The historic Warren pony truss bridge was built in 1903 to serve a different unknown location in Wayne County. It was moved to Wangum Road in 1944 to replace a former bridge at the location. Wangum Road is actually a former railroad line, the Pennsylvania Coal Company Gravity Railroad. Research conducted by a consultant for PennDOT states that the Gravity Railroad began in 1850 and operated until the 1880s. It also states that the railroad had a wooden trestle type bridge that crossed Middle Creek at the location where the truss bridge resides today. HistoricBridges.org also found a website that displays the crossing in a postcard, and shows what appears to be an iron bowstring truss bridge, of the design that was popular in the 1870s. The postcard has a handwritten date of 1907 written on it. This bowstring was likely the bridge that was replaced with the Warren pony truss in 1944.
The bowstring does raise some unanswered questions. If the railroad was using the roadway and its wooden trestle bridge into the 1880s, one has to wonder when the bowstring ended up at the crossing. Even if the wooden trestle was immediately demolished when the railroad line was converted to a highway in the 1880s (which would be odd, since railroad bridges often were repurposed for highway use), the 1880s would be relatively late for a bowstring truss. It may be that the bowstring truss seen in the postcard may have been relocated and reused from someplace else (either immediately when the highway was created, or anytime before 1907), in the same way that the Warren pony truss was relocated and reused decades later in 1944.
The road, bridge, and nearby falls have all been found to be spelled two ways: Wangaum and Wangum. It is not known which is correct; both spellings have been found in documents from reputable government sources.
This bridge is an early surviving example of a truss bridge with riveted connections in Pennsylvania. The bridge's trusses also retain excellent historic integrity with the replacement of lateral bracing under the deck being the only major alteration. For these reasons it is historically and technologically significant. The builder of the bridge is not known. However, the lattice railings on the bridge end in a curved section of railing that has a pattern of horizontal and vertical bars (rather than diagonal bars as in a lattice) This style of railing with the horizontal and vertical bars usually is only found on bridges built by the York Bridge Company of York, Pennsylvania, so it is possible the bridge was built by that company.
In addition to its historic and technological significance, the bridge is also set in one of the most unique and beautiful settings that a historic bridge has ever been seen in. The bridge crosses the creek immediately next to a cascading waterfall that can be easily seen from the bridge. The curving, narrow approaching roadway with the solid rock lining each side of the road is also unique. Aside from the road and bridge the setting lacks any sign of human intervention, with only rocks and trees visible at the location. The attractive, historic appearance of the bridge contributes greatly to the beauty of the setting.
It is HistoricBridges.org's opinion that this bridge could have and should have been rehabilitated in a way that maintained the historic integrity of the bridge. Instead, the bridge is being demolished and replaced. It is HistoricBridges.org's further opinion that the project development process including the manner in which Section 106 was conducted with this bridge, resulted in the failure to choose rehabilitation for this historic bridge. HistoricBridges.org noted several issues with the project development process as well as with the condition of the bridge and the roadway it serves. These observations are presented below.
The Preliminary Case Report created for PennDOT during project planning found the following regarding the roadway leading up to the bridge.
"The road / former rail bed approaching the structure is cut between the rock formations. The rock cuts create a narrow and curved alignment with poor visibility, allowing for only a single lane of traffic on Wangum Falls Road for several hundred feet in either direction from the bridge."
HistoricBridges.org could not agree more. The road is an extremely narrow one-lane facility with winding curves and solid rock on either side on the final curves that lead to the bridge, which would make pulling over to allow oncoming traffic to pass difficult.
The Average Daily Traffic (ADT) reported for the road and bridge is a miniscule 65. The threshold for an AASHTO-defined Very Low Volume Local Road is 400 ADT. Very Low Volume Local Roads have AASHTO guidelines that allow for narrower bridge deck widths, etc.
The historic bridge was repeatedly described as having significant deterioration. The reality is that the bridge really was not in very bad condition. Rehabilitation proposals considered during project development involved substantial alteration including replacement and retrofit of a number of truss members. This is particularly suspicious because one rehabilitation scenario would yield a 15 ton weight limit, which is actually what the deteriorated historic bridge was already posted for, suggesting that aggressive replacement of members would not be needed to maintain a 15 ton limit. The other scenario was intended to raise the weight limit modestly to 20 tons, which would be a full legal load for the road. It is unclear why so much complete member replacement was needed, especially for a rehabilitation scenario to maintain the existing weight limit. The likely reality is that the hired consultant was inexperienced in the rehabilitation of historic metal truss bridges. Inexperienced firms will wrongly claim that section loss and pack rust cannot be repaired, when in fact pneumatic hammering techniques can remove pack rust, and pad welding or welding pieces of plate to members can repair and correct section loss. Complete replacement of the members could likely have been avoided by repairing the deterioration on existing members.
Despite the somewhat aggressive rehabilitation proposals, which would have resulted in a loss of historic integrity and increased rehabilitation cost, both rehabilitation costs estimates were $390,000 for 15 ton limit and $430,000 for 20 ton limit. Both of these were less expensive than any of the demolition and replacement options considered.
The replacement bridge is a waste because it will not offer anything substantial beyond what a rehabilitated historic bridge would offer, and anything extra it does offer is likely negated by the unusually narrow, curved road that the bridge will be serving. A common reason given for destroying a historic bridge is that the historic bridge is one lane or otherwise too narrow for modern traffic. However, with this bridge, the replacement bridge will still only be one lane. Therefore, a replacement bridge does not provide a wider structure. The legal load for the road was listed as 20 tons. Thus, a replacement bridge need not have anything higher than a 20 ton weight limit. A rehabilitation scenario for a 20 ton bridge was proposed, and HistoricBridges.org suggests that the 20 ton scenario could be revised to retain a greater number of original members. Therefore, a replacement bridge does not offer anything more in terms of a weight limit. Finally, the replacement bridge costs substantially more than any rehabilitation alternative. A box beam bridge would cost $530,000, a pre-fabricated welded truss would cost $520,000, and a steel stringer would cost $585,000. The county chose to replace the historic bridge with a truss, resulting in a cost that was $90,000 more than rehabilitating the historic bridge for 20 tons would have cost.
Also, note that the cost estimates provided in the above two paragraphs were taken from the initial documents provided to consulting parties during the Section 106 process including the Determination of Effects Report. Later, a revised set of estimates were provided in a Determination of Effects Addendum. HistoricBridges.org finds it quite interesting indeed, that in this revised set of estimates, the cost to rehabilitate the bridge has suddenly been inflated so that rehabilitation is listed as more expensive than replacing the bridge. It should be noted that for a bridge in the condition of the historic Wangum Road Bridge, similar bridges elsewhere in the country usually cost significantly less than replacing them, which makes the revised cost estimates questionable. The revised costs were as follows:
Historic Bridge Rehabilitation (15-ton) $532,000
Historic Bridge Rehabilitation (20-ton) $591,000
Welded Truss Replacement: $574,000
Box Beam Replacement: $727,000
Steel Stringer Replacement: $854,000
It gets even more bizarre. Another document provided in the project development process, a memorandum presented to consulting parties, after the updated costs in the Determination of Effects Addendum raised the rehabilitation costs even higher, while also listing higher target weight limits of 27 and 36 tons respectively. Costs were as follows: 27 ton rehab: $540,000, 36 ton rehab: $600,000, replace with welded truss bridge for 45 ton limit: $580,000. It is unclear why such high weight limits were suddenly so high, when earlier project development indicated that a bridge with a 15-20 weight limit would be sufficient. Related to this, a list of "typical vehicles that may utilize the Wayne County Bridge" was provided, and a bunch of trucks heavier than 20 tons have been provided such as 3-4 axle dump trucks and 4000 fuel oil trucks. No evidence is provided as to why this narrow one-lane road with an ADT of 65 would suddenly become a major truck route. As for the 45 ton weight limit on the replacement bridge, this is pointless. A typical legal load in Pennsylvania on main highways is only 40 tons. Furthermore, given the narrow one-lane design of the bridge and approaching roadway combined, it is unclear if a truck carrying 45 tons could even use the road anyway. It has been HistoricBridges.org's experience that fully loaded semi trucks generally find one lane roads with shear rock on each side and sharp winding curves to be difficult to utilize.
The Purpose and Need Statement highlighted the need for large fire trucks to be able to cross the bridge. However, the replacement bridge is not to be any wider than the historic bridge. Further, the narrow, winding approach will not be removed during the project. It is therefore unclear that replacing the bridge would result in any increase in fire response as opposed to rehabilitating the historic bridge. How fast can a large fire truck go down a barely one lane dirt road with sharp curves?
The agencies and consultants involved in the development of this bridge project also made a mockery of the Section 106 process. The Purpose and Need Statement for the initial proposed Determination of Effects Report stated that "The overall goal of this project is to replace the existing structure, which has deteriorated, on the same alignment in order to meet current design criteria while preserving the integrity of setting within the project area. The new structure will be a truss bridge, similar in design to the existing structure, that will match both the rural and historic nature of the project area." Such a statement is inappropriate for a Purpose and Need Statement. Section 106 Review process requires the unbiased consideration of alternatives in an attempt to avoid adverse effect to a historic bridge. Beginning the project by stating that the intent is to demolish and replace the bridge implies that an alternative has been chosen before the alternatives are even considered. This is inappropriate, and it suggests the bias with which the involved agencies entered the project development process.
The involved agencies misled the consulting parties and the general public by including the following statement in the Determination of Effects Addendum: "The proposed bridge will match the existing bridge in length, width, design, and appearance." This statement lacks truth because the replacement bridge is to be a welded truss bridge from US Bridge Company. The historic bridge is a riveted truss bridge. Further, the members and chords on the replacement bridge are to be rolled beams, while the beams on the historic bridge are built-up using rivets as fasteners. To say that a welded truss would "match" the appearance of the historic bridge is untrue. The only thing similar is the general type (metal truss) and the truss configuration (Warren).
Information and Findings From Pennsylvania's Historic Bridge Inventory
Discussion of Bridge
The single span, 89'-long, riveted Warren with verticals pony truss bridge built in 1903 is supported on one stone abutment and one concrete abutment placed in 1944. It is traditionally composed with all members made up of angles and plate. There are very minor welded repairs, otherwise the bridge appears to be complete, including the lattice railings inside the truss lines. It is an early regional example of riveted field connections. The transition from pinned to riveted connections for non-railroad related highway bridges was about 1900. The bridge is historically and technologically significant.
Discussion of Surrounding Area
The single lane bridge carries an unimproved road over a stream in a wooded setting. The area is sparsely developed, and no buildings are visible from the bridge.
The single span, five panel, 89'-long and 20'-wide, riveted Warren with verticals pony truss bridge has one dry laid stone abutment and one concrete abutment that was placed in 1944, according to the bridge inspection reports. The members are built up of angles and battens, and the upper chords are composed of channels and plate. The outriggers are original. The bridge is finished with lattice railings attached to the roadway face of the trusses. The bridge underside is not accessible. There are very minor welded repairs.
Historical and Technological Significance
Built in 1903, the riveted Warren with verticals pony truss bridge is historically and technologically significant as an early example of its type and design with riveted field connections in the region (Criterion C). The Warren truss design emerged as the most commonly used truss design after 1895 because of advances in metallurgy and the mid 1890s improvements to field pneumatic riveting. The result was a rapid shift from pinned to riveted connections and the Warren design that is particularly well suited for rigid connections. The railroads starting using riveted field connections about 1895, and it appeared in non-railroad related highway applications about 1900. The riveted Warren truss design proved to be so successful that it is still used today. It was patented in 1848 by British engineers James Warren and Willoughby Monzani and is distinguished by its simplicity of design, ease of construction with equal sized members and ability of some of the diagonals to reverse stresses. Capacity could be increased by adding a second set of diagonals or the addition of verticals. Its use peaked during the first two decades of the 20th century, and there are 125 examples in the state dating from the 1890s through 1956.
Boundary Description and Justification
The bridge is evaluated as individually significant. The boundary is limited to the substructure and superstructure of the bridge.
Bridge Considered Historic By Survey: Yes
Information About Gravity Railroad From Determination of Effects Report
Discussion of Bridge
The Gravity Railroad was constructed during the early to mid-nineteenth century with operations beginning in 1850. The Gravity Railroad was constructed as a transportation resource that would be able to move large quantities of anthracite coal found in the Pittston area to the Delaware & Hudson (D&H) Canal located in Hawley. The Gravity Railroad consisted of two tracks: the loaded track and light track. Within the Wangum Bridge over the Middle Creek area, the loaded track crossed the creek using an earlier wood trestle located at the foot of Wangum Falls. After the railroad was discontinued in the 1880s, the loaded track was removed and the railroad ROW was used as a road. This road still exists today and is now called Wangum Road (T.R. 367). Still evident in this area are the large rock cuts that were created to allow for passage of the loaded track. Although the tracks were removed, parts of the original Gravity Railroad are still evident, as is the case at the Wangum Road Bridge, where the original rock cuts and the railroad ROW still exist.
The Gravity Railroad has been determined eligible for listing in the National Register (Appendix B). The resource is eligible under Criterion A for its association with transportation and the role that the Gravity Railroad played in the development of coal as a viable natural resource. The railroad is also technologically significant for its association with the use of the inclined plane and pulley systems, considered to be innovative engineering for the time (Criterion C). The National Register boundary for the Gravity Railroad includes the remaining railroad corridor and any other related resources that may still be evident throughout the regional landscape. Within the Wangum Bridge area, this is evident in the remaining rock cuts that represent the historic ROW of the Gravity Railroad.
This bridge is tagged with the following special condition(s): Available
This historic bridge has been demolished. This map is shown for reference purposes only.
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