Trestles Bridge

For the type of bridge, see Trestle.
New concrete bridge in 2015

Trestles Bridge, more formally known as Railroad Bridge 207.6 or the San Mateo Creek Bridge, is a low railroad viaduct on the coast of Southern California, in northern San Diego County near its border with Orange County. The bridge lies within San Onofre State Beach and gave its nickname to the famed Trestles surfing site at that beach.[1][2][3][4][5]

Usage

The bridge, carrying a single railway track, forms part of the only northern rail connection out of San Diego and part of the LOSSAN Corridor, the second busiest segment of railway in the United States. Approximately 45 trains per day and 2.7 million people per year travel on the bridge; it is used by Amtrak's Pacific Surfliner trains, the Orange County Line of the Metrolink commuter rail service, and freight trains on the BNSF Railway.[1][3][4][6]

History

A railroad first bridged the creek in this location in 1891.[2] In 1941, a wooden trestle bridge 858 feet (262 m) long was built in this location.[1][2][7] The nearby waves had already been surfed as early as 1937, and by 1951, local surfers had named the beach and its surf break "Trestles", after the bridge there.[8]

In 1992, the railway line containing the bridge was purchased by the North County Transportation District from the Atchison, Topeka and Santa Fe Railway.[3] Storms caused by the El Niño of 1998 damaged the bridge, leading a center section of the bridge 200 feet (61 m) long to be replaced by concrete and leaving separated wooden sections 100 feet (30 m) long in the south and 558 feet (170 m) long in the north.[2][7][9]

By 2007, inspectors determined that the northern segment of the bridge needed replacement.[2] Salt from the beach environment had rotted the wooden support beams, they had been damaged by fires set by beachgoers, the creosote protecting the beams had been worn away, and the bridge did not meet seismic standards.[2][3][6][7] Trains could not travel on the bridge at full speeds,[1][7] and frequent bridge maintenance was costing US$250,000 per year.[5][10] Construction began in 2010,[3][6][11] and a new concrete replacement for this bridge segment opened in 2012 at a cost of eight million dollars,[1][4] paid by federal funds from the American Recovery and Reinvestment Act of 2009.[7]

Design

In order to protect the 2012 bridge segment against corrosion, its rebar was protected by an epoxy coating and calcium nitrite was added as a corrosion inhibitor to its reinforced concrete.[12] The new concrete supports for the bridge structure are etched with letters spelling "Trestles", the nickname of the bridge.[1][4]

References

  1. 1 2 3 4 5 6 Rojas, Rick (May 14, 2012), "New Trestles bridge opens: Much of the original, 1941 wooden structure near the famed San Diego County surf spot has been replaced – under budget and six months ahead of schedule – with reinforced concrete", Los Angeles Times: AA3.
  2. 1 2 3 4 5 6 Volzke, Jonathan (April 29, 2009), "Trestles Losing its Trestles", San Clemente Times.
  3. 1 2 3 4 5 San Mateo Creek Bridge Replacement at Trestles Beach Fact Sheet, North County Transportation District, April 2011, retrieved 2012-05-15.
  4. 1 2 3 4 Swegles, Fred (May 14, 2012), "Gleaming new bridge adorns iconic Trestles surf spot", Orange County Register.
  5. 1 2 Anton, Mike (September 6, 2009), "Trestles is losing its race with time: Most of the old bridge wooden bridge, a doorway to one of the coast's best surf breaks, will soon be replaced with concrete", Los Angeles Times.
  6. 1 2 3 Joyce, Ed (August 31, 2010), "Concrete To Replace Wooden Trestles Bridge At San Onofre: Salt Air, Fires, Vandalism Take Toll On 70-Year-Old Structure", KPBS.
  7. 1 2 3 4 5 Sisson, Paul (April 17, 2009), SAN ONOFRE: Iconic railroad bridge in for a change at Trestles. Only 100 feet of original wooden structure will remain.
  8. ↑ Pezman, Steve (2006), "Capers in the key of "T": Trestles memories", in Diamond, Paul, Surfing's Greatest Misadventures: Dropping In on the Unexpected, Casagrande Press, pp. 139–156, ISBN 9780976951605.
  9. ↑ "First part of work to repair creek mouth nears completion", San Diego Union-Tribune, December 22, 1998.
  10. ↑ Trestles Bridge Improvements, TransNet, retrieved 2012-05-15.
  11. ↑ Hawkins, Robert J. (August 31, 2010), "Trestles Bridge nearing its end", San Diego Union-Tribune.
  12. ↑ Smith, B. G.; Creveling, M.; Teig, J. W. (2011), "Sustainable Concrete Mix Designs for 100-year Service Life for Bridges in San Diego County Coastal Environments", Coastal Engineering Practice: 184–197. See in particular example 4.2, San Mateo Creek Rail Bridge 207.6, pp. 195–196.

Coordinates: 33°23′12″N 117°35′38″W / 33.38659°N 117.59385°W / 33.38659; -117.59385

This article is issued from Wikipedia - version of the Sunday, April 17, 2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.