Wendel Bollman
Wendel Bollman (born January 21, 1814 in Baltimore , † January 2, 1884 ) was an American self-taught civil engineer who introduced the construction of iron railroad bridges through the development of the Bollman girder on a large scale in the United States .
Ann B. Bollman and Thomas Bollman († April 17, 1819), the parents of Wendel Bollman, were German immigrants . Thomas Bollman was a baker and had his shop on the corner of Water St and Grant St, near what is now Grand Street Station . He fought in the defense of the city at the Battle of Baltimore .
Adolescent years
Wendel was born the seventh of eight children. His father died at the age of 44 when he was 5 years old. Until Wendel was 11 years old, he attended state and private schools in Baltimore, after which he finished his education in order to better support the family. He trained with pharmacists in what is now West Virginia - first in Sheperdstown , then in Harpers Ferry . In 1826 or 1827, Wendel fell ill and returned to Baltimore to recover.
On July 4, 1828, Wendel took part in the procession to celebrate the laying of the foundation stone for the Baltimore and Ohio Railroad (B&O). Shortly afterwards he took a short time apprenticeship with a carpenter , but when there was less work there he started to work for B&O. At that time, the railway had built about eight kilometers of substructure, but had not yet laid any rails. Wendel started out as a handyman , but soon rose to become a measuring assistant and continuously improved his skills with the surveying equipment . In the autumn of 1829 he was there when the first track was laid. Because his mother was afraid that he would not finish his training as a carpenter, he returned to an apprenticeship as a carpenter in 1830, which he also completed. As a trained carpenter, Wendel helped build a plantation owner's house in Natchez and returned to Baltimore in 1837, where he started his own business. The next year when he was building a house in Harpers Ferry, the B&O asked him to re-enter to repair parts of the long wooden bridge over the Potomac River that had only been in operation for a year.
Development of the Bollman carrier
Shortly after the Harpers Ferry bridge was repaired, Wendel Bollman was appointed head of bridge construction for the railway. Obviously, because of his practical skills and theoretical knowledge he had acquired himself, Bollman was able to support senior engineer Benjamin H. Latrobe in the construction of bridges. He later took over this work completely, so that Latrobe could devote himself to the construction of the route from Cumberland to Wheeling . In 1848, Bollman was appointed chief railway foreman of the B&O, who had the entire infrastructure of the railway under himself.
Bollman was one of the first engineers who no longer relied purely on empirically found dimensions, but introduced the first calculation methods. He developed the construction method used by Latrobe of wooden bridges with wrought-iron elements subjected to tensile loads to the Bollman girder, which was made entirely of iron and was first used in 1850. He did not receive the patent for his design until 1852, a year after he had replaced a 38 meter long section of the bridge over the Potomac River at Harpers Ferry with a girder of his design.
Bollman as an entrepreneur
In 1858, Bollman left the railway company and devoted himself entirely to his own bridge construction company in Baltimore, which had been founded in 1855 and which was the first company in the United States to devote itself entirely to iron bridge construction. The W. Bollman & Company was continued for former stronghold Mans employer, the Baltimore & Ohio Railroad, active, but also exported bridges to Mexico , Cuba and Chile . In addition to the bridges, Bollman also developed the construction of pillars, later known as Phoenix pillars, which were riveted together from several wrought iron segments and were therefore less sensitive to buckling. Among other things, they were used on the pillars of high trestle bridges .
During the Civil War , the company ceased its activities and Bollman mainly occupied himself with the reconstruction of the repeatedly destroyed bridge over the Potomac River at Harpers Ferry. After the war, Bollman became the sole owner of the Patapsco Bridge and Iron Works .
Bollman renewed the patent for his girder in 1866, but his design was rarely used outside of the Baltimore and Ohio Railroad, because in the meantime more material-saving girder designs had been developed that were less sensitive to thermal expansion. Bollman was able to build a bridge for the Chicago, Burlington and Quincy Railroad in 1868 , which contained a swing bridge consisting of two Bollman girders . Between 1867 and 1868 Bollman built two bridges over the Cape Fear River, in which for the first time pneumatically sunk cast iron cylinders were used to support the pillars. In the last decade of his career, Bollman built hundreds of small bridges and other structures. In 1873 he supplied the castings for the dome of Baltimore City Hall. In 1877, Bollman created a unique road bridge in Baltimore that used a main water line as a supporting structure.
literature
- Robert M. Vogel: The Engineering Contributions of Wendel Bollman. In: Smithsonian Institution United States National Museum Bulletin. Smithsonian Press, accessed January 19, 2014 .
Web links
Individual evidence
- ↑ Wendel Bollman, self-taught engineer and “Master of the Road,” born in Baltimore. In: Baltimore 1814. January 21, 2014, accessed April 6, 2014 .
- ↑ a b Wendel Bollman. (No longer available online.) In: Bridge Conference 2006. Archived from the original on April 22, 2014 ; accessed on April 6, 2014 .
| personal data | |
|---|---|
| SURNAME | Bollman, Wendel |
| BRIEF DESCRIPTION | American self-taught civil engineer |
| DATE OF BIRTH | January 21, 1814 |
| PLACE OF BIRTH | Baltimore |
| DATE OF DEATH | January 2, 1884 |