USA

In 1866, the Covington and Cincinnati Suspension Bridge was the largest suspension bridge in the world. Also called the Ohio Bridge, it was officially renamed the John A. Roebling Bridge in 1983. It was the first permanent bridge over the Ohio River and the only public project in America financed by private investors during the Civil War.

Renowned bridge designer John A. Roebling proposed the structure in 1846; but building the bridge would become a 20-year saga, with heated lobbying both for and against the crossing.

Although not the first four-wheel-drive vehicle or the first designed for rough, multipurpose field use, the Jeep MB was built as an unusual combination of these and other features of modern vehicle design in the World War II era.

The 16-story Ingalls Building, still in use today, was the world's first reinforced concrete skyscraper. Its success led to the acceptance of high-rise concrete construction in the United States.

Melville E. Ingalls, for whom the building is named, spent two years convincing city officials to issue a building permit. Skepticism was high, because the existing height record for a concrete building was only six stories.

In operation since 1944, the Icing Research Tunnel is the oldest and largest refrigerated icing wind tunnel in the world. Technology developed there enables aircraft to fly safely through icing clouds. Two firsts include the unique heat exchanger and the spray system that simulates a natural icing cloud of tiny droplets.

When completed in 1888 to a height of 90 feet, Sweetwater Dam was once the tallest masonry arch dam in the United States, and it led to many others of the same basic design. The original construction began in November 1886 under the direction of Frank E. Brown (civil engineer for Bear Valley Dam) with the rubble-masonry thin-arch design being 50 feet in height. Subsequently, the owner of the water system called upon civil engineer James D. Schuyler to continue and complete the project. Although the field of hydrology was very new and not fully understood at the time, Mr.