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Poplar Street Bridge

Photos 

Photo taken by Daniel McFarland

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BH Photo #132688

Map 

Street View 

Description 

Delaware DOT:

The Poplar Street bridge is a 112-long, 17-wide, center-bearing, swing span bridge with a Warren pony truss superstructure. Constructed in 1915, the Poplar Street bridge is Delaware's oldest movable highway bridge. Currently, it is inoperable, although the turning mechanism remains in place. The bridge was operated manually by turning a capstan to engage the rack and pinion mounted on the center pivot pier. The bridge is listed in the National Register of Historic Places as a contributing resource to the Laurel Historic District, once an important rural commercial center with waterfront warehouses and canneries.

Swing span bridges were the dominant movable bridge type in Delaware from the 1870s to the 1910s. The Poplar Street bridge, when built in 1915, was a late example of the movable bridge technology that had been standard for several decades and was being rapidly superseded by the new bascule technology. The bridge pivoted on a center bearing post with eight balance wheels traveling on a circular rack for stability. The Warren pony truss superstructure is composed of standard built-up steel angle and channel sections. Warren pony trusses were a popular early 20th century highway bridge type and were applied to both movable and fixed spans. Two rail high pipe railings are attached to the inside of the trusses. The bridge is supported on concrete abutments and a timber pile center pivot pier.

Little is known about the history of the Poplar Street bridge. Presumably it was constructed under the auspices of the Sussex County Levy Court. It was taken over by the Delaware State Highway Department in 1935 as part of its expanded responsibilities for all former county roads and bridges. In 1946, the state highway department replaced the deteriorated concrete pivot pier with a timber pile pier. The repair plans note that the bridge was built in 1915, and that the swing span was opened about 100 times in 1946. The plans also show that there was a one-story frame operators house located on the northwest embankment.

The Poplar Street bridge was last opened to navigation in 1975. Since that time, it has undergone alterations that have rendered it inoperable but also have resulted in the preservation of the trusses and operating mechanism in situ. In 1994, the Delaware Department of Transportation removed the trusses to have them cleaned and painted. The beams that support and stabilize the bridge when it is opened were replaced in-kind. Original riveted connections were replaced by high strength bolts. The operating mechanism, including gears, shafting, and center bearing, were reset but not returned to operating condition.

Facts 

Overview
Swing bridge over Broad Creek on Poplar Street in Laurel
Location
Sussex County, Delaware
Status
Open to traffic
History
Built 1915; rehabilitated 1996
Design
Built as swing Warren pony truss; no longer used as movable bridge
Dimensions
Length of largest span: 56.1 ft.
Total length: 111.9 ft.
Deck width: 14.1 ft.
Recognition
Posted to the National Register of Historic Places
Approximate latitude, longitude
+38.55889, -75.57278   (decimal degrees)
38°33'32" N, 75°34'22" W   (degrees°minutes'seconds")
Approximate UTM coordinates
18/450095/4267983 (zone/easting/northing)
Quadrangle map:
Laurel
Inventory numbers
Delaware S-161
BH 12312 (Bridgehunter.com ID)
Inspection (as of 05/2015)
Deck condition rating: Good (7 out of 9)
Superstructure condition rating: Fair (5 out of 9)
Substructure condition rating: Satisfactory (6 out of 9)
Appraisal: Functionally obsolete
Sufficiency rating: 46.2 (out of 100)
Average daily traffic (as of 2013)
3,980

Categories 

Built 1915 (1,130)
Built during 1910s (8,758)
Delaware (125)
Functionally obsolete (7,990)
Have street view (22,087)
Movable (2,705)
NR-listed (2,844)
Navigable waterway (1,998)
One-lane traffic (7,422)
Open (36,587)
Owned by state (13,692)
Pony truss (15,049)
Span length 50-75 feet (8,902)
Steel grate deck (430)
Sussex County, Delaware (13)
Swing (1,248)
Total length 100-125 feet (4,648)
Truss (29,442)
Warren pony truss (2,947)
Warren truss (5,790)

Update Log 

  • August 18, 2016: Updated by Alexander D. Mitchell IV: Description from DelDOT added
  • December 26, 2015: Updated by Alexander D. Mitchell IV: Updated truss and status
  • December 10, 2015: New Street View added by Douglas Butler
  • August 22, 2013: New photo from Douglas Butler
  • April 19, 2010: New Street View added by Nathan Holth
  • January 28, 2009: New photo from Daniel McFarland

Sources 

  • Daniel McFarland
  • Nathan Holth
  • Douglas Butler
  • Alexander D. Mitchell IV

Comments 

Poplar Street Bridge
Posted July 24, 2008, by Anonymous

This bridge no longer operates.