2 votes

Big Flat Brook Bridge


North face

Note semicircular builder's plate at center of upper chord.

Photo taken by Roger Deschner in August 2015

License: Creative Commons Attribution-Share-Alike (CC BY-SA)


BH Photo #335703


Very rickety bridge, Walpack Center, NJ

4 January 2007 Crossing the Big Flat Brook Bridge. Passengers in the car can be heard worrying if it will collapse under them. Builders plate at center of bridge can be seen at 0:10.

Video posted to Youtube by Umweltfreundlich07. Posted to bridgehunter by Roger Deschner

Play video on YouTube

Abandoned Town of Walpack New Jersey (Axis Video/Pine Barren Films)

Good still photos of bridge starting at 4:08

Video posted by Roger Deschner

Play video on YouTube


Pony truss bridge over Big Flat Brook on Main Street
Walpack Center, Sussex County, New Jersey
Open to traffic; posted for load
Built 1889; rehabilitated 1935 and 2002; repaired after flood 2013
- Groton Bridge Co. of Groton, New York
Half-hip Pratt pony truss
Span length: 68.2 ft.
Total length: 68.2 ft.
Deck width: 12.1 ft.
Eligible for the National Register of Historic Places
Also called
Main Street Bridge
Approximate latitude, longitude
+41.15721, -74.87721   (decimal degrees)
41°09'26" N, 74°52'38" W   (degrees°minutes'seconds")
Approximate UTM coordinates
18/510302/4556216 (zone/easting/northing)
Quadrangle map:
Lake Maskenozha
Average daily traffic (as of 2011)
Inventory numbers
NJ 4320040P0000000 (New Jersey bridge number)
BH 25553 (Bridgehunter.com ID)
Inspection report (as of November 2017)
Overall condition: Fair
Superstructure condition rating: Satisfactory (6 out of 9)
Substructure condition rating: Satisfactory (6 out of 9)
Deck condition rating: Very Good (8 out of 9)
Sufficiency rating: 44.2 (out of 100)
View more at BridgeReports.com

Update Log 

  • July 6, 2020: New photos from Patrick Gurwell
  • June 22, 2018: New photos from John Christeson
  • October 22, 2017: Updated by Christopher Finigan: Added category "Pin-connected"
  • August 17, 2015: New photos from Roger Deschner
  • May 15, 2015: New video from Roger Deschner
  • May 24, 2014: Updated by Roger Deschner: Incorporate NBI data
  • May 15, 2013: Updated by Roger Deschner: Add location, photo, video


  • Roger Deschner - rogerdeschner [at] gmail [dot] com
  • Historicbridges.org - by Nathan Holth
  • John Christeson - john_christeson [at] yahoo [dot] com
  • Patrick Gurwell - pgurwell [at] gmail [dot] com


Big Flat Brook Bridge
Posted May 24, 2013, by Michael J Lynch (mikengineer2 [at] netscape [dot] net)

Bridge under repairs from May 15 through Jun 15 2013. Two terrific floods that had water a few feet over the deck most likely caused undermining. It is a beautiful old bridge in a remote rural setting....... By the way...the water is almost always only 6-12 inches deep under the deck. the deck is about 10 feet over the normal water level.