North 21st Street Bridge


The North 21st Street Bridge in Tacoma, Washington was built in 1910. It was designed by engineers Waddell & Harrington and is a continuous concrete rigid-frame girder bridge. It is significant as one of the very earliest examples of its type. It was built "almost simultaneously" with the Asylum Avenue Aqueduct in Knoxville, Tennessee, which was documented by Carl W. Condit to be the first continuous concrete girder bridge to be built.
It has three reinforced concrete spans with four continuous girders. Its spans are supported by reinforced concrete columns and abutments. The bridge has "massive and over-designed" slabs and beams from wide, from deep. It is wide to accommodate trolley tracks in the middle.
The bridge was listed on the National Register of Historic Places in 1982.