Bridges

The Fink Deck Truss Bridge is thought to have been originally used on the Norfolk and Western mainline railway. It was moved to its present location and converted to a vehicular bridge over a railroad spur in 1893 when the Norfolk and Western mainline was moved. It was relocated again in 1985 to Lynchburg's Riverside Park to serve as a pedestrian bridge.

The Wheeling Suspension Bridge was the first bridge to span the Ohio River. It was initially completed in 1849, but destroyed by a tornado five years later. The bridge was rebuilt in 1856. The replacement bridge has the same general appearance of the original structure; the massive towers, anchorage housings, and island approach are all the original stone masonry.

Not only was Dunlap's Creek Bridge the first cast-iron bridge in America, it was the first metal bridge anywhere to use what its builder, Capt. Richard Delafield, U.S. Army Corps of Engineers, described as "standardized, interchangeable, manufactured parts." The bridge was built as part of the federal government's effort to make repairs on the National Road  before handing authority over to the states. Dunlap's Creek at Brownsville was an especially troublesome crossing, having destroyed three previous bridges since 1801.

The significance of the 15-mile Whitewater Canal was not in its ability to create a profit, but rather its effect on the economic growth of the Whitewater River Valley, considered the gateway to the interior of Indiana. Before the canal, travel was challenging. Most waterways in Indiana were only navigable by canoe, and the alternative - horse and wagon - was difficult, slow and expensive.  

The Delaware Aqueduct provided an important transportation link between the Pennsylvania's coalmines and New York's booming industrial marketplace. It is the earliest surviving work of John A. Roebling, who designed the Brooklyn Bridge  30 years later. The cable anchorage system first used on this project was also used on the Brooklyn Bridge. The aqueduct is patterned after Roebling's design of the Pennsylvania Canal over the Allegheny River, and is the oldest metal strand cable suspension bridge still standing in the U.S.

This elegant cast iron arch bridge designed by Scotland's famous Thomas Telford was built from 1812 to 1814.  It is the earliest surviving example of a portable lattice-braced standard type that Telford developed for use at wide and deep water crossing sites unsuitable for masonry spans.  At least 10 of these bridge types were erected throughout Britain between 1814 and 1829.

In 1899, engineers from the City of Chicago's Division of Bridges and Viaducts performed a survey of moveable bridge design in the U.S. and Europe. Their study led to the conclusion that the unusual trunnion bascule design would best meet their needs.

The Cornish-Windsor Covered Bridge is the longest wooden bridge in the United States and the longest two-span, covered bridge in the world. It is also a classic example of wooden bridge-building in 19th-century America. With copious supplies of timber at hand and a generous reserve of carpentry skills available, bridge builders in early America quickly discarded the masonry arches prevalent in the Old World. Instead, they opted for a revival of timber-truss designs dating from 14th century Europe.

Built by Robert Stephenson to carry the Chester and Holyhead Railway across the River Conwy, this bridge was erected between 1846 and 1848. It consists of a single span 400 feet long, formed by two parallel rectangular wrought iron tubes, each weighing 1300 tons. Masonry towers were built on the abutments and topped with battlements and turrets to harmonize with the nearby Conwy Castle. The Conwy Tubular Bridge was the first railway bridge in which trains ran through the main girders. It represents a pioneering use of wrought iron for bridges.

When a new road bridge was constructed alongside it, plans were made to demolish the Conwy Suspension Bridge. There was a national outcry and, since 1958, the bridge has been in the care of the National Trust and closed to vehicular traffic.