Search WWW

Historic American Engineering Record
West End-North Side Bridge, Pittsburgh, PA (PA-96)

Previous Page   --   Page 2 of 2


The northern approach spans of the West End-North Side Bridge carry L.R. 76, Spur 1, from Route 51 on the south to the Ohio River Boulevard on the north. The bridge crosses the Ohio River approximately one mile below the "Point," the confluence of the Monongahela and Allegheny rivers. The four northern approach spans are Warren half-through or pony trusses and were constructed in 1931-1932.

Examination of the original design drawings and field inspection of the four northern pony truss bridges reveal that they are virtually identical except in length and in the number of panels. Span 8, nearest Western Avenue, and span 5, nearest the masonry pier (spans 6 and 7) measures 152.75 feet in length. Table 1 presents the major measurements of the different trusses components. The northernmost pony truss (span 8) is typical of the four and has been selected for detailed description and photographic documentation. An extensive series of the original design drawings has been photographically reproduced (8x10-inch format) for the HAER recordation package and xerographically reproduced for the bound report. A second series of 4x5-inch negatives and contact photographs of members and components of span 8 is included in the HAER documentation; xerographic copies are included in the bound report.

A. Physical Description

The truss members, buckle plates, floor beams, roadway and sidewalk stringers, and the bents are made of structural carbon steel. The deck, sidewalk, abutment, foundations, and river pier are made of concrete. The river pier (pier 5) is encased in black granite. The clear roadway width is 40 feet between the curbs, which consist of steel bent plates. The clear sidewalk width is 6 feet 2 inches, and the vertical clearance has no restriction except for the signs about 15 feet above the outside southbound lane. The minimum vertical clearance under span 8 between Reedsdale Street and the bottom of the bridge is 16 feet 1 inch. A 20-inch diameter gas line is suspended from the upstream sidewalk support brackets by means of U-shaped bolts. Four 2-inch Bell Telephone conduits run through an angle-framed window through the floor beams between the second and third stringers from the upstream (east) end. The telephone conduit is supported between the floor beams by steel hangers. Six 4-inch Duquesne Light Company electric ducts once passed through the floor beam at an angle-framed window between the sixth and seventh stringers from the east side. Here the expansion dams, both the telephone and electric companies have platforms adjacent to their respective lines. The platforms are attached to the stringers and accessed through manholes in the deck.

Spans 5 and 8 are identical, as are spans 6 and 7. The major difference between the two types of spans in the length of the panels. The eight panel points in spans 5 and 8 are spaced 21 feet 4-1/2 inches apart, for a total span length of 171 feet. The panels in spans 6 and 7 are 19 feet 1-1/8 inch each, for a total length of 152 feet 9 inches. The bottom chords of the trusses consist of two web plates and four flange angles with top and bottom lacing bars. Chords L2-L3, L3-L4, L4-L3', and L3'-L2' also have side plates attached to the web plates. The top chords are composed of two web plates, four angles, bottom lacing, and a top cover plate.

As in the bottom chord, members from panels 2 to 2' have larger cross sections accommodated by the use of side plates attached to the webs. Vertical posts consist of one web plate and four flange angles arranged in a manner that is similar to an I-beam. Diagonal members U1-L2, L2-U3, U3'-L2 and L2-U1' consist of a web plate, four small flange angles, and two large channels acting as flanges also arranged in an I-beam pattern. Diagonal members U3-L4' and L4-U3' consist of one web plate and four angles that form the flanges.

The floor beams consist of a 69x3/8-inch web, four 6x6x9/6-inch angles, and two cover plates (18x1/2-inch top and 14x9/6-inch bottom), acting as the top and bottom flanges. Each bay consists of eight stringers. Exterior stringers 1, 2, 7, and 8 are CB21x55s and the interior stringers 3, 4, 5, and 6 are CB24x70s. All stringers are seated on two 6x6x9/16-inch angles and are connected at their web to the floor beam web by two 4x3x3/8-inch angles. There are 3/8-inch buckle plates between each pair of stringers in each bay. The buckle plates are 6x6-foot pan-shaped plates; the deepest part is at the center which has a weep hole. The sidewalk stringers are composed of a 20x3/8-inch web plate, two 3-1/2x5-3/8-inch bottom flange angles and two 4x3x3/;8-inch top flange angles. The stringer is supported by a triangular truss consisting of two 3x3x3/8-inch angles, two 3-1/2x3x3/8-inch angles and two 3/8-inch connecting plates.

The concrete deck is 5 inches thick on the sidewalk and varies from 5-7/8-inch thick at the edge of the roadway to 8-3/8-inch thick at the center of the roadway. These dimensions do not include the depression at the center of the buckle plates which is about 2-1/2-inches.

Steel bents 7 and 8 are trusses that are anchored into concrete foundations. Each truss member consists of four angles, two back-to-back and connected to the other two by two 3/4x1/2-inch lacing bars or 21x9/16-inch stay plates. Each bent is 44 feet wide. Bent 7 is about 22 feet high, while bent 8 is 19 feet high. Steel bent 6 consists of two 10-feet deep trusses which support two 6-feet deep girders. The bottom of the truss is about 16 feet above the roadway surface. This permits traffic access to several of the businesses under the bridge. The girders are composed of a 72x1-inch web, four 8x8x5/8-inch angles, and 18-inch cover plates along the top and bottom flange. The trusses consist of four 4x3x3/8-inch angles connected by a web of 2-3/4x3/8-inch lacing bars and 12x3/8-inch stay plates. All three steel bent vertical members consist of two boxed members connected by a 45x3/4-inch plate and four 4x4x3/8-inch angles. Each box consists of 20x5/8-inch plates on three sides and 2-3/4x3/8-inch lacing bars on the outer side. The plates are connected by four 6x4x5/8-inch angles.

Pier 5 is a large masonry pier that sits on the bank of the Ohio River. The pier is encased in large black granite blocks that not only give it an aesthetic quality, but endure river action and weather well. The north abutment consists of concrete retaining walls, including a back wall, the bearing wall, and the side walls.

Rocker bearings are at bents 6 and 8. Each 27x13-inch rocker has a radius of 1 feet 8 inches from the centerline of the 6-inch diameter pine to the 1-1/2-inch thick iron bearing plate, all of which sit on a 27x27x3-inch steel plate. The fixed bearings are at the northern abutment and at piers 5 and 7. Each fixed shoe sites on a 3 foot 4 inch by 2 foot 10 inch base. The bearing is 2 feet high from the centerline of the 6-inch diameter pin to the base.

B. Structural Information

Although fifty-five years old, the main structural components of the northern trusses are still in good physical condition. The tied-arch bridge (main river span) is currently posted to restrict trucks from using the outside lanes of the bridge. The outside stringer supports under the northern span trusses appear to be in better condition than those of the main span and southern approach spans. The probable reason for the better condition of the stringer supports in the northern approach trusses is the better condition of the expansion dams, specifically, the copper water troughs, in this section. The deteriorated troughs of the main span and southern spans have allowed the intrusion of corrosive deicing salts.

Through the years, several repairs have been performed on the entire bridge. In 1948, bridge improvements included a bituminous overlay for the deck, a raised median, repairs to the expansion dams and drainage systems, and repair of the concrete on the abutments and stairs. In 1955, a new concrete deck, reinforced with wire mesh and a raised median barrier, were placed on the existing buckle plates. In 1958, the structure was painted. In April 1977, during an in-depth inspection, temporary stringer repairs were made at 63 locations. The bridge was painted again in 1980.

The bridge deck and sidewalk deck are in bad condition. Severely delaminated and spalled concrete areas are present throughout the bridge. There are several holes in the concrete deck along the roadway gutter line and inside curb of the sidewalk.

The only significant problem with the structure is the section loss of the vertical and diagonal truss members at the intersection of the concrete sidewalk. Span 8 has the most deterioration. All members at the top of the sidewalk deck show 10 percent to 25 percent loss in cross-section. Member U1-L1, span 8, west truss; member U1-L1, span 8, east truss, and members U1-L1, spans 6 and 7, west trusses, show 50 percent section loss in their respective webs. Members U1-L1 in spans 5 and 6, east trusses, have 50 percent loss in web. Members U5-L3 and U4-L4, span 5, east truss, have 40 percent loss in web. Member U4-L4, span 6, east truss, members L3'-U3', spans 6 and 7, east trusses, and members U1-L1, spans 5 and 6, east trusses, all have 50 percent loss in web. Member U1'-L0', span 5, east truss, has 30 percent loss of web section and three rivets with badly deteriorated heads. Most truss members at the intersection of the bottom side of the sidewalk slab show 10 percent to 25 percent section loss.

The west truss of span 8 has four separate areas where flanges were bent due to collision by vehicles. Other areas where members were bent by vehicles are span 8, east truss, U1'-L0', and span 7, west truss, members U2'-L2' and U1'-L0'.

The floor beams and stringers are in fairly good condition. There are about 15 pitted and scaled rivet heads on the bottom flange of about ten floor beams (some exhibit 30 percent loss in the head). The north floor beam over bent 7 at stringers 2 and 3 has 30 rivets with 50 percent head loss each. The floor beam beneath stringer 6 has 20 percent web loss in a one square-foot area. There are about ten rivets on the east end and the west end of the bottom flanges of both floor beams that exhibit 50 percent section loss. At bent 8, there are temporary supports under the outer two stringers (stringers 1 and 8) in each floor beam. The first stringer between both floor beams is paper thin and full of holes. The span 7 end floor beam web has 25 percent loss in a one-foot square area underneath stringer 1. The floor beam from span 7 over bent 8 has 10 percent web loss under stringer 7 and a 50 percent loss under stringer 8, both about one square foot in area.

Bent 7 has four lacing bars on the top chord that have lost a quarter of their sections Bent 8 has about 20 rivets on the top chord that show approximately 50 percent head loss. Also in the top chord intersection, the stay plate is heavily scaled; the lacing bars have 25 percent loss of area at this juncture. The river pier (pier 5) is in good condition. There are two hair-line cracks in the granite on each face of the pier that run three-quarters of the way up from the river and the railroad. The concrete northern abutment is heavily spalled in the upper west corner of the bearing wall and efflorescent stains are evident. A quarter-inch crack and a 1/8-inch crack run vertically along the face of the bearing wall. A 4x2-foot area is heavily spalled along the joint between the back wall and the bearing wall on the west side of the abutment. The 1969 in-depth inspection report showed that the northern abutment had rotated about its base 2 to 2-1/2 inches toward the river (southward). No additional movement of the abutment has been noted. Span 8 is fixed at the northern abutment, so the movement of the abutment was absorbed by the expansion dams and rockers at piers 5 and 8, and by the longitudinal deflection of pier 7, which is fixed. The shoes appear to be in good condition; however, expansion shoes at bents 6 and 8 are overly inclined to the south due to the inclination of the northern abutment.

All visible bearings and anchor bolts at the foundations are in good condition, except at pier 8 where two anchor bolts are scaled and have lost about 5 percent of their cross-sections.


The U. S. Department of Transportation, Federal Highway Administration (FHWA), and the Pennsylvania Department of Transportation (PennDOT) have undertaken to complete the 4000-foot missing link in the Ohio River Boulevard (L.R. 1059, Section 4) and to provide a full interchange with the West End-North Side Bridge. in order to do this, the single northern approach to the West End-North Side Bridge. consisting of four Warren half-through or pony trusses, is being replaced by three elevated approaches. A final Environmental Impact Statement and a final Section 4(f) evaluation have been approved. A Memorandum of Agreement (MOA) has been entered into by FHWA, PennDOT, the Pennsylvania State Historic Preservation Office, and the Advisory Council on Historic Preservation, stipulating measures to protect the Manchester Historic District. The MOA also stipulates that a HAER recording of the northern approach spans of the West End-North Side Bridge be made prior to their demolition. This recording has been conducted by GAI Consultants, Inc., under the overall direction of Dr. William P. McHugh. Robert J. Houston served as project manager. John S. Prizner, P.E., served as engineering manager, and Dennis M. West served as senior engineer. Dr. John Bauman conducted the historical research. Dan Shaw, Sr., and Dan Shaw, Jr., photographed the pony trusses on August 7, 1985, and printed the 4x5-inch photographs. Original design drawings were photographed in the 8x10-inch format by The Darkroom, Pittsburgh, Pennsylvania. The drafted figures were prepared by Mr. Frank Policicchio and Mr. Gregory S. Jones. Photostatic copying of the design drawings and photographs and report reproduction was completed by Messrs. James H. Wylie and Gregory J. Jones. Word processing was conducted under the supervision of Ms. Norma J. Knopp.


A. Original Design Drawings, West End-North Side Bridge, No. 3, Ohio River. Pittsburgh, PA., Department of Public Works, Allegheny County, Bureau of Bridges, November 1929 to February 1932. (ca. 50 sheets) Bridges, November 1929 to February 1932. (ca. 50 sheets)

B. Carnegie Library, Photographic Archives

C. Carnegie Library, Pennsylvania Room, Newspaper Archives

D. Bibliography:

1. Primary and unpublished sources

Allegheny County Controller's Office
- - 1928 Sixty-Seventh Annual Report of Fiscal Affairs of Allegheny County. December 31.
- - 1930 Sixty-Eighth Annual Report of Fiscal Affairs of Allegheny County. December 31.
- - 1931 Sixty-Ninth Annual Report of Fiscal Affairs of Allegheny County. December 31.
- - 1932 Seventieth Annual Report of Fiscal Affairs of Allegheny County. December 31.

Allegheny County Court of Quarter Sessions
- - 1929 Commissioners' Road Docket. November sessions.

Allegheny County Department of Public Works, Bureau of Bridges
- - 1929 Commissioners' Road Docket, November Sessions, Map of West End-North Side Bridge Showing Owners of Property Affected by Bridge Construction.

Allegheny County Record of Deeds
- - Deed Books, County Courthouse, Pittsburgh, Pennsylvania.

Hopkins, G. M., pub.
- - 1886 Atlas of the Vicinity of the Cities of Pittsburgh and Allegheny. Hopkins, Philadelphia.

International Institute of Pittsburgh
- - 1935 A Report of the General Secretary of the International Institute of Her Work with Foreign Communities of Pittsburgh During a Period of Ten Years, 1925-1955.
Volume 2. Supplement to Audit Completed in 1928 by Miss Elizabeth A. Campbell.

Polk, R. L., comp.
- - 1913-1930 Polk's Pittsburgh City Directory. R. D. Polk and Company, Pittsburgh.
- - 1906 Pittsburgh and Allegheny Directory. R. D. Polk and Company, Pittsburgh.

Sanborn Map Company
- - 1927 Insurance Maps of Pittsburgh, Pennsylvania. Sanborn Map Company, New York.

U. S. Department of Commerce, Bureau of the Census
- - 1932 Fifteenth Census of the United States: Population and Housing, Statistics for Census Tracts, Pittsburgh, PA. U. S. Government Printing Office, Washington, D. C.

U. S. Department of Commerce, Bureau of the Census
- - 1942 Sixteenth Census of the United States: Population and Housing, Statistics for Census Tracts, Pittsburgh, Pa. U. S. Government Printing Office, Washington, D. C.

U. S. Department of Commerce, Bureau of the Census
- - 1960 U. S. Census of Population and Housing: 1970 Census Tracts, Pittsburgh, Pa., U. S. Government Printing Office, Washington, D. C.

U. S. Department of the Interior, National Park Service
- - 1967 National Register of Historic Places Inventory - Nomination Form for the West End Bridge.

U. S. Department of Transportation
- - 1984 Final Environmental Impact Statement and Final Section 4(f) Evaluation, Ohio River Boulevard-West End Bridge Interchange, B.R. 1039, Section 4. U. S. Department of Transportation (FHWA) and Pennsylvania Department of Transportation.

2. Secondary and published sources

Campbell, W. G.
- - 1926 "Tunnels for Traffic -- Pittsburgh's New Auto Tubes of Widespread Interest". Greater Pittsburgh (October 2).

Caro, Robert A.
- - 1974 The Power Broker: Robert Moses and the Fall of New York. Alfred A. Knopp, New York.

Civic Club of Allegheny County
- - 1923-1933 Civic Club Bulletin.

Foster, Mark
- - 1979 "City Planners and Urban Transportation: The American Response, 1900-1940". Journal of Urban History 5:365-396.

Goldfield, David R., and Blaine A. Brownell
- - 1979 Urban America: From Downtown to No Town. Houghton-Mifflin, Boston.

Greater Pittsburgh
- - 1926 Journal of the Pittsburgh Chamber of Commerce.

Herberton, Elizabeth Taylor
- - 1970 Pittsburgh Bridges. Exposition Press, New York.

Hershberg, Theodore, ed.
- - 1981 Philadelphia: Work, Space, Family and Group Experience in the Nineteenth Century, Essays Toward an Interdisciplinary History of the City. Oxford University Press, New York.

Park, Robert E., and Ernest W. Burgess
- - 1967 The City. University of Chicago Press, Chicago.

Pittsburgh First
- - 1926-1928 Journal of the Pittsburgh Chamber of Commerce.

Pittsburgh Post Gazette (various articles cited in text).

Pittsburgh Press (various articles cited in text).

Rimmel, William M.
- - 1969 "Old Allegheny". Western Pennsylvania Historical Society Magazine 52:141-152.

Scott, Mel
- - 1969 American City Planning Since 1890. University of California Press, Berkeley.

Stevens, Sylvester K.
- - 1969 Pennsylvania: Heritage of a Commonwealth. Volume 5. American History Company, Inc., West Palm Beach.

Tarr, Joel A.
- - 1978 Transportation Innovations and Changing Spatial Patterns in Pittsburgh, 1850-1934. Public Works Historical Society, Chicago.

Previous Page   --   Page 2 of 2

Page created:
Last modified: 07-Oct-1999

Historic American Engineeering Record (HAER) Text: William P. McHugh, Ph. D.; GAI Consultants, Inc.; 1985