The Rogue River Bridge was the most advanced concrete bridge in America when it was built. Distinguished bridge engineer Conde McCullough employed the techniques of Frenchman Eugene Freyssinet to create thin, graceful concrete arches for this seven-span structure.
Pre-compression of the concrete arch was achieved and, as a result of its success, pre-stressing became one of the hallmarks of American bridge building techniques.
The granite milestones marking the Mason-Dixon Line bear crests from the two parties involved in the land-grant dispute, the families of William Penn and Charles Calvert (also known as Lord Baltimore).
Designed by Claude A. P. Turner, a pioneer of reinforced concrete construction, the Marshall Building was constructed originally in 1906 as a five-story building. In 1911 the sixth floor of the building was added as per Turner's original design. This building is the oldest extant example of Turner's "mushroom" flat-slab system which transformed the design and construction of reinforced-concrete floors worldwide.
When opened in 1909, the 1,470 foot long main span of the Manhattan Bridge was the third longest suspension bridge span in the world, after the nearby Brooklyn and Williamsburg Bridges. The Manhattan Bridge has two 725 foot long suspended side spans for an overall length of 2,920 feet. The bridge deck is supported by 4 main cables of 20.75 inch diameter, each composed of more than 35,000 individual wires. The bridge deck is stiffened by four parallel trusses of 24 foot depth, hinged at the towers.
The Mackinac (pronounced "Mack-in-awe") Bridge (1957) spans the Straits of Mackinac between Lake Michigan and Lake Huron, connecting the Lower and Upper peninsulas of Michigan. Prior to the construction of the bridge, a fleet of nine ferries would carry as many as 9,000 vehicles per day, with traffic backups stretching as long as 16 miles.
Machu Picchu represents the culmination of Inca public works building standards and technology, as well as 4,000 years of Andean community development. This landmark is the most well known archaeological site in South America and serves as a destination site for world travelers. It was a royal estate for Emperor Pachacuti.
Ancient Chinese literature refers to the Zhaozhou Bridge as a "crescent moon rising from the clouds" or a "rainbow in the sky." Throughout its history, it has been known as the Anchi or Anji Bridge (literally "safe crossing"), the Dashi Bridge ("big stone"), and the Dashiqiao ("great stone") Bridge.
In the 1850s, the Lexington and Danville Railroad began building a suspension bridge over the Kentucky River. The bridge was designed by John A Roebling. Due to unforeseen increases in train loads, the Roebling bridge was never completed. The High Bridge would then be built 20 years later on the existing foundations.
Some of the station's notable achievements:
The first method for detecting radioactive particles in water supplies
A successful system of slow-sand filter beds for drinking water
The landmark demonstration that microorganisms carried within filter media could degrade sewage
The Lake Moeris Quarry Road, in the Faiyum District of Eygpt, is the oldest road in the world of which a considerable part of its original pavement is still preserved. This road was used to help transport the heavy blocks of basalt from the quarry 43 miles southwest of Cairo to the royal sarcophagi and pavements for the mortuary temples at Giza just outside Cairo. The road covered the 7.5 miles from the quarry to Lake Moeris which, at that time, was 66 ft above sea level.
