The Armstrong Tunnel, which is currently undergoing a $13.1 million rehabilitation, is a local engineering landmark. It connects Second Avenue to Forbes Avenue through the Bluff, which was previously called Boyd’s Hill. After completion of the first steel South Tenth Street Bridge in 1904, Boyd’s Hill was seen as a significant barrier to transportation in the area.

So, in 1907, Joseph G. Armstrong, who was then a member of Pittsburgh’s City Council, proposed and advocated for what would become the Armstrong Tunnel. In 1924, the Allegheny County Board of Commissioners, chaired by Armstrong, initiated a four-year public works improvements program that entailed a bond issue of more than $29 million. Construction of the Armstrong Tunnel was part of that program and cost $1.6 million.

The Armstrong Tunnel itself was designed by the Allegheny County Department of Public Works under the supervision of engineer Vernon R. Covell. He also played a significant role in designing the Roberto Clemente (Sixth Street), Andy Warhol (Seventh Street), Rachel Carson (Ninth), Philip Murray (South Tenth Street), Liberty, McKees Rocks, and George Westinghouse Bridges. The Armstrong Tunnel entrances and exits – often referred to as portals – were designed by architect Stanley L. Roush. In addition to numerous bridges throughout the region, Roush also designed the County Office Building, Corliss Tunnel, and Allegheny County Airport.

Construction of the Armstrong Tunnel began on January 15, 1926. Booth & Flinn was the primary contractor. It also built the Liberty Tunnel, Wabash Tunnel, and Mt. Washington Transit Tunnel in Pittsburgh as well as New York’s renowned Holland Tunnel. Construction of the Armstrong Tunnel required removal of more than 85,000 cubic yards of dirt and rock – enough to fill nearly 26 Olympic-size swimming pools – and it was built using 330 tons of steel and 27,000 cubic yards of concrete.

On November 6, 1926, while the tunnel was still under construction, it was officially dedicated as the Armstrong Tunnel. Joseph G. Armstrong was an accomplished public servant, having served as an Allegheny County Commissioner, County Coroner, County Treasurer, Pittsburgh Mayor, Pittsburgh City Councilman, and as Pittsburgh’s Director of Public Works. He became known as “Joe the Builder” for his extensive public works projects.

Armstrong and more than 2,000 others celebrated the opening of the Armstrong Tunnel on May 25, 1927, with a parade and a ribbon cutting. That was followed by a banquet in the South Side Market auditorium that included more than 1,000 attendees. On the event program was written: “The Realization of a Dream of 20 Years.”

Allegheny County takes great pride in maintaining the historic tunnel, and the current rehabilitation project will make the structure better than ever. The project, which is expected to end in 2025, includes concrete repairs; removal of ceramic tiles and replacement with fireproof wall panels; masonry cleaning at the tunnel entrances and exits; lighting, electrical, and fire detection and suppression system upgrades; installation of a CCTV monitoring system; and placement of new pavement, curb, sidewalk, signage, and pavement markings. 

For more information about this and other county public works projects, visit alleghenycounty.us/publicworks.