Sunday, August 28, 2016

Monterey County, California Bridges: San Lucas Road Bridge across the Salinas River

July 2016 (36.11697-121.02749) San Lucas Road Bridge
We pick up the Salinas River again in the town of San Lucas about 40 miles south of Chualar. The (Lockwood) San Lucas Road Bridge (44C0007) is a six span, 870 ft long truss bridge that was built in 1915. The west end of the bridge is composed of two pin connected Pratt truss spans (see photo below) and the east end is composed of four Warren truss spans (see photo above). Perhaps the older looking Pratt trusses were the original design from 1915 and the newer looking Warren trusses were added as part of the rehabilitation in 1960? Actually, that makes little sense since the bridge has to be at least four spans long to cross the river. Note that the bridge is a single lane, which means you need to be sure a driver on the other side of the bridge is going to wait before you set off across this long structure.
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Sunday, August 21, 2016

Monterey County, California Bridges: Chualar River Road Bridge across the Salinas River

July 2016 (36.5557, -121.5487) Chualar River Road Bridge
We picked up the Salinas River again about 20 miles south of last week's Union Pacific Railroad Bridge. At this location the original eight span, pin connected, Pratt truss bridge was replaced with a ten span continuous concrete box girder bridge in 1991 (photo of old bridge provided by Library of Congress).
The new Chualar River Road Bridge (44C0021) is 1050 ft long with an 108 ft main span on pier walls.
State Route 101 follows the Salinas River for 100 miles through Monterey County. To find these Salinas River Bridges one simply takes the various exits from 101. The Salinas River switches back and forth from the east to the west side of 101 as we continue southward. The Chualar River Road Bridge is on the west side of 101.
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Sunday, August 14, 2016

Monterey County, California Bridges: Union Pacific Salinas River Bridge

July 2016 (36.73152, -121.78169) UP Salinas River Bridge
The Salinas River is one of the few bodies of water in California that flows northward. It starts in San Luis Obispo County and ends in Monterey Bay. During high-water flows, the river can be several hundred feet wide and requires long bridges to span it. Over the next few weeks we'll study some of the long Salinas River Bridges.

We begin our study at the north end of the river just before it empties into the Pacific. The Monterey Branch of the Southern Pacific Railroad opened in 1880 and served the canneries, packing houses, lumberyards, and army bases along the coast. It also provided a luxurious passenger train service between San Francisco and Pacific Grove, the 'Del Monte.' More information on this abandoned rail line is available online.
The Union Pacific Salinas River Bridge is a five span Warren truss structure (built with rivets) in the town of Neponset. It's 718 feet long with a 142 ft long main span. It's only 14 ft wide and sits on  broad concrete piers.
This abandoned bridge has been severed from the surrounding railroad tracks with fencing (which I had to climb over). There it remains, slowly rusting until it is either removed or the railroad line is put back in use.
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Sunday, August 7, 2016

Monterey County, California Bridges: Larkin Street Bridge across Hartnell Gulch

July 2016 (36.5969, -121.9000) Larkin Street Bridge
Hidden among the heavy foliage of Hartnell Gulch on the north side of Monterey High School is another original bridge structure by John B. Leonard. According to the book Historic Highway Bridges of California, "This bridge is one of three remaining examples of John B. Leonard's 'canticrete' design (a bridge carried on cantilevered steel trusses encased in concrete). It is 20 feet wide and 102 feet long. It features neoclassical detail and is almost completely unmodified."
The National Bridge Inventory reports that it was rehabilitated (widened?) in 2007.
The Larkin Street Bridge was built to provide access to the property that would become Monterey High School in 1914. It is a two span arch bridge that has remained in service (along with the high school) for over 100 years.
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