THERE are older, higher, longer and more unusual spans in the world but none created the excitement during construction or weathered the passing of nearly a century with anything like the fame of the Brooklyn Bridge. It carried its first passengers across the East River in carriages and on foot but later served for rapid-transit trains bearing thousands. It was the cause of the designer’s death and the builder’s permanent paralysis but it still stands as a functioning, viable monument to vigor and brave men’s dreams.

Brooklyn Bridge designed by a German-immigrant John Augustus Roebling — whose son, Washington A. Roebling after his father’s tragic death, followed in his footsteps to continue his greatness. Opened way back in May 1883, the superstructure was New York City’s greatest and longest of its kind at the time of completion. Its 6,016 feet length & 6 traffic lanes along with the pedestrian promenade in the middle would stun any tourist or native New Yorker!

In 1860, due to population explosion in New York City and Brooklyn, it was realized that a bridge was necessary to connect these cities that are separated by East River. In 1866 New York State Legislature passed the bill for construction of a bridge over the East River and New York Bridge Company was formed.

Its genesis is shrouded in rumor, but it is known that John Roebling, the immigrant German engineer who designed it, was stranded on an East River ferry for hours one day by an ice pack built up during the 1852 winter freeze. He was then building a span across the Niagara gorge but his discomfiture in the ice jam was never forgotten. A bridge would have to be built there some day, he told himself.

In 1831 Roebling and his brother immigrated to Pennsylvania to farm. When this venture failed, Roebling accepted the position of Pennsylvania state engineer. In this position, he surveyed and supervised the construction of canals, locks, and dams.

New York Bridge Company appointed John Augustus Roebling as its Chief Engineer on 23rd May 1867. Roebling was born on June 12, 1806, in Germany. While in school he developed an interest in both metaphysics and in bridge building. He graduated with a degree in civil engineering from the Royal Polytechnic Institute of Berlin in 1826.

This figure of German immigrant John Augustus Roebling, designer of the Brooklyn Bridge was created by Sculptor Richard J. Miller in 1988 commemorating his contributions. This philosopher-engineer was so strong-willed that he underwent amputation of his toe without anesthesia

Roebling went on to erect the Niagara railroad bridge and another across the Ohio at Cincinnati. His son, Washington, who shared his profession and his dreams, was interrupted in his work by the Civil War, but rejoined his father in time to share in the labor and worry of constructing the Brooklyn span.

Roebling’s Proposal
Roebling proposed that steel wire, rather than the usual iron, be used; that the span be built as close to City Hall park as possible and that the structure be not only safe beyond all doubt but esthetically satisfying. Although the figure seems unrealistic in view of today’s inflated prices, he estimated the bridge could be built for $7 million.

Invention that Made all the Difference
In 1841, Roebling invented the twisted wire-rope cable, an invention which foreshadowed the use of wire cable supports for the decks of suspension bridges. Six years later he established a factory in New Jersey for the manufacture of this cable. Because the cable could support long spans and extremely heavy loads, Roebling quickly gained a reputation as a quality bridge engineer.
John A. Roebling, appointed on a salary of $8000 per year on May 23, 1867 as ‘Chief Engineer of the Brooklyn Bridge’ remarked in his “Report” to the New York Bridge Company on September 1, 1867:

Plan and Details of Anchorage, Approaches, Towers, and Steel Cables:

“The contemplated work, when constructed in accordance with my design, will not only be the greatest bridge in existence, but it will be the great engineering work of the Continent and of the age. Its most conspicuous feature - the great towers - will serve as landmarks to the adjoining cities, and they will be entitled to be ranked as national monuments. As a great work-of-art, and a successful specimen of advanced bridge engineering, the structure will forever testify to the energy, enterprise, and wealth of that community which shall secure its erection.”

Half a Km in a Single Span!
The gap between two the two ends to be covered was 1600 ft (almost half a km) in a single span, so that ships can cross over under the span while the clear height required was 135 feet. As a chief engineer of the company, Roebling designed the Cable Suspension Bridge to meet all these requirements. Roebling then called the board of consulting engineers after completing his design to examine his plans, three other engineers from war department also examined to see whether or not the bridge would be an obstruction to navigation. By 1869 everything had been approved.

Tragedy Befalls Perfect Scheme
The scheme was perfect; structurally and architecturally, and the plans of Roebling were fully endorsed by both, board of engineers and the government commission. Then fate intervened for the first time. It would not be the last.

Just two months after the approval on July 9, 1869 while fixing the location of the tower on Brooklyn side, a boat bashed the slide where Roebling was standing. Standing on a cluster of piles at the outboard end of the Fulton Street ferry slip, John Roebling was measuring to determine precisely where the Brooklyn tower should stand. He forgot about the ferry. A boat slid into the slip, nudging the piles against the fender rack. The engineer’s foot was caught and crushed. Two weeks later he was dead of gangrene from blood poisoning.

Accomplished Associate
It was a great setback for this monumental project, realizing the fact that the Roebling’s cable wire manufacturing company was the world leader in this technology; his son was anonymously chosen as his successor. Washington A. Roebling, who had not only been the accomplished associate of his father in some of his principal works, but had aided him most efficiently in the preparation of the designs and plans of this bridge.

Upon untimely death of John Augustus Roebling - his son Washington A. Roebling, stepped into his father’s shoes to guide construction of the mammoth structure

One marvels at the harmonious relationship between John Augustus Roebling and Washington Roebling. The father envisioned the need for a bridge over the East River and designed a structure which time has proved is correct, safe, and enduringly beneficial to the community. When he died his son was ready to go forward with his plans, which were altered but little. They were two individuals but their minds worked as if governed by a common impulse.

Eight-Storey High Foundations!
The construc-tion of bridge began on 3rd January 1870 and the site-preparation for Brooklyn side tower started. Two towers of height 276 feet each (4 storey higher than Qutab Minar) with twin gothic arches were to be erected at the side of the river. How will they do it with foundation as deep as 78 feet? It was eight-storey high foundations with solid concrete!

Digging via Pressurised Caissons
Digging could not be done along the side of river, as water would percolate making the digging impossible. To resolve this, caissons were built for each bank. It is box-structure open from one side, the open side is put on the ground; workers then go inside from trap door on the top and work inside this caisson. As digging proceeds the caisson descends by enormous wait that is put on it. To stop the water to percolate from ground, enough air pressure is generated inside the caisson which is airtight structure.

For this project, huge caissons were built for each side.

Using the newly devised caisson to reach bedrock, the workers plunged into the work of building the towers. It was maddeningly slow, with progress some- times limited to six inches a week because of the cement-like bottom hardpan. Young Roebling con. ceived the idea of blasting inside the compressed air chamber, something never before tried. First he fired several revolver shots to test his theory, then tried small explosive charges. Nothing dangerous occurred, so he went on to heavy charges.

One of his engineers said the scene in the caisson was straight out of Dante’s Inferno, with half naked men moving in the dim light, the noise of hammers and drills shattering the eardrums and smoke from powder charges adding to the Stygian gloom. When Roebling switched to smokeless powder, just invented by Alfred Nobel, the work went faster. But not always smoothly. Once the caisson “blew out,” again the timber roof caught fire and smoldered for weeks, and once the men managed to shut a hatch against the waters of the river just in time.

The Brooklyn pier under construction as the 39th course of masonry was completed on September 21, 1872

Workers were working under the closed wet cabin that had double the pressure that we experience normally. Under this extreme pressure nitrogen gas that is present in atmosphere is dissolved in blood which is not actually harmful, but sudden release in pressure make this gas bubble out quickly from body creating a violent pain. Also the higher pressure drives blood into central part of the body like brain, spinal cord and bone joints.

Because no one was aware of this fact workers continued to work, the result was workers were having caisson disease, they had joint pains and some of them completely paralyzed and soon died. As Washington A Roebling visited these Caissons occasionally, he contracted the same disease in May 1872 just after completing the foundations, however he was managing the project as it was his father’s dream and he had to accomplish.

Finally, the Brooklyn tower rested firmly on bedrock 44-1/2 feet below the surface.
The New York tower presented more hazardous prospects. Bedrock was found seventy-eight feet down, almost twice as deep as at the other side of the river . The caisson would have to operate with a pressure of thirty-five pounds per square inch and this meant that air compression illness, commonly called “the bends,” would be a ,constant enemy. And there was quicksand under the silt!

Soon workmen were seized by the horrible cramps of caisson illness. On April 12, 1872 the first worker died. The number of stricken rose until a hundred or more were unable to work. Two more sandhogs died. Then on a summer day that year they carried 35-year-old Colonel Roebling out of the caisson, paralyzed for life.

Construction Parameters
Depth of Brooklyn caisson - 44'-6" feet below mean high tide, bearing on consolidated materials (bedrock at 90 feet)

Design weight supported by Brooklyn Caisson - 80,000 tons

Thickness of top of Brooklyn wooden caisson - 15 feet of yellow pine.

Brooklyn caisson launched from Greenpoint shipyard (5 miles North) - 19 March 1870

Launching Size of Brooklyn Caisson - 168' x 102' x 141/2'

Launching Weight of Brooklyn Caisson - 3000 tons

Holes in the top of the Brooklyn caisson -
(2) water shafts
(2) man shafts
(2) supply shafts
Pipes for gas, air and water.

Weight necessary to sink caisson - (3) courses of tower masonry

With Pier-construction over, strenuous task of positioning of supporting cables began

Methods of Excavation
Shovel, pick, wheelbarrow, steel bar stone breakers, winches and ten ton hydraulic jacks, eventually blasting after a serise of experiments conducted in the caisson by Washington Roebling

Initial rate of caisson excavation and lowering - 6 inches per week

Workforce on Brooklyn Tower - 360

Maximum air pressure in Brooklyn Caisson - 23 psig

Height achieved by stones and mud from “Big Blowout” in Fall 1870 - 500 feet

Granite and Brick
After the foundations, the towers were erected. The specifications were changed from brick and stone masonry to granite and brick to make structure sturdier. The towers were fascinating and many people were visiting to see these gigantic structures across the East River. Two workers fell from these towers while construction and died instantly.

Cabling: The Tough Challenge
After completing the towers four main cables had to be put in place across the span that would ultimately hold the bridge deck. The cables were made of 19 strands and each of these strands was having 258 wires of 3.2mm thick each, making cable almost 16 inches thick. Each cable extending from one anchorage to other was having 320 km of wire. Very meticulously each wire was put from one end to another and then wrapped finally.

Obviously, a wire cable large enough to help sup- port a bridge with its great weight plus the burden of the vehicles on it could not be lifted to the tower tops or strung across a river. It had to be fashioned, small wire by small wire, until it reached the desired strength. This means that first there must be what were called traveler ropes suspended over the river to hold flimsy platforms on which men could work bonding the wires into a cable.

In the summer of 1876 a great reel of rope was anchored at the Brooklyn end, then rolled on a reel placed on a scow. The scow was towed to the Man- hattan side, paying out rope as it went. The traveler rope sank to the river bottom, out of the way of ships and boats. Then a hoisting engine lifted the rope over the New York tower, taking up the slack until the rope emerged from the water and was pulled high in the air above the cross.

Other ropes followed, but not before E. F. Farrington, chief carpenter, rode across the single strand in a boatswain’s chair while thou- sands of spectators held their breath, wept or cheered. Whistles blew, bells rang, ferry boats stopped in midstream to give passengers a better view, and when Farrington touched down on the Manhattan side he was mobbed by the hysterical crowds. He had been the first across the Niagara gorge and across the Ohio. Now he was a hero in an age that could not yet dream of a
John Glenn or a Neil Armstrong.

Catwalks were built under the traveler ropes and the work of spinning the cables began. One by one, wires were drawn from the Brooklyn end on a travel. ing wheel, up the eastern tower, sinking in a graceful curve over the river, over the Manhattan tower and down to the anchorage on that side. Each wire was continuous from end to end.

Cabling finally completed: The 85' feet deck weighing 6000 tons was built with steel-structure resting on the main four cables through 1520 suspenders and 400 diagonal stays. The arches of the two towers through which the roadways ran were, in fact, inspired by the majesty of ancient Gothic cathedrals

From the ground or from a boat on the water, the four cables from which the bridge is suspended appear only as large black lines against the sky. But each one is made to bear an incredible load. The workmen fed the wires, one by one, across the river until they had nearly 300. Then these were tied together, without twisting, into a single strand. Each wire was gal- vanized (coated with zinc) to fight the corrosion of salt air from the ocean. Each strand was also protected. Finally nineteen strands were tied together to fash- ion one finished cable. In other words, each of the four main cables consists of about 5,700 individual steel wires.

Cabling was indeed a dangerous task, people were working on phobias height; any error could be fatal. Once, while taking each wire one by one from one end to other, accidentally one wire slipped and cable went into the river chopping off one of the workers head. Till this stage more than a dozen workers died. Tough site conditions were becoming the greatest challenge and further to increase the humiliation of this team of 600 workers, another setback hit the project.

Supervising from Death-Bed near Window
Washington A Roebling’s health was getting worse, he was not able to move now, he was almost paralyzed, partly blind, deaf, and mute. He now not able to supervise the project at site took his bed along the window in Brooklyn where he could see the bridge and managed the rest from there.

Rare example of untiring devotion to the husband’s cause - - wife, Emily Roebling became the surrogate Chief Engineer for the bridge and continued the work of her departed husband.

His wife Emily was liaisoning the project now and brought messages to the work site from his bed side. Emily Roebling became the surrogate Chief Engineer for the bridge and continued the work of her husband. She learned higher math and engineering through “on-the-job” training.

Extra Strength
Someone quarreled with the John Roebling theory of extra strength. This concept had led to the placement of extra heavy steel trusses so that locomotives and heavy steel cars could eventually use the bridge. New York newspapers seized upon this aspect of the construction as an excuse to excoriate the crippled engineer in articles and editorials.

Washington Roebling knew that added strength would mean the span could carry the heavier loads which he foresaw would inevitably come in the future. He supported his father’s design, which was based on an extra margin of safety.

An example of this was the placing of wire stays radiating downwards from tower tops to bridge floor. Most bridges then, and many built long after, rely only on their cables which support the bridge; they use smaller cables suspended vertically from the four supporting strands. Roebling, the elder, wanted this method fortified by another.

He ran strong steel stays from each tower, like spokes of a wheel. Each stay was the hypotenuse of a triangle formed by the stay, the tower and the bridge floor structure. He saw them not only as an added measure of strength and rigidity-he said they could support the bridge even if the cables failed-but also as an esthetic addition to the beauty of the structure.

To guard against the forces of possible gales and hurricanes, Roebling’s design also called for steel trusses to keep the bridge from buckling. It was the cost of these portions that angered curbstone superintendents.

Brooklyn Bridge Construction Accidents Was it a nature’s curse? Some of the worst accidents of the bridge construction happened during the cable rigging. In June of 1878, a cable strand secured at the New York anchorage broke loose during adjustment. The strand flew over the New York tower and into the East River, taking off the top of one rigger’s head and knocking another off the anchorage along the way. Another rigger was guiding wire onto a drum. He kicked at it to keep it in line, and his foot was caught. His leg was wrapped around the drum, killing him almost instantly. Several others died due to falls or falling equipment. At least three men died of the bends (caisson disease) during the caisson work. A couple of men were crushed by blocks being swung into place. All told, roughly 27 people died during the construction of the Brooklyn Bridge.

The New York Times criticized the “stupidity” of the designer for using so much steel and, without benefit of any scientific evidence to support its case, asserted that the extra weight would cause the whole span to collapse. A prominent engineering magazine refuted the paper’s accusation but its voice was unheard and unheeded in the storm of criticism.

The public outcry did not abate. The crippled Roebling submitted a scientific defense showing that the cables would support four times the anticipated total dead and live weight. Still the howling and dire warnings persisted.

The 85' feet deck weighing 6000 tons was built with steel-structure resting on the main four cables through 1520 suspenders and 400 diagonal stays. The bridge had two lanes on either side with elevated pedestrian way in the centre.

Finally, the bridge was completed on 24th May 1883 2.00 PM. The bridge at many times seemed impossible due to nature’s curse, shattered all records for suspension bridges of the day. It was 500 feet longer than the largest suspension bridge and extended 6000 feet from end to end.

In spite of Roebling’s inability to supervise the work, his wife did excellent effort, she was so involved in the project, that she was the first person to ride across the span during the opening ceremony while president Chester Arthur and New York Governor Grover Cleveland followed Mrs. Roebling. This was the greatest gratitude that the citizens could give to the Roebling family.

The article has been prepared by CBS Team. Excerpts taken from various sources and compiled. With permission from CBS Forum. www.cbsforum.com