Washington Augustus Roebling
Washington Augustus Roebling (* 26. May 1837 in Saxonburg , Pennsylvania , † 21st July 1926 in Trenton , New Jersey ) was an American engineer , known for his work on the Brooklyn Bridge , which by his father John A. Roebling began .
Live and act
Roebling received his training at the Rensselaer Polytechnic Institute in Troy , New York . Then he supported his father's work as a bridge builder. During the American Civil War he served in the United States Army , where he repeatedly witnessed combat operations. It was in December 1864 Brevet appointed -Oberstleutnant for valiant service.
After the Civil War, he returned to his work with his father and took over the construction management of the Brooklyn Bridge after his death in 1869 because he experience with the production of the bridge required ropes and cables and with the necessary establishing the pillars Caisson possessed process . He made many significant improvements in bridge construction and the development of main bridge construction techniques.
Pillar construction
In order to produce the pillar foundations, solid ground, according to the reading of the time, must be reached. The caisson method, which was new at the time, was used for this, whereby a wooden box girder, which was open at the bottom, was weighed down from above against the buoyancy , which was then lowered into the water of the East River . With overpressure, the air displaces the water from the hollow box. Roebling connected several caisson boxes that were connected by locks. This enabled the workers to enter the actual work area for the foundations and dig it centimeter by centimeter in the kerosene light and poor ventilation. Until 1870 only 15 cm per week were slaughtered in this way. Now Roebling decided to use dynamite for blasting. The first pillar on the Brooklyn side reached stable ground at a depth of 13 m.
The problems with the second pillar were much greater because after the first test drilling, the foundation would have had to be driven to a depth of 30 m. The pressure had to be increased more and more, causing many workers to develop symptoms of the diving disease that was already known. Roebling then had the shifts shortened more and more until they were at two and a half hours, which foreseeably increased the construction time. Nevertheless, several so-called " sandhogs " (sand pigs ) died. When they had reached a depth of around 23 m, the subsoil consisted of a sand that was so hard due to the thousands of years of pressure over it that it was extremely difficult to remove. Roebling then decided that this subsoil had the necessary load-bearing capacity and had the foundation of this pillar on the Manhattan side poured in concrete there .
At times he had to contend with a careless fire in his wooden hollow box, which burned into the wood inaccessible for days due to the oxygen blown under high pressure and which could not be extinguished by the high pressure water sprayed by ten fire engines . The source of the fire could only be uncovered and extinguished after drilling a series of holes in the caisson boxes. Later there was water ingress because the box girder could no longer withstand the pressure.
Setbacks
However, overwork and decompression sickness also afflicted Roebling, who also supported the hard work of the men on site, and made him bedridden for months in the early summer of 1872. After that he was in a wheelchair and could only concentrate for a short time every day. Nevertheless, he continued his planning work from home and despite various attempts to exchange him for other engineers with the help of rumors that he was insane, he achieved the completion of the bridge in 1883 with the effective, tenacious, intelligent support of his wife Emily Warren Roebling . She had taught herself the mathematical and engineering skills required for this in self-study and at the same time, as site manager, implemented the instructions given verbally and in writing extremely carefully and carefully.
Roebling's financiers, despite knowing that his company was famous throughout the United States for its high quality and experience in the production of wire ropes and cables, chose the product of a Brooklyn competitor as a supplier whose products were not known for perfect quality were. When three steel cables tore and three workers were killed and several injured, Roebling had a quality management system set up: He doubled the number of quality controllers who continuously checked the products on the factory premises. It was discovered that poor quality wire ropes were used in the cables and the quality certificates were forged. Some were even rusted. As a result, the tensile strength of the cables was significantly reduced. The cables, which were inferior due to the damaged wire ropes, could not be distinguished from the outside from the faultless ones. Since Roebling had previously designed the steel cables for six times the maximum load, the manufacturer's quality defects presumably reduced their load capacity to four times the maximum load, but this was sufficient. To this day, they have served their purpose perfectly. The supplier was allowed to keep the order, but had to repay the amount he had saved by using the inferior wires.
Roebling's hobby consisted of collecting rocks and minerals. His collection of more than 16,000 objects was donated to the Smithsonian Institution after his death . It is a significant part of the United States' National Mineral and Gem Collection. Him the award in honor of Mineralogical Society of America , the Roebling Medal for achievements in mineralogy .
Fonts
- Washington Roebling: My father John A. Roebling: the German builder of the Brooklyn Bridge. Translation Konrad Linke. Mitteldeutscher Verlag, Halle (Saale) 2011, ISBN 978-3-89812-731-8 .
literature
- Erica Wagner: Chief Engineer: Washington Roebling. The Man Who Built the Brooklyn Bridge . Bloomsbury, 2017
Web links
- Washington Augustus Roebling on inventionfactory.com
- Washington Augustus Roebling. In: Structurae
Individual evidence
- ↑ Bernd Nebel: The Brooklyn Bridge
| personal data | |
|---|---|
| SURNAME | Roebling, Washington Augustus |
| ALTERNATIVE NAMES | Roebling, Washington |
| BRIEF DESCRIPTION | American bridge engineer |
| DATE OF BIRTH | May 26, 1837 |
| PLACE OF BIRTH | Saxonburg , Pennsylvania |
| DATE OF DEATH | July 21, 1926 |
| Place of death | Trenton , New Jersey |