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8 None of Theodore Burr's Pennsylvania bridges remain, but many of the nation's best examples of Burr-arch trusses are found in this state. Pine Grove Bridge (1884) completed over Octoraro Creek between Chester County and Lancaster County, is an example and one of at least twenty-five covered bridges erected by Capt. Elias McMellen, a prolific Pennsylvania bridge builder. HAER PA-586, sheet 2, Vuong Dang and Dave Groff, delineators, 2002.
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At present, the study of the torsion performance of the steel-concrete composite bridge with open sections are usually simplified to study the torsion performance of single-girder steel-concrete composite bridge added the influence of transverse vehicle distribution. Due to the existence of transverse connections between the bridge girders, the ove...
Citations
... For a full illustrated discussion of trusses and their use in the construction process, seeMiller and Knapp (2014), 54-117. AndChristianson and Marston (2005), 4-48. ...
America’s first documented wooden covered bridge was erected at Philadelphia, Pennsylvania in 1805. Hundreds were constructed within two decades and at least 10,000 by the later 1800s. As settlers moved West, broad rivers were crossed with inventive structures incorporating timber trusses ingeniously developed by carpenters. Called covered bridges because of the roof and siding needed to protect the timber trusses, they became ubiquitous features on the American landscape. Over the past two centuries, most covered bridges were lost to flood, ice, arson, lightening, decay, as well as “progress,” replaced by “modern” iron, concrete, and steel spans. Of some 700 covered bridges remaining, many are mere replicas of their original forms no longer supported by timber trusses. Genuine historic bridges remain largely from the last half of the 1800s while civic boosterism has led to claims of earlier dates with often questionable authenticity. This essay presents three wooden covered bridges constructed in the 1820s along a 10-mile stretch of the Wallkill River in New Paltz, New York. Of the three, only Perrine’s Bridge, constructed first in 1821 and covered in 1822, is still standing with intact Burr timber trusses. Perrine’s is an iconic structure with exceptional heritage value because of authentic re-building and restoration in 1834, 1846, 1917, and 1968. Using documentary records, this essay establishes an accurate intertwined chronology for the three bridges, detailing nineteenth century building practices and contentious mid-twentieth century struggles pitting preservationists wanting authentic restoration against those wanting removal.
... For a full illustrated discussion of trusses and their use in the construction process, seeMiller and Knapp (2014), 54-117. AndChristianson and Marston (2005), 4-48. ...
America’s first documented wooden covered bridge was erected at Philadelphia, Pennsylvania in 1805. Hundreds
were constructed within two decades and at least 10,000 by the later 1800s. As settlers moved West, broad rivers
were crossed with inventive structures incorporating timber trusses ingeniously developed by carpenters. Called
covered bridges because of the roof and siding needed to protect the timber trusses, they became ubiquitous
features on the American landscape. Over the past two centuries, most covered bridges were lost to flood, ice,
arson, lightening, decay, as well as “progress,” replaced by “modern” iron, concrete, and steel spans. Of some 700
covered bridges remaining, many are mere replicas of their original forms no longer supported by timber
trusses. Genuine historic bridges remain largely from the last half of the 1800s while civic boosterism has led to
claims of earlier dates with often questionable authenticity.
This essay presents three wooden covered bridges
constructed in the 1820s along a 10-mile stretch of the Wallkill River in New Paltz, New York. Of the three, only
Perrine’s Bridge, constructed first in 1821 and covered in 1822, is still standing with intact Burr timber trusses.
Perrine’s is an iconic structure with exceptional heritage value because of authentic re-building and restoration in
1834, 1846, 1917, and 1968. Using documentary records, this essay establishes an accurate intertwined chronology
for the three bridges, detailing nineteenth century building practices and contentious mid-twentieth century
struggles pitting preservationists wanting authentic restoration against those wanting removal.
The Guidelines that adapt the "Secretary of the Interior’s Standards for the Treatment of Historic Properties with Guidelines for Preservation, Rehabilitation, Restoration, and Reconstruction" to historic covered bridges. They have been prepared to illustrate best practices and provide technical examples that can be used in planning and executing projects for preserving and maintaining historic covered bridges.
Focusing on rehabilitation, the Guidelines are organized by function. Following general principles, chapters examine superstructure, substructure, exterior envelope, site features, and safety/protection systems. Each section discusses recommended and non-recommended treatments, with illustrated examples of retaining, protecting, maintaining, repairing, and replacing various elements of an historic covered bridge.
The book concludes with several case studies (written by the engineers, bridgewrights, and public officials who worked on them), comprised of various covered bridge truss types, locations, rehabilitation issues, and budgets. The Guidelines will be a useful resource for educating craftsmen, engineers, Department of Transportation officials, State Historic Preservation Officers, bridge owners, preservationists, students, and residents in maintaining these historic symbols of American engineering for future generations.
These guidelines are designed for decision makers (selectmen, county commissioners, city planners, preservation officers, etc.) that have responsibility for repairing and maintaining existing covered bridges to help them understand what goes into making effective decisions about how, and when, to repair a covered bridge. The purpose of these guidelines is to present the steps necessary for decision makers to identify effective rehabilitation techniques for restoring the structural integrity of covered bridge members. The intent is to retain the maximum amount of historic fabric while ensuring public safety and minimizing future maintenance requirements. To make informed repair decisions about existing covered bridges, it is important to (1) start with a basic understanding of the type of bridge, (2) know the current condition, (3) be informed of what to consider when conducting an engineering analysis, and (4) be aware of various repair options that can meet the long-term goals for the bridge. Only after the decision maker knows the type of bridge, its condition, and to what loads it is subjected can a repair strategy be developed. How to support the bridge during the repair phase, what repairs are appropriate, and how to maintain the bridge after repairs are implemented are all critical to ensuring a long service life for the covered bridge.
