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The Percy V. Pennybacker Jr. Bridge in Austin, Texas, is a through-arch bridge across Lake Austin which connects the northern and southern sections of the Loop 360 highway, also known as the "Capital of Texas Highway." Due to its arched weathering-steel bridge and the rolling hills on its northern side, this structure is regarded as a scenic route in Texas.[1]
Pennybacker Bridge | |
|---|---|
 | |
| Coordinates | 30°21′00″N 97°47′49″W / 30.3500°N 97.7970°W |
| Carries | 4 lanes of  Loop 360, pedestrians, and bicycles |
| Crosses | Lake Austin, Colorado River |
| Locale | Austin, Texas |
| Other name(s) | 360 Bridge |
| Maintained by | Texas Department of Transportation |
| Characteristics | |
| Design | Through arch |
| Total length | 1,150 feet (351 m) |
| Longest span | 600 feet (183 m) |
| Clearance below | 100 feet (30 m) |
| History | |
| Opened | December 3, 1982 |
| Statistics | |
| Daily traffic | 48,000 |
| Toll | Free both ways |
| Location | |
 | |
In 2001, 48,000 vehicles crossed the bridge daily. Ten years prior to this, 22,000 vehicles had crossed the bridge daily.
Specifications
editThe bridge is constructed such that no part of the structure touches the water 100 feet (30 m) below. The bridge is 1,150 feet (351 m) long with a 600-foot (183 m) central arched span. This design keeps Lake Austin free from support columns because the recreational lake (really a dammed stretch of the Colorado River) is popular with boaters and waterskiers. The untied arch suspension span is suspended by 72 steel cables. At the time of its construction, it was only the second bridge of its design in the world.
The bridge has four lanes, two in each direction, separated by a middle barrier wall. The bridge also has a 6-foot-wide (1.8 m) bike and pedestrian lane. The bike access on the bridge is one reason for Loop 360's popularity with cyclists. The south approach provides a turnaround under the bridge along with lake access for public boating.
Aesthetics
editThe steel bridge has a uniform weathered rust finish allowing the bridge to blend in with the surrounding hills and lake.
History
editPlanning
editOriginally envisioned as a western circular road, Loop 360 began planning in 1962.[2] As part of Loop 360's construction, a contractor was selected to cut into the rock at the site of the future bridge and approach roads due to the area's terrain. This rock debris was deposited along the lakeshore at the site of the proposed bridge, raising environmental concerns.[3] At one point, the Austin Navigation Board considered legal action against the contractor responsible for the rock debris.[4]
Throughout the design and build process, concerns were expressed by elected officials and residents over the environmental effects of such a bridge, particularly the possibility of concrete pillars being driven into the lakebed.[5] The bridge was redesigned in 1978 as a tied-arch bridge to avoid placing pillars into the water.[6]
The contract for the bridge was let in late 1979.[7]
Construction
edit
The 600 short tons (544,311 kg) of steel for the bridge were produced in Japan. The bridge structures were fabricated in Ulsan, Korea by Hyundai Heavy Industries.[7] The steel structures were shipped on the Jundale freighter to the Port of Houston and then trucked to the bridge site. The bridge was erected by Bristol Steel of Bristol, Virginia. The roadway surface is built from 3,400 short tons (3,000,000 kg) of concrete. The finish was sandblasted to ensure even weathering for an amber patina. The construction was coordinated by Clearwater Constructors (Hensel Phelps) of Denver, Colorado. Ed Westall was the project coordinator, Buddy Johnson was the project supervisor and David W. McDonnold was the bridge designing engineer. The bridge cost US$10 million to build.
Additionally, a local metal fabricator, Beck Tool & Manufacturing (Thomas L. Beck, Owner) was contracted to machine many of the critical components that anchor the cables suspending the roadway. Major structural steelwork was finished by July 1982
Completion
editThe bridge was dedicated officially November 29, 1982 by Austin mayor Carole McClellan and other public officials and opened for traffic December 3, 1982.
Naming
edit
The bridge is named for Percy V. Pennybacker Jr., who designed bridges for the Texas Highway Department and was a pioneer in the technology of welded structures.[8] Pennybacker, a resident of Austin since 1939, worked for the department for over 20 years before retiring in 1957.[9]
Awards
editThe bridge won first place in the 1984 Federal Highway Administration's Excellence in Highway Design competition. In 1992, the Austin members of the Consulting Engineers Council of Texas were surveyed and selected the bridge as the most innovative example of Austin architecture.[8]
See also
editReferences
edit- ^ "Scenic Route: Pennybacker Bridge". Texas Highways. February 25, 2016.
- ^ "History". Texas Department of Transportation. Retrieved May 27, 2024.
- ^ Fernandez, Julie (January 9, 1976). "Lake shore cut complaint-causer 'for some time'". Austin American-Statesman. p. 17. ProQuest 1671725782. Retrieved May 27, 2024 – via Proquest.
- ^ "Board to urge leaving debris". Austin American-Statesman. May 31, 1976. p. 1. ProQuest 1671717571. Retrieved May 27, 2024 – via Proquest.
- ^ Barry, Tom (July 24, 1974). "Councilmen Push Need for Lake Plan". Austin American-Statesman. p. 17. ProQuest 1504003664. Retrieved May 27, 2024 – via Proquest.
- ^ "Loop 360 bridge redesigned". Austin American-Statesman. January 5, 1978. p. 5. ProQuest 1923408455. Retrieved May 27, 2024 – via Proquest.
- ^ a b Baumhauer, Charles (October 11, 1979). "Construction begins on Loop 360 overpass". Austin American-Statesman. pp. 1–2. ProQuest 2027671497. Retrieved May 27, 2024.
- ^ a b Jayson, Sharon (November 26, 1992). "360 BRIDGE A DECADE OLD - $100,000 light project to improve landmark". Austin American-Statesman. p. 1.
- ^ "Pennybacker Succumbs In His Home". Austin American-Statesman. February 5, 1963. p. 17 – via Proquest.