This pin connected through truss bridge is among the most beautiful bridges in Venango County. Not only is it an impressive structure in its own right, it is in a very scenic area. It is surrounded by Oil Creek State Park. The Miller Farm Bridge was built in 1888 by the Massillon Bridge Company of Massillon, Ohio. It is a large single span Pratt through truss, with nine panels for a total of 154 feet. There is v-lacing on the verticals, and the portal bracing is a lattice design. There are pipe railings present on the bridge.
There is a commemorative plaque on this bridge that proudly declares that this is a restored bridge. It is not clear how the bridge was "restored" All that could be seen done to this bridge that might be as recent as 2000 is that the wooden deck was replaced. No sandblasting and painting of the structure was done. Deck replacement is indeed a preservation activity, but it is hardly a "restoration" of the bridge if the historically significant trusses were not improved. This plaque also misleads visitors to the bridge, since it suggests that Venango County actually cares about preserving this bridge. Nothing could be further from the truth. Despite being a bridge in a surprisingly decent condition with even the hard-to-please National Bridge Inventory giving the truss a "Fair" rating, and despite the fact that this is a bridge in the middle of nowhere on a seasonal road that hardly anyone uses, this bridge is slated for demolition and replacement. What a waste of both history and tax dollars! The bridge could likely be rehabilitated by a firm skilled with such work for less than it would cost to replace the bridge.
As part of the Section 106 Review process to consider alternatives to demolition, a Rehabilitation Feasibility Analysis was conducted. A link to this document is available at the top of this narrative. The content of this document suggests that the people involved with its creation had little or no knowledge of how to rehabilitate a historic metal truss bridge. Concerns are noted below.
This Rehabilitation Feasibility Analysis suggests that it was compiled without input from anyone with even a modest understanding of the rehabilitation of historic metal truss bridges. First off, consider these statements made in the document:
1. The owner of the bridge, Venango County, desires a minimum posting of 15 tons...
2. The lowest load rated member, is rated at 15 tons, the member that controls the current seven (7) ton posting is the stringers because they are only rated for seven (7) tons.
The consultant makes the statement "Based on the current Load Ratings of the existing truss members, the heavier deck and bridge barrier would require the replacement or rehabilitation of 50 percent of the truss members (36 out of 72) in order for each member to reach a Load Rating above the targeted 15 tons." This is because the consultant plans to use a concrete deck and a concrete barrier on the bridge. The use of concrete barriers on a pin-connected truss bridge is unheard of and no one who had half a clue what they were talking about and was serious about rehabilitating a bridge of this type would use such a barrier. It goes against common practice as observed nationwide. Most states that rehabilitate this type of bridge employ a crash-tested steel "two tube" or similar guardrail barrier. Such a barrier takes up less width on the deck. Other deck types that weigh less are also available and were not explored in the document.
The consultant makes the statement "Due to the crevices between the lower chords, cleaning and painting is difficult and crevice corrosion and rusting would be expected within five (5) years of any rehabilitation." The consultant has failed to consider a construction sequence that would dismantle the truss to be cleaned, repaired, and repainted in a shop setting. This process would drastically increase the quality of the rehabilitation. It would be possible to completely clean all "crevices" and bring the bridge to like-new condition, which means the bridge should be ready for another century of reliable service, just like it has provided for the past century.
The Consultant makes the statement regarding rehabilitation: "This alternative does not appear to be prudent due to the following reasons:
Future maintenance costs of the steel truss structure
The lack of redundancy in the structure"
It is not clear that maintenance costs would be significantly more than that for a replacement bridge, provided that the rehabilitation is of a high quality. Also, the Miller Farm Bridge is, from a general design and construction standpoint, a typical example of a pin-connected truss bridge. If the Department's position is that a bridge like the Miller Farm Bridge is not prudent to rehabilitate because it lacks redundancy and because someone thinks that this design of bridge costs too much to maintain, the Department is essentially stating that it considers the preservation of nearly all historic pin-connected truss bridges in the Commonwealth to not be prudent. That a state with such a rich history of the iron and steel industry would maintain a position that inevitably would lead to the demolition of nearly all bridges of this type is extremely alarming. Additionally, because many other states find it feasible and prudent to rehabilitate many bridges of this type, it is questionable whether the Department's concerns about maintenance costs and redundancy issues have validity.
Information and Findings From Pennsylvania's Historic Bridge Inventory
Discussion of Bridge
The 1888, pin connected, single span, 154'-long, Pratt thru truss bridge is supported on ashlar abutments with flared wingwalls. The traditionally composed trusses have built up upper chords and verticals. The lower chords and diagonals are eye bars are historically and technologically significant as an early example of its technology (Criterion C). One of 16 surviving pin connected truss bridges in Venango County, the bridge stands out as a complete example of its type and design. Adding to its significance is the documentation to the Massillon Bridge Company of Massillon Ohio, a regional fabricator of metal truss bridges. The bridge is historically and technologically significant.
Discussion of Surrounding Area
The bridge carries 1 lane of an unimproved road over a stream in a sparsely developed, forested setting that does not have historic district potential.
Bridge Considered Historic By Survey: Yes
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