Engineering

The University Avenue Bridge, an impressive adaptation of modern classicism to a limestone-faced, concrete on steel double leaf bascule bridge, carries university Avenue across the Schuylkill River. Its sweeping monumental piers and towers with bridge operator's houses remain visible from many vantage points. This graceful span forms an integral part of its surrounding cityscape, and serves as a visual landmark along the Schuylkill River.

The University Avenue Bridge runs north/south across the Schuylkill River, and links University Avenue in West Philadelphia, with South 34th Street in the Grays Ferry section of South Philadelphia. The bridge which has a clear height of thirty feet, measures 536 feet in length, and 100 feet in width. Five lanes wide, it accommodates four lanes of traffic going in two directions. The bridge has a pedestrian walkway on either side.

David Bernard Steinman: Born on 11 June 1886 in Khomsk, Brest, Belarus. Deceased on 21 August 1960 in New York, New York, USA. Associated with the following firms:Formerly:Founder(s): Robinson & Steinman; Steinman, Boynton, Gronquist & Birdsall; Steinman, Boynton, Gronquist & London.

Cret’s plan shows that he had learned to manipulate the École’s graphic conventions and to put a program “in order” (see Fig. 13). The contrast between the mosaique, the tapestry of broken lines that represent decorative floor and ceiling patterns, and the poché, the more heavily inked lines that indicate structure, make clear that the arrangement is a linear succession of volumes, with two relatively narrow rooms bracketing the more ample one at the center. The heavy unbroken outline of the main space underscores the lack of windows and reliance on top lighting, and thus its use for paintings and works on paper. The mosaique is more than decoration; it visually interweaves the volumes and defines a broad axial promenade, or path of movement, from the entrance to what is presumably the sidelit sculpture gallery that opens to a cascade of stairs leading down to the garden of fragments. All the pieces of a good Beaux-Arts plan are here: the clear proportions of the independent volumes, the axial disposition of openings, the warp and weft of the details, and the telling use of the graphic conventions of poché and mosaique so the design appears at once simpler than the sum of its parts and more ample than one might expect of a small museum

This an historic occasion. Today we are gathered here to dedicate a famous pioneer structure -- the oldest cable suspension highway bridge in the world -- as a national monument. Because this span has played a dramatic and significant role in the development of bridge engineering, and because its outstanding record of more than a century of distinguished service is interwoven with the unfolding panorama of American history, it is altogether fitting and proper that the shrine to thrill and inspire future generations.

When this great structure -- the first bridge over the Ohio River -- was completed in 1849, it was truly notable achievement. Its span of 1,010 feet was by far the longest in the world, the first time human courage and resourcefulness had achieved a span exceeding one-thousand feet.

I'm looking at two photographs, both taken in late August, 1907. In one, a great cantilever structure extends almost 900 feet from its pier -- half a huge bridge over the St. Lawrence River -- 40 million pounds of structural steel reaching toward Quebec. The second photograph is not so pretty. It shows 40 million pounds of what looks like wet spaghetti, splashed across the ground, leading away from the pier and off into the water.

For eight years the Quebec bridge project had been under the direction of an American engineer. He was Theodore Cooper, the biggest name in bridge building. Cooper had never produced a true superlative, and his first move was to extend the span from 1600 to 1800 feet. That got the piers out of the water and on to dry land. But it also made this the largest cantilever span ever attempted.

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.

A self-made man and one of America’s greatest engineers, James Buchanan Eads led a life inextricably intertwined with the nation’s most important waterway, the Mississippi River. He explored the river bottom in a diving bell of his own design; made a fortune salvaging wrecks; in the 1870s built the world's first steel bridge over the Mississippi at St. Louis; then deepened the river at its mouth, turning New Orleans into the second largest port in the nation. By the time of his death in 1887, Eads was widely acknowledged to be one of the most influential men of his day.

Paul Philippe Cret, architect, was born in Lyons, France, on October 23, 1876, the son of Paul Adolphe and Anna Caroline (Durand) Cret. He attended a Lycee in Bourg and studied architecture at the L'Ecole des Beaux-Arts in Lyons and the L'Ecole des Beaux Arts, Paris, where he graduated in 1903. At the Paris school he was awarded the Rougevin Prize and the Grand Medal of Emulation, both in recognition of his remarkable skill as a draftsman. In 1903 he was invited to teach architecture at the University of Pennsylvania, where he remained until his retirement in 1937.

In 1867 a convention for the improvements of the Mississippi and its tributaries met in St. Louis. Even at this early date the people were beginning to see vaguely that the Mississippi Valley was destined to be the ruling section of the country. Eads in his address to the convention showed that he foresaw it plainly. It was at this time he made clear his remarkable plans for the bridge. A little later in the same year the long-talked-of bridge at St. Louis was at last begun. The population of St. Louis at this time was about 100,000 inhabitants. The estimated cost of the bridge, $736,000, caused consternation among the city officials and there was some delay in the plans.

Drury Blakeley Alexander (1924-), architectural educator, served as professor at the University of Texas School of Architecture and continues to serve the city through the Historic Landmarks Commission and the University as a champion of the preservation of the University's historic buildings, resident historian, and special friend to the Architecture and Planning Library. Creative works, correspondence, memoirs, printed material, minutes, maps, images, photographs, student work, slides, and artifacts, (1887-1995) created or collected by Drury Blakely Alexander, evidence his career in education and interests in architectural history and preservation.