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Ojuela Bridge
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Ojuela Bridge Puente de Ojuela | |
|---|---|
 People crossing the Ojuela Bridge | |
| Coordinates | 25°47′37″N 103°47′29″W / 25.793619°N 103.791358°W |
| Crosses | Canyon at the Ojuela mining complex |
| Locale | Mapimí Municipality, Durango, Mexico |
| Characteristics | |
| Design | Suspension bridge |
| Material | Steel cables and wood |
| Total length | 314 m (1,030 ft) (approx.) |
| Width | 1.8 m (5.9 ft) (present deck) |
| Longest span | 271.5 m (891 ft) (estimated) |
| History | |
| Designer | Wilhelm Hildenbrand |
| Constructed by | John A. Roebling's Sons Company |
| Built | 1899 |
| Rebuilt | 1992 |
| Statistics | |
| Daily traffic | Pedestrian |
| Location | |
 Interactive map of Ojuela Bridge | |
The Ojuela Bridge (Puente de Ojuela), also known as the Mapimí Bridge, is a historic suspension bridge at the former Ojuela mining settlement in the Mapimí Municipality of the Mexican state of Durango. The bridge spans a deep canyon within the historic Ojuela mining complex. It was constructed as part of the transportation system of the Ojuela Mine and originally carried a railway used to transport mined ore. It is now used exclusively by pedestrians.
The bridge forms part of the historic landscape of Ojuela, an important mining district that developed from the late 16th century and became a major industrial mining operation during the late 19th and early 20th centuries.[1]
The date of construction has been reported differently in historical sources. Some sources give 1892, while other historical evidence places construction in the late 1890s, with completion in 1899 and operation beginning around 1900. The bridge itself formerly displayed a plaque commemorating 1892–1992. Contemporary engineering literature, however, describes the bridge as a structure constructed by the John A. Roebling Company in 1899.[1]
The bridge is approximately 314 m (1,030 ft) long, with an estimated main span of approximately 271.5 m (891 ft). Its original deck was substantially wider than the present pedestrian walkway and carried a track for mine cars.[1]
History
Mining at Ojuela
Mining at Ojuela dates to the late 16th century. The Mapimí mining district was established in 1598, and Ojuela became one of the area's principal mining localities. Spanish miners exploited silver-bearing deposits in the area for centuries.
By the late 19th century the Ojuela mine had developed into a large industrial operation. The difficult terrain around the mine presented major transportation problems, particularly because the workings were separated by deep ravines and steep slopes. The modernization of the mine therefore required improved transportation infrastructure.[1]
The Compañía Minera de Peñoles acquired the Ojuela property during the final decade of the 19th century and introduced modern mining and transportation methods. The company developed railways, mechanical equipment, improved processing facilities and other industrial infrastructure. The resulting mining complex included extensive underground workings and a company settlement.
Construction
The Ojuela Bridge was constructed to connect portions of the mining operation separated by a deep canyon. The bridge provided a direct route for transporting ore and supplies and formed part of a railway system associated with the mine.[1]
The bridge is generally associated with German-born engineer Wilhelm Hildenbrand, who is identified in historical accounts as its principal designer. Engineers Henry Grattan Tyrrell and Santiago Menghini have also been associated with the project.
The structure used steel suspension cables combined with a wooden deck and other wooden structural elements. The bridge was designed to carry mine cars rather than ordinary road traffic. A contemporary account published in 1908 described the bridge as approximately 1,100 feet long and about 300 feet above the bottom of the canyon.[1]
The principal steelwork was supplied by the John A. Roebling's Sons Company of Trenton, New Jersey. The company was one of the major American manufacturers of suspension-bridge cable systems during the late 19th century.
Date of construction
The exact construction date of the Ojuela Bridge is disputed.
The date 1892 has appeared in later historical and tourist descriptions and is commemorated by a plaque associated with the bridge. Other accounts give 1898 as the beginning of construction and 1899 as the completion date.
The strongest contemporary engineering evidence comes from Claude T. Rice's report on the Peñoles mines, published in The Engineering and Mining Journal in 1908. Rice stated that the suspension bridge was built by the John A. Roebling Company in 1899.[1]
A municipal history of Mapimí likewise describes construction during 1898–1899, with completion in November 1899 and operation beginning in 1900.[2]
Because different historical sources give different dates, the construction date should not be regarded as completely settled. The late-1890s date, particularly 1899, is supported by contemporary engineering documentation.
Engineering significance
The Ojuela Bridge was an industrial suspension bridge built for mining transportation. Its original railway deck was designed to carry mine cars across the canyon.
Rice's 1908 description gives the bridge a length of approximately 1,100 feet and identifies it as one of the longest suspension bridges then in existence.[1]
Later measurements give a total length of approximately 314 metres and an estimated main span of approximately 271.5 metres. The present deck is considerably narrower than the original industrial roadway and is intended for pedestrians.
The combination of a very long suspension span, a narrow railway deck and the steep canyon setting made the bridge an unusual example of late-19th-century mining infrastructure.
Industrial operation
The bridge formed part of the transportation system of the Peñoles mining operation.
The Ojuela mine was connected to Mapimí and the company's other facilities by railway. Because of the steep terrain, portions of the railway system required special engineering, including a rack railway. Ore was transported from the mine toward processing and smelting facilities.[1]
The bridge allowed the mining railway to cross the canyon without following the much longer and more difficult terrain around it. Its construction was therefore directly related to the industrial modernization of Ojuela.
The 1908 engineering account provides detailed descriptions of the mine, its railway system and its transportation arrangements and illustrates the scale of the Peñoles operation during the period when the bridge was in active industrial use.[1]
Ojuela mining settlement
The mining operation supported a substantial settlement containing housing, commercial buildings and industrial facilities. The settlement included a church, miners' residences, warehouses, mine buildings and other structures associated with the mining industry.
As mining expanded, Ojuela became an important industrial community in the Mapimí district. Its surviving ruins provide evidence of the transition from colonial and early Mexican mining to large-scale industrial mining during the Porfiriato.
The settlement declined as industrial mining activity diminished during the 20th century. Many of the original buildings have disappeared or survive only as ruins, while the bridge remains the most conspicuous surviving engineering structure.
Decline of mining
Mining at Ojuela continued into the 20th century but eventually declined because of changing economic conditions, flooding of underground workings and difficulties in obtaining economically recoverable ore.
The municipal history of Mapimí records the Ojuela operation as active from the late 19th century until 1932.[2]
After large-scale industrial operations ended, Ojuela ceased to function as a major mining settlement. The abandoned mine and settlement subsequently became important as historical and mineralogical sites.
Mineralogical significance
The Ojuela mining district is internationally known for its mineral specimens. Mining exposed a highly diverse assemblage of primary and secondary minerals, particularly arsenates.
Mineralogical research has documented numerous species from the Ojuela deposit. These include adamite, legrandite, paradamite, scorodite, hemimorphite, köttigite, calcite, fluorite, mimetite, wulfenite and several other minerals.[3]
Ojuela has been particularly important for the study and collection of secondary arsenate minerals. Moore and Megaw documented more than one hundred mineral species from the locality and described it as one of Mexico's most important mineral localities.[3]
Several minerals have their type locality at Ojuela, meaning that the locality is the original site from which the mineral species was scientifically described. Among the minerals associated with Ojuela are paradamite, lotharmeyerite, metaköttigite, mapimite and ojuelaite.[3]
The mineralogical importance of Ojuela is closely connected to its mining history. The extensive mining workings exposed mineralized zones that subsequently became internationally significant to mineral collectors and mineralogists.
Restoration
After the abandonment of large-scale mining, the bridge ceased to serve its original railway function.
The structure was restored during the late 20th century for preservation and tourism. A major restoration was carried out in 1992. The restoration included replacement or reconstruction of structural components and conversion of the bridge for pedestrian use.
The restoration allowed visitors to cross the bridge and made it the principal surviving functional structure associated with the historic Ojuela settlement.
The bridge's restoration is commemorated by plaques installed at the site. One of these plaques gives the date 1892–1992, reflecting one of the historical construction dates that has subsequently appeared in descriptions of the bridge.
Heritage
The Ojuela mining site forms part of the Camino Real de Tierra Adentro, which was inscribed on the UNESCO World Heritage List in 2010.
UNESCO identifies the Mine of Ojuela as component 1351-057 of the Camino Real de Tierra Adentro World Heritage property. The component covers the historic mining site rather than treating the bridge as a separate World Heritage property.[4]
The Camino Real de Tierra Adentro, also known as the Silver Route, developed as a major communication and transportation route associated with the mining economy of northern Mexico. UNESCO's World Heritage property includes numerous historic towns, bridges, haciendas, religious buildings, mining sites and sections of the historic road.[4]
The inclusion of the Mine of Ojuela reflects the importance of mining to the development of the historic route and to the economic and cultural development of northern Mexico.
Present day
The Ojuela Bridge is now used exclusively by pedestrians.
Visitors can cross the bridge and explore portions of the former mining settlement. Surviving features include ruins of buildings, mine entrances and other remnants of the historic industrial complex.
The bridge is the most prominent surviving structure at Ojuela and has become a major tourist attraction in the Mapimí area.
The surrounding mining district also remains important to mineral collectors because of the exceptional mineral specimens associated with the Ojuela deposit.
Gallery
The Ojuela Bridge in Mapimí, Durango, Mexico
The Ojuela Bridge
The Ojuela Bridge
The Ojuela Bridge plaque
The Ojuela Bridge plaque
Exterior seen from inside the mine
People crossing the bridge
See also
References
- 1 2 3 4 5 6 7 8 9 10 Rice, Claude T. (1908). "Mines of Peñoles Company, Mapimí, Mexico—I". The Engineering and Mining Journal. 86 (7): 309–314.
- 1 2 Mapimí IV Centenario. Archivo Municipal de Torreón. 2012.
- 1 2 3 Moore, Thomas P.; Megaw, Peter K. M. (2003). "The Ojuela mine: Mapimí, Durango, Mexico". The Mineralogical Record. 34 (5): 1–91.
- 1 2 Camino Real de Tierra Adentro. UNESCO World Heritage Centre. 2010.
Bibliography
- Moore, Thomas P.; Megaw, Peter K. M. (2003). "The Ojuela mine: Mapimí, Durango, Mexico". The Mineralogical Record. 34 (5): 1–91.
- Hoffmann, Victor Joseph (1968). The Mineralogy of the Mapimí Mining District, Durango, Mexico (PhD dissertation). University of Arizona.
- Rice, Claude T. (1908). "Mines of Peñoles Company, Mapimí, Mexico—I". The Engineering and Mining Journal. 86 (7): 309–314.
- Mapimí IV Centenario. Archivo Municipal de Torreón. 2012.
- Burian, Edward R. (2015). The Architecture and Cities of Northern Mexico from Independence to the Present. University of Texas Press. ISBN 978-0-292-77190-1.
External links
- Camino Real de Tierra Adentro — UNESCO World Heritage Centre
- Ojuela Mine — Mindat
| Authority control databases: Geographic |
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