1985

Before the Davis Island Lock & Dam were built, the flow of the Ohio River slowed to little more than a trickle during dry periods. For several months each year, the unreliable flow stranded Pittsburgh's steamboats, towboats, and barges.    

The Davis Island Lock & Chanoine Dam experimental project was the first lock and dam ever constructed on the Ohio River. Its achievements also included the first rolling lock gates, the largest movable dam built in the 19th century, and the widest chamber in world history.    

When erected by Peter Grubb to smelt the rich iron ore of the nearby Cornwall ore banks, this stone-built blast furnace was typical for its time, producing about 20 tons of pig-iron and cast-iron products a week. A major reconstruction in 1856 to 1857 produced important changes: the furnace itself was enlarged; the blast-air bellows were replaced by a pair of wooden cylinder "blowing tubs"; the waterwheel that had powered them was replaced by a 20-horsepower steam engine; and a pair of waste-heat boilers to supply the engine was built into the open stack of the furnace.

The Chesapeake & Delaware Canal is the only canal built in 19th-century America that still operates today as a major shipping route. Connecting the Port of Baltimore and Upper Chesapeake Bay with the mouth of the Delaware River and the Port of Philadelphia, the canal was one of the first civil engineering projects proposed in the New World and one of the most difficult to carry out. Although only 14 miles long, the canal's original cost made it one of the most expensive canals ever built in America.  

The idea of a canal eliminating the costly and dangerous sea trip around the Massachusetts peninsula of Cape Cod was envisioned as early as 1623 by Pilgrim leader Miles Standish. It was not until financier August Belmont became involved in 1906, however, that sufficient funds for the project could be raised. Belmont had been the primary backer of New York City's first subway, and chose the subway's chief engineer, William Barclay Parsons, as the canal's project director.  

The longest steel-arch bridge in the world for 46 years, the Bayonne Bridge continues to be celebrated today as a major aesthetic and technical achievement. The 1,675-foot bridge replaced a ferry service which until then was the only means of crossing from  the Bayonne peninsula to Staten Island. While providing this essential link in the transportation network of greater New York City, the bridge's mid-span clearance of 150 feet also allows for unobstructed navigation on Newark Bay, the main shipping channel to the inland ports of Newark and Elizabeth, New Jersey.

This is one of the three original 60-ton vessels by which the basic oxygen process (BOP) of steel making was introduced into this country from Austria, where it was invented. It heralded the first new technology in fifty years to become the basis of a major process for steel production throughout the world. In this process, a water-cooled lance injected a jet of high-purity oxygen into the bath of molten iron. Various chemical reactions produced a quality low-nitrogen steel at a ton-per-hour rate nearly three times that of the open hearth furnace.

The Atlas E-2 Space Booster, or launch vehicle, is a modified intercontinental ballistic missile developed by the Convair Division of General Dynamics and the U.S. Air Force. The basic concept of the Atlas system was proven in its first flight on June 11, 1957, followed over the years by the launching more than five hundred vehicles including the Pioneer, Ranger, Mariner, and Surveyor. Many payloads were sent into orbit as detachable sections of Atlas missiles.