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Mine Road Bridge


Oblique View Before Rehabilitation

CC BY-NC-ND 2.0 http://www.flickr.com/photos/cjtengi/418380842/

Photo taken by Chris Tengi

License: Creative Commons Attribution-NonCommercial-NoDerivs (CC BY-NC-ND)

View this photo at farm1.staticflickr.com

BH Photo #249413



Excellent condition except portal damage from a fallen tree.

Copied and slightly edited from 2002 update of the 1987 NJ historic bridge survey

SETTING / CONTEXT On a rural two-lane road, the one-lane bridge crosses a small stream. The bridge enjoys integrity of setting in a rural area dominated by working farms. It is located in the sparsely developed northwestern portion of the county east of busy NJ 31.

SUMMARY One of two [now the last intact] well-preserved King Iron Bridge Co. pin-connected Pratt thru trusses in Mercer County, the Mine Road bridge is three years later than Bear Tavern Road (1100060) [now lost with altered parts reused as decoration on the new Valley Road concrete slab over Moore's Creek], but is nevertheless an important example of its type. Supported on unaltered ashlar abutments, the 5-panel bridge has few visible repairs. The floor beams may not be original. It is one of four thru truss bridges in the county and ranks as the second oldest and one of the least altered.

INFORMATION Bibliography: Simmons, David A. "Bridge Building on a National Scale: The King Iron Bridge and Manufacturing Company." The Journal of the Society for Industrial Archaeology. Vol. 15, No. 2, 1989. Mercer County Engineers Office. Transfer File 230.3.

Physical Description: The seven panel half-hip pin-connected Pratt thru truss with a steel grate deck installed in 1976 has true hangers that twist 90 degrees out of phase and then pick up the end floor beams. The bearings rest on ashlar abutments. The inclined end posts and upper chord are built-up members composed of shallow channels with a face plate. The same dimension channels are used for the laced verticals. Diagonals (of bar stock with loop-forged eyes) and counters (rods) are fitted with turnbuckles for tuning the bridge, and the bottom chord is die-forged eyebars. The originality of the rolled I beam floor beams is not known, but it is believed that they are not original. They are cut back in section for the suspenders and large square nuts that do appear to be original. The floor beams are fitted with the original brackets for the lateral bracing. The portal struts have a lattice bracing, as does the sway bracing, and each end carries a King Iron Bridge and Manufacturing Co. plaque. The lateral bracing is connected to a crimped bracket that connects at the upper panel point pins. A few welded repairs to the verticals at the panel points are visible, but otherwise the bridge is very well preserved. The modern beam guide rail is attached to the verticals by bolts.

Historical and Technological Significance: The well-preserved 102'-long pin-connected thru truss by the King Iron Bridge and Manufacturing Company of Cleveland, Ohio was erected in 1885, according to its plaque, and is one of two well preserved King thru trusses from the 1880s in Mercer County. The Mine Road bridge, the longer, heavier, and newer of the two, as well as its counterpart on Bear Tavern Road (1100060), are of statewide importance as early examples of a historic bridge type. They are also examples of bridges fabricated by one of the largest and most successful late-19th century manufacturers. The two Mercer County bridges are believed to be the only documented King Iron Bridge and Manufacturing Company in the state. Technologically they reflect early metal truss bridge construction details, such as the true floor beam hangers, the lateral bracing connections, and the prong-like floor beam connectors at the verticals. The bridge is an early and very well preserved example of its type.

The King Iron Bridge and Manufacturing Company was established by Zenas King in Cleveland about 1860. Learning the bridge selling business in the 1850s as a salesman representing the Moseley Bridge Company (a patented tubular bowstring), King patented his own tubular bowstring bridge that was to be the company's chief product through the 1870s, and he successfully marketed it nationally through a network of regional representatives. He published catalogues in 1875 and 1884 as well as annual reports. As the market moved away from the light bowstring truss about 1880, he diversified his product line to include the what was becoming standard thru and pony trusses. The King company was one of the largest and most prolific bridge fabricating firms in the country yet only approximately half a dozen documented examples of the firm's work survive in New Jersey. While the company remained an active, viable concern for about a decade after the founder's death in 1892, it was not a regional force in this century.

The King Iron Bridge and Manufacturing Company, known as the King Bridge Company after 1892, represents, in addition to period engineering and technology, the manner in which iron and early steel bridges were marketed in this country. The fabricator served as both engineer and builder. That practice was to disappear with the rise of the consulting engineer and the professionally trained county engineer in the early years of this century.

CONSULT DOCUMENTS SHPO Letter 6/30/95 HISTORIC BRIDGE MANAGEMENT PLAN ( EVALUATED ) No Page 45 A. G. Lichtenstein & Associates, Inc. performed initial survey. NJDOT updated data 03-01-2001. Correction Updates Etc should be sent to Correspondence.Unit@DOT.State.NJ.US November 12 , 2002


Through truss bridge over Stony Brook on Mine Road
Hopewell, Mercer County, New Jersey
Intact but closed to all traffic
Future prospects
Tree fell on portal in 2017. Minor damage but county is trying to replace rather than repair. At severe risk of replacement or neutering (being placed on top of a concrete slab as decoration.
Built 1885; rehabilitated 1976; rehabilitated ~2011,portal damaged by falling tree in 2017 - closed since
- King Bridge Co. of Cleveland, Ohio
Pratt through truss
Length of largest span: 101.1 ft.
Total length: 102.0 ft.
Deck width: 16.7 ft.
Vertical clearance above deck: 12.2 ft.
Eligible for the National Register of Historic Places
Approximate latitude, longitude
+40.37404, -74.79390   (decimal degrees)
40°22'27" N, 74°47'38" W   (degrees°minutes'seconds")
Approximate UTM coordinates
18/517496/4469294 (zone/easting/northing)
Quadrangle map:
Average daily traffic (as of 2017)
Inventory numbers
NJ 1100072 (New Jersey bridge number)
BH 25356 (Bridgehunter.com ID)
Inspection report (as of April 2017)
Overall condition: Poor
Superstructure condition rating: Poor (4 out of 9)
Substructure condition rating: Satisfactory (6 out of 9)
Deck condition rating: Good (7 out of 9)
Sufficiency rating: 24.6 (out of 100)
View more at BridgeReports.com

Update Log 

  • February 8, 2020: Updated by Art Suckewer: updated pin, status, street view, pics, etc.
  • January 21, 2020: Updated by Art Suckewer: Added details and history of bridge
  • August 28, 2019: New Street View added by Geoff Hubbs
  • July 2, 2018: Updated by Art Suckewer: Updated status
  • May 30, 2017: Updated by Christopher Finigan: Added category "Pin-connected"
  • February 21, 2013: Photo imported by Nathan Holth


  • Geoff Hubbs


Mine Road Bridge
Posted February 9, 2020, by Art S. (asuckewer [at] knite [dot] com)


So do I. I tried to resolve this quietly but to no avail. It has nothing to do with reality. Its merely the County taking advantage of an opportunity.

Its now time to make noise. Due to incompetence and arrogance, they would rather spend $1-$2 Million on a replacement than $30K-$35K on a skilled and correct repair.


Art S.

Mine Road Bridge
Posted February 8, 2020, by Tony Dillon (spansaver [at] hotmail [dot] com)

I know some folks that could fix the damage in short order. I love how the county seems to think this is fatal.

Mine Road Bridge
Posted February 8, 2020, by Art Suckewer

Unfortunately, this bridge is at significant risk of replacement or being placed as decoration on top of a new concrete slab.

A tree fell on and damaged the portal bracing in 2017. The county is using this as an excuse to replace the bridge with a new bridge (possibly using the old bridge as decoration).

This is the last historic truss still in use under the care and responsibility of Mercer County. What is sad is that the damage is minor and the bridge has been very well cared for throughout its life.


Art S.

Mine Road Bridge
Posted May 3, 2013, by Art S. (asuckewer [at] knite [dot] com)

Here are some pictures of Mine Road Bridge I shot this morning:

Mine Road Bridge
Posted April 24, 2013, by Art S. (Asuckewer [at] knite [dot] com)

The Mine Road bridge was restored in summer of 2011. It was one of very few bridges over Stony Brook that was not washed out as a result of Hurricane Irene.

Mine Road Bridge
Posted February 21, 2013, by ART S (asuckewer [at] knite [dot] com)

Nathan, Mine Road bridge looks much better now. It is a pretty shade of dark green and looks like new.

I'll try to get some pictures in the next week or two.


Art S.