The Carlton Bridge is located in central eastern Swanzey, in a rural setting on Carlton Road east of New Hampshire Route 32. Carlton Road is one of the main routes connecting Swanzey village with East Swanzey. The bridge is a single span 67 feet 3 inches (20.50 m) in length and 16 feet 6 inches (5.03 m) wide, resting on granite abutments. Its roadway is 12 feet 4 inches (3.76 m) wide, sufficient for one lane of traffic.[2] Its exterior is sheathed in vertical board siding and is topped by a gabled roof. Its trusses have been reinforced with iron tie rods and other metal elements.[3]
The bridge was built in 1869 on a site that is believed to have had a bridge since 1789.[2] It is believed to be the only example of a Queenspost truss bridge in southern New Hampshire. This truss method is quite old, and is based on techniques used for building large structures such as churches and barns.[3]
The Carlton Bridge was repaired in 1997 by Wright Construction Co., Inc. of Mount Holly, Vermont. Work began with dismantling the bridge to provide access to the bottom chord; reusable pieces were stored in a nearby field. Crews replaced rotted wood throughout the bridge, including the trusses, floorboards, and rails. The repairs cost $414,025, with the State Bridge Aid Program covering 80 percent. The Carlton Bridge reopened on October 4, 1997. [4]