Ashokan-Turnwood Covered Bridge, Olivebridge New York

Date added: April 11, 2024 Categories:
South and east elevations (1999)

The Ashokan-Turnwood Covered Bridge, originally erected in 1885 at Turnwood in western Ulster County, the 60' 6", single-span, timber bridge was fabricated by local craftsmen using native materials. Incorporating the patented Town lattice truss design, the Ashokan-Turnwood span is one of only ten extant examples of its type remaining in New York State. First built as a wagon bridge serving a rural manufacturing community, the timber truss structure subsequently was sold, disassembled and re-erected at its present location near Olivebridge in 1939. Preserved as part of a private estate until conveyed to the State University of New York in 1955, the Ashokan-Turnwood Covered Bridge remains a rare and important vernacular engineering structure associated with the history of transportation in the Catskill Mountain region. The bridge remains in light use as part of the Ashokan Field Campus of SUNY College at New Paltz.

The bridge originally was built in 1885 to span the Beaver Kill in the remote town of Hardenbergh, Ulster County. First settled ca. 1800, Hardenbergh remains sparsely settled to the present day. Forest products became the chief output of this wooded, mountainous region of the western Catskills. In the late 1800s, there were still thick forests of hemlock in the Beaver Kill Valley, with some trees exceeding three feet in diameter at the base. The leather tanning industry was prevalent in this period and the practice of de-barking hemlock trees left much ready-to-mill timber. Laced by numerous streams, this isolated area relied upon the abundant local timber supply and available rural craft skills to provide needed bridges, a trend that continued until the early twentieth century. The nearby Grant Mills Covered Bridge in the town of Hardenbergh was built in 1902. In 1885, local timber framer Nelson Tompkins was awarded a contract to erect a bridge at Turnwood, an early seat of wood products manufacturing. Tompkins employed the reliable Town lattice truss design, a sturdy and easily constructed plank configuration suited to wagon traffic serving the local forest-based industries. Local hemlock timber was used to construct the Turnwood Covered Bridge.

The Turnwood span remained in use at its original location for five decades. As automobile and truck traffic supplanted horse-drawn vehicles, however, the covered timber bridge became increasingly hazardous because its alignment created limited sight distances and required sharp turning angles at both portals. As the span approached 50 years of age, the local government declared the bridge unsafe in 1934. Following severe flood damage to the stone abutments in 1938, Ulster County replaced the covered bridge with a new steel span built by the Phoenix Bridge Company of Pennsylvania. The county conducted a public auction in 1939, at which time the surplus covered bridge was purchased by Lester A. Moehring, comptroller of the Chrysler Corporation, for one dollar. Moehring's workmen numbered and dismantled the Town lattice truss structure, transported the components by truck to his estate property at Olive, and reassembled the bridge in its original configuration at its present location. Here the bridge continued to be used by vehicles and pedestrians on Moehring's rustic estate, preserved as a functional historic artifact.

The Moehring family sold their Catskill camp to another private owner, Frank V. Banks, in 1955; Banks named the estate "Barrington Lodge". In 1957, the State University of New York purchased the property from Banks. Developed as the Ashokan Field Campus of the College at New Paltz, the facility currently hosts an environmental education program and retreat center that continues to preserve the historic covered bridge.

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

The history of covered timber bridge construction in New York State spans the period from the first decade of the nineteenth century to the era of the First World War. The earliest known extant covered bridge was built in 1825; the latest in 1912.

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 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 during the period of significance. 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 Ashokan-Turnwood Covered Bridge is a plank framed, gable-roofed, single-span, covered timber bridge located northeast of the hamlet of Olivebridge, town of Olive, Ulster County. Situated on the Ashokan Field Campus of the State University at New Paltz, the bridge spans the Esopus Creek immediately east of Winchell Falls. The portal ends are oriented north and south. The covered bridge originally was erected in 1885 as a vehicular bridge over the Beaver Kill at Turnwood, a small manufacturing hamlet in the extreme western corner of Ulster County in the town of Hardenbergh. In 1939, the timber span was disassembled and moved approximately 25 miles to a private woodland estate, where it was re-erected in its present setting. The Ashokan-Turnwood Covered Bridge currently remains in seasonal use as a pedestrian and light vehicle crossing on an unpaved road of the environmental education center campus.

The general dimensions of the Ashokan-Turnwood Covered Bridge are as follows:

Overall length: 72'6"

Overall width: 16'4"
Deck length: 60' 6"
Deck width: 13' 1"
Portal height: 11' 5"
Portal width: 13' 1"

This timber bridge is a single-span structure carried on abutments constructed of dry-laid fieldstone capped with concrete. The web of the superstructure incorporates the Town lattice truss. Heavy paired planks form the top chord; the bottom chord consists of four heavy hemlock planks, two enclosing each side of the lattice truss. Planks also form the intersecting diagonal members, which are joined by wood pins ('"trunnels") driven through each point of intersection. A pair of inclined timber abutments braces the sides of both portals. An extension of the gable roof supported on timber diagonal members shelters each portal. The bridge deck consists of planks laid longitudinally between the portal ends above a supporting system of saddle-notched timber floor beams and wood stringers. The entire bridge is covered in vertical board sheathing attached to wood nailers. Some of the original sheathing appears to have been re-used after the bridge was moved in 1939. To provide light to the interior of the span, a 3 by 24-foot, horizontal opening was cut through the sheathing on both side walls at an undetermined date before 1939. The roof sheathing consists of wood shingles fastened to wood nail strips. The present shingles applied in 1982 identically match the roofing material used when the bridge was reassembled on its present site in 1939.

A painted inscription on an interior portion of the truss web bears the legend, "Built 1885 by N. Tompkins". Extant numerals painted on individual truss members denote that the components were labeled according to their original configuration before the structure was relocated from Turnwood to Olivebridge.

Ashokan-Turnwood Covered Bridge, Olivebridge  New York North portal (1999)
North portal (1999)

Ashokan-Turnwood Covered Bridge, Olivebridge  New York South portal (1999)
South portal (1999)

Ashokan-Turnwood Covered Bridge, Olivebridge  New York South and east elevations (1999)
South and east elevations (1999)

Ashokan-Turnwood Covered Bridge, Olivebridge  New York West upstream elevation (1999)
West upstream elevation (1999)

Ashokan-Turnwood Covered Bridge, Olivebridge  New York Lattice Truss detail (1999)
Lattice Truss detail (1999)