Union Arch Bridge
Coordinates: 38 ° 58 '22 " N , 77 ° 8' 55" W.
| Union Arch Bridge | ||
|---|---|---|
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| use | Aqueduct , road bridge | |
| Crossing of | Cabin John Parkway | |
| place | Cabin John , Maryland , USA | |
| construction | Stone arch bridge | |
| overall length | 137 m | |
| width | 6.10 m | |
| Number of openings | a | |
| Longest span | 67 m | |
| Arrow height | 17.45 m | |
| start of building | 1857 | |
| completion | 1864 | |
| planner | Alfred L. Reeves | |
| location | ||
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The Union Arch Bridge , also called Cabin John Bridge , is a stone arch bridge in Cabin John , Maryland , a small town northwest of Washington, DC.It is part of the Washington Aqueduct that connects the city of Washington and part of its suburbs with water from the Great Falls of the Potomac River is supplied. At the same time it is a road bridge.
location
The bridge leads over the four-lane Cabin John Parkway , which connects the Clara Barton Parkway with the Capital Beltway . It still contains the aqueduct on which MacArthur Boulevard was later built, which has only one lane and one walkway on the bridge.
description
The Union Arch Bridge is a total of 137 m long and 6.10 m wide stone arch bridge. It's made of Massachusetts granite and the same sandstone from nearby Seneca Quarry that was used in the Smithsonian Institution Building on the National Mall in Washington, DC.
It has a large segment arch with a span of 67 m and an arrow height of 17.45 m. The arch consists of a layer of carefully hewn granite blocks and a layer of several sandstones laid over it, which are only roughly worked on the facade side. The facade of regular sandstone masonry gives the impression that it is a massive bridge, which is not the case. A total of nine round arches are hidden behind the facade on both sides in order to reduce the weight on the bridge arch. The water pipe laid over the bridge and the second pipe built in the 1920s are not visible from the outside, and the road built over the water pipes is also hidden behind its boundary walls when viewed from below.
The bridge had the largest span of any stone arch bridge in the world when it was completed and still has the largest stone arch in the United States.
The bridge was added to the List of National Historic Civil Engineering Landmarks by the American Society of Civil Engineers in 1972 under the name Cabin John Aqueduct . The Washington Aqueduct as a whole was declared a United States National Historic Landmark in 1973 .
history
The Union Arch Bridge was built in the years 1857-1864 by the United States Army Corps of Engineers under the direction of Montgomery C. Meigs . It was based on plans drawn up by his division engineer Alfred L. Rives. Alfred L. Rives was born in Paris in 1830 as the son of the US ambassador, grew up in the USA, but was the first American graduate of the École nationale des ponts et chaussées in Paris. He had also studied a similar bridge with a large arch in England, the Grosvenor Bridge in Chester, opened in 1832 . He was 25 years old when Meigs hired him to work on the Washington Aqueduct. Since there had not been a bridge of this type in the USA before, a bridge with six arches was originally planned. Alfred L. Rives applied the knowledge he had acquired in France and England and calculation methods not yet known in the USA, and won Meigs for the idea of a bridge with a single large arch. It surpassed the Grosvenor Bridge and at the time of its completion had the largest span of all stone arch bridges in the world. Only in 1903 was it exceeded by the Adolphe Bridge in Luxembourg . Although Meigs had originally recognized Rives' achievement, the events of the Civil War (1861–1865) led to Rives, a supporter of the southern states , not being mentioned on the memorial plaques on the bridge.
Individual evidence
- ↑ Stone Arch Bridges: Other Significant Stone Arch Bridges (PDF; 9 kB) from: Maryland State Highway Administration, Baltimore, MD: Historic Highway Bridges in Maryland: 1631-1960: Historic Context Report. (1995); Retrieved April 8, 2012
- ↑ a b c Gasparini, Dario A .; Simmons, David A .: Cabin John Bridge: Role of Alfred L. Rives, CE (PDF; 2.0 MB), Journal of Performance of constructed facilities © ASCE, March / April 2010, pp. 188–203; Retrieved April 8, 2012
- ↑ date s. National Park Service, National Historic Landmarks Program, Listing of National Historic Landmarks by State - Maryland (PDF) , page 3 of the PDF document; Description see National Register of Historic Places, Washington Aqueduct, Digital Asset 73002123 and the linked PDF document; both links accessed March 21, 2017.
- ↑ John Kelly: Md. Bridge history includes breach that couldn't be spanned , April 21, 2010, The Washington Post; Retrieved April 8, 2012
