I Street Bridge

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I Street Bridge
I Street Bridge
use I Street (two lanes)
UP , BNSF , Amtrak (two tracks)
Crossing of Sacramento River
location Sacramento and
West Sacramento
Building number 22C0153
construction Truss bridge
with swing bridge
overall length 260 m (railway level)
669 m (street level)
broad 9.4 m (truss central axes )
Longest span 59 m
Construction height 20 m
Clear height about 6 m at low tide
building-costs $ 786,000
opening 1911
planner John D. Isaacs
location
Coordinates 38 ° 35 '11 "  N , 121 ° 30' 25"  W Coordinates: 38 ° 35 '11 "  N , 121 ° 30' 25"  W.
I Street Bridge (California)
I Street Bridge

The I Street Bridge is a combined rail and road bridge over the Sacramento River between Sacramento and West Sacramento , California . The truss - double-deck bridge leads the eponymous street on the upper level and the lower level of the two tracks Martinez Subdivision of the Union Pacific Railroad , also from the BNSF Railway and Amtrak (Capitol Corridor) are used. It was built by the Southern Pacific Company until 1911 and the integrated swing bridge , at 3000 tons, had the heaviest rotating steel truss in the world at the time. The bridge has been on the National Register of Historic Places since 1982 .

It is the fourth railway bridge at this point, the predecessor structures of which date back to 1870. The history of the river crossing is closely linked to the development of the Sacramento Shops to the east , which were the largest railway depot in the western United States in the era of steam locomotives . After the demolition of most of the railway systems and buildings, a new Sacramento district is to be built here by the end of the 2020s. At the beginning of the 2010s it was therefore decided to build a new road bridge, which will be built a few hundred meters upstream by 2023 and replace the connection over the street level of the I Street Bridge , which is too narrow for today's conditions . After the driveways have been dismantled, it is planned to use the upper level for pedestrians and cyclists.

story

First railway bridge in 1870 with connection to the First Transcontinental Railroad

The First Transcontinental Railroad was built between California and Nebraska from 1863–1869 ( Western Pacific )Quindio DEP.jpgQuindio DEP.jpg
Route of the California Pacific between Sacramento and Vallejo 1869

In the 1860s, the first transcontinental railroad connection between California and the settlement areas on the Missouri River in eastern Nebraska was established in the USA . The two main routes were built by the Union Pacific Railroad in the east (1746 km) and the Central Pacific Railroad in the west (1110 km). The driving force behind the Central Pacific was the railroad engineer Theodore Judah , who proposed the construction of a rail link through the Sierra Nevada as early as the mid-1850s . With the support of investors later known as the "Big Four" , the Central Pacific was founded in 1861. From 1863 she built the route between Sacramento and Promontory Summit near Salt Lake City in Utah , where it was connected to the eastern part of the Union Pacific in May 1869. The section from Sacramento to San Francisco was built by the Western Pacific Railroad until September 1869. It led via Stockton and Alameda County to Oakland , where there was a ferry connection to San Francisco. A year later the Western Pacific was absorbed into the Central Pacific, but a shorter connection to San Francisco was already being sought.

The focus was on the California Pacific Railroad , which had completed a route from Vallejo to Sacramento by 1870 . Due to its route north of the Bay of San Francisco , it significantly reduced the travel time despite a longer ferry connection to San Francisco. In order to connect to the transcontinental route, the first railroad bridge over the Sacramento River had to be built in the west of Sacramento , which was completed at the end of January 1870. It replaced a road bridge from 1857, but the use of the new wooden bridge was also possible for wagons and pedestrians when the train traffic was idle. A characteristic feature of the bridge, as with the predecessor and all subsequent buildings, was a swing bridge over the shipping channel. After the first failed takeover attempts, the Central Pacific was finally able to gain control of the California Pacific in 1876, thereby shortening its connection to the Bay Area. With the construction of a route through the Suisun March to Benicia , east of Vallejo, the connection could then be shortened again. Until the Benicia – Martinez Bridge was built in 1930, there was a railway ferry across the Carquinez Street and the rest of the route then led to the next ferry in Oakland; the section from Sacramento to Oakland is now part of the Capitol Corridor of Amtrak .

Further combined wooden bridges and, for the first time, separate traffic routes from 1895

City map of Sacramento from 1873, on the left the bridge over the Sacramento River
Development of the Sacramento Shops ; the east of the railway bridge Red circle thick.svglocated Bahnbetriebswerk the SP was up to the 1990-year, now there are only the passenger station Sacramento Valley Station of Amtrak

In 1878, the Central Pacific replaced the old wooden bridge in Sacramento with a new one made of the same material, which also had Howe trusses (named after its inventor William Howe ) and served as a road bridge on the platform level. As a result of the increase in rail traffic and the associated expansion of the railway depot to the east (Sacramento Shops) , as well as the increase in road traffic over the only bridge into what is now the developing West Sacramento (then still Town of Washington ), the decision was not made to twenty Years later again for a new building, whereby the traffic routes were to be separated for the first time by means of a double-decker bridge. The Sacramento and Yolo County participated in the financing and the bridge should now be built from steel. However, disputes with the railway company about the level of participation ultimately led to the new structure being rebuilt from wood by December 1895.

  • California Pacific's first railway bridge (1870–1878), Sacramento on the right

  • Second bridge (1878–1895) of the Central Pacific with the passenger station in the background

  • Third bridge (1895–1911) of the Southern Pacific Company, first double-decker bridge

At that time, the Central Pacific was already part of the Central Pacific and Southern Pacific railroad companies, which were reorganized by the Big Four in 1885 as the Southern Pacific Company (SP) . At the beginning of the 20th century, this company came under the control of the Union Pacific Railroad (UP) from Edward Henry Harriman (until 1913), who invested in the modernization and two-track expansion of the SP. In the course of this, the Sacramento Shops were also expanded to become the largest railway depot in the western United States, and the single-track bridge over the Sacramento River had to make way for a new building again.

I Street Bridge of the Southern Pacific Company 1911

The half-opened truss of the swing bridge in 2014

The I Street Bridge was under the direction of then-consulting engineer of Harriman Lines John D. Isaacs as steel bunk - truss bridge with swing bridge designed. It should have two tracks on the lower level and the eponymous I Street on the upper level. The neighboring counties once again contributed to the financing of the US $ 786,000 construction project . In contrast to the previous wooden structures, whose bridge piers consisted exclusively of wooden piles, reinforced concrete piers had to be built using caissons in the river bed for the heavy steel girders , which were then lowered to a depth of 17 meters. Work on the bridge piers by the Missouri Bridge & Iron Company began in June 1910, and the Southern Pacific erected the steel superstructure manufactured by the American Bridge Company by the following year. The integrated, 120-meter and 3,000-ton rotating truss was then the world's worst carriers of a swing bridge and was in length only by a few two-track versions such. B. at the Illinois Central Missouri River Bridge (158 m, 1903) and the Willamette River Railroad Bridge (159 m, 1908), but all of them were lighter.

Until the construction of the downstream M Street Bridge in 1913 (later replaced by Tower Bridge ), I Street Bridge remained the only road bridge to West Sacramento. Changes to the approaches to street level were made in 1937 on the east side - here, Jibboom Street coming from the north was also connected to the bridge via a viaduct - and in 1959 on the west side, where the connection in West Sacramento was moved from D Street to C Street . Until the 1980s, California State Route 16 , which merged in Sacramento with US Highway 40 running over Tower Bridge , ran over the bridge. The volume of traffic above street level was 4,900 vehicles per day in 2017 (Tower Bridge approx. 12,000 vehicles), use by buses and trucks is only possible to a limited extent due to the narrow lanes.

Amtrak's Capitol Corridor runs over the I Street Bridge (Sacramento) and in San Francisco Bay over the Benicia – Martinez Bridge ( Carquinez Street )

With the expansion of the road network in the USA, passenger and freight transport increasingly shifted from the railroad to the road, which made the major rail networks in North America increasingly unprofitable from the 1960s onwards and subsequently led to several bankruptcies and mergers of the railway companies. After a failed merger of the holding companies of the Southern Pacific and Atchison, Topeka and Santa Fe Railway , Southern Pacific Company and Santa Fe Industries , the SP was sold to Rio Grande Industries in 1988. In 1996 it was finally taken over by the Union Pacific Railroad , which now operates the bridge as part of the Martinez Subdivision between Roseville and Oakland for rail freight traffic; the Santa Fe Pacific Corporation merged with the Burlington Northern Railroad at the end of 1995 to form today's BNSF Railway (Burlington Northern Santa Fe), which can also use the bridge. Passenger transport was completely taken over by the National Railroad Passenger Corporation , founded in 1971 and known under the brand name Amtrak , until the early 1980s . The I Street Bridge is now part of the Capitol Corridor between San Jose and Auburn (named after the route through the current and some former capitals of California ), with a daily traffic volume of about 30 passenger trains. Including rail freight traffic, the bridge is used by a total of around 80 trains a day.

The bridge was listed on the National Register of Historic Places in 1982 (NRHP # 82002233). The last major repair work on the truss bridge took place in 1993, with parts of the central bearing and the control and steering mechanism of the swing bridge being replaced.

New construction of a separate road bridge by 2023

Planned new road bridge (Replacement Project) to replace the upper level of the I Street BridgeBlue02.png Blue02.png Blue02.png

With the introduction of diesel locomotives from the 1930s and the expansion of Roseville Yard 25 kilometers to the east, maintenance work on the SP fleet shifted more and more from Sacramento to Roseville and other locations. After the takeover by UP in 1996, the Roseville Yard was expanded to become the main hub in California, where a large part of all maintenance work on the diesel locomotive fleet is carried out today (in 2004 this was 21,000 maintenance work on the approximately 8,700 diesel locomotives). This meant the end of the Sacramento Shops and in 2015, after the demolition of most of the buildings, around 80 percent of the almost 100 hectare area was sold by the UP to private investors; only Amtrak still uses parts for its Sacramento Valley Station passenger station today . As part of the Sacramento Railyards Project , new residential and office buildings as well as a.o. a football stadium with 25,000 seats will also be built. Against this background, the cities of Sacramento and West Sacramento began planning a new road bridge in the 2010s , which will replace the over 100-year-old connection over the upper level of the I Street Bridge , which is only 5.5 meters wide Roadway no longer meets the requirements for two current lanes (each only 2.75 m). In spring 2020, the renowned engineering firm Modjeski and Masters, which specializes in bridges, won the tender with a design for a lift bridge designed as a network arch bridge . This is to be built a few hundred meters upstream by 2023 and connect C Street in West Sacramento with the new Railyards Boulevard in Sacramento. It is then planned to dismantle the access roads to the I Street Bridge and to use the current street level for pedestrians and cyclists.

description

Complete overview

The structure is divided into a 260 m long truss bridge and several viaducts for the accesses to the street level, with a total length of 669 m between C Street in West Sacramento and I Street in Sacramento. The truss bridge consists of two single-span girders 50.9 m long, a 120.3 m long swing bridge and another single-span girder 33.4 m long from west to east . The lattice girders are designed as Baltimore truss , which roughly corresponds to a parallel -belted stud framework, in which the framework fields are further subdivided and reinforced in the lower area by means of additional struts and studs in order to realize higher loads . For use as a double-decker bridge, the track level is at the level of the lower chords and eight meters above the street level at the height of the upper chords of the following single-span girders - roughly in the middle of the higher girder of the swing bridge (15.2 m). The trusses are 9.4 m apart in relation to their central axes and offer space for two standard-gauge tracks at the bottom and a 5.5 m wide carriageway above with a 1.5 m wide footpath on each side.

and display information about the image
The truss bridge of the I Street Bridge in June 2012 at low tide, view to the northwest

The truss bridge rests on four of reinforced concrete -made river piers and abutments . The three pillars between the single span girders or the swing bridge have a foundation area of ​​7.3 m × 18.3 m and taper to about 3 m × 12 m up to the bearing support. 8 m and a foundation in the form of an octagon m with a diameter of 16.5. It reaches a height of over 25 m and protrudes at low water about five feet from the water, the clear height to the lower flange of the carrier is about six meters. At low tide, the water depth in the fairway around the swing bridge is at least three meters, but is subject to long-term fluctuations due to deposits and erosion.

Swing bridge

Middle part of the swing bridge, above the pillar the ring gear and the stabilizing wheels, in the upper part of the truss the eye bar connections and the company building
Sectional view of the center bearing, highlighted in color are the lubricated metal disks
(⌀ 1.3 m, red = bronze, yellow = steel)

The 120.3 meter long lattice girder of the swing bridge has a height of 15.2 m in the area of ​​the parallel chords and reaches 20.3 m in the center above the pivot point, where the upper chords of the two halves are connected by eye rods . The 3061 t heavy girder is rotated by means of a central bearing embedded in the round pillar, which is made up of three 14-15 cm thick metal disks, each with a diameter of 1.3 m. The upper and lower disk made of nickel steel serve as bearing shells and have an inwardly facing concave surface between which a lubricated, double-sided convex disk made of phosphor bronze is located. The pillar also has a steel ring on its upper edge, which functions as a toothed ring on the outside and as a running surface for twelve stabilizing wheels on the inside; four on the outside of the trusses and two on each side below the girder. In the ideal case of the balanced truss, the wheels do not rest on the steel ring and are only intended to absorb wind loads . Two electric motors act via gears on four gears on the ring gear, which enables clockwise or counterclockwise rotation. When closed, the support is fixed by devices with movable wedges at the end and in the middle, which then form the supports . The mechanisms originally operated by electric motors were replaced by hydraulic devices in 1993. The retraction of the wedges and the rotation of the girder by 90 degrees takes about 2.5 minutes, the control is carried out from an operating building, which is located above street level directly above the pivot point and is manned daily by an UP employee.

Driveways

Aerial view of the I Street Bridge from 2014 (looking north), on the right parallel to the Sacramento River the entrance to Jibboom Street and next to it Interstate 5 , above the mouth of the American River

The height of the lower track level corresponds to the height of the adjacent track and the bridge begins or ends for rail traffic at the corresponding abutments. Several viaducts lead to the eight-meter-higher street level, which have been changed and expanded several times over the course of the bridge's more than hundred years of existence. On the west side in West Sacramento, the approximately 170 m long viaduct describes an S-curve and connects C Street, which runs roughly parallel to the north, to the street level, which is accessible in both directions. On the east side in Sacramento there are three viaducts that unite in front of the truss bridge at an intersection at street level. Access is from I Street, which is offset to the south, via a viaduct that ends below Interstate 5 (I-5); Length about 240 m. The exit is only possible on the parallel road J Street, which follows south, the corresponding viaduct of about the same length ends here parallel to I-5 and is part of the exit from the interstate. From the north, access and exit is also possible via an approximately 200 m long viaduct from Jibboom Street, which runs parallel to I-5.

literature

Web links

Commons : I Street Bridge  - collection of pictures, videos and audio files

Individual evidence

  1. ^ John Debo Galloway: Theodore Dehone Judah - Railroad Pioneer. In: Civil Engineering. Vol. 11, No. 10 and 11, 1941, pp. 586-588 and 648-651.
  2. ^ Donald B. Robertson: Encyclopedia of Western Railroad History: California. Caxton Press, 1986, ISBN 978-0-87004-385-7 , p. 296.
  3. ^ Donald B. Robertson: Encyclopedia of Western Railroad History: California. Caxton Press, 1986, ISBN 978-0-87004-385-7 , pp. 90 f.
  4. ^ A b c G. Walter Reed: History of Sacramento County, California. Historic Record Co., Los Angeles 1923, p. 262 f. ( Digitized version ).
  5. ↑ Jerry Bowen: Benicia-Martinez Bridge makes history: Ferries popularity disappears. ( Memento of December 23, 2005 on the Internet Archive ) The Reporter, March 4, 2001.
  6. ^ A b Carolyn Dougherty, LeeAnn Bishop Lands, J. Lawrence Lee, Camille Vicenti: Southern Pacific, Sacramento Shops, 111 I Street, Sacramento, Sacramento County, CA. Historic American Engineering Record, HAER CA-303, Washington, DC 2001, pp. 3-20 and 218-221.
  7. ↑ a b c d e f John W. Snyder: I Street Bridge. National Register of Historic Places Inventory: Nomination Form, Sacramento 1981.
  8. ↑ a b c Southern Pacific Bridge At Sacramento. In: Railway Age Gazette. Vol. 54, No. 15, 1913, pp. 846-849.
  9. ^ John Alexander Low Waddell : Bridge Engineering. Wiley, New York 1916, Volume 1, pp. 694 f. ( Digitized version ) and Volume 2, p. 1174 ( digitized version ).
  10. ^ Alfred M. Staehli: Burlington Northern Railroad Bridge (Willamette River Bridge 5.1). Historic American Engineering Record, HAER No. OR-7, San Francisco 1985, p. 2.
  11. ↑ Heaviest Swing-Span Steel Bridge in the World. In: Architect and Engineer. Vol. 27, December 1911, p. 87.
  12. ^ John W. Snyder: Tower Bridge. National Register of Historic Places Inventory: Nomination Form, Sacramento 1981.
  13. ^ "I" Street Bridge. BridgeHunter.com, accessed July 20, 2020.
  14. ↑ Tower Bridge. BridgeHunter.com, accessed July 20, 2020.
  15. ↑ Jeff Wilson, Randy Rehberg: The Historical Guide to North American Railroads. Kalmbach Media, 2014, ISBN 978-0-89024-970-3 , pp. 278 f.
  16. ↑ a b c Brandon Darnell: I Street Bridge turns 100.Sacramento Press, December 22, 2011, accessed July 20, 2020.
  17. ↑ Ron Hand, Pingkuan Di, Anthony Servin, Larry Hunsaker, Carolyn Suer: Roseville Rail Yard Study. California Air Resources Board, State of California, 2004, pp. 27-30.
  18. ^ I Street Bridge Replacement. City of Sacramento, accessed July 23, 2020.
  19. ^ I Street Bridge Replacement. Modjeski and Masters, accessed July 23, 2020.
  20. ^ A b WSP USA Inc .: I Street Bridge Deck Conversion For Active Transportation Project. City of West Sacramento, 2019, p. 4 f.
  21. ^ WSP USA Inc .: I Street Bridge Deck Conversion For Active Transportation Project. City of West Sacramento, 2019, Appendix D: Preliminary Scour Assessment, pp. 3–5.
  22. ^ Otis Ellis Hovey: Movable Bridges. John Wiley & Sons, Volume 1, 1926, pp. 40 & 48-53 and Volume 2, 1927, pp. 46-54.