Arch bridge

An arch bridge is a bridge with abutments at each end shaped as a curved arch. Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side. A viaduct (a long bridge) may be made from a series of arches, although other more economical structures are typically used today.

History

Possibly the oldest existing arch bridge is the Mycenaean Arkadiko bridge in Greece from about 1300 BC. The stone corbel arch bridge is still used by the local populace. The well-preserved Hellenistic Eleutherna Bridge has a triangular corbel arch. The 4th century BC Rhodes Footbridge rests on an early voussoir arch.

Although true arches were already known by the Etruscans and ancient Greeks, the Romans were - as with the vault and the dome - the first to fully realize the potential of arches for bridge construction. A list of Roman bridges compiled by the engineer Colin O'Connor features 330 Roman stone bridges for traffic, 34 Roman timber bridges and 54 Roman aqueduct bridges, a substantial part still standing and even used to carry vehicles. A more complete survey by the Italian scholar Vittorio Galliazzo found 931 Roman bridges, mostly of stone, in as many as 26 different countries (including former Yugoslavia).

Arch Bridge (Bristol, Maine)

The Arch Bridge is a historic stone arch bridge, carrying Benner Road over the Pemaquid River near the village of Bristol Falls in Bristol, Maine. Probably built before 1857, it is one of the state's oldest stone bridges, and is remarkably well-preserved for its age. It was listed on the National Register of Historic Places in 2003.

Description and history

The Pemaquid River roughly bisects the peninsula on the Maine coast that the town of Bristol occupies. The village of Bristol Falls is located near the peninsula's geographic center, stretching out along Bristol Road (Maine State Route 130). Near its northern end, Benner Road crosses the river just below the outlet of Biscay Pond, providing access from the village to the northeastern part of the peninsula. The bridge it crosses on is a dry-laid stone arch structure with span of 14 feet (4.3 m) and a total length of 21 feet (6.4 m). It is built out of roughly quarried stone and river cobbles, with its base laid directly on bedrock. The top of the arch is about 14 feet (4.3 m) above the bedrock, and it is built up another 4 feet (1.2 m) to the paved roadway. The sides of the bridge are lined with granite curbing and modern wooden guardrails.

Arch Bridge (Bellows Falls)

The Bellows Falls Arch Bridge was a three-hinged steel through arch bridge over the Connecticut River between Bellows Falls, Vermont and North Walpole, New Hampshire. It was structurally significant as the longest arch bridge in the United States when it was completed in 1905.

The bridge was built to circumvent an existing toll bridge and prevent people from using the Boston and Maine Railroad bridge, a practice the railroad preferred to discourage.

History

Due to industrial and transportation expansion, residential needs in the Bellows Falls and Walpole area expanded in the late 1800s. The only means of crossing the river was provided by the Tucker Toll Bridge and the Sullivan Railroad Bridge.

The Tucker Toll Bridge was a Town lattice truss covered bridge completed in 1840, which was acquired by the towns in 1904 and free thereafter. The Sullivan Railroad Bridge was originally built by the Sullivan Railroad, built in 1882 as a replacement for a 1852 span.

Residents didn't like the toll, and the Boston and Maine Railroad objected to pedestrians on its bridge, so following the town meetings in March 1904, the two communities formed a joint committee to buy out the toll bridge and replace it with a new bridge, with five members from each town. Walpole budgeted US$30,000 (US$790,000 with inflation), and Rockingham, Vermont, which includes Bellows Falls, offered US$15,000 (US$400,000 with inflation). The two towns established an agreement whereby maintenance costs would be shouldered two-thirds by Walpole and one-third by Rockingham.