William Howe (engineer)
William Howe (born May 12, 1803 in Spencer , Massachusetts , † September 19, 1852 in Springfield , Massachusetts) was an American bridge construction engineer who built truss bridges (lattice bridges) with so-called How girders, in which the struts made of wood and the tension struts were constructed of iron.
He was the uncle of Elias Howe , the inventor of sewing machines. Until 1838 he worked as a farmer. From then on he built bridges , first for the Boston and Albany Railroad in Warren, Massachusetts. He further developed older bridge types and received two patents for his support structure in 1840 .
Until then, bridges were made entirely of wood. Wood is cheap and can take compressive forces well, but does not tolerate tensile forces, especially at the joints. So Howe used round iron bars for the vertical struts of the truss bridges , which were tensioned with screw nuts. The diagonal struts were made of wood. The diagonals rise up to the middle of the bridge and can sometimes cross in the middle fields. The carrier was named after him How carrier. Bridges of this type were mainly built until 1870, but also into the 20th century. It was a preliminary stage to the later bridges, which were then built entirely on iron.
Examples of bridges of this type are:
- Railroad bridge over the Connecticut River near Springfield, 402 m long, seven openings with 54.9 m span, 1840
- Elbe bridge in Wittenberge in Brandenburg with three How girders with 40 m span each and 11 Hah girders with 54 m span each, built in 1847–1852, total length 750 m. In 1884 the hay girders were replaced by swedish girders made of steel.
- Bridge over the Sulm for the Austrian State Railways, 1845, with two openings of 47 m each
- Bridge over the Drau with three openings of 57 m each
- Bridge over the Msta of the St. Petersburg - Moscow railway, completed in 1851, 588 m long, with nine openings of almost 60 m
- The King Ludwig Bridge in Kempten from 1851 is the last remaining bridge with How girders in Germany; today it is only used by pedestrians and cyclists. The spans are 35, 53 and 26 m.
- First Dale Creek Bridge from 1868 in the state of Wyoming, USA
- Bridge at Union Covered Bridge State Historic Site in the USA
- Wooden bridge Fulenbach – Murgenthal in Switzerland
- Punt d'En bridge from 1878 in Scuol , Graubünden, Switzerland
literature
- Antoine Picon: L'art de l'ingénieur. Éditions du Center Georges Pompidou, Paris 1997, ISBN 2-85850-911-5 , p. 228.
- Gérald Arbor: Les ponts couverts au Québec Association des transports du Canada, Ottawa 2004, ISBN 2-551-19636-1 .
Web links
| personal data | |
|---|---|
| SURNAME | Howe, William |
| BRIEF DESCRIPTION | American bridge construction engineer, inventor of truss bridges with how girders |
| DATE OF BIRTH | May 12, 1803 |
| PLACE OF BIRTH | Spencer , Massachusetts |
| DATE OF DEATH | September 19, 1852 |
| Place of death | Springfield , Massachusetts |