Coraopolis Bridge
Encyclopedia
The Coraopolis Bridge is a girder bridge
over the back channel of the Ohio River
connecting Grand Avenue on Neville Island to Ferree Street in Coraopolis, Pennsylvania
. It opened in 1995 to replace a structure of historic significance. The original Pratt/Bowstring/Pennsylvania through truss
spans, designed by Theodore Cooper
, were formerly the (third) Sixth Street Bridge, spanning the Allegheny River
, in downtown Pittsburgh
, and were built in 1892 by the Union Bridge Company
. They were floated downstream by the Foundation Company in 1927 rather than being demolished when the bridge was removed to enable construction of the present (fourth) Three Sisters (Pittsburgh)
Sixth Street Self-anchored suspension bridge
. However, by the late 1980s, the old bridge could no longer support traffic volumes and was replacd by a modern structure.
The through truss spans incorporated in the present Coraopolis Bridge were originally erected across the Allegheny River at Sixth Street in Pittsburgh, linking Pittsburgh with the main business thoroughfare of neighboring Allegheny City
. This was the third of four bridges to serve that location, which is considered among Pittsburgh's most important river crossings. The growth of Pittsburgh was strongly influenced by its numerous waterways, and the successful linking of the city with its neighboring communities by means of bridges was a significant factor in the development of its metropolitan identity. Allegheny City was annexed by Pittsburgh in 1907, becoming the city's "North Side".
constructed in 1819. This bridge had a total length of 1,037 feet, consisting of four 185 foot spans, a 170 foot span, and a 137 foot span. The design and construction of this bridge have traditionally been attributed to a Mr. Lothrop; it was presumably a Burr arch truss
, like the Ninth (Hand) Street Bridge, another of Lothrop's products. Physical evidence for this assumption survived until the 1890s, when an observer reported that the skewbacks from the wooden arches remained visible in the north abutment.
, replaced the decaying timber structure. This bridge was four spans long, with two 344-foot main spans, and approach spans measuring 177 and 171 feet each. The bridge was dominated by cast iron towers, each formed by four cast iron columns.
Although the Roebling bridge, with its iron superstructure, was generally believed non-flammable, it fell victim to fire on June 19, 1881. The bridge was not destroyed, but its floor system of white pine and white oak was severely damaged. John Harper, president of the Allegheny Bridge Company, which owned and operated the structure, stated that he believed the fire was the result of "sparks and perhaps flame from the stacks" of passing steamboats igniting bird nests located under the superstructure of the bridge. After heavy electric streetcars were introduced to the bridge in 1890, concern over its functional capacity grew, and in 1891 plans were begun to replace the suspension bridge with one that could better handle the steadily increasing traffic, as well as permit trolleys to cross without reducing their speed.
The third Sixth Street Bridge was designed by the nationally-significant engineer Theodore Cooper
(1839–1919). This bridge has been identified as the last surviving structure entirely designed by Cooper, whose involvement extended even to such details as the bridge's handrail, lamps, and fascia.
The third Sixth Street Bridge, like most roadway river bridges in the 19th century, was privately built and operated as a toll
crossing. The total cost of construction was $560,000. This cost was underwritten by the Sixth Street Bridge Company and Fidelity Title and Trust Company, successors to the Allegheny Bridge Company, which had received its charter in 1810. When the bridge was opened in 1893, the toll was set at two cents for each man, while women crossed at no charge. Beginning in the late 1890s, Allegheny County and the City of Pittsburgh undertook a systematic program of acquiring the privately owned bridges within their jurisdiction and eliminating their tolls. The Sixth Street Bridge was purchased by Allegheny County in 1911 along with nine other bridges at the combined price of $2,851,000; all ten of these bridges were subsequently declared free.
The trusses for the third Sixth Street Bridge were fabricated by the Union Bridge Company. This company had been formed in 1884 by the merging of the Central Bridge Company of Buffalo, New York, and Kellogg and Maurice of Athens, Pennsylvania. The Buffalo plant was closed around 1890, so presumably the trusses were produced in the shops which remained at Athens.
The superstructure was erected by the Baird Brothers, John and William, who first advertised in the Pittsburgh and Allegheny City Directory in 1886 as contractors located at Home and Valley Streets. In the 1891 and 1892 editions of the Directory they were listed as bridge builders; their listings no longer appeared by 1900, and by 1911 William Baird had left the construction business and had begun managing a hotel.
The Baird Brothers had been involved with numerous bridge projects and companies in the late nineteenth century. William Baird had worked on seven bridges crossing the Missouri River, the Merchants Bridge across the Mississippi River at St. Louis, two bridges crossing the Ohio River at Wheeling, West Virginia
, the bridge carrying the Baltimore & Ohio Railroad across the Susquehanna River
, and bridges at Steubenville, Ohio
, and Poughkeepsie, New York
. John Baird had also been involved in the construction of the Eads Bridge
in St. Louis
and the Cairo bridge in Memphis
, and had been employed by the McCann Construction Company, the Keystone Bridge Company and American Bridge Company
.
This bridge was also outgrown.
While the Pittsburgh City Council and the Municipal Affairs Committee of the Chamber of Commerce argued for the retention and upgrading of the existing bridges, the issue was ultimately decided by the Department of War
, acting under the authority of Section 18 of the Rivers and Harbors Act of March 3, 1890 (30 Stat., 1121–1153). This act empowered the Secretary of War to require the removal or alteration of any bridge which " ... is an unreasonable obstruction to the free navigation . . . on account of insufficient height, width of span, or otherwise". So, unfortunately, the War Department decreed that the numerous bridges over the Allegheny with their differing spacing of piers, main spans, and generally low clearances, were an impediment to navigation, and decreed that all bridges would have to be replaced. Although the decree was discussed in the early 1900s, and first issued in 1917, serious work did not begin till 1924. As part of the Three Sisters (Pittsburgh)
project, the bridges at Sixth, Seventh, and Ninth Streets were to be demolished and replaced. The other two bridges were destroyed and scrapped, but the Cooper Bowstring trusses were moved to Coraopolis and reused.
The 1892 Sixth Street Bridge (as described above, a pair of camelback Pratt trusses and the third bridge built in this location) had a second chance. In 1927, it was lowered from its piers, the top chords partially disassembled. The structure was floated downriver to a new location over the Ohio River back channel between Coraopolis and Neville Island to make way for the current Sixth Street Bridge structure.
Each truss consisted of sixteen eye-bar panels pinned together. Removing one part would break the structure's rigidity and make moving it very difficult. Instead of shifting the spans off piers for lowering or pivoting them from their present support, the Foundation Company lowered the structure in position, taking off the masonry and using substitute supports for resting the structure without getting in the way of the process. The contractor attached a frame to each of the piers and abutments, used straps to bind the trusses to each frame, and lowered them using the straps.
With twenty-six 7" holes punched in the strap, the company used a matching chain to counter the eight straps. Using pins to move the strap by hole sets, the company brought the spans downward 15" at a time with jacks. The pins attached to the plungers of eight 500-ton jacks. The jacks remained in place while the pins moved 15". The water-cylinder jacks were also 15" high, capable of exerting 3200 psi after pumping. By bleeding water out of the cylinders of the jacks all at once, workers used the four jacks on each side of the bridge to lower the spans on alternate sides to the full depth of 16-0.
The Farris Engineering Company, a Pittsburgh company located in the Empire Building, performed a great deal of work on the bridge at its new location. The original approved contract for their work had a price total of $271,811.50. They built portions of the substructure that the Foundation Company had not done. Farris also erected the two pony truss approach spans, repaired and painted the main superstructure, and paved the bridge deck and the two approaches.
The approach spans, and the end bearings for the main spans, were fabricated by the American Bridge Company at its shops located in Ambridge, Pennsylvania.
After nearly 50 years of additional service, which included weight restrictions and closings during cold weather (for a time it was restricted to carrying vehicles with a maximum weight of three tons, and it was only open to vehicular traffic during periods when the temperature is above 30 degrees Fahrenheit), the old bridge was replaced by a deck girder bridge which was completed in 1995.
Thus, eventually it was closed, demolished, and replaced, ending a unique chapter in American bridge history.
Girder bridge
A girder bridge, in general, is a bridge built of girders placed on bridge abutments and foundation piers. In turn, a bridge deck is built on top of the girders in order to carry traffic. There are several different subtypes of girder bridges:...
over the back channel of the Ohio River
Ohio River
The Ohio River is the largest tributary, by volume, of the Mississippi River. At the confluence, the Ohio is even bigger than the Mississippi and, thus, is hydrologically the main stream of the whole river system, including the Allegheny River further upstream...
connecting Grand Avenue on Neville Island to Ferree Street in Coraopolis, Pennsylvania
Coraopolis, Pennsylvania
Coraopolis is a borough in Allegheny County, Pennsylvania, USA. The population was 5,677 at the 2010 census. In 1940 the population peaked at 11,086. It is a small community located to the west of Pittsburgh, along the Ohio River and to the east of the Pittsburgh International Airport...
. It opened in 1995 to replace a structure of historic significance. The original Pratt/Bowstring/Pennsylvania through truss
Truss
In architecture and structural engineering, a truss is a structure comprising one or more triangular units constructed with straight members whose ends are connected at joints referred to as nodes. External forces and reactions to those forces are considered to act only at the nodes and result in...
spans, designed by Theodore Cooper
Theodore Cooper
Theodore Cooper was an American civil engineer. He may be best known as supervising engineer on the Quebec Bridge when it collapsed in 1907....
, were formerly the (third) Sixth Street Bridge, spanning the Allegheny River
Allegheny River
The Allegheny River is a principal tributary of the Ohio River; it is located in the Eastern United States. The Allegheny River joins with the Monongahela River to form the Ohio River at the "Point" of Point State Park in Downtown Pittsburgh, Pennsylvania...
, in downtown Pittsburgh
Pittsburgh, Pennsylvania
Pittsburgh is the second-largest city in the US Commonwealth of Pennsylvania and the county seat of Allegheny County. Regionally, it anchors the largest urban area of Appalachia and the Ohio River Valley, and nationally, it is the 22nd-largest urban area in the United States...
, and were built in 1892 by the Union Bridge Company
Union Bridge Company
The Union Bridge Company was a bridge fabricator and contractor with works in Buffalo, New York, and Athens, Pennsylvania. The Union Bridge company was formed in 1884 as a merger of several other bridge-building firms. Partners included George S. Field of Buffalo, Edumund Hayes of Buffalo,...
. They were floated downstream by the Foundation Company in 1927 rather than being demolished when the bridge was removed to enable construction of the present (fourth) Three Sisters (Pittsburgh)
Three Sisters (Pittsburgh)
A suspension bridge works by hanging a roadway from cables or chains under tension. Though a few unstiffened suspension bridges exist, a longitudinal stiffening truss or girder is usually added to prevent excessive movement of the deck. The cables pass over towers and are anchored at both ends...
Sixth Street Self-anchored suspension bridge
Self-anchored suspension bridge
A self-anchored suspension bridge is a suspension bridge in which the main cables attach to the ends of the deck, rather than to the ground via large anchorages...
. However, by the late 1980s, the old bridge could no longer support traffic volumes and was replacd by a modern structure.
The Sixth Street bridges
Note: Material from this section is adopted from the HAER report on this bridge.The through truss spans incorporated in the present Coraopolis Bridge were originally erected across the Allegheny River at Sixth Street in Pittsburgh, linking Pittsburgh with the main business thoroughfare of neighboring Allegheny City
Allegheny, Pennsylvania
Allegheny City was a Pennsylvania municipality located on the north side of the junction of the Allegheny and Ohio rivers, across from downtown Pittsburgh. It was annexed by Pittsburgh in 1907...
. This was the third of four bridges to serve that location, which is considered among Pittsburgh's most important river crossings. The growth of Pittsburgh was strongly influenced by its numerous waterways, and the successful linking of the city with its neighboring communities by means of bridges was a significant factor in the development of its metropolitan identity. Allegheny City was annexed by Pittsburgh in 1907, becoming the city's "North Side".
First Sixth Street Bridge
The first bridge to cross the Allegheny at Sixth Street was a six-span, flat-roofed, covered wooden bridgeCovered bridge
A covered bridge is a bridge with enclosed sides and a roof, often accommodating only a single lane of traffic. Most covered bridges are wooden; some newer ones are concrete or metal with glass sides...
constructed in 1819. This bridge had a total length of 1,037 feet, consisting of four 185 foot spans, a 170 foot span, and a 137 foot span. The design and construction of this bridge have traditionally been attributed to a Mr. Lothrop; it was presumably a Burr arch truss
Truss arch bridge
A truss arch bridge combines the elements of the truss bridge and the arch bridge. The actual resolution of forces will depend upon the design. If no horizontal thrusting forces are generated this becomes an arch-shaped truss, essentially a bent beam — see moon bridge for an example...
, like the Ninth (Hand) Street Bridge, another of Lothrop's products. Physical evidence for this assumption survived until the 1890s, when an observer reported that the skewbacks from the wooden arches remained visible in the north abutment.
Second Sixth Street Bridge
In 1860, a wire-suspension bridge, designed by John A. RoeblingJohn A. Roebling
John Augustus Roebling was a German-born American civil engineer. He is famous for his wire rope suspension bridge designs, in particular, the design of the Brooklyn Bridge.-Early life:...
, replaced the decaying timber structure. This bridge was four spans long, with two 344-foot main spans, and approach spans measuring 177 and 171 feet each. The bridge was dominated by cast iron towers, each formed by four cast iron columns.
Although the Roebling bridge, with its iron superstructure, was generally believed non-flammable, it fell victim to fire on June 19, 1881. The bridge was not destroyed, but its floor system of white pine and white oak was severely damaged. John Harper, president of the Allegheny Bridge Company, which owned and operated the structure, stated that he believed the fire was the result of "sparks and perhaps flame from the stacks" of passing steamboats igniting bird nests located under the superstructure of the bridge. After heavy electric streetcars were introduced to the bridge in 1890, concern over its functional capacity grew, and in 1891 plans were begun to replace the suspension bridge with one that could better handle the steadily increasing traffic, as well as permit trolleys to cross without reducing their speed.
Third Sixth Street Bridge
Theodore Cooper
Theodore Cooper was an American civil engineer. He may be best known as supervising engineer on the Quebec Bridge when it collapsed in 1907....
(1839–1919). This bridge has been identified as the last surviving structure entirely designed by Cooper, whose involvement extended even to such details as the bridge's handrail, lamps, and fascia.
The third Sixth Street Bridge, like most roadway river bridges in the 19th century, was privately built and operated as a toll
Toll bridge
A toll bridge is a bridge over which traffic may pass upon payment of a toll, or fee.- History :The practice of collecting tolls on bridges probably harks back to the days of ferry crossings where people paid a fee to be ferried across stretches of water. As boats became impractical to carry large...
crossing. The total cost of construction was $560,000. This cost was underwritten by the Sixth Street Bridge Company and Fidelity Title and Trust Company, successors to the Allegheny Bridge Company, which had received its charter in 1810. When the bridge was opened in 1893, the toll was set at two cents for each man, while women crossed at no charge. Beginning in the late 1890s, Allegheny County and the City of Pittsburgh undertook a systematic program of acquiring the privately owned bridges within their jurisdiction and eliminating their tolls. The Sixth Street Bridge was purchased by Allegheny County in 1911 along with nine other bridges at the combined price of $2,851,000; all ten of these bridges were subsequently declared free.
The trusses for the third Sixth Street Bridge were fabricated by the Union Bridge Company. This company had been formed in 1884 by the merging of the Central Bridge Company of Buffalo, New York, and Kellogg and Maurice of Athens, Pennsylvania. The Buffalo plant was closed around 1890, so presumably the trusses were produced in the shops which remained at Athens.
The Baird Brothers had been involved with numerous bridge projects and companies in the late nineteenth century. William Baird had worked on seven bridges crossing the Missouri River, the Merchants Bridge across the Mississippi River at St. Louis, two bridges crossing the Ohio River at Wheeling, West Virginia
Wheeling, West Virginia
Wheeling is a city in Ohio and Marshall counties in the U.S. state of West Virginia; it is the county seat of Ohio County. Wheeling is the principal city of the Wheeling Metropolitan Statistical Area...
, the bridge carrying the Baltimore & Ohio Railroad across the Susquehanna River
Susquehanna River
The Susquehanna River is a river located in the northeastern United States. At long, it is the longest river on the American east coast that drains into the Atlantic Ocean, and with its watershed it is the 16th largest river in the United States, and the longest river in the continental United...
, and bridges at Steubenville, Ohio
Steubenville, Ohio
Steubenville is a city located along the Ohio River in Jefferson County, Ohio on the Ohio-West Virginia border in the United States. It is the political county seat of Jefferson County. It is also a principal city of the Weirton–Steubenville, WV-OH Metropolitan Statistical Area...
, and Poughkeepsie, New York
Poughkeepsie Bridge
The Poughkeepsie Bridge is a steel cantilever bridge spanning the Hudson River between Poughkeepsie, New York on the east bank and Highland, New York on the west bank...
. John Baird had also been involved in the construction of the Eads Bridge
Eads Bridge
The Eads Bridge is a combined road and railway bridge over the Mississippi River at St. Louis, connecting St. Louis and East St. Louis, Illinois....
in St. Louis
St. Louis, Missouri
St. Louis is an independent city on the eastern border of Missouri, United States. With a population of 319,294, it was the 58th-largest U.S. city at the 2010 U.S. Census. The Greater St...
and the Cairo bridge in Memphis
Memphis, Tennessee
Memphis is a city in the southwestern corner of the U.S. state of Tennessee, and the county seat of Shelby County. The city is located on the 4th Chickasaw Bluff, south of the confluence of the Wolf and Mississippi rivers....
, and had been employed by the McCann Construction Company, the Keystone Bridge Company and American Bridge Company
American Bridge Company
The American Bridge Company is a privately held civil engineering firm specializing in the construction and renovation of bridges and other large civil engineering projects, founded in 1900, and headquartered in Coraopolis, Pennsylvania, a suburb of Pittsburgh.-Products and industry positioning:The...
.
This bridge was also outgrown.
While the Pittsburgh City Council and the Municipal Affairs Committee of the Chamber of Commerce argued for the retention and upgrading of the existing bridges, the issue was ultimately decided by the Department of War
United States Department of War
The United States Department of War, also called the War Department , was the United States Cabinet department originally responsible for the operation and maintenance of the United States Army...
, acting under the authority of Section 18 of the Rivers and Harbors Act of March 3, 1890 (30 Stat., 1121–1153). This act empowered the Secretary of War to require the removal or alteration of any bridge which " ... is an unreasonable obstruction to the free navigation . . . on account of insufficient height, width of span, or otherwise". So, unfortunately, the War Department decreed that the numerous bridges over the Allegheny with their differing spacing of piers, main spans, and generally low clearances, were an impediment to navigation, and decreed that all bridges would have to be replaced. Although the decree was discussed in the early 1900s, and first issued in 1917, serious work did not begin till 1924. As part of the Three Sisters (Pittsburgh)
Three Sisters (Pittsburgh)
A suspension bridge works by hanging a roadway from cables or chains under tension. Though a few unstiffened suspension bridges exist, a longitudinal stiffening truss or girder is usually added to prevent excessive movement of the deck. The cables pass over towers and are anchored at both ends...
project, the bridges at Sixth, Seventh, and Ninth Streets were to be demolished and replaced. The other two bridges were destroyed and scrapped, but the Cooper Bowstring trusses were moved to Coraopolis and reused.
Moving the Sixth Street Bridge to Coraopolis
Note: The material in this section is taken from a different HAER report.The 1892 Sixth Street Bridge (as described above, a pair of camelback Pratt trusses and the third bridge built in this location) had a second chance. In 1927, it was lowered from its piers, the top chords partially disassembled. The structure was floated downriver to a new location over the Ohio River back channel between Coraopolis and Neville Island to make way for the current Sixth Street Bridge structure.
A forced opportunity
The Cooper spans remained in good shape, and concerns for economizing in public works projects led to recycling of the 1892 bridge. Commissioner Armstrong took credit for proposing to reuse the Cooper bridge instead of building an entirely new structure in nearby Coraopolis, saving Allegheny County $350,000. The Foundation Company bid on a contract to move the Sixth Street Bridge from its site in downtown Pittsburgh to Coraopolis, twelve miles away. Winning the contract at a bid of $316,200, the company also assumed any risk that the spans would sink or be damaged during the project. The company allowed pedestrians to cross the structure while roadway removal proceeded in the fall of 1926 in order to reduce the inconvenience for residents. Workers took off half of the roadway at a time, leaving pedestrian areas accessible until final segments were taken awayRemoval process
The bowstring trusses, in addition to weighing 1,600 tons each, presented the difficult problem of being slightly too tall to fit under two bridges along the journey. Because of the stresses inherent in a bowstring truss, the Foundation Company could not merely disassemble them; instead, the firm had to transport the entire 450'-0" spans, which were 44'-0" wide and 80'-0" high.Each truss consisted of sixteen eye-bar panels pinned together. Removing one part would break the structure's rigidity and make moving it very difficult. Instead of shifting the spans off piers for lowering or pivoting them from their present support, the Foundation Company lowered the structure in position, taking off the masonry and using substitute supports for resting the structure without getting in the way of the process. The contractor attached a frame to each of the piers and abutments, used straps to bind the trusses to each frame, and lowered them using the straps.
With twenty-six 7" holes punched in the strap, the company used a matching chain to counter the eight straps. Using pins to move the strap by hole sets, the company brought the spans downward 15" at a time with jacks. The pins attached to the plungers of eight 500-ton jacks. The jacks remained in place while the pins moved 15". The water-cylinder jacks were also 15" high, capable of exerting 3200 psi after pumping. By bleeding water out of the cylinders of the jacks all at once, workers used the four jacks on each side of the bridge to lower the spans on alternate sides to the full depth of 16-0.
Transport
Workers made a pontoon out of two pairs of barges, spaced to create a platform 400'-0" long and 52'-0" wide, which carried the bridge with 20'-0" of overhang. Stringers supported the bridge in forty-two places, with a 40-ton screw jack at each stringer for easier loading and unloading. When workers reached the Manchester Bridge, they had to adjust the bridge to fit the clearance, which was 14'-0" and 12'-0" less than the bridge’s height. After supporting the bridge under the floor beams, they disassembled the top chord and stabilized each panel point on the trusses. Steering the bridge under the Manchester Bridge and the railroad bridge at Brunot's Island, the tugboat captains went through the Ohio River lock and up the back channel toward Coraopolis, where piers and abutments had been constructed.Reassembly
Reversing the process and using the same jacks and steel frames to raise the structure 32'-O", the company erected the Cooper bridge 30 days after the project began.The Farris Engineering Company, a Pittsburgh company located in the Empire Building, performed a great deal of work on the bridge at its new location. The original approved contract for their work had a price total of $271,811.50. They built portions of the substructure that the Foundation Company had not done. Farris also erected the two pony truss approach spans, repaired and painted the main superstructure, and paved the bridge deck and the two approaches.
The approach spans, and the end bearings for the main spans, were fabricated by the American Bridge Company at its shops located in Ambridge, Pennsylvania.
End of life
Allegheny County ended up replacing the Coraopolis Bridge with a new bridge at this location. By the 1980s, due to its deteriorated condition and inadequate load carrying capacity, the four span truss bridge did not meet the transportation needs of its location.After nearly 50 years of additional service, which included weight restrictions and closings during cold weather (for a time it was restricted to carrying vehicles with a maximum weight of three tons, and it was only open to vehicular traffic during periods when the temperature is above 30 degrees Fahrenheit), the old bridge was replaced by a deck girder bridge which was completed in 1995.
Thus, eventually it was closed, demolished, and replaced, ending a unique chapter in American bridge history.
Current bridge at location
The current Coraopolis-Neville Island Bridge at this location (OB02) was built in 1994 and completed in 1995. This steel deck girder bridge spans the back channel of the Ohio River between Coraopolis, Pennsylvania, and Neville Township, Pennsylvania. The main span is approximately 199 feet, and the height of the deck is approximately 45 feet.External links
- Historic American Engineering Record (HAER) No. PA-217, "Coraopolis Bridge"
- Image at HAER.
- report HAER "Corapolis Bridge, Spanning Ohio River back channel at Ferree Street & Grand Avenue, Corapolis, Allegheny County, PA" 21 pages
- Text of 21 page HAER writeup at pghbridges.comPghbridges.comPghbridges.com is a reference site created by Bruce S. Cridlebaugh. Formally titled, Bridges and Tunnels of Allegheny County and Pittsburgh, PA, pghbridges.com has information on many of the structures of the area...
(this text is in the public domain since it is taken from the Library of CongressLibrary of CongressThe Library of Congress is the research library of the United States Congress, de facto national library of the United States, and the oldest federal cultural institution in the United States. Located in three buildings in Washington, D.C., it is the largest library in the world by shelf space and...
HAER report). - report HAER "Three Sisters Bridges, Spanning Allegheny River at Sixth, Seventh & Ninth Streets, Pittsburgh, Allegheny County, PA" 43 pages.
- Text of 43 page HAER writeup at pghbridges.comPghbridges.comPghbridges.com is a reference site created by Bruce S. Cridlebaugh. Formally titled, Bridges and Tunnels of Allegheny County and Pittsburgh, PA, pghbridges.com has information on many of the structures of the area...
(this text is in the public domain since it is taken from the Library of CongressLibrary of CongressThe Library of Congress is the research library of the United States Congress, de facto national library of the United States, and the oldest federal cultural institution in the United States. Located in three buildings in Washington, D.C., it is the largest library in the world by shelf space and...
HAER report). - article at pghbridges.comPghbridges.comPghbridges.com is a reference site created by Bruce S. Cridlebaugh. Formally titled, Bridges and Tunnels of Allegheny County and Pittsburgh, PA, pghbridges.com has information on many of the structures of the area...
- Google Maps Composite image zoomed in, showing replacement bridge.
