Othmar Ammann's Glory

Genius, willpower and thousands of miles of steel wire went into the George Washington Bridge

  • By Valerie Jablow
  • Smithsonian magazine, October 1999

Article Tools

  • Font
    		•  Share/Save/Bookmark Share
  • Email
    		•
  • Print
    		•  Digg Digg
  • Comments
    		•  StumbleUpon StumbleUpon
  • RSS
    		•  Reddit Reddit

    (Page 2 of 3)

    Through all of this, Lindenthal's dream for a span over the Hudson continued. But what was grand in 1888 had, through decades of deferment, become fantastical. By 1923, Lindenthal's plan called for a bridge more than 200 feet wide, with two decks, one for 12 railroad tracks, the other for 20 vehicle lanes, including two for trolleys. Its massive concrete towers, at 825 feet high, would rise above even the ten-year-old Woolworth Building, then the world's tallest skyscraper. The price: at least a cool $200 million (nearly two billion in today's dollars). Ammann deferentially warned Lindenthal that such a costly project would never be realized. But the old master sharply rebuked his assistant for his "timidity and shortsightedness in not looking far enough ahead," as Ammann noted in his diary. "He stated that he was looking ahead for 1,000 years."

    A thousand years or no, his professional relationship with Lindenthal quickly deteriorated. "In vain," wrote a frustrated Ammann to his mother later that year, "I as well as others have been fighting against the unlimited ambition of a genius that is obsessed with illusions of grandeur. He has the power in his hands and refuses to bring moderation into his gigantic plans. Instead, his illusions lead him to enlarge his plans more and more."

    Working on his own, Ammann had developed another scheme. Quietly, he wrote to the governor of New Jersey with suggestions for a smaller, cheaper suspension bridge to be built across the Hudson at 179th Street. The newly formed Port of New York Authority, which enjoyed both states' cooperation and had a short time before rejected Lindenthal's expensive monstrosity, was immediately interested — to Lindenthal's understandable dismay. "Now it appears that A. has used his position of trust, the knowledge acquired in my service...to compete with me in plans for a bridge over the Hudson and to discredit my work on which I had employed him," Lindenthal wrote despairingly to the governor. "He does not seem to see that his action is unethical and dishonorable."

    But new forces were at work. With construction under way for what would be known as the Holland Tunnel, it was assumed that connecting the metropolis to its burgeoning New Jersey suburbs by underwater routes would be cheaper than a bridge (a notion proved wrong well before the tunnel's 1927 completion). By that time, too, necessarily heavy (and expensive) railroad spans across the Hudson were steadily being eclipsed by less costly ones dedicated to a newly popular conveyance: the car. Already, in Philadelphia and Detroit, huge suspension bridges had been built for cars. The future was clear.

    By 1925, Ammann was bridge engineer for the Port Authority, charged with designing not only the 179th Street bridge (then known as the Hudson River Bridge) but also a bridge between Staten Island and New Jersey—both mainly for cars. Construction of the Hudson bridge began in the fall of 1927, with more than 100,000 miles of cable wire strung across the river by John Roebling's company.

    By any standard, the bridge was monumental. With a 3,500-foot main span — nearly twice that of the next largest suspension bridge, built just two years before — its slender deck was to arch gracefully more than 200 feet above the Hudson. Its twin 604-foot towers would stand nearly 50 feet taller than the Washington Monument. And each of its four cables could support more than 90,000 tons — ten times more than each Brooklyn Bridge cable.

    For his design, Ammann owed as much to material advances since that 1883 wonder as he did to his own ingenuity. Improved steel ensured that when drawn to only 0.196 inch in diameter, each of the 26,474 wires that made one cable had a strength of at least 240,000 pounds per square inch—more than one and a half times that of the cable wires in the Brooklyn Bridge. And better machinery allowed the wires to be hung from the towers (a process called spinning) 16 times faster than in 1883. Engineers followed what they had learned from the behavior of their model, that ten-foot section of cable today in the Smithsonian's collections, to compress the wires together into their final, three-foot-diameter, cylindrical form.

    In the relentless Great Depression, the bridge became a sort of savior in steel. Completed six months ahead of schedule, it cost less than the $60 million originally allocated. "Fulfilling a dream of three-quarters of a century," ran the ecstatic headline in the New York Times. On October 24, 1931, in front of thousands of spectators, New York governor (and soon to be President) Franklin Roosevelt and New Jersey governor Morgan Larson opened the bridge, newly named in honor of George Washington. In tribute to his mentor, Ammann drove with Gustav Lindenthal onto the bridge that the older man had spent his lifetime fruitlessly dreaming of.

    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.

    No matter when it was built, the first bridge to span the Hudson River from New Jersey to New York City was destined for fame. After the Civil War, a single span was determined most suitable for the wide, heavily trafficked river just west of the fast-growing metropolis. But materials and engineering skill lagged far behind the dream.

    Until 1888. Just five years after the completion of John Roebling's Brooklyn Bridge, then the world's longest suspension bridge, 38-year-old Austrian-born engineer Gustav Lindenthal put forth a plan for a suspension bridge across the Hudson. It was a grand concoction: six railroad tracks, more than a mile in total length. Its center span was to be nearly twice as long as that of Roebling's widely admired masterpiece.

    Great feats of engineering require greater feats of imagination. For both, Lindenthal was well qualified. With little formal education and a physique to match the size of his dreams, he had taught himself English and the rudiments of engineering. Immigrating to America in 1874, he quickly prospered in his adopted land, whose engineers had more use for quick thinking and practical energy than college degrees.

    By the turn of the century, Lindenthal was renowned among his peers. His Seventh Street and Smithfield Street bridges in Pittsburgh were some of the most significant of their time. In 1902, Lindenthal became commissioner of bridges for New York City, a political appointment that gave him considerable power and prestige as an engineer and designer. But his dream bridge still had not been built. Despite endorsement of Lindenthal's Hudson River bridge plan by the War Department, a rival bridge concern had sued to stop the project. By the time the case was settled, the depression of the early 1890s had dried up most of the funds. Replaced as commissioner after the 1903 city elections, Lindenthal found himself in the odd position of peddling new Hudson River bridge designs to myriad interested groups — with no agreement on location, cost or funding.

    In the meantime, the city grew. By 1912, Lindenthal was busy completing plans for a railroad bridge — the world's longest steel arch bridge, in fact — across the dangerous channel between Manhattan and Queens called Hell Gate. To help with the task, the august designer took on a 33-year-old assistant not long arrived from Switzerland.

    Slight in stature, with a quiet demeanor that hid a steely core, Othmar Ammann seemed the opposite of the large, bluff, practically educated Lindenthal. Ammann's degree, unlike any that Lindenthal might occasionally claim, was from a Swiss institute of technology considered one of the most prestigious in the world. Ammann was impressed by his mentor, one of the world's preeminent bridge builders — and the favor was returned. "I estimate an engineer one-third by his character, one-third by his ability, and one-third by his experience," Ammann recalled Lindenthal saying before promoting him for outstanding work on the Hell Gate Bridge project.

    Through all of this, Lindenthal's dream for a span over the Hudson continued. But what was grand in 1888 had, through decades of deferment, become fantastical. By 1923, Lindenthal's plan called for a bridge more than 200 feet wide, with two decks, one for 12 railroad tracks, the other for 20 vehicle lanes, including two for trolleys. Its massive concrete towers, at 825 feet high, would rise above even the ten-year-old Woolworth Building, then the world's tallest skyscraper. The price: at least a cool $200 million (nearly two billion in today's dollars). Ammann deferentially warned Lindenthal that such a costly project would never be realized. But the old master sharply rebuked his assistant for his "timidity and shortsightedness in not looking far enough ahead," as Ammann noted in his diary. "He stated that he was looking ahead for 1,000 years."

    A thousand years or no, his professional relationship with Lindenthal quickly deteriorated. "In vain," wrote a frustrated Ammann to his mother later that year, "I as well as others have been fighting against the unlimited ambition of a genius that is obsessed with illusions of grandeur. He has the power in his hands and refuses to bring moderation into his gigantic plans. Instead, his illusions lead him to enlarge his plans more and more."

    Working on his own, Ammann had developed another scheme. Quietly, he wrote to the governor of New Jersey with suggestions for a smaller, cheaper suspension bridge to be built across the Hudson at 179th Street. The newly formed Port of New York Authority, which enjoyed both states' cooperation and had a short time before rejected Lindenthal's expensive monstrosity, was immediately interested — to Lindenthal's understandable dismay. "Now it appears that A. has used his position of trust, the knowledge acquired in my service...to compete with me in plans for a bridge over the Hudson and to discredit my work on which I had employed him," Lindenthal wrote despairingly to the governor. "He does not seem to see that his action is unethical and dishonorable."

    But new forces were at work. With construction under way for what would be known as the Holland Tunnel, it was assumed that connecting the metropolis to its burgeoning New Jersey suburbs by underwater routes would be cheaper than a bridge (a notion proved wrong well before the tunnel's 1927 completion). By that time, too, necessarily heavy (and expensive) railroad spans across the Hudson were steadily being eclipsed by less costly ones dedicated to a newly popular conveyance: the car. Already, in Philadelphia and Detroit, huge suspension bridges had been built for cars. The future was clear.

    By 1925, Ammann was bridge engineer for the Port Authority, charged with designing not only the 179th Street bridge (then known as the Hudson River Bridge) but also a bridge between Staten Island and New Jersey—both mainly for cars. Construction of the Hudson bridge began in the fall of 1927, with more than 100,000 miles of cable wire strung across the river by John Roebling's company.

    By any standard, the bridge was monumental. With a 3,500-foot main span — nearly twice that of the next largest suspension bridge, built just two years before — its slender deck was to arch gracefully more than 200 feet above the Hudson. Its twin 604-foot towers would stand nearly 50 feet taller than the Washington Monument. And each of its four cables could support more than 90,000 tons — ten times more than each Brooklyn Bridge cable.

    For his design, Ammann owed as much to material advances since that 1883 wonder as he did to his own ingenuity. Improved steel ensured that when drawn to only 0.196 inch in diameter, each of the 26,474 wires that made one cable had a strength of at least 240,000 pounds per square inch—more than one and a half times that of the cable wires in the Brooklyn Bridge. And better machinery allowed the wires to be hung from the towers (a process called spinning) 16 times faster than in 1883. Engineers followed what they had learned from the behavior of their model, that ten-foot section of cable today in the Smithsonian's collections, to compress the wires together into their final, three-foot-diameter, cylindrical form.

    In the relentless Great Depression, the bridge became a sort of savior in steel. Completed six months ahead of schedule, it cost less than the $60 million originally allocated. "Fulfilling a dream of three-quarters of a century," ran the ecstatic headline in the New York Times. On October 24, 1931, in front of thousands of spectators, New York governor (and soon to be President) Franklin Roosevelt and New Jersey governor Morgan Larson opened the bridge, newly named in honor of George Washington. In tribute to his mentor, Ammann drove with Gustav Lindenthal onto the bridge that the older man had spent his lifetime fruitlessly dreaming of.

    Even more revolutionary than its length was the bridge's lack of a common design feature. Until the George Washington, modern suspension bridges were stiffened with steel trusses and beams to limit motion in traffic and wind (an important consideration when a bridge's length is large relative to its width and depth, like the George Washington's). But such stiffening often gave bridges less attractive, thicker decks — and added cost. Ammann reasoned that the sheer weight of his span, and its necessarily heavy cables, would by themselves provide sufficient stiffness.

    The George Washington's resulting slender profile — both from the side as well as from above — fueled engineers' aesthetic sensibilities. Just six years later, the Golden Gate Bridge astounded the world with a narrower and yet even longer span. If such gracefully thin and relatively light bridges were sometimes disconcertingly flexible in a breeze (as drivers and engineers noted), they also were lovely to look at.

    In 1940, however, the extremes of Ammann's innovation were dramatically demonstrated in the wind-driven collapse of the aptly nicknamed "Galloping Gertie," otherwise known as the Tacoma Narrows Bridge. After his investigation of that famous failure, which had been captured on film for the nation to see, Ammann wrote, "Its smaller weight and extreme narrowness has drastically revealed that this practice has gone too far."

    By the early 1960s, when the George Washington's lower deck was added (as specified in the original plans), Ammann had all but eclipsed his mentor. Ammann's other 1931 creation, the Bayonne Bridge connecting Staten Island and New Jersey, was until 1977 the world's largest steel arch bridge — more than 600 feet longer than the previous record holder, Lindenthal's Hell Gate Bridge.

    Months before his death in 1965, Ammann gazed through a telescope from his 32nd-floor Manhattan apartment. In his viewfinder was a brand-new sight some 12 miles away: his Verrazano-Narrows suspension bridge. As if in tribute to the engineering prowess that made Ammann's George Washington Bridge great, this equally slender, graceful span would not be surpassed in length for another 17 years.

    By Valerie Jablow


    1 2 3


     
    Comments

    we want more about engineering all the pioneers the greatest things the did please

    Posted by JOJO on March 1,2008 | 10:21AM

    Post a Comment


    Name: (required)

    Email: (required)

    Comment:



    Advertisement


    - - - Advertisements - - -


    Join Us

    Facebook

    Facebook

    Become a fan of Smithsonian magazine's official Facebook page!

    Twitter

    Follow Smithsonian magazine on Twitter

    Smithsonian magazine presents

    6th Annual Smithsonian Photo Contest Winners

    Out of more than 17,000 entries contributed from around the world, Smithsonian and its readers select the year's best