Dalton Covered Bridge, Warner New Hampshire
Split by the Warner River, the town of Warner required many bridges in the nineteenth century to connect its many small mills and associated population centers. The first of many bridgings of the Warner River occurred at the Lower Village in 1774. The number of bridges, their names referring to mills and farmers that no longer exist, and the lack of nineteenth-century maps with place and owners' names make it difficult to determine whether or not the Dalton Bridge is the first bridge to occupy its site. The Dalton Bridge was built in 1853 for $630.12 by Joshua Sanborn, who constructed the wood part of the bridge, George Sawyer and Webster B. Davis, both of whom built the abutments. In 1871 extensive repairs were made to the bridge costing $134.81.
The panel truss system of the bridge is an almost complete duplication of an 1837 patented truss by Stephen Long; it seems that Long must have patented more than one truss design, for the one referred to here differs from what is commonly labeled a Long truss by the addition of an auxiliary queenpost. The presence of Long's brother, Dr. Moses Long, as a resident and the postmaster of Warner combined with his active role in promoting his brother's designs might explain the faithfulness to the patent design as well as give the bridge a more direct relationship with its truss designer than is the case with most other bridges.
Referred to in 1853 as the "Bridge near Mrs. Dalton's", the bridge has been subsequently referred to as the bridge near "Widow Dalton's", finally shortened to Dalton Bridge which is the current name for the bridge. The bridge has been in use since 1853 and continues to provide passage with a weight restriction of six tons on a one-lane roadbed. It mainly serves a rural population with little or no commercial traffic.
Bridge Description
The Dalton Bridge crosses the Warner River, connecting the town-owned Joppa Road on both sides of the river. The crossing is made in one span of multiple kingpost design with an auxiliary queenpost system.
The kingpost truss is eight panels with posts (9½" x 7½" each) which are notched to pass through a three-inch space that separates the top and bottom chords. Each chord is of two 9" x 5" members which are separated as described and joined to the posts by iron bolts. Each panel (except for the next to last panel at each end) is braced by a 9½" x 4½" board set on bearing blocks at either end; the center four panels have wooden counterbraces which are mortised and tenoned through the center of the braces. The outer three panels at both ends have iron tension rods as counterbraces (the end panels of the center four panels, thus, have both wooden and iron counterbracing). Overriding this system is a queenpost system that flanks both truss walls. Its top chord (10½" x 4½") is iron bolted onto the posts of the center four panels of the kingpost system, on both sides of the truss wall. The braces to this system pass largely through the next to last panel at each end of the bridge, providing bracing for these panels, from there they pass through the lower inside corner of the last panel at each end, and onto a footing on the abutments. They are visible from beneath the bridge. All members of the truss appear to be bolted in place or held by pressure. The truss is laterally braced by beams which are bolted to each post above the top chord and extend across the roadbed. These beams are connected by cross-bracing. The bottom chord has five sets of cross-bracing to provide lateral stability.
The truss rests on concrete footings on top of rectangular-shaped abutments of split and field stone laid up without mortar. The north abutment, itself, sits on a concrete footing in the river. The truss is secured to the abutments by an iron ten Sion rod at each corner; these rods extend from the top chord to the sidewalls of each abutment.
The bridge has an overall roof length of 84'4" connected to a roadbed of 76'4" by cutaway portals at each end, each portal having a vertical clearance of 11'. Overall width is 17'4" with a roadbed width of 14'1" narrowed to a passable width of 12'11" by guard rails on either side. The roadbed consists of four-inch thick boards laid lengthwise in the direction of the road, on top of 9" x 4" supports which rest on top of the bottom chord.
The exterior walls are sheathed in vertical boarding with four windows in each wall; most of the boarding is relatively new and being allowed to weather gray. The roof is of corrugated metal set on thin rafters that rise from the top chord and are supported by two vertical braces at each beam of the truss's top lateral bracing.
The bridge has been assigned the following numbers: 29-07-05 in the World Guide to Covered Bridges published by the National Society for the Preservation of Covered Bridges; 191-122 by the New Hampshire Department of Public Works and Highways.
In 1964 the Dalton Bridge was repaired at a total cost of $18,000 of which $10,800 was provided by the town of Warner, the rest was from the State of New Hampshire under the Town Bridge Aid Program. It seems apparent that the new concrete footings of the abutments as well as the new exterior boarding and possibly the roof covering date from this renovation.
North portal and east wall (1974)
