Santa Cruz County, California Bridges: Wood's Lagoon Bridges

March 2014 (36.96778, -122.00278) Wood's Lagoon Bridges

A little east of the mouth of the San Lorenzo River is Wood's Lagoon, which is crossed by two bridges. The Murray-Eaton Street Bridge (36C0108) is a 544 ft long, 9-span precast girder bridge that was built in 1963.   The spans are 60 ft long and sit on two column bents with large caissons. Next to the highway bridge is the SCBG Railway bridge with precast box girder spans on tapered pier walls and with similar caissons, which were made by filling soldier pile cofferdams with concrete. 

Wood's Lagoon was turned into a protected harbor for yachts and other small craft.  The two bridges look similar enough to suggest they were built by the same contractor, maybe at around the time they were building the harbor.

Santa Cruz County, California Bridges: Wood's Lagoon Bridges by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Santa Cruz County, California Bridges: Cabrillo Highway (SR-1) Bridges across the San Lorenzo River

March 2014 (36.98500, -122.02667 Degrees) Cabrillo Highway Bridges

One last pair of bridges across the San Lorenzo River. The Cabrillo Highway (State Route 1) Bridges (36 0071L/R) are 4-span T beam bridges that share a single set of pier walls. The bridges were built in 1956 and were never renovated or retrofitted. They are 230 ft long with a pair of 80 foot spans over the river. 

Santa Cruz County seems like a land lost to time. There were a lot of bridges built 50 to 100 years ago, but nothing much has been built recently. There are no major highways and it's a long, difficult drive on two lane roads to get in and out of Santa Cruz County. The Google earth photo below shows the county is between the San Gregorio and the San Andreas Faults, which have pushed up the land and created the San Lorenzo River between them.

Santa Cruz County, California Bridges: Cabrillo Highway (SR-1) Bridges across the San Lorenzo River by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Santa Cruz County, California Bridges: Powder Works Bridge across the San Lorenzo River

March 2014 (37.01049 Degrees, -122.04384 Degrees) Powder Works Bridge

Two miles north of downtown Santa Cruz on the San Lorenzo River is the Powder Works Bridge. A paper mill was built at this location in 1860 but the area gained renown as the site of an explosives plant that began operations in 1864. The US Library of Congress writes:"The Powder Works Bridge is the second oldest of twenty-one extant Smith truss covered bridges in the United States. It was built in 1872 for the California Powder Works, the first powder mill on the Pacific Coast, and is one of the last vestiges of the company's extensive manufacturing complex that occupied the site from 1861 to 1914. The bridge is an excellent example of the early work of the Pacific Bridge Company, a nationally significant bridge engineering firm.

In 1924 the property was purchased by the Freemasons and turned into Paradise Park with picnic grounds and brightly painted houses. 

The Powder Works Bridge is a 180 ft long two span timber truss covered bridge. It is currently being considered by the National Park Service as a National Historic Landmark. The Felton Covered Bridge that we studied on March 18, 2014 is registered as a historic place, but it was rebuilt and moved and so it wouldn't qualify as a historic landmark. Since the Powder Works Bridge is on private land, it's up to the park residents to decide if they want their bridge to become a famous landmark.

Santa Cruz County, California Bridges: Powder Works Bridge across the San Lorenzo River by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Santa Cruz County, California Bridges: Grant Street UC across State Route 1

June 2007 (  36.9862 Degrees, -122.0237 Degrees) Grant Street UC

Surprisingly, although the epicenter of the 1989 M7.1 Loma Prieta Earthquake was in Santa Cruz County, almost all the bridge damage was 60 miles to the north in San Francisco and Alameda Counties. There were only two state bridges that were damaged in Santa Cruz County besides the Struve Slough Bridge that we studied on March 8, 2014. These were the Corallitos Creek Bridge and today's bridge, the Grant Street Undercrossing. However, the damage to these bridges was much less serious than at Struve Slough and it was quickly repaired. There were also several county bridges that were damaged during the 1989 Earthquake. More information on bridge damage during the Loma Prieta Earthquake can be found in the USGS Professional Paper 1552-B Highway Systems.

The Grant Street UC (36 0075) is a four span precast I girder bridge on two-column bents. During the earthquake the expansion joints banged together spalling some concrete (see photo above), the bearing keeper plates were knocked off at the abutments (see photo below), and the embankments around the abutments settled, which damaged the bridge approaches.

 A repair contract was written after the earthquake (see figure below) and the bridge was also seismically strengthened with an infill wall retrofit in 1996. However, some of the earthquake damage can still be seen today (see figure at bottom).

Santa Cruz County, California Bridges: Grant Street UC across State Route 1 by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Santa Cruz County, California Bridges: South Marsh to Hummingbird Island Ford across a tributary of Elkhorn Slough

October 1997 (36.824025 Degrees, -121.73945 Degrees) South Marsh Ford

A ford is an inexpensive bridge designed to carry people across bodies of water when they are below flood stage and to survive with minor damage during flood stage. We have studied fords in India and also in many rural parts of California where there is no money to build a bridge.

Today's ford carries pedestrians from South Marsh to Hummingbird Island across a tributary of the Elkhorn Slough. We can see a transmission tower from the Moss Landing Power Plant, which is nearby on the beach.

Santa Cruz County, California Bridges: South Marsh to Hummingbird Island Ford across a tributary of Elkhorn Slough by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Santa Cruz County, California Bridges: Riverside Avenue Bridge across the San Lorenzo River (2)

January 1983 (36.9678 Degrees, -122.0189 Degrees) Riverside Avenue Bridge

City workers using a crane on the Riverside Avenue Bridge try to loosen a log jam. The photo was taken during one of the storms of 1983 that caused the San Lorenzo River to flood.
Date: January 3, 1983
Place: Santa Cruz City
Source of Information: Graham Hill Water Treatment Plant
Related Articles:

History of Floods on the San Lorenzo River in the City of Santa Cruz

Bridges Span Santa Cruz's Past

Santa Cruz County, California Bridges: Riverside Avenue Bridge across the San Lorenzo River (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Santa Cruz County, California Bridges: SR17-SR1 Cnnnection Separation

March 2014 (36.99039 Degrees,  -122.02141 Degrees) SR17-SR1 Connectors

You get to Santa Cruz either by driving west through the mountains on SR17 or by driving along the coast on SR1. The SR17-SR1 Connector Separation (36 0069L/R) is a pair of precast girder bridges that carry traffic over SR1. They were built in 1958 and seismically retrofit in 1996. It looks like the bridges have bin-type abutments, which means they have curtain walls that hide the slope and abutment. The open barrier rail makes the bridges look older. Probably open barrier rail was the architectural treatment for bridges near the coast. 

Santa Cruz County, California Bridges: SR17-SR1 Cnnnection Separation by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Santa Cruz County, California Bridges: State Route 9 Highway Bridge and SCBG Railway Bridge across Rincon Gulch

March 2014 (37.00556, -122.04500) Rincon Gulch Bridges

A concrete T girder highway bridge and a timber trestle railway bridge were built side by side across Rincon Gulch in Big Trees State Park. 

The Rincon Gulch Highway Bridge (36 0037) carries State Route 9 on a three span T girder superstructure with two column bents that were built in 1930 and retrofitted with infill walls in 1996.

The timber trestle bridge includes a steel girder span over a dirt road that rests on a steel tower pier to help support the near side. 

Santa Cruz County, California Bridges: State Route 9 Highway Bridge and SCBG Railway Bridge across Rincon Gulch by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Santa Cruz County, California Bridges: SCBG Railway Bridge across the San Lorenzo River

March 2014 (37.03379 Degrees, -122.05809 Degrees) San Lorenzo River Bridge   

You can tell the role railroads played in the development of Santa Cruz County because of the number of railroad bridges that are still around. Today's bridge is now part of the Santa Cruz, Big Trees, and Pacific Railway (SCBG). We have seen a few old railroad lines being reused as tourist trains like the wine train in Napa and the SCBG. Today's bridge can be identified as location #3 on the map below. 

The bridge consists of a steel plate through girder span and a Warren through truss span over the San Lorenzo River. This bridge was built in 1906 and was used for carrying everything from fresh strawberries to lumber and it's now a passenger train.

Santa Cruz County, California Bridges: SCBG Railway Bridge across the San Lorenzo River by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Santa Cruz County, California Bridges: Big Trees Bridge across the San Lorenzo River

March 2014 (37.04333, -122.07167 Degrees) Big Trees Bridge

Continuing south on State Route 9 we arrived at the Henry Cowell Redwoods State Park and another three span haunched T girder bridge across the San Lorenzo River. The Big Trees Bridge (36P0013) is 143 ft long with a 75 ft main span and a 36 ft wide deck that carries Big Trees Park Road. The bridge was built in 1931 and it's owned by the State Park Service.

Santa Cruz County, California Bridges: Big Trees Bridge across the San Lorenzo River by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Santa Cruz County, California Bridges: Conference Center Drive Bridge and Overhead over Zayante Creek

March 2014 (37.05056 Degrees, -122.06472 Degrees) Conference Center Drive Br. and OH

Half a mile east of yesterday's bridge is the Conference Center Drive and Overhead Bridge (36C0038). This 523 ft long bridge crosses over East Zayante Road, Zayante Creek, and the South Pacific Coast Railroad (now owned by the Santa Cruz Big Trees and Pacific Railway). This bridge carries vehicle and foot traffic to the idyllic Mount Hermon Christian Conference Center.

The bridge is in surprisingly good shape for a structure built in 1930. Maybe it's maintained by the Conference Center? While I was photographing it groups of conference attendees kept strolling by on the timber sidewalk. 

It's a rather odd bridge because it's composed almost entirely of steel wide flange girders. The columns are steel girders, the superstructure is steel girders, and even the timber railing is supported by steel girders. Anyway, the bridge is composed of 50 ft spans and the deck is 24 ft wide.

I also wanted to photograph the Zayante Railroad Trestle Bridge but I couldn't figure out how to get down to it. The only photograph I was able to get (shown above) was from the deck of the Conference Center Bridge. Anyway, it's a steel plate girder bridge on reinforced concrete pier walls that was built in 1917. More information is available from Santa Cruz Trains Website.

Santa Cruz County, California Bridges: Conference Center Drive Bridge and Overhead over Zayante Creek by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Santa Cruz County, California Bridges: Felton Covered Bridge across the San Lorenzo River

March 2014 (37.05081, -122.07092) Felton Covered Bridge

A covered bridge across the San Lorenzo River was built in the town of Felton in 1892. It was originally built as a timber through truss but it was covered with a roof a few years later to protect the vulnerable timber deck from all the rain.

The Felton Covered Bridge is one of the newer and one of the shorter covered bridges in California. However, the addition of the roof truss also made it the tallest (at 35 ft) covered bridge in the United States. It is also one of the last covered bridges made of redwood.

The bridge was closed to traffic in 1937 and became the first bypassed bridge in the western U.S. to be restored as an historic landmark. Money was raised for the original bridge with a costume ball and the bridge continues to be maintained with an annual pancake breakfast.

Information on the Felton Covered Bridge comes from many sources. A plaque beside the bridge describes how after it became a pedestrian bridge it was used in many movies until it was damaged by a flood on the San Lorenzo River in 1962 and rebuilt by local residents in 1967. The Santa Cruz Public Library's website also contributed information about this and the other San Cruz covered bridges. Drawings and other information was provided by 'Historic Highway Bridges in California.'

Santa Cruz County, California Bridges: Felton Covered Bridge across the San Lorenzo River by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Santa Cruz County, California Bridges: Graham Hill Road across the San Lorenzo River

March 2014 (37.05278 Degrees, -122.07194 Degrees) Graham Hill Road Bridge

Just downstream from yesterday's truss arch bridge is a three span haunched box girder bridge across the San Lorenzo River. The Graham Hill Road Bridge (36C0101) was built in 1938 and rehabilitated (widened) in 1989. 

We are in the town of Felton, which like Boulder Creek has a history as a logging town during the later half of the 19th century. This is a pretty and a historic area with a variety of interesting bridges that we'll study over the next few days.

The Graham Hill Road Bridge is a 221 ft long bridge with a 116 ft long main span. The deck is now 78 ft wide and on a 40 degree skew. The bridge is in 'Good' condition, it carries over 25,000 vehicles a day, and it has a sufficiency rating of 85.

Santa Cruz County, California Bridges: Graham Hill Road across the San Lorenzo River by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.