Downsville Covered Bridge, Downsville New York

Date added: April 15, 2024 Categories:

The Downsville Covered Bridge is significant under criteria A and C as a rare and substantially intact example of rural vernacular bridge design and construction in the Catskill region.

The Downsville Covered Bridge, erected across the East Branch of the Delaware River in 1854, the 174-foot, single-span, timber bridge incorporates the truss design patented by Col. Stephen H. Long. The Downsville Covered Bridge is one of only 3 intact, extant Long truss bridges remaining in New York State. Removed from service in 1993 and restored in 1998, the imposing wood span remains an important transportation and vernacular engineering landmark in Delaware County and the Catskill region.

The first permanent settlement around Downsville occurred ca. 1792, although the area has remained remote and sparsely settled to the present. Forest products quickly became the chief output of this wooded, mountainous region of the Catskills. Laced by numerous streams, this area relied upon abundant local materials and available craft skills to provide needed road bridges, a regional trend that persisted into the first decades of the twentieth century. Built using native oak and hemlock timber cut to dimension in local sawmills, the Downsville Covered Bridge is a reflection of this building tradition. The span at Downsville was the first bridge in Delaware County erected by builder/contactor Robert Murray. (Murray also built the Hamden Covered Bridge in Delaware County in 1859.) In 1854, Murray received the contract to construct the crossing needed over the East Branch of the Delaware. The builder employed the time-tested Long truss design, a sturdy and easily constructed configuration that he knew was suited to the traffic loads the Downsville bridge would carry. Built as a highway bridge to carry vehicles traveling from Downsville to Walton and Roscoe, the Long truss of the Downsville Covered Bridge is an intact, representative example of its type and method of construction. The Downsville structure is one of a limited set of timber truss bridges remaining in New York State and is one of only 3 examples of the Long truss type.

The Downsville Covered Bridge has had many repairs throughout the years. In 1951, the Department of Public Works repaired the roof, tightened the chords, put on new siding, and installed a new roof. In 1976, a new nail laminated deck was installed. During 1983-1985, local contractors and carpenters were retained to install new shingles, replace any necessary boards, and fill in missing side boards. The lumber for the project was cut in the town of Colchester and trucked to a local sawmill. An extensive program of restoration was completed in 1998 by the Delaware County Department of Public Works, which currently maintains the Downsville Covered Bridge as a local historic landmark.

Although hundreds of covered wood truss bridges were built throughout New York, only 24 examples remain.

Throughout much of the nineteenth century, New York was predominantly rural; its settlement pattern generally consisted of widely separated communities whose economy was based upon subsistence agriculture and local water-powered industry. Few improved roads connected population centers. As the Empire State grew and its economy expanded, however, road and bridge improvements became essential for linking emerging centers of civic and market activity.

The earliest permanent bridges in New York were constructed using readily available local materials and skills. Because the cost of constructing bridges generally was the responsibility of local governments, they turned to readily available materials and skills for this purpose.

The abundant timber and stone resources found throughout much of New York State made these materials the logical choice for bridge construction. The relative ease of construction was another factor that mitigated in favor of wooden bridge construction. The timber framing skills of local millwrights and joiners were readily adaptable to the construction of timber bridges.

During the Colonial period, the first timber bridges incorporated the Kingpost or the Queenpost truss configuration. These simple, open structures with plank decks were widely erected across small streams, though their use was limited to clear spans less than fifty feet in length. Longer crossings were possible using multiple spans supported by mid-stream piers or timber cribbing. The open timber truss bridge remained an inexpensive and popular form for farm bridges and crossings on minor roads until the early twentieth century, when it was supplanted by the metal span. The open trusswork was sometimes sheathed with protective weather boards to preserve the life of the truss. Because of its horizontal top chord, it was possible to cover a Queenpost truss bridge with a protective roof. The Copeland Covered Bridge (1879), a farmer's bridge in rural Saratoga County, is an extant example of a covered Queenpost truss bridge remaining in New York. From the early decades of the nineteenth century, the cost of building and maintaining timber bridges generally fell upon local governments or state-chartered bridge or turnpike companies, which were established as for-profit ventures. It soon became evident that protecting the bridge's structural system from the elements would reduce the burden of maintenance and replacement costs. This protection was most readily achieved by covering the timber truss bridge with a roof and board sheathing to enclose the frame structure.

During the Federal period, inventor Theodore Burr (1772-1822) designed a highly successful long-span bridge form that combined the structural advantages of a simple timber truss with a relieving arch. Burr patented his timber truss design in 1817. His first successful bridge was a four-span structure erected across the Hudson River at Waterford, New York in 1804. Built of hand-hewn pine structural members, the Waterford bridge was sheathed with pine plank siding and covered by a shingled roof. Burr's bridge stood for more than a century until it was destroyed by fire in 1909. The Burr Arch Truss is represented in New York by three extant historic covered bridges: Perrine's Bridge (1844), Ulster County, Salisbury Center Bridge (1875), Herkimer County, and the Hyde Hall Bridge (1825), Otsego County.

A successful truss design nearly contemporary with the Burr truss was the Town lattice truss, patented in 1820 by the versatile builder/architect Ithiel Town (1784-1844). Consisting of a horizontal top and bottom chord connected by a web of closely spaced, alternating diagonal timbers, the Town lattice truss included no vertical members; the required stiffness was achieved by connecting the intersecting diagonals with wood pins. Carried on piers placed at intervals, bridges incorporating the Town lattice truss could span considerable distances. Its inherent strength coupled with its ease of construction made the Town truss design a popular design for highway and early railroad bridges until the post-Civil War era. The covered bridges at Eagleville and Shushan, Washington County, are notable examples of the Town truss form.

During the 1830s, Colonel Stephen H. Long (1784-1864) of the U.S. Army Corps of Topographical Engineers perfected a rigid timber truss form that incorporated panels consisting of intersecting diagonals and counters. Long's initial patented design of 1830 for an "assisted truss" included a redundant Kingpost relieving truss above the center panel points (where the greatest flex would occur). With practical experience, Long refined his design to eliminate its "overbuilt" characteristics, receiving additional patents in 1836 and 1839. The Old Blenheim Bridge (1855), Schoharie County, (destroyed 2011) was a notable example of the Long truss design.

The final major timber truss design to achieve widespread popularity during the late nineteenth century was first patented in 1840 by William Howe (1803-1852). The Howe truss consisted of horizontal timber top and bottom chords and diagonal wood compression members combined with vertical tension members made of wrought iron. The ends of the iron tensions rods were threaded and secured to iron shoes at the panel points of the web. The inherent properties of wood and iron as construction materials were effectively used in Howe's truss; this hybrid truss became the most widely constructed, standard American timber bridge form of the nineteenth century. The Rexleigh (1874) and Buskirk (1857) Covered Bridges in Washington County and the Jay Covered Bridge (1857), Essex County, are Howe truss structures.

By the third quarter of the nineteenth century, the covered timber truss bridge was being supplanted by the manufactured metal truss bridge on the roads and rail lines of New York State. Stimulated by wartime growth and development, iron manufacturers turned to production of standardized metal bridge components in the post-Civil War era. The increased strength, ease of construction, and reduced cost associated with metal bridges won favor among local governments and railroad companies; by the 1880s, the heyday of wooden bridge-building had passed. Although several examples of covered timber truss spans remain from the early twentieth century in rural areas of New York, the advantages of iron bridges were clearly understood and widely applied well before 1900.

Bridge Description

The Downsville Covered Bridge is a wood timber and plank framed, gable-roofed single-span structure located in the hamlet of Downsville, Delaware County. Erected in 1854, this span was constructed as a vehicular bridge carrying Bridge Street over the East Branch of the Delaware River. Set amid the picturesque surroundings of the western Catskill Mountains, the bridge remains on its original site spanning the East Branch with its portal ends oriented north and south.

The general dimensions of the Downsville Covered Bridge are as follows:

Overall length: 174'
Overall width: 19'
Deck width: 14' 3"
Portal height: 12'
Portal width: 16' 4"

The timber bridge is a single span carried on abutments constructed of dry-laid fieldstone capped with concrete. The web of the superstructure incorporates the patented Long truss, reinforced by an auxiliary queenpost truss. Heavy paired planks and a center beam form the top chord. The bottom chord consists of three laminated beams on each side. Each web panel consists of heavy timber vertical posts separated by paired timber diagonals and single counters. Diagonals of the queenpost truss span three panels to tie into the top and bottom chords. Truss members are connected to the chords using mortise and tenon joinery and long, threaded iron bolts with nuts. Original sway bracing of the top chords is constructed of diagonal cross timbers in "X" configuration; horizontal iron tension rods added in the twentieth century provide additional cross-bracing. Timber floor beams extend beyond the sides of the bridge to form a series of four small buttresses spaced at regular intervals along the truss web. The bridge deck consists of planks laid on the edge and longitudinally to the portals. The entire bridge is covered with vertical board sheathing secured using laminated beams attached to horizontal nailers; the buttresses are shielded by board coverings. The roof consists of nail strips covered with wood shingles.

The Downsville Covered Bridge was removed from service in 1993. The span has experienced periodic, selective replacement of deteriorated elements over time, as well as a program of comprehensive restoration completed in 1998. As part of this rehabilitation, the deteriorated sheathing and roof were replaced with modern compatible materials.