HistoricBridges.org Menu: HistoricBridges.org Menu:


We Recommend These Resources:
Bach Steel - Experts at historic truss bridge restoration.

HistoricBridges.org: Bridge Browser

Dunbar Bridge

Harmon Creek Road Bridge

Dunbar Bridge

Primary Photographer(s): Nathan Holth

Bridge Documented: July 4, 2006 and May 3, 2013

View Photos
and Videos
View Maps
and Links

Key Facts

Facility Carried / Feature Intersected
Harmon Creek Road (TR-843) Over Raccoon Creek
Location
Rural: Washington County, Pennsylvania: United States
Construction Date and Builder / Engineer
1889 By Builder/Contractor: Pittsburgh Bridge Company of Pittsburgh, Pennsylvania

Technical Facts

Rehabilitation Date
Not Available or Not Applicable
Main Span Length
60 Feet (18 Meters)
Structure Length
20 Feet (6 Meters)
Roadway Width
10.5 Feet (3.2 Meters)
Spans
1 Main Span(s)
NBI Number
627224084340200

Historic Significance Rating (HSR)
View Information About HSR Ratings

Bridge Documentation

This bridge no longer exists!

View Archived National Bridge Inventory Report - Has Additional Details and Evaluation

You know that when even Pennsylvania's outdated and overly conservative Historic Bridge Inventory says a truss bridge is historic, that the bridge is something extra special! Indeed, that is the case with this very old 1889 half-hip Pratt pony truss with pinned connections. The bridge features latticed vertical members. There is v-lacing on both sides of the end posts, which is unusual since normally cover plate would be expected on top of the built-up box section. Original pole railings remain on this bridge. The other unusual feature is the use of rolled star iron, also called cruciform, on the outriggers. Star iron usually shows up on 1870s truss bridges, such as the bowstring truss bridges that were common during that period. If the 1889 construction date listed for this bridge is accurate, this would be a late example of a bridge with star iron on it. Regardless, any bridge that has star iron on it is rare and has historic significance. This bridge is, based on its style, assumed to have been built by the Pittsburgh Bridge Company.

Information and Findings From Pennsylvania's Historic Bridge Inventory

Discussion of Bridge

The single-span, 64'-long and 12' wide, pin-connected Pratt pony truss bridge built in 1889 is supported on one stone abutment and one concrete abutment. The lower chords and diagonals are loop forged eyebars, and the upper chords are channels and lacing. The verticals are laced back to back angles. Original features include the built up floor beams, pipe railings inside the truss lines and the outriggers. In a county and region with a deep and varied collection of metal truss bridges from the mid 1880s through the 1930s, this pony truss bridge stands out as an early and complete example.

Discussion of Surrounding Area

The bridge carries a single lane road over a stream in a sparsely developed, forested setting.

Bridge Considered Historic By Survey: Yes

Divider

Photo Galleries and Videos: Dunbar Bridge

 
View Photo Gallery
Bridge Photo-Documentation
Original / Full Size Photos
A collection of overview and detail photos. This gallery offers photos in the highest available resolution and file size in a touch-friendly popup viewer. Alternatively, Browse Without Using Viewer
View Photo Gallery
Bridge Photo-Documentation
Mobile Optimized Photos
A collection of overview and detail photos. This gallery features data-friendly, fast-loading photos in a touch-friendly popup viewer. Alternatively, Browse Without Using Viewer

Divider

Maps and Links: Dunbar Bridge

This historic bridge has been demolished. This map is shown for reference purposes only.

Coordinates (Latitude, Longitude):

View Bridge Location In:

Bridgehunter.com: View listed bridges within a half mile of this bridge.

Bridgehunter.com: View listed bridges within 10 miles of this bridge.

Google Maps

Google Streetview (If Available)

Bing Maps

OpenStreetMap

Apple Maps (Via DuckDuckGo Search)

Apple Maps (Apple devices only)

MapQuest

HERE We Go Maps

ACME Mapper

Waze Map

Android: Open Location In Your Map or GPS App

Flickr Gallery (Find Nearby Photos)

Wikimedia Commons (Find Nearby Photos)

Directions Via Sygic For Android

Directions Via Sygic For iOS and Android Dolphin Browser

USGS National Map (United States Only)

Historical USGS Topo Maps (United States Only)

CalTopo Maps (United States Only)


Divider
 
Home Top

Divider

About - Contact

© Copyright 2003-2021, HistoricBridges.org. All Rights Reserved. Disclaimer: HistoricBridges.org is a volunteer group of private citizens. HistoricBridges.org is NOT a government agency, does not represent or work with any governmental agencies, nor is it in any way associated with any government agency or any non-profit organization. While we strive for accuracy in our factual content, HistoricBridges.org offers no guarantee of accuracy. Information is provided "as is" without warranty of any kind, either expressed or implied. Information could include technical inaccuracies or errors of omission. Opinions and commentary are the opinions of the respective HistoricBridges.org member who made them and do not necessarily represent the views of anyone else, including any outside photographers whose images may appear on the page in which the commentary appears. HistoricBridges.org does not bear any responsibility for any consequences resulting from the use of this or any other HistoricBridges.org information. Owners and users of bridges have the responsibility of correctly following all applicable laws, rules, and regulations, regardless of any HistoricBridges.org information.

Divider