Contemporary (Post-WWII)

There are three basic types of movable bridges; the bascule, the vertical lift and the swing bridge. Multnomah County operates four movable bridges; one vertical lift and three bascule. The purpose of the following pages is to provide information on how Multnomah County operates these bridges and the distinguishing features of each type.

...Bascule bridges have sections that rotate upward and away from the centerline of the river, providing clear passage for river traffic. Side-by-side on the Willamette River in downtown Portland, the Morrison (left) and Burnside (right) bridges are two examples of bascule bridges. These two bascule type bridges have a very clean, uncluttered look to them because the counterweights and operating machinery are located out of sight in the piers supporting the bridge. The Morrison Bridge is a Chicago-type bascule bridge and the Burnside Bridge is a Strauss-type bascule bridge. Please refer to our pages titled Operation of a Chicago type Bascule Bridge and Operation of a Strauss type Bascule Bridge for a discussion on the workings of these types of bridges.

During the course of researching the Cabell family, I became curious about a relative on my pedigree chart named Charles Ellet, Jr. But the curiosity rose to full bloom when a childhood friend, Joan Poland, from my native home of Alexandria, Virginia mailed me clues about him in a book. Joan has been a DAR member all of her adult life, and she wanted me to read about one of DAR’s organizing members, Mary Virginia Ellet Cabell.

"Turn to page 45," Joan wrote. "This lady must be related to you." The book was A Century of Service: The Story of the DAR.

The current structure is the third bridge on this site. Lewis Wernwag built the covered wooden Monongahela Bridge in 1818, the first river crossing bridge in Pittsburgh. It replaced a ferry and cost $102,000. It was destroyed in the Great Fire of 1845 and replaced the following year.
Drawing of 1818 bridge

John Roebling, creator of the Brooklyn Bridge, designed a wire rope suspension bridge which used the 6 piers and abutments from the earlier bridge (8 spans, 188 ft each). Roebling's first highway bridge operated as a toll bridge. Increasing live loads from added traffic resulted in excessive deflections and swaying, leading to its closure and replacement with current structure.

Nearly 150 years ago, William Hamilton Merritt was the man who dreamed of building the first bridge over the Niagara River. He was the same man who had planned and built the first Welland Canal making it possible for shipping to circumvent the Falls at Niagara.

In 1846, permission was received from the Governments of Upper Canada and the State of New York for the formation of two companies with the ability to construct a bridge at or near the Falls. They were the Niagara Falls Suspension Bridge Company of Canada and the International Bridge Company of New York. Both companies would build and own the bridge jointly.

In the Fall of 1847, the bridge companies commissioned Charles Ellet Jr. to construct a bridge at a site selected along the Niagara River. This site was located along the Niagara Gorge above the beginning of the Whirlpool Rapids and was the narrowest point from shoreline to shoreline. This bridge would connect the site of what would become the Village of Elgin (now Niagara Falls).

In 1885, Gustav Lindenthal, a bridge engineer who established his reputation on two notable Pittsburgh spans, was approached by officials at the Pennsylvania Railroad regarding the feasibility of a railroad crossing across the Hudson River. At that time, the Pennsylvania Railroad was at a disadvantage vis-à-vis its chief competitor, the New York Central Railroad, because it did not have a direct entrance into Manhattan.

Because of the smoke that emanated from the locomotives of the era, the railroad favored a bridge across the Hudson rather than a tunnel. After giving serious thought to a cantilever design, Lindenthal decided upon a suspension bridge because such a design would allow wider distances between piers. However, the suspension bridge would have to have a main span of about 3,000 feet, nearly twice the length of the main span of the Brooklyn Bridge completed two years earlier.

Gustav Lindenthal had a dream. He wanted to build a bridge across the lower Hudson River, connecting Manhattan with New Jersey. I've got a far more modest dream. I want to run across the Hudson River on one of the bridges that has subsequently been built.

...Lindenthal was already a successful bridge builder when he came to New York City in 1885. He made his reputation in Pittsburgh, where he designed and supervised construction of bridges, including the Smithfield Street Bridge. Pittsburgh is a living primer of bridge construction. I don't know of a city with a denser collection of varied bridge designs. The Smithfield Street Bridge crosses the Monongahela River, connecting downtown Pittsburgh with "Sahside". This beautiful bridge is immediately recognizable with its lenticular trusses.

Few American cities can claim a landmark as distinctive as Cincinnati's Suspension Bridge. The Covington and Cincinnati Bridge, in 1984 renamed after designer John A. Roebling, and all the while called by locals simply "The Suspension Bridge", has been a symbol of the city since its opening in December of 1866. Images of the bridge can be seen today in all parts of the city hanging in homes, offices, restaurants, bars, waiting rooms, and as backdrops for the local television news. More than just a nostalgic decoration, the old bridge remains an important river crossing for thousands of cars and buses each day.

...The bridge opened to pedestrians in December 1866, and the 1,057ft. main span was at that time the longest in the world, surpassing the Wheeling, WV suspension bridge (1849). Not only was the Cincinnati Suspension Bridge the world's longest, but it was also the first to utilize both vertical suspenders and diagonal stays fanning from either tower. This advance was next seen on the Brooklyn Bridge (also designed by John Roebling), which surpassed the Cincinnati bridge in length and almost every other statistical category in 1883.

Some of Oregon's most noteworthy public works projects first saw life on the drawing tables of Frank G. Hutchinson and Harold L. Spooner. Other drawings by the two men were destined to remain dreams. The works shown here represent a small portion of the 110 drawings they produced from 1935 to 1957.

The bridge maker’s signs advertised the builders of the wrought iron bridges that were popular at the turn of the century. These were collected in Central Illinois during 1968-70. There are over 180 signs represented under the “Maker’s Sign” icon. The bridge signs and the bridges they represent are under the major category icon “Iron Bridges”.

Technocapitalism is a new form of market capitalism that is rooted in technological invention and innovation.  It can be considered an emerging era, now in its early stage, that is supported by such intangibles as creativity and knowledge.