Stark Covered Bridge, Groveton New Hampshire
The graceful design and picturesque setting of the mid-19th century Stark Covered Bridge makes it one of New Hampshire's best-known covered bridges; the subject of innumerable calendars, Christmas cards, paintings, and illustrations; a favored stop on the Canadian National Railroad annual North Country foliage tours; the scene of "Covered Bridge Dances" for local fundraising projects; and, illuminated at Christmas, a traditional focal point for holiday celebrations. The Stark Bridge owes its existence to artists and covered bridge buffs, who convinced the state legislature to appropriate funds to preserve the structure as a bridge "of historic value and an asset to the state" (Senate Joint Resolution #9, 1947) although the town had voted to replace it with a steel span. Following standard state practice, the Stark Covered Bridge has been modified structurally over the years in response to flood damage and increasing traffic loadings.
The Stark Covered Bridge is also important as an example of the Paddleford truss type, an unpatented regional variant of the Long truss, originated by Peter Paddleford of Littleton, New Hampshire; other examples are located in nearby Groveton and Lancaster, New Hampshire, as well as in Carroll County, New Hampshire and Oxford County, Maine. It is noteworthy that almost all of the Paddleford truss bridges were later, like the Stark Bridge, strengthened with added Burr-type arches, suggesting an inherent (but not irremediable) flaw in the truss design. At Stark, the ultimate substitution of steel stringers and a new center pier, replacing a poorly built successor to a flood-damaged support, made it possible to recapture the original Paddleford truss configuration by removing the arches. However, even the use of concrete and carefully concealed steel stringers has not entirely alleviated the dangers of overloading. The Stark Covered Bridge is the only crossing of the Upper Ammonoosuc for approximately four miles downstream and two miles upstream, and has historically been an important transportation link between communities on the north and south sides of the river. With the increasing importance of wood harvesting in the area, the bridge has been subjected to substantial truck and heavy equipment traffic; during 1979 the portals were damaged by large trucks loaded with logs. This prompted two different responses in the town: one, that the bridge was an extraordinary local and state resource that should be preserved intact; the other, that the bridge was an impediment to local economic activity and should be replaced, or the roof and superstructure removed, to eliminate the need for large trucks to detour around it.
Bridge Description
The Stark Covered Bridge was built in the mid-nineteenth century (some sources specify a date of 1857, while others cite 1862) across the upper Ammonoosuc River in Stark, New Hampshire, linking what is today New Hampshire Route #110 with the local "Northside Road". It replaced a floating bridge positioned a short distance eastward (upriver).
The approximate dimensions of the bridge are 138 feet shore-to-shore, with a portal extension of 6.5 feet at each end, for an overall length of 151 feet; the bridge carries an 18-foot roadway and two external sidewalks, making a total width of 29 feet.
The bridge was originally built as a 2-span Paddleford truss; but in 1890 (1895, according to one reference) a spring freshet tore away the center pier and carried the bridge downstream, where it is said to have been saved by being snagged in debris. The stone abutments were reconstructed and the bridge was hauled back and set in place again. At that time laminated arches were introduced to eliminate the need for the center pier, which was considered a source of danger during floods. The bridge remained intact until 1938 when the arches were repaired; but they subsequently began to sag, and in 1946 a temporary center pier of wood was introduced.
In 1954 the bridge was reconstructed: the wooden center pier was replaced with one of concrete, the arches were removed, the roof was repaired, and four concealed steel beam stringers were introduced to bring the live load capacity up to 15 tons. (This attests to the importance of the Stark bridge as a transportation link: most covered bridges in New Hampshire are maintained at a 6 to 8 ton live load capacity.)
At present, the Stark Covered Bridge is a single-lane, two-span wooden Paddleford-type wooden covered truss bridge. It rests on flared abutments of rectangular split granite blocks set in mortar; the central pier is constructed of reinforced concrete with smoothly finished downward-sloping sides and integral rounded ends; the eastern (upstream) side of the pier has a greater flare, to deflect flood-borne debris. The open (unenclosed) upper portion of the truss consists of 18 panels of single-component crossed diagonals secured to crossed-diagonal lateral ceiling bracing by angled keenbraces. Vertical panel posts are single units, except over the center pier where they are doubled. Top chords are laminated; bottom chords, floor construction, and lower lateral bracing are concealed by the floor and sidewalk decking of wood plank laid crosswise between the trusses. A heavy timber curb protects the lower edge of the truss from traffic and supports the sidewalk flooring. The two sidewalks are attached to the exterior sides of the trusses, beneath the flared eaves of the gabled portals, and are supported by vertical wooden posts lighter than the truss uprights. The lower portion of the sidewalks is enclosed by an exterior 'wainscot" of flush-boarded planking. A handrail of two horizontal planks, attached to round wooden posts along the top of the abutment wing walls, links each sidewalk to the roadway shoulders.
The projected, flared gable portals of the Stark Covered Bridge, though typical of the configuration favored by mid-19th century New Hampshire bridge builders, are particularly graceful examples of their type. The medium-pitch roof encompasses three semi-elliptical openings: two smaller sidewalk entrances flanking a large central archway over the roadway. Each is delineated by a plain wooden casing centered with a wooden keystone; the adjoining ellipses spring from shared plain wooden impost blocks from which acorn-shaped turned wooden drops are pendant. A segmental ellipse links the outer imposts and the projected eaves, which have plain enclosed "box" soffits, a plain wooden fascia band, and a plain unmoulded wooden frieze. The roof is covered with wooden shingles laid on purlins without sheathing. The entire portal unit is extended approximately a 2/3 bay distance beyond the truss ends, through use of a diagonal wooden strut projected from the first panel upright on each side of the truss. The overall effect, particularly when the bridge is viewed obliquely from either end, is almost ethereal, belying the massive proportions of the trusswork and the length of the span.
The portals (including trim and diagonal struts), the sidewalks (including vertical supports and exterior sheathing), and the approach handrails are painted white; the remainder of the timber components of the bridge are natural weathered wood.
The bridge is classified by the New Hampshire Department of Public Works & Highways as Bridge #115/091 and by the New Hampshire Department of Resources & Economic Development as Covered Bridge #37; it is listed in the World Guide to Covered Bridges as Bridge #29-04-05.
Northwest portal (which faces Northside Rd.) looking through bridge to Rt. 110. Note damage to portals from large trucks (1980)
