Secondary Source

Against the city's gleaming spires,

Above the ships that ply the stream,

A bridge of haunting beauty stands –

Fulfillment of an artist's dream.

Welcome to the Portland Bridges page, presented by Environmental Services, Oregon Department of Transportation. The bridges of Portland, Oregon are numerous and diverse. The structures, ranging in age from 27 years to 90 years of age, represent a variety of construction types including vertical lift spans, double-leaf Bascule drawspans, and the longest tied arch span in the world.

It was called the most beautiful bridge in the world. At the time of its 1931 opening, it certainly was the longest single span. To honor the engineering feat it represented, a stamp with its picture was issued, and the bridge became the subject of music, even a children's book.

Yet, a section of suspension cable for the George Washington Bridge in the collections of the National Museum of American History can only hint at such glories. Three feet in diameter and ten feet long, the massive cylinder weighs an ungainly 34,000 pounds. From its ends protrude 26,474 individual steel wires, compacted under 400 tons of pressure. Before computers, this experimental section helped engineers model the effects of compression on the finished bridge's cables. Today, it represents an engineering marvel, whose creation spanned half a century of depressions, politics and the passions of two of America's greatest bridge designers.

John Job Crew Bradfield was born in Sandgate, Queensland on the 26 December 1867; the son of John Edward Bradfield and Maria Crew.

He received the first part of his education at Ipswich State School and Ipswich Grammar School. Bradfield was the winner of the three exhibitions given each year by the Queensland government, which enabled him to study at Sydney University. He graduated as a Bachelor of Engineering in 1889.

Eleven major bridges unite New York City together and with the rest of the nation. One engineer was responsible for more than half of them, yet hardly anyone knows his name.

Othmar Ammann came to America as a graduate of Swiss engineering schools and learned bridge building from the reigning bridge engineer, Gustav Lindenthal. As his protégé, Ammann worked on the Hell Gate Railroad Bridge, an arch bridge of unprecedented strength and beauty. Lindenthal had plans for an enormous rail bridge across the Hudson River, but they were rejected as too expensive. Ammann proposed a lighter, less expensive span for automobiles and trucks. In a painful parting, he left Lindenthal and built the landmark George Washington Bridge, a span twice as long as any suspension bridge in the world.

One of the most interesting papers presented to the American Society of Engineers at the Seabright Convention is that of Mr. THEODORE COOPER on "American Railway Bridges." It is interesting from the historical matter contained in it, and here first systematically gathered together, and valuable as showing the progress of a branch of engineering that has made our country famous for its works of this nature. The paper is necessarily long, so that we cannot publish it in full, even did the rules of the society permit, and we must content ourselves with the following abstract. We congratulate Mr. COOPER upon the success attending his efforts to unearth and arrange much matter relating to the early history of wooden bridge building that has usually been considered inaccessible.

Aware that control of the country's river systems would important to both sides in the Civil War, Eads proposed the U.S. government invest in the development of steam-powered, ironclad warships. Eads made his proposal before the war, but his idea was coolly received. When he was awarded a contract, he employed upwards of 4,000 men to build the U.S. ironclad armada that would prove decisive in Union efforts against Forts Henry and Donelson, at Memphis, Island No. 10, Vicksburg, and Mobile Bay. In a remarkable feat Eads turned out his first ironclad 45 days after he began production. The ironclad idea would be adopted by the Confederacy and both sides would improve on Eads' idea throughout the war. After the war Eads found a new project, the spanning of the Mississippi with a suitable bridge to carry everything from people to trains. The self-trained engineer proposed a triple-arch design fabricated from steel. Each span was roughly 500 hundred feet and rested on piers resting on bedrock some 100 feet beneath the river bottom. The building of the arches involved steel supplied by Andrew Carnegie's steel works. Eads required that the 18 inch diameter hollow tubes conform to a test strength of 60,000 pounds. Many times during construction steel was returned to be re-rolled so that it might meet Eads' exacting standards. Keeping the shipping lanes open was necessary during construction, so Eads designed a cantilever system to support the unjoined arches. A system of pulleys stretched over the piers and supported the arches. Eads was also innovative in that he employed a threaded iron plug to close the arches. He allowed five inches on each arch to be used for threading the plug and closing the distance between the arches. The Eads Bridge was the largest of its kind and quickly became world renowned.

A gift of John F. Harbeson, the archive consists of Cret's student and professional work and is displayed on approximately four hundred and seventy-six sheets containing one or more drawings, photos, or prints per sheet. The archival holdings may be broadly divided into eighty-eight sheets of student work at the Ecole des Beaux Arts in Lyon and Paris, fifty-three student and professional watercolors, thirteen sheets of bookplates, seals, medals and title pages, fifty-six sheets of competitions (thirty-two of various university designs), nine sheets of commercial work, one hundred and two of memorials, twenty-two sheets of government buildings, twelve residential designs, twenty-one sheets of bridge designs, five sheets of watercolors and ink sketches by Col. Oscar Lahalle (Cret's father-in-law), and one hundred and eleven sheets of varied design work.

Begun in 1867 and completed in 1874, the Eads Bridge was named after its designer, James Buchanan Eads. It was the first bridge to span the Mississippi at St. Louis, the first bridge to make significant of steel, and one of the first bridges in the U.S. to make use of pneumatic caissons (the caissons sunk for the bridge are still among the deepest ever). It was also the first bridge to be built entirely using cantilever construction methods, avoiding the need for falsework, and the first bridge designed so that any part could be removed for repair or replacement. The bridge is now a National Historic Landmark.

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.