North 21st Street Bridge

{{Use American English|date=January 2025}}

{{Use mdy dates|date=August 2023}}

{{Infobox NRHP

| name = North 21st Street Bridge

| nrhp_type =

| image = North 21st Street Bridge.jpg

| caption =

| location = Spans Buckley Gulch and North Fife and Oakes streets, Tacoma, Washington

| coordinates = {{Coord|47|16|3|N|122|28|11|W|display=inline,title}}

| locmapin = Washington#USA

| built = 1910

| architect = Waddell & Harrington

| builder = Creelman, Putnam & Healy

| architecture = Rigid-frame girder bridge

| added = July 16, 1982

| area = Less than one acre

| mpsub = {{NRHP url|id=64000902|title=Historic Bridges/Tunnels in Washington State TR}}

| refnum = 82004280{{NRISref|version=2010a}}

}}

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 {{convert|950|ft|m|adj=on}} Asylum Avenue Aqueduct in Knoxville, Tennessee, which was documented by Carl W. Condit to be the first continuous concrete girder bridge to be built.{{Cite web |url={{NRHP url|id=82004280}} |title=HAER/Washington State Bridge Inventory: North 21st Street Bridge |publisher=National Park Service |access-date=2016-06-10 |last=Soderberg |first=Lisa |date=1979}} with {{NRHP url|id=82004280|photos=y|title=two photos}}{{rp|1–2}}

It has three {{convert|60|ft|m}} 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 ({{Convert|9|ft}} deep) and beams from {{Convert|4|to|7|ft}} wide, from {{Convert|9|to|11|ft}} deep. It is {{Convert|48|ft}} wide to accommodate trolley tracks in the middle.

The bridge was listed on the National Register of Historic Places in 1982.