 350,000 cubic feet of earth and rock were removed during the eleven month project, which was completed in January 1928.

The Bluff Hillside, covered in billboards, on July 13, 1921. The Boulevard of the Allies and subsequent Liberty Bridge
construction required substantial excavation and cuts into the hillside and ground-breaking engineering.

  
Conditions at Forbes Avenue in March 1927 (left) and the beginning of the Bluff excavation in April.

Beginning the construction of the high wall along the Bluff in April 1927.

The lower wall along the Pennsylvania Railroad car yard extending to Forbes Avenue in June 1927.

  
The lower wall at Forbes Avenue (left) and work proceeds with the hillside excavation in June 1927.

Conditions during the excavation of the hillside in June 1927.

The beginning of the sloping retaining wall at Forbes Avenue in July 1927.

  
Excavations along Shingiss Street and the first sections of the main retaining wall in July 1927.

350,000 cubic feet of earth and rock were hauled away from the cut one truckload at a time.

  
Two views of the hillside excavation. At its peak, the retaining wall would rise ninety feet.

Excavation at the Boulevard of the Allies Viaduct One in July 1927. The bridge ramps to Forbes Avenue
would extend through the viaduct, under the broad boulevard and over Second Avenue.

The excavation was complete in September 1927 and work was beginning on the tall section of the retaining wall.

  
Two views of the sloping wall as it rises in sections in October 1927. Long anchor beams were pounded into
the rock and attached to the cement wall, making the wall an integral part of the hillside.

The sloping wall was considered the highest of its kind in world at the time of construction.

Workers for Booth and Flinn at work building the upper sections of the sloping wall.

A view of the Forbes Avenue exit in 1951, before the Crosstown Boulevard ramps were built.

Highest and Costliest Span

At the time the Liberty Bridge was completed in March 1928, it was the largest, tallest (113 feet above the water level at it's highest point) and costliest span ($3.436 million) built in Allegheny County. Some said that the construction of the bridge was "one of the most pretentious projects ever undertaken."

The Pratt deck truss bridge measures 2663 feet in length, featuring two 450' cantilevered main spans over the river. The driveway was thirty-eight feet wide and two sidewalks measured eight and a half feet in width.

Constructed of steel and concrete, with granite facing on the piers to the water's edge, the bridge contains 11,000 tons of structural steel. The pavement was asphaltic concrete with a concrete base.

All phases of construction were completed by mid-March and the city of Pittsburgh prepared for the grand opening, to be held on March 27, 1928.

Liberty Bridge Dedication

The Liberty Bridge was dedicated on March 27, 1928. Coupled with the opening of the Liberty Tunnels in 1924, the new bridge was a major achievement for the City of Pittsburgh in the advancement of its evolving transportation network. The combined cost of the new tunnels and bridge was $9,400,000.

A parade of automobiles streams across the Liberty Bridge on Dedication Day - March 27, 1928.

The day began in Mount Lebanon, where the largest motorcade in the history of the City of Pittsburgh had gathered. The five mile long procession flowed north on West Liberty Avenue through Dormont and Brookline, then turned left onto Warrington Avenue. It passed through Beltzhoover and Allentown, then onto Arlington Avenue.

The parade of vehicles winded down the hill to Carson Street, then crossed the Smithfield Street Bridge and moved on to the Boulevard of the Allies. When it reached the intersection with the bridge the lead car came to a stop.

City, County and State officials were on hand to dedicate the bridge and restart the procession. The honor of actually cutting the red, while and blue ribbon went to Allen H. Lemon, aged seven, of 919 Carson Street, and Joseph G. Armstrong III, aged two, grandson of County Commissioner Joseph Armstrong.

Once the ribbon was cut the vehicles, four abreast, slowly crossed the bridge and continued on through the tunnels, then back up West Liberty Avenue to the starting point. The motorcade continued for ninety minutes while crossing the bridge.

Another image of the Liberty Bridge dedication on March 27, 1928.

The tunnels themselves shortened the travel time from the South Hills to downtown significantly. The accompanying bridge lessened that time even more. A motorist could now get from the intersection of Saw Mill Run Road and West Liberty Avenue to downtown Pittsburgh in less than five minutes on a good day.

Only five years earlier, the same drive took nearly an hour or longer. Prior to the advent of the automobile, that trip could last several hours. The Liberty Tunnels and the Liberty Bridge were responsible for a near quadrupling of property values in the South Hills.

The Liberty Bridge in 1928, shortly after the March dedication. Tha span towers over
all other Monongahela River bridges in Pittsburgh's Golden Triangle.

Traffic Circle and Safety Concerns

The North Portal of the Liberty Tunnels and the traffic circle shown here in 1930.

The northern bridge approach, outside the tunnels, was adorned with a decorative traffic circle containing a monument to Liberty. In time, as the flow of traffic increased, this large circle became a hindrance to smooth vehicular flow.

The traffic circle at the tunnel entrance was condensed in 1933.

In 1933, in an effort to increase safety at the busy intersection, the traffic circle was condensed to facilitate the ever-increasing flow of vehicles. By the 1940s, the circle had been reduced to a small island with a traffic signal.

Another early safety improvement for motorists and pedestrians using the bridge was the 1935 installation of heavy, reinforced concrete guard rails along the sides of the roadway. This was to prevent out-of-control vehicles from plunging off the bridge.

Pouring concrete for the installation of guard rails on August 29, 1935.

Mount Washington Roadway

Mount Washington Roadway, which scales the Coal Hill cliffside from the Liberty Tunnel entrance to Grandview Avenue, opened in July 1928, just four months after the Liberty Bridge dedication.

In another major improvement for South Hills residents, coupled with the Liberty Bridge, the Mount Washington Roadway provided another timely option to reach downtown Pittsburgh, and a convenient detour in case of tunnel closure.

Later renamed McArdle Roadway, this major civic improvement provided further fuel to the escalating real estate values of South Hills property.

A view of the Liberty Bridge from the Duquesne Bluff, looking to the southwest, shortly after opening in 1928.
Also visible is the Mount Washington Roadway, running up the side of the hillside to Grandview Avenue.

Liberty Bridge Improvements - 1982/1984

In 1976, the Liberty Bridge, which handled 45,000 vehicles a day, was beginning to show serious signs of deterioration. Fifty years of wear and tear had taken it's toll on the majestic Pittsburgh span.

A fifteen ton weight restriction was placed on vehicles and the sidewalks were closed. In places, small sections of the walkways had completely worn down to the point where a pedestrian could look through the steel rebar strips to river below.

The new road surface was poured on the outbound lane by April of 1983.

In April 1982, a $31 million bridge rehabilitation project was begun. Traffic continued to flow on a limited basis throughout the two-year construction period, with one lane open in each direction. During weekdays, the traffic flow was either inbound or outbound for twelve hour periods.

The bridge was completely refurbished, from the steel superstructure to the sidewalks, deck, road surface and other infrastructure. Four million pounds of structural steel and over one million rivets were replaced. Several thousand cubic feet of concrete were poured around the crumbling piers.

  
Ironworkers made major repairs to the bridge superstructure. The boat sitting idly down on the
river was a safety precaution in case any of the workers accidentally fell into the water.

Changes to the bridge included the addition of 240 braces that were attached to both sides to make the span sixteen feet wider. The bridge was also repainted in Aztec Gold, in lieu of the former Silver coat, to match other Pittsburgh bridges. The Liberty Bridge rehabilitation was completed in the summer of 1984.

Liberty Bridge Improvements - 2016/2018

In April 2016, PennDot kicked off a three-year, $87 million construction project on the aging bridge. The project, which was carried out by Joseph B Fay Company, included deck replacement, ramp reconstruction, a new walkway, structural steel repairs, painting of the entire structure and concrete repairs.

The outbound deck being replaced while three lanes of traffic proceed to the right.

Signage improvements were made and a new overhead lane control system was installed to allow the direction of traffic flows to be switched. The overall project was completed in July 2018.

When the reconstruction project was completed, the venerable Liberty Bridge looked better than ever and is in condition to serve City of Pittsburgh motorists without need of major repairs for the next several decades.

An Dave DiCello print showing the Liberty Bridge in 1933 superimposed on a picture of modern Pittsburgh.

Fire Nearly Causes Collapse

On September 2, 2016, during the bridge rehabilitation project, a careless mishap came close to causing a catastrophic bridge collapse.

Sparks from a welder cutting steel ignited plastic ventilation pipe and a construction tarp. The items quickly engulfed that area in flame, with the PVC products burning at a temperature of over 1,200 degrees.

It took Pittsburgh firefighters about a half-hour to put out the blaze.

The Liberty Bridge on fire - September 2, 2017.

  
The accidental blaze burns under the Liberty Bridge (left) while firefighters work quickly to extinguish the flames.

When the fire was extinguished it was discovered that the intense heat had caused one of the major structural beams to warp at a critical juncture. The damage was so significant that there were fears that the historic bridge could collapse.

Construction was halted for several weeks and, once bridge stability was secured, severe weight restrictions were implemented.

In the meantime, experts from Carnegie Mellon and Lehigh Universities designed a pair of 26.5-foot braces that were attached to each side of the damaged chord. The repair was successful. All weight limits were removed and construction restarted.

Construction workers reinforce the critical beam damaged by the September fire.

Photos of Pittsburgh's Liberty Bridge
(National Register of Historic Places - 1988)

The Liberty Bridge as seen from the Bluff looking south on April 16, 1928.

Cars enter the bridge off ofthe Boulevard of the Allies north ramp on May 28, 1928.

The Liberty Bridge and the Northern Portals of the Liberty Tunnels in August 1928, shortly after the opening
of another major South Hills traffic improvement, the Mount Washington (McCardle) Roadway.

Bumper to bumper traffic outbound on May 17, 1932.

The Liberty Bridge in 1933. The traffic circle outside the tunnels is being removed.

Pedestian, vehicular and horse-drawn traffic passes over the Liberty Bridge in 1933.

The southern half of the Liberty Bridge on April 20, 1936.

The Liberty Bridge and the North Portals of the Liberty Tunnels in 1936.

Rush hour traffic on the Liberty Bridge - August 10, 1937.

Liberty Bridge traffic is rerouted during an outbound tunnel closure on March 13, 1939.

Repaving the pavement of the inbound lanes on June 5, 1942.

The Liberty Bridge in 1951 during the height of rush hour traffic.

Cars make the turn off the Liberty Bridge onto the Boulevard of the Allies in 1951.

The Liberty Bridge in 1951 during mid-day traffic. A large advertisement announces the Allegheny County Free Fair.

The Liberty Bridge in 1951 during the height of the evening rush hour. As is still done today there are three
lanes heading in the outbound direction to accomodate the large numbers of vehicles leaving the city.

The Liberty Bridge in 1951. Note the Balantine Beer sign and clock on the Mount Washington hillside.

  
On May 16, 1952, this car blew a tire in the tunnels, lost control on the bridge, crossed the divider and bounced
over the four-foot retaining wall, coming to a stop lodged on the sidewalk between the wall and the bridge rail.
Two of the four occupants were injured. It took special tow trucks to remove the car from the bridge.

A welder working on the cover plate at one of the expansion joints on June 5, 1956.

The intersection of the Liberty Bridge and the Boulevard of the Allies during rush hour in June 1958.

Three lands of traffic congestion heading outbound during rush hour in June 1958.

A traffic cop mans his post on the southern side of the bridge, outside the Liberty Tunnels on April 20, 1960.

Approaching the North Portals of the Liberty Tunnels in 1973.

Reconstruction the lower part of McArdle Roadway at the northern tunnel intersection on November 14, 1974
in preparation for the 1974-1977 Liberty Tunnel renovation project.

The Liberty Bridge, shown in 2004, is one of several bridges spanning the Monongahela River in Pittsburgh.

The Liberty Bridge in 2009, looking south from Second Avenue towards Mount Washington.

The Liberty Bridge in 2011, looking north towards the skyline of Pittsburgh in the evening.

The Liberty Bridge in 2011, looking north towards the skyline of Pittsburgh in the daytime.

The Liberty Bridge in 2013, as seen from underneath the span along Second Avenue.

Vintage Postcards Of The Liberty Tunnels And Bridge

The North Portal of the Liberty Tunnels shown on a postcard from the late-1920s.

  
Postcards from the early 1930s showing the North Portals of the Liberty Tunnels and the traffic circle.

The Liberty Bridge in the late-1930s.

  
Postcards from the early 1930s showing the Liberty Bridge, looking to the south (left) and towards downtown.