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Thompson Crossing Bridge

Hillsborough County, New Hampshire

Photos 

Thompson Crossing Bridge

Southeast abutment.

Photo taken by Michael Quiet

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BH Photo #305004

Map 

Description 

The Berlin Iron Bridge Company is usually associated its patented lenticular truss, which accounted for the majority of their bridge construction. Although less common, they also made examples of other common truss types, of which only a handful survive today. This bridge, while historically significant just as a production of this prolific 19th century bridge fabricator, is even more unique as this example is a straight Pratt through truss.

This example shows the changing times for the Berlin Iron Bridge Company as the main truss material was steel (the switch from wrought iron to steel was made about 1892), but still retains the pin-connected construction style that was used until 1900.

The bridge is incredibly simple compared to other Berlin Iron Bridge Company productions...an indication that cost was important in this area. Standard details that are seen on several other surviving examples (portal decorations, ornate builders plaque, decorative railings) are all absent on this bridge, giving it a very spare look.

This Bridge was abandoned around 1976, and the elements have taken their toll. Most of the simple steel tube railings have fallen off, and the deck stringers are also disappearing. The abutments and superstructure seem sound enough though, so it doesn't appear that the bridge is at risk of collapsing anytime soon.

Facts 

Overview
Pin connected Pratt through Truss over Contoocook River on abandonded section of Thompson Crossing road in Antrim
Location
Hillsborough County, New Hampshire
Status
Derelict/abandoned
History
Built 1893 by Berlin Iron Bridge Co.; Abandoned 1976
Builder
- Berlin Iron Bridge Co. of East Berlin, Connecticut
Design
Pin connected Pratt Through truss
Dimensions
Span length: 96.1 ft.
Total length: 96.1 ft.
Deck width: 13.8 ft.
Recognition
Eligible for the National Register of Historic Places
Approximate latitude, longitude
+43.04667, -71.91806   (decimal degrees)
43°02'48" N, 71°55'05" W   (degrees°minutes'seconds")
Approximate UTM coordinates
19/262326/4770130 (zone/easting/northing)
Quadrangle map:
Hillsboro
Inventory number
BH 24943 (Bridgehunter.com ID)
Inspection report (as of June 2012)
Overall condition: Fair
Substructure condition rating: Satisfactory (6 out of 9)
Sufficiency rating: 17 (out of 100)
View more at BridgeReports.com

Categories 

19th Century (7,640)
4-panel truss (272)
Abandoned (3,681)
Berlin Iron Bridge Co. (178)
Built 1893 (215)
Built during 1890s (2,997)
Deck removed (45)
Hillsborough County, New Hampshire (106)
NR-eligible (4,057)
New Hampshire (671)
One-lane traffic (7,615)
 Owned by city (5,501)
Pin-connected (3,932)
Pratt through truss (5,436)
Pratt truss (9,361)
Span length 75-100 feet (6,454)
Sufficiency rating zero (215)
Through truss (15,217)
Total length 75-100 feet (6,599)
Truss (33,022)
Wooden deck (6,084)

Update Log 

  • October 10, 2015: New photo from Mike Garland
  • October 7, 2015: New photos from Mike Garland
  • October 20, 2014: Updated by Michael Quiet: Added categories "Pin-connected", "One-lane traffic", "4-panel truss"
  • September 11, 2011: Updated by J.P.: its actually a through truss via bing eagle view.

Sources 

  • J.P. - wildcatjon2000 [at] gmail [dot] com
  • Michael Quiet - mquiet [at] gmail [dot] com
  • Mike Garland - Rapier342 [at] comcast [dot] net

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