1806 – 1869
John Augustus Roebling was born on June 12, 1806, in Muhlhausen, Germany.
Roebling later attended the Royal Polytechnic School at Berlin. At this Institute, his course included architecture and engineering, bridge construction, hydraulics, languages, and philosophy. Upon his graduation in 1826, John Roebling worked for the government for three years. He spent most of this time on road building in Westphalia.
In 1831, Roebling immigrated to the United States and settled in Pittsburgh, Pennsylvania. Upon arrival he purchased a tract of wild land, and devoted himself for several years to reclaiming it. His goal was to build up a small country town, which he would call Saxonburg.
The life of a farmer proved to be rather monotonous to Roebling, who was trained for the life of an engineer. When the opportunity was brought forward, Roebling took jobs related to his chosen profession.
John Roebling began his engineering career in America as an assistant engineer on the slack-water navigation of the Beaver River, a tributary of the Ohio River. This was followed by a job working on the Sandy and Beaver Canal. The work was intended to connect the waters of Lake Erie with the Ohio River, but this was never completed.
Roebling’s last employment on works of this kind was on the upper Allegheny River. This is where Roebling located a feeder for the Pennsylvania State Canal. He was employed for three years for the task of surveying and locating three railway lines across the Allegheny Mountains.
John Roebling established the manufacturing of wire rope in America. It was in this manufacturing that his experience was gained. Mostly it was in regard to the nature and qualities of wire that was to be brought into play in the construction of the first suspension aqueduct in the United States.
The general idea of suspension bridges had been a favorite with Roebling.
In 1844 at Pittsburgh Pennsylvania, Roebling was hired to replace an outdated aqueduct. The wooden aqueduct of the Pennsylvania Canal across the Allegheny River, had become so unsafe that it was required to be removed. A new structure was needed to be built The project was completed on time by Roebling. It was opened on May, 1845.
This aqueduct comprised seven spans of 163 feet each consisting of a wooden trunk to hold the water, and supported by a continuous wire cable on each side, of seven inches diameter.
In 1846, John A. Roebling built the Monongahela River Suspension Bridge at Pittsburgh, Pennsylvania. This bridge consisted of eight spans of 188 feet each, supported by two four-and one-half inch cables, which, in this instance, were made on land separately for each span, and then hoisted in place from flatboats.
In this bridge the pendulum principle was applied to counterbalance adjoining spans under the action of unequal loads.
In 1848, John Roebling built a series of four suspension aqueducts on the line of the Delaware and Hudson Canal, connecting the anthracite coal regions of Pennsylvania with the tidewater of the Hudson River.
They were all completed in the course of two years, as follows:
1) Lackawaxen Aqueduct, 2 spans of 115 feet each, and two 7-inch cables
2) Delaware Aqueduct, 4 spans of 134 feet each, and two 8-inch cables
3) High Falls Aqueduct, 1 span of 145 feet, and two 8 1/2-inch cables
4) Neversink Aqueduct, 1 span of 170 feet, and two 8 1/2-inch cables
During this period Mr. Roebling moved establishing his company and his residence in Trenton, New Jersey.
Roebling’s attention was then drawn to Niagara Falls where a need for a suspension bridge was required to connect the New York Central and Great Western Railway across the Niagara River Gorge.
A company had been formed several years before for that purpose, and had selected Charles Ellet to build the first suspension bridge at Niagara Falls.
Under Ellet’s guidance, a temporary bridge was erected at the site for foot travel and light carriages. This was in use several years, being subsequently removed. When the time arrived, for beginning the main construction work, Charles Ellet had become embroiled in financial difficulties with the bridge company. Charles Ellet left Niagara as a result of this dispute.
John A. Roebling was invited to make plans and estimates for the bridge, and was at the same time appointed the engineer.
In 1851, Roebling began building this suspension bridge. Work continued without interruption until March of 1855.
Following completion of this bridge, the first locomotive and train crossed a railway suspension bridge, and it may be safely said that up to the present day it is still the only example of the kind of any magnitude.
The bridge had a span of 825 feet (251.4m), and was supported by four wire cables of ten-inch diameter each and had two decks: the lower deck was devoted to vehicles and the upper deck was devoted to the railway traffic. The two decks were connected by struts and diagonal tension rods, so that the superstructure formed a continuous. hollow girder, stiff enough to support the action of rolling load; the weight, however, being supported by the cables.
Simultaneous with the progress of the Niagara Falls Suspension Bridge, Roebling began construction of another railway suspension bridge across the Kentucky River, on the line of the Southern Railroad leading from Cincinnati to Chattanooga.
The gorge of the Chattanooga River is deeper and wider than that of the Niagara Gorge, requiring a clear span of no less than 1,224 feet (373m).
The girder principle adopted was essentially different from that carried out in the Niagara Bridge. No floor for vehicles was required in this case. Before construction could be completed the Southern Railway went bankrupt, immediately stopping work on the bridge.
In the fall of 1856, work was resumed on the bridge for a short time before running into financial difficulty again.
In the meantime, John A. Roebling secured the building of another replacement suspension bridge at Pittsburgh to take the place of the old wooden bridge which had been built in 1818, and now no longer safe.
The removal of the old structure, and construction of the new permanent work required three years, from 1858-60 inclusive.
The total length of the this suspension bridge was 1,030 feet (313.9m), divided into two spans of 344 feet (105m) each, and two side spans of 171 feet (52m) each. The floor had a width of forty feet (12m), included two sidewalks, and ten feet wide (3m). The framework of the superstructure was composed essentially of iron girders, with a floor of wood.
Ornamental open towers of cast iron support the cables, four in number, two of seven-inch diameter, attached to the floor between the sidewalks and carriage-way, and two of four-inch diameter cables attached to the ends of the floor-beams. In addition to the cables there is an effective system of stays.
When this bridge was near completion, all construction by Roebling was stopped for a couple of years by the outbreak of the American Civil War.
In 1863, operations were resumed on the suspension bridge at Cincinnati. It was completed in 1867.
During 1867, John A. Roebling was chosen as chief engineer of the proposed Brooklyn Suspension Bridge in Brooklyn, New York. He immediately entered upon the work of preparing the plans and specifications, and was superintending the initial operations of its construction when John A. Roebling was fatally injured during an on the job construction accident on July 6th 1867.
While John Roebling and his son, Washington A. Roebling were surveying near the Fulton ferry slip, a ferry-boat crushed of one of Roebling’s feet between the piling and rack of one of the slips. Washington Roebling sustained serious head injuries.
Roebling died of lockjaw in spite of medical treatment sixteen days later.
The Brooklyn Bridge designed by John A. Roebling was later completed by his son, Washington Roebling.
John Augustus Roebling died in Brooklyn, New York on July 22, 1869.