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This website is a constant work-in-progress, with articles updated regularly throughout the site. Much of the information comes from local railroad fans such as yourselves. If you have information regarding local railroads, photographs or railroad documents, or you feel a mistake has been made or information omitted from an article, leave a comment on the appropriate page or email me at author@santacruztrains.com. This site would not be possible without your help and support. Thank you! – Derek R. Whaley

Friday, December 1, 2017

Bridges: Upper Los Gatos Creek

The five miles of trackage between Lexington and the Summit Tunnel at Wright was some of the most rugged terrain the South Pacific Coast Railroad encountered on their ascent into the Santa Cruz Mountains, although one must remember that there were few trees in the right-of-way since most had been logged over the preceding two decades. Besides the frequent obstacle that Los Gatos Creek presented to railroad graders, there were also numerous large and small feeder creeks that descended from the adjacent mountains and required bridges to cross. While some of these were later filled and culverted, most remained and one even survives to this day. Photographs of all of these myriad bridges do not survive, but enough exist to give an idea of the type of engineering work required of the South Pacific Coast and the Southern Pacific Railroad that followed it.

In summary, all of the bridges between Lexington and the Summit Tunnel were built with narrow-gauge tracks in mind and required upgrading by the Southern Pacific to support the larger gauge of their rolling stock. The bridges were all initially constructed in 1877 and most, if not all, were built using standard trestle designs. Trestles in the Santa Cruz Mountains were all constructed of large redwood posts, usually between three and five, held together by connecting pieces of lumber, called bents. Atop this structure sat an open redwood deck with ties and tracks. In some instances, decks alone could suffice to span a short gulch, with only abutments on either side supporting the span. In a few instances, usually where there were no firm places to install posts, a truss bridge of varying types may be installed. These essentially inverted the trestle work by lifting it off the ground. A truss is a mathematically-calculated series of bends designed in such a way to redistributed weight to the ends of the structure, which would rest on abutments or piers. In later years, many of the trestles were replaced with either fills or prefabricated open-deck plate-girder bridges which would rest on concrete piers and abutments. However, a number of redwood trestles still survived, either through upgrades or through outright replacement. Relics of nearly all of these bridges survive beyond Aldercroft.

Through the basin that today houses Lexington Reservoir, the railroad never crossed Los Gatos Creek. However, it did have a number other important obstacles to overtake. The first was Limekiln Canyon, located directly across Los Gatos Creek from Lexington. This was initially built as a standard redwood trestle and the only known photo of it is from this time. It was certainly replaced around 1900 with a studier, standard-gauge structure but whether that was a trestle or some other construction is unknown.

Limekiln Canyon trestle with the future Alma Bridge Road in the background, 1895. [Bruce MacGregor]
Smaller bridges undoubted leapt over other small canyons and gulches between Lexington and Alma but the next significant obstacle was the Conoyer Creek—later renamed Soda Springs Creek—bridge. This was a relatively short bridge that spanned a deep gully via a standard redwood trestle. Due to the short span of this bridge, it was probably converted into a fill with a culvert during standard-gauging. The inundating of the valley in 1953 by Lexington Reservoir destroyed any evidence of this bridge.

The Soda Springs Creek bridge in the foreground with Alma in the trees behind, c. 1890. [Bancroft Library]
South of Alma, a more problematic area was encountered that required significant trestlework. The grade ran along the eastern side of the valley but had to maintain a continuous incline to reach Wright. But a repercussion of this was that the route had to pass beside the expansive Hendrys Creek floodplain. Hendrys Creek sits today at the southern end of Lexington Reservoir (when it is full) and the canyon that causes the creek to drain is one of the widest in the region. The railroad had to build a long redwood causeway trestle across these flats to reach the solid land on the other side. When the line was standard-gauged, this bridge was simply replaced with a wider version, perhaps even keeping the old pilings in place. A proposal in 1910 would have bypassed this bridge, replacing it with two bridges that would have been situated more in the center of the floodplain, but the plan never came to fruition. After the railroad was abandoned in 1940, the bridge was repurposed to support water pipes from Lake Elsman. It remains the only intact Southern Pacific Railroad bridge in this area visible to the public without trespassing and can be viewed just to the south of Aldercroft Heights Road along Alma Bridge Road.

A modern view of Hendrys Creek trestle, 1977. [George Pepper]
Beyond Aldercroft, explorers today enter into the restricted domain of the San Jose Water Company. It is not advised to hike through this area and it is certainly not recommended that one parks a car anywhere on Aldercroft Heights Road. That being said, remains of virtually all of these bridges survive and some are quite spectacular. Between Aldercroft and Wright, Los Gatos Creek was bridged five times, while there was also once a significant bridge over Hooker Gulch over Aldercroft Heights Road.

Following the right-of-way south toward Wright from Aldercroft, the tracks crossed Los Gatos Creek just beyond Aldercroft around a curve. This was one of the shortest crossings over the creek. What the original bridge looked like is unknown, but the standard-gauge replacement was a prefabricated open-deck plate girder span mounted atop two concrete abutments. It was probably the first or second bridge to be upgraded along this stretch owing to the older style of the abutments. At some point in the 1950s, a permanent dam was installed beneath this bridge with an accompanying concrete spillway and fish ladder which was named Rylan Dam. Clearly the water levels once were higher on both portions of this dam since the fish ladder today has no inlet and lets out on solid ground. At one time, both ends would have been submerged. When Southern Pacific crews removed the plate girder span in 1941, they left the piers and dam in place. The water company in 2010 recently built atop the piers and installed a pipe bridge in place of the train bridge, using the old foundations to supplement their additions. This addition was added through a helicopter air drop operation. Overall, the concrete remains remarkably intact leaving a beautiful scene for trespassers to find hidden in the woods of Los Gatos Creek.

Rylan Dam today, looking east, with the trestle abutments on either side holding aloft a pipe, 2013. [Derek R. Whaley]
Less than half a mile to the south, the right-of-way passes back to the east bank of Los Gatos Creek over another bridge. The original narrow-gauge structure here was a series of truss bridges over a trio of redwood piers supplemented by wood abutments on either bank. The creek is shallower here, so the the trains would drive through the trusses rather than ride on decks above the spans. When the line was upgraded around 1901, the redwood was torn up and replaced with two hexagonal concrete piers flanked by concrete abutments that held aloft an open-deck plate girder bridge. Although the piers and abutments for this survive, the water district chose a slightly different path for their pipe from Lake Elsman and they have only repurposed the northern abutment for their uses. The other three remaining parts sit unused in the creek bed.

A crossing over Los Gatos Creek between Aldercroft and Eva, 2002. [George Pepper]
The railroad continued to run on the east bank of Los Gatos Creek for over a mile at this point, but before it reached Eva, it crossed Hooker Gulch, a crossing which passed over not only the gulch itself, but the creek that ran down the gulch and the public road to Wright (now Aldercroft Heights Road). The construction of the original bridge is unknown but probably appeared much as the later bridge appeared. When the line was upgraded to standard gauge, a concrete abutment was built on the northern side, beside the road, and a short plate girder deck bridge was installed over the road. South of that, a trestlework causeway left to the opposite embankment, beside the creek, reuniting the line with a long fill and solid ground. Thus, this was very much a hybrid construction unlike most of the other bridges in this section of the line. The abutment still survives above the road and sawed off piers can still be followed all the way to the overgrown grade directly opposite. This is the only other bridge visible from the road without trespassing. It can be viewed by driving down Aldercroft Heights Road and looking toward the north when the road turns west suddenly through a narrow gap beside a small creek and embankment.

Hooker Gulch bridge abutment above the road, 2002. Pilings are visible opposite this spot. [George Pepper]
The railroad crossed Los Gatos Creek three more times before making a final dramatic turn into the Summit Tunnel at Wright. All three are completely inaccessible to explorers due to the fact that they lie behind the severely protected San Jose Water Company gate and also require a good measure of bush-wacking. The first is located just past the site of Call of the Wild. It is the least photographed and very little is known about its current condition. From the scant evidence, it seems that the later iteration of this bridge had only a single hexagonal pier that has since collapsed and been ground down to nearly its foundation to allow for a modern automobile ford to be built around it. Remnant pilings on one bank suggest at least some trestlework was used to bridge the creek here, although an existing concrete abutment implies that a plate-girder bridge completed the span. Further investigation is required to determine the final structure of this bridge.

Remnants of bridge immediately south of Call of the Wild, 2002. Abutment visible in trees on hillside. [George Pepper]
The style of the second bridge closely resembled that of the first but two hexagonal concrete piers suggest it supported a full plate girder span across the creek. The bridge brought the tracks back to the east bank to allow for a more gradual turn into the Summit Tunnel. Like the previous bridge, the piers have been left to rot, with one collapsed on its side and all evidence of the other entirely erased.

The single remaining concrete pier a bridge between Call of the Wild and Wright on Los Gatos Creek. [Brian Liddicoat] 
The final bridge between Aldercroft and the Summit Tunnel was located between the Summit Tunnel and the later location of Wright Station on the east bank of Los Gatos Creek. This is the only bridge in the Los Gatos Creek area that its entire history is known since it appears in many photographs of Wright. The first bridge was a standard trestle design without any embellishments except a footpath that ran along the northern side of the track.

The original trestle over Los Gatos Creek at Wright, c. 1880. [Derek Whaley]
When the standard-gauging of the line began, Wright was the last place to receive an upgraded bridge. Around 1902 the original narrow-gauged structure was replaced with a sturdier bridge. The new bridge was composed of redwood timber piers and abutments which upheld a Warren truss upon which the trains would cross. Following the earthquake, a narrow-gauge service track was added to the inside curve of the bridge, replacing the footpath that originally ran beside the bridge on that side. This remained in place until 1908, when repair crews finished upgrading the Summit and Glenwood tunnels.

The bridge over Los Gatos Creek at Wright, February 22, 1907. Photo by Frank Herman Mattern. [Greg De Santis]
Around 1910, the bridge was replaced a second time, this time with a much more modern style. New circular concrete piers were installed, reinforced with the latest quality of rebar and a open deck plate girder bridge was set atop the piers. Photographs of this final bridge seem to be lacking, probably because the popularity of Wright as a town and vacation area substantially declined following the earthquake. Nonetheless, it is this final version that survives today and is visible to those who can find them in the woods near north of the Wright townsite. A warning still printed on the base of one of the piers reads "Danger: Keep out from under bridge as rocks etc. might fall from passing train." Once an important warning for anglers and adventurers, this message now stands as a reminder that these hills were once alive with the rumbling passage of steam trains.

The two piers of the final bridge over Los Gatos Creek outside of Wright, 1977. [George Pepper]
There were at least three other small crossings along the route include two on either side of Alma bridging gulches and one between the final third and fourth Los Gatos Creek crossings that passed atop a small creek. Remains of this latter bridge survive and it appears to have been an open deck bridge like the others, although the name of the creek is unknown and only a few remnants in the creek suggest there may have been a pier built for it. Numerous culverts also survive along this route. The upper Los Gatos Creek basin was certainly one of the most rugged portions of the entire South Pacific Coast line and the fact that so much of it survives today is a testament to the durability of Southern Pacific engineering.

Citations & Credits:
  • De Leu, Cather & Co., "Santa Cruz - Los Gatos Rail Corridor Feasibility Study: Draft Final Report", prepared for the Joint Policy Board (December 1994).
  • Hamman, Rick. California Central Coast Railways. Second edition. Santa Cruz, CA: Otter B Books, 2002.
  • MacGregor, Bruce, and Richard Truesdale. South Pacific Coast: A Centennial. Boulder, CO: Pruett Publishing, 1982.
  • Whaley, Derek R. Santa Cruz Trains: Railroads of the Santa Cruz Mountains. Santa Cruz, CA, 2015.

3 comments:

  1. Yet, there is still a trestle that is not listed here that you can still see the remains of. It is halfway in between the small concrete trestle pier by Call of the Wild stop (rubber dam) and the broken concrete trestle piers of Wrights north. The trestle is made of wood and once forded a small feeder creek created by a gulch. The large wooden trusses are still on the north and south sides of the gulch but the center of the trestle has collapsed. You can see the gulch originating from around Old Santa Cruz Highway and heads toward Los Gatos Creek on a topo map but the gulch has no name. The trestle is at 37.145361Lat, -121.955794Long +/- 10ft.

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  2. Alma South Trestles are really fascinating. They are VERY high, compared to the others, and are built into the hills, as opposed to the free standing structures. While they were obviously decommissioned in 1940, they became the focus of another Los Gatos Creek project in the 1950s, when "Ryland Dam" was constructed in between them. Ryland Dam is simply a spillway with a salmon ladder that ensures the creek goes between the trestles, and now around them.

    It stayed that way, slowly crumbling due to the 24/7 365 water flow for nearly 60 years. In 2010, the San Jose Water Company built the metal bridge so they could extend a functional addition to their pipeline coming from Lake Elsman/Rubber Dam. The bridge was actually LOWERED into place by a tandem rotor helicopter. They cut down a ton of trees to make the space.

    I grew up in Chemeketa Park just south of Lexington Resevoir and within walking distance of the Alma Trestles. I heard them lower the bridge in place from my house and I had neighbors who went down to watch it happen.

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  3. That sign on the trestle pier at Wrights which is shown on page 261 of MacGregor's SOUTH PACIFIC COAST and reads " Danger. Keep out from under bridge..." seems to have disappeared since I first saw it in 1964. In 1964,
    it was so clear from Wrights Station Road, I did not even have to trespass
    to photograph it. But a couple of years ago, it looked like the elements had
    eradicated it. Has anyone else been there lately to see if it is still there?

    ReplyDelete