Brooklyn Bridge

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Brooklyn Bridge


Bianca A. Tripșa, Andrei Popa


Fig. 1. Brooklyn Bridge[3]


Abstract

The Brooklyn Bridge (Fig. 1) over the East River in New York City is one of the oldest
suspension bridges with cable-stays in the United States, stretching 1825 m over the East River
connecting the New York City boroughs of Manhattan and Brooklyn. It’s largest span is of 487
m. The construction of the bridge was a bit of a challenge because the bridge’s designer and
constructor died while conducting surveys for the brigde project and had to place his son in
charge of the project. Also an estimated number of 27 people died during its construction. In
addition to being a major thoroughfare for commuters between Brooklyn and Manhattan, during
which it carries approximately 145,000 vehicles per day, the Brooklyn Bridge makes for a
wonderful walk, popular with New Yorkers and tourists alike, allowing for great views of Lower
Manhattan and all of New York City[1][2].

Keywords: suspension bridge, challenge, footbridge, city icon, road bridge, cable-stays, steel-
wire.





1. General information

The Brooklyn Bridge is a suspension bridge with cable-stays (Fig. 2) with the function of
pedestrian bridge (footbridge) also called “Great East River Bridge”. It’s construction started in
1869 and ended in 1883. It crosses the East River, linking Manhattan (New York, USA, North
America) with Brooklyn (New York, USA, North America). Since its opening, it has become an
icon of New York City, and was designated a National Historic Landmark in 1964 and a
National Historic Civil Engineering Landmark in 1972[2].



Fig. 2. Cable-stays of the Brooklyn Bridge[3]


2. Technical information (Table 1):

Table 1: List of technical information[2]
Carries Motor vehicles (cars only)
Elevated trains (until 1944)
Streetcars (until 1950)
Pedestrians and bicycles
Designer John Augustus Roebling
Design Suspension/Cable-stay Hybrid
Total length 1825 m
Width 26 m
Height 84.3 m above mean high water
Longest span 486.3 m
Clearance below 41 m at mid-span
Used materials Cables and deck – steel, towers - masonry
Opened 130 years ago

3. Construction

The Brooklyn Bridge was initially designed by German immigrant John Augustus Roebling, who
had previously designed and constructed shorter suspension bridges, such as Roebling's
Delaware Aqueduct in Lackawaxen, Pennsylvania, Waco Suspension Bridge in Waco, Texas,
and the John A. Roebling Suspension Bridge in Cincinnati, Ohio.

While conducting surveys for the bridge project, Roebling sustained a crush injury to his foot
when a ferry pinned it against a piling. After amputation of his crushed toes he developed a
tetanus infection which left him incapacitated and soon resulted in his death, not long after he
had placed his 32-year-old son Washington Roebling in charge of the project. Washington
Roebling also suffered a paralyzing injury as a result of decompression sickness shortly after the
beginning of construction on January 3, 1870. This condition, first called "caisson disease" by
the project physician Andrew Smith, afflicted many of the workers working within the caissons.
Roebling's debilitating condition left him unable to physically supervise the construction
firsthand.

Roebling conducted the entire construction from his apartment with a view of the work,
designing and redesigning caissons and other equipment. He was aided by his wife Emily
Warren Roebling who provided the critical written link between her husband and the engineers
on site. Under her husband's guidance, Emily studied higher mathematics, the calculations of
catenary curves, the strengths of materials, bridge specifications, and the intricacies of cable
construction. She spent the next 11 years assisting Washington Roebling, helping to supervise
the bridge's construction.

When iron probes underneath the caisson found the bedrock to be even deeper than expected,
Roebling halted construction due to the increased risk of decompression sickness. He later
deemed the aggregate overlying the bedrock 9 m below it to be firm enough to support the tower
base, and construction continued. Harbor pilot Joseph Henderson was called upon as an expert
seaman to determine the height of the water span of the Brooklyn Bridge.

The towers are built of limestone, granite, and Rosendale cement. The granite blocks were
quarried and shaped on Vinalhaven Island, Maine, under a contract with the Bodwell Granite
Company, and delivered from Maine to New York by schooner.

The Brooklyn Bridge was opened for use on May 24, 1883. The opening ceremony was attended
by several thousand people and many ships were present in the East Bay for the occasion.
President Chester A. Arthur and New York Mayor Franklin Edson crossed the bridge to
celebratory cannon fire and were greeted by Brooklyn Mayor Seth Low when they reached the
Brooklyn-side tower. Arthur shook hands with Washington Roebling at the latter's home, after
the ceremony. Roebling was unable to attend the ceremony (and in fact rarely visited the site
again), but held a celebratory banquet at his house on the day of the bridge opening. Further
festivity included the performance of a band, gunfire from ships, and a fireworks display.

On that first day, a total of 1,800 vehicles and 150,300 people crossed what was then the only
land passage between Manhattan and Brooklyn. Emily Warren Roebling was the first to cross the
bridge. The bridge's main span over the East River 486.3 m. The bridge cost $15.5
million[clarification needed] to build and an estimated number of 27 people died during its
construction.

On May 30, 1883, six days after the opening, a rumor that the Bridge was going to collapse
caused a stampede, which was responsible for at least twelve people being crushed and killed.
On May 17, 1884, P. T. Barnum helped to squelch doubts about the bridge's stability—while
publicizing his famous circus—when one of his most famous attractions, Jumbo, led a parade of
21 elephants over the Brooklyn Bridge.


Fig. 3. Plan of one tower for the Brooklyn Bridge, 1867[2]


At the time it opened, and for several years, it was the longest suspension bridge in the world—
50% longer than any previously built—and it has become a treasured landmark. Since the 1980s,
it has been floodlit at night to highlight its architectural features. The architectural style is neo-
Gothic, with characteristic pointed arches above the passageways through the stone towers. The
paint scheme of the bridge is "Brooklyn Bridge Tan" and "Silver", although it has been argued
that the original paint was "Rawlins Red". At the time the bridge was built, the aerodynamics of
bridge building had not been worked out. Bridges were not tested in wind tunnels until the
1950s, well after the collapse of the original Tacoma Narrows Bridge (Galloping Gertie) in 1940.
It is therefore fortunate that the open truss structure (Fig. 4) supporting the deck (Fig. 5) is by its
nature less subject to aerodynamic problems. Roebling designed a bridge and truss system that
was six times as strong as he thought it needed to be. Because of this, the Brooklyn Bridge is still
standing when many of the bridges built around the same time have vanished into history and
been replaced. This is also in spite of the substitution of inferior quality wire in the cabling
supplied by the contractor J. Lloyd Haigh—by the time it was discovered, it was too late to
replace the cabling that had already been constructed. Roebling determined that the poorer wire
would leave the bridge four rather than six times as strong as necessary, so it was eventually
allowed to stand, with the addition of 250 cables. Diagonal cables were installed from the towers
to the deck, intended to stiffen the bridge. They turned out to be unnecessary, but were kept for
their distinctive beauty.

Fig. 4. Bridge truss structure[3]



Fig. 5. Bridge deck[3]

After the collapse in 2007 of the I-35W highway bridge in the city of Minneapolis, increased
public attention has been brought to bear on the condition of bridges across the US, and it has
been reported that the Brooklyn Bridge approach ramps received a rating of "poor" at its last
inspection. According to a NYC Department of Transportation spokesman, "The poor rating it
received does not mean it is unsafe. Poor means there are some components that have to be
rehabilitated." A $508 million [clarification needed] project to replace the approaches began in
2010 and is scheduled to run until 2014. As part of this project, two approach ramps will be
widened from one lane to two, and clearance over the Brooklyn Queens Expressway will be
increased.


The bridge was built with numerous passageways and compartments in its anchorage. One
compartment on the Manhattan side was famously used to store champagne and wine for a local
dealer because of the consistent temperatures the space provided[2].


4. Cultural significance

Contemporaries marveled at what technology was capable of and the bridge became a symbol of
the optimism of the time. John Perry Barlow wrote in the late 20th century of the "literal and
genuinely religious leap of faith" embodied in the Brooklyn Bridge ... "the Brooklyn Bridge
required of its builders faith in their ability to control technology."

The Cuban poet José Martí wrote an article named "The Bridge of Brooklyn" for the magazine
La América, published in June 1883, shortly after the bridge opened to the public. The article
was published in his book "Escenas norteamericanas". In the article, Martí made comparisons
between certain animals (like snakes) and the structure of the bridge.

References to "selling the Brooklyn Bridge" abound in American culture, sometimes as
examples of rural gullibility but more often in connection with an idea that strains credulity. For
example, "If you believe that, I've got a bridge to sell you." George C. Parker and William
McCloundy are two early 20th-century con-men who had (allegedly) successfully perpetrated
this scam on unwitting tourists. The 1949 Bugs Bunny cartoon Bowery Bugs is a joking
reference to Bugs "selling" a story of the Brooklyn Bridge to a naïve tourist.

The Modernist American poet Hart Crane used the Brooklyn Bridge as a central metaphor and
organizing structure for his second and most important book of poetry, The Bridge. This book
takes the form of a long poem spanning eight parts, beginning with an ode ("Proem: To Brooklyn
Bridge") and ending with a transfigured vision of the bridge as the unifying symbol of America
("Atlantis"). Crane briefly lived in an apartment overlooking the bridge that, he later learned,
once housed Washington Roebling, the Brooklyn Bridge's builder and son of its architect, John
A. Roebling.

The bridge has been shown in films such as Annie Hall, Gangs of New York, Kate & Leopold, It
Happened in Brooklyn, I Am Legend, The Dark Knight Rises, and The Avengers. It has also
prominently featured in various television series, especially those set in New York City such as
CSI: NY[2].

Fig. 6. Bronze plaque[3]
A bronze plaque (Fig. 6) is attached to one of the bridge's anchorages, which was constructed on
a piece of property occupied by a mansion, the Osgood House, at 1 Cherry Street in Manhattan.
It served as the first Presidential Mansion, housing George Washington, his family, and
household staff from April 23, 1789 to February 23, 1790, during the two-year period when New
York City was the national capital. Its owner, Samuel Osgood, was a Massachusetts politician
and lawyer, who married Maria Bowne Franklin, widow of Walter Franklin, the New York
merchant who built it in 1770. Washington moved in a week before his 1789 inauguration as first
President of the United States. In addition to living quarters, the Osgood House contained the
President's private office and the public business office, making it the first seat of the executive
branch of the federal government.

"Love locks" is a practice by which a couple inscribe a date and their initials onto a lock, attach it
to the bridge and throw the key into the water as a sign of their "everlasting love". Although the
origin of the practice is unknown, it is more popular in Europe where 22 countries have at least
one city with a similar location. It has reportedly caused damage to certain bridges, and is
officially against New York city rules. The love locks are occasionally removed from the
Brooklyn Bridge[2].


5. References

[1] https://www.youtube.com/watch?v=Mh-6cEPiYUo, video description.

[2] http://en.wikipedia.org/wiki/Brooklyn_Bridge

[3] http://structurae.net/structures/data/photos.cfm?id=s0000011&min=50



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