Canton Viaduct

NA The Canton Viaduct is a multiple-arch granite viaduct 615 feet in length, 22 feet wide, and approximately 70 feet above the surface of the East Branch of the Neponset River. The viaduct was the principal structure on the Boston & Providence Railroad's main line, and the last to be completed, opening July 28, 1835. At the time, noted Hayward's Gazeteer of 1847, the structure was "widely conceded the most elegant and massive structure of masonry in the United states."1 In an unusual departure from contemporary construction practice, the structure is not solid, composed instead of two parallel walls, 4 feet apart and each 5 feet thick, extending the entire length of the viaduct.

At intervals of 27-1/2 feet, the walls are connected with buttresses 5-1/2 feet thick, extending transversely across the walls and projecting 4 feet beyond their faces.2 A series of segmental arches link the buttresses at the top of the viaduct, supporting the cantilevered roadbed. At the base of the viaduct, six rounded arches 8 feet 4 inches in span allow the East Branch to pass beneath, while Neponset Street passes through a larger 22-1/2-foot arch. Foundations of the structure extend to a depth of eight feet below the ground level. The entire viaduct is built on a 1-degree curve. In 1860 a second track was laid on the narrow structure.

To accomplish this, the original parapet walls were removed and a skeleton platform constructed of transverse double-cantilever wooden beams on top of the masonry and under the track rails.3 This placed the outer rail of each track directly over the arches. Although the wooden beams were replaced by those of iron in 1880, the increasing weight of trains directly on the arches finally caused a failure of several arches in 1909.

(in one paragraph) Builder/Architect William Gibbs McNeill, Dodd and Baldwin The Canton Viaduct possessesintegrity of location, design, setting, materials, and workmanship. The viaduct is significant structure as well as for its association with the development of the Boston & Providence Railroad. The engineers responsible for its construction, William Gibbs McNeill and George Washington Whistler, were then among the nation's preeminent railroad engineers. Together with the Baltimore & Ohio's Carrolton and Thomas viaducts (constructed in 1829 and 1835 respectively), the structure is one of the oldest surviving multiple-arch stone railroad bridges in the United States. The structure thus meets criteria A, B, C, and D of the National Register of Historic Places.

The East Branch of the Neponset provided one of the most important collection of mill privileges in this part of the county, and from 1700 on, the nearby village of South Canton was the industrial center of town and the surrounding area. In addition to the ordinary saw and grist mills, a gunpowder mill operated here prior to and during the Revolution; Leonard & Kinsley produced some of the first steel implements in the country; and in 1800, less than 100 yards above the future site of the viaduct, Paul Revere constructed one of the first copper rolling mills. The same distance downstream is the site of the earliest cotton spinning mill in Massachusetts, established by James Beaumont in 1803. Later manufacturers would include large factories for the production of silk and stove polish.

The coming of the railroad was an important factor in the industrial growth of South Canton. The Boston & Providence Railroad was incorporated in 1831. In laying out the railroad, nine different routes between Boston and Providence were considered.