(1892 Bridge Hunter, 1944 Bridge Hunter, HAER, Satellite)
The Pecos River gorge has been the location of two of the world's highest bridges: the 1892 Pecos Viaduct and the current structure, its 1944 successor. Increased traffic during World War II necessitated the replacement of this critical link on a major east-west railroad. Though built
under material and labor constraints caused by the war, this 1390'-6"-long continuous steel cantilever truss' austere design is nonetheless in harmony with its remote desert setting. The Pecos River High Bridge is also significant for technical achievements, such as its 275'-high slip-formed concrete piers. [HAER data, p1]
The record breaking 320'-10 3/4" high 1892 bridge replaced a low bridge built a decade earlier that required 11 torturous miles of track to descend down to river level. [HAER data, p3]
"The second Pecos River High Bridge's structural form allowed it to support greater loads
than its predecessor while using a comparable amount of metal." But it used steel instead of iron. " While a pier ideally would taper uniformly from top to bottom, it would require a great
deal of form work, especially over the 275'-4 1/2" of the Pecos River bridge's tallest pier (pier
C). Modjeski and Masters instead chose slip-forming, a method whereby a short form is moved
upward for another concrete pour when the previous pour reaches sufficient strength. Slipforming required the Pecos River bridge's piers to have "vertical sides, narrowed in occasional
steps."20 The piers are hollow octagonal shells, to reduce the amount of concrete and speed
curing. In the sloped transition piece at the junction between each shell and the narrower one
above, steel reinforcement is like that found in a reinforced concrete dome." [HAER data, pp5-6]
1892 Phoenix Bridge 37 photographs showing the construction sequence
The photos confirm that the travelling derrick built half the center span, and then they moved the derrick and built from the other direction.
The Pecos River gorge has been the location of two of the world's highest bridges: the 1892 Pecos Viaduct and the current structure, its 1944 successor. Increased traffic during World War II necessitated the replacement of this critical link on a major east-west railroad. Though built
under material and labor constraints caused by the war, this 1390'-6"-long continuous steel cantilever truss' austere design is nonetheless in harmony with its remote desert setting. The Pecos River High Bridge is also significant for technical achievements, such as its 275'-high slip-formed concrete piers. [HAER data, p1]
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| Mark Fuller posted This is one of my favorite. Don’t look down! Lang Thompson Says. Pecos High Bridge Ht 321 Ft, L 2100 Ft, The old bridge over the Pecos River near Langtry, Texas. Peter Metrinko This is a fascinating bridge. I found a complete history of it.https://www.nps.gov/amis/learn/historyculture/viaduct.htmStrengthened, it was in use through WWII! The page also has construction photos, and a mystery - are parts of the bridge still in use on other bridges? Thanks, Mark Fuller. Oh, another page shows you the replacement bridge. There's a picnic site - so if anyone wants to go to Langtry TX.http://www.texasescapes.com/.../Langtry_scenic_overlook.htm Jeff Baumann Looks like a 5mph wind would just blow it right over! Not enough cross beams for my liking! I'm amazed it's supporting that train. |
"The second Pecos River High Bridge's structural form allowed it to support greater loads
than its predecessor while using a comparable amount of metal." But it used steel instead of iron. " While a pier ideally would taper uniformly from top to bottom, it would require a great
deal of form work, especially over the 275'-4 1/2" of the Pecos River bridge's tallest pier (pier
C). Modjeski and Masters instead chose slip-forming, a method whereby a short form is moved
upward for another concrete pour when the previous pour reaches sufficient strength. Slipforming required the Pecos River bridge's piers to have "vertical sides, narrowed in occasional
steps."20 The piers are hollow octagonal shells, to reduce the amount of concrete and speed
curing. In the sloped transition piece at the junction between each shell and the narrower one
above, steel reinforcement is like that found in a reinforced concrete dome." [HAER data, pp5-6]
 |
| Photo from HAER TX,233-LANG.V,1--9 (CT) from tx0894 |
The photos confirm that the travelling derrick built half the center span, and then they moved the derrick and built from the other direction.
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| Photo 30 |
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| Photo 37 |
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| Electrical West, Vol. 14, p56 [This article claims the 1892 structure contained steel.] |
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| Railway Times, Vol. 87, p403 [This article confirms the concrete piers are high because during a flood the river can rise 20' to 30' in just 24 hours.] |
UP/SP/Texas & New Orleans Pecos River High Bridges near Langtry, TX
Reviewed by Unknown
on
October 05, 2018
Rating:
Reviewed by Unknown
on
October 05, 2018
Rating:
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