The 1881/1910 Hays Street Bridge is a viaduct consisting of two wrought iron truss spans (one Phoenix Whipple 225-ft span, and one Pratt 130-ft span), and approximately 1000-LF of concrete approaches.
In 1910, the City of San Antonio required the Galveston, Harrisburg & San Antonio Railway Co. (eventually part of Southern Pacific) to construct a viaduct over the railroad tracks at Hays Street. The railway company relocated the two truss spans from elsewhere
on its lines.
Records of the Phoenix Bridge Company  archived at the Hagley Library in Wilmington, Delaware show that the Whipple truss dates from 1881 and was reconstructed from salvaged spans over the Nueces River west of San Antonio. These records include entries in the company’s customer index as well as copies of the 1910 repair shop drawings showing replacement joint blocks, bearing seats, and lateral bracing struts. Both spans were widened from about 16-feet to the current 25-feet.
The Whipple truss span is a Phoenix patent design using the now rare Phoenix segmental wrought iron columns with cast-iron joint blocks. This bridge was Customer Order 1460, as evidenced by the stamp on the joint blocks and tubular sections, and dated 1881 in the ledger of the Phoenix Company.
The Pratt span is also wrought iron and has Phoenix-branded components, including the floor beams. It is likely an approach span from the same original river crossing as the Whipple span as it has exactly the same original width and is a type that was being made by Phoenix in 1881; however, it may have been taken from another location.
The bridge was rehabilitated as a bicycle and pedestrian facility by the City of San Antonio, using a Transportation Enhancement grant from the Texas Department of Transportation. Sparks Engineering, Inc. was the design consultant for the project. Plans and specifications were completed in November 2006 and the project was finished in 2010 .
 Hagley Library, Wilmington, DE:
Records of the Phoenix Bridge Co.
Index of Orders, No. 2, pg. 61
Series F/C.O. 582/April 9/’10/Hays St. Viaduct at San Antonio, Texas:
1 Roller Foot “R.R.”, 1 Wall Plate “F.P.” & 22 Phx Col. Struts for Alteration of 1-225’ Thro’
Span from Nueces R. Bridge (O. 1372), to be widened fr. 16’ to 25’ and re-erected as a Highway
Span/Engineer in Charge: MGL/
“ “/C.O. 623/Sep. 10,’10/Repair of Old 225’ Phoenix Thro’ Span, C.O. 1460 (built in 1881) 1
Inter. Top Chord Casting/Engineer in Charge: F. Geo. Lippert/
 “Ironclad” Civil Engineering Magazine, American Society of Civil Engineers, August 2010