Friday, April 5, 2013

Glenwood Tunnel

Map of the route of Glenwood Tunnel. (Courtesy Duncan Nanney)
Neglected and largely forgotten due to the overwhelming shadow cast by the Summit Tunnel and its history, the nearly equally-long Glenwood Tunnel, also known extensively as Laurel Tunnel, bridged a mile-long gap between Burns Creek in Laurel Canyon and Glenwood along Bean Creek. During this passage, the tunnel would rise from 885 feet above sea level at Glenwood to 910 feet at Laurel, which marked the highest point on the entire Mountain Route. Unlike its troubled cousin, the Glenwood Tunnel would never experience major problems and remained a trustworthy and stable tunnel from 1880 until its demolition in April 1942.

Glenwood Tunnel's north portal visible in the background outside the town of Laurel before 1906.
The South Pacific Coast Railroad began construction of the original wood-timbered narrow-gauged tunnel around 1878 along with the other tunnels of the route. Since Glenwood Tunnel did not pass beneath any major fault line and did not include natural gas deposits, it did not experience the problems that delayed Summit Tunnel's opening until 1880. Additionally, a community already existed on one side of the tunnel at Glenwood so construction crews didn't have to create a new camp like they did at Laurel, Highland, and Wrights. Still, on the northern end of the tunnel, Laurel developed slowly from its roots as a labor camp for the northern portal of Glenwood Tunnel.

When completed, Glenwood Tunnel was officially branded SPC Tunnel #3 and was a bore 5,792 feet long, running directly under Highway 17 today. The 1899 Station Book notes it spanning the gap between the 62 and 64 mile posts from San Francisco via Alameda Point. Early photographs of its north portal show that the tunnel had a wood-frame portal, at least on the northern side, until it was upgraded after the 1906 Earthquake. It is highly possible that the southern side, however, had a cement or stone portal early on, as Glenwood Highway, the main thoroughfare over the Santa Cruz Mountains during this period, ran directly over the tunnel's south portal.

The Southern Pacific Company purchased leasing rights to the South Pacific Coast's holdings in 1887 and began upgrading the tracks to broad gauge by the early 1890s. It is unclear if the Glenwood Tunnel was already wide enough to support broad-gauged trains but it was likely expanded during this time. In 1903, Tunnel #1 in Cats Canyon was daylighted because of this construction, and Glenwood Tunnel was renumbered Tunnel #2.

The San Francisco Earthquake of April 1906 did minor damage to the Glenwood Tunnel but timetables from 1907 show through service to Laurel via Glenwood by that year, suggesting that the damage to Glenwood Tunnel was mostly superficial and easily repaired. Upgrading of the tunnel, including the erection of large and sturdy cement portals, began in ernest in late 1908, shutting down the tunnel for at least part of the year, as timetables during this time imply. The imprints above the two portals both read 1909, suggesting that construction was completed early that year. The Glenwood Tunnel was the last tunnel along the Mountain Route to be upgraded to standard gauge.

Exposed wood plank imprints visible along the top of the Glenwood Tunnel's north portal at Laurel.
The "Santa Cruz-Los Gatos Rail Corridor Feasibility Study" adds some information relevant to Glenwood Tunnel.  Despite its years of good repair, the tunnel experienced periodic internal landslides from a variety of loosely-packed sedimentary rock and shale. As is in evidence today, the tunnel exposed numerous springs that were drained through side culverts out the portals north and south of the tunnel and continue to seep out today though the portals are filled. It is possible that parts of the Glenwood Tunnel were water damaged during the 1940 storm that eventually closed the line.

The re-opening of Glenwood Highway after a major construction project, 1915. The south portal of Glenwood Tunnel cannot be seen in full, but the horses are marching over it at left. (Note the metal barricade along its top).
The Glenwood Tunnel remained in regular daily use from 1880 until 1939 with few interruptions. The storm of the winter of 1939-1940 ended that, however. As rain pummeled the right-of-way, causing slides and sinks, the last trains passed through Glenwood Tunnel. Photographs of the north portal show it in apparently good repair, though the surrounding right-of-way is heavily damaged. In April 1942, H.A. Christie's railroad salvage firm finished pulling up the tracks from inside Glenwood Tunnel and blasted the entrances very near the portal mouths. Both tunnels, being composed of light sedimentary rock, collapsed heavily and definitively. Both portals are blocked only a few feet into the tunnels. The northern portal has large rocks blocking the way while the south portal seems to have been reinforced with steel girders to ensure that the road running above the tunnel remains safe for traffic. Both portals can be easily viewed today.

The approach to Glenwood Tunnel's north portal near Laurel, February 29, 1940. Note the sand on the tracks and the debris. The portal, on the other hand, seems to be intact. (Courtesy Bruce MacGregor)
Glenwood Tunnel's north portal today.
The north portal itself is actually kept in decent repair. There is little to be seen from the inside, although it is only portal that you can climb on top of and see the actual wood imprints of the planks used to build the entrance. A metal fence that dates back to at least the 1930s is on top. The portal is used today as a cistern and collection basin for water, which is then used to help maintain the few houses in the area.   Prior to 1989, the tunnel provided all the water for the local residents. Unfortunately, the 1989 Loma Prieta Earthquake blocked the major spring that provided the cistern with purpose and it now only supplements the local populace's water supply. As a warning, you may get wet if you try to visit this tunnel. However, it and the Atomic Vault in Zayante are the most easily accessed portal on the mountain route. A simple drive down Laurel Drive off of Highway 17 will pop you out at the house that guards this tunnel.

Glenwood Tunnel's south
portal today.
The south portal runs immediately beneath Glenwood Drive but is actually fairly difficult to see with detail. The small spring that runs out of the portal has allowed for the growth of a vast ecological niche, turning the right-of-way into a gully. Accessing the portal requires a climb, thought the portal can be observed from a distance. Drive down Glenwood Drive from Scotts Valley and park at a driveway at right just where the large field at right narrows to a point. There should be some horse corrals immediately adjacent to the driveway. The portal is to the left under the road. There are some old metal barriers that date to at least the 1930s that block pedestrians from falling over the ledge alongside the road, marking the portal. A very steep path runs down to the portal from either side, but beware of poison oak and trash that has collected at the bottom of the gully.


Jeff Escott standing over the 1909 date over the Glenwood Tunnel's South Portal. (Courtesy Jeff Escott)
Glenwood Tunnel's south portal as viewed from Glenwood Drive above.
Glenwood Tunnel's south portal as viewed from inside. Note the sandy fill and the major steel girders
supporting the back of the portal. The entrance of the portal is overhead. 
Regrettably, I have not found an known image of the Glenwood Tunnel's south portal documenting it during its many decades in use. This is not unexpected but unfortunate. It was located just around the corner from Charles Martin's Glenwood Magnetic Springs Resort and its appearance compared to other portals, especially in the years prior to 1909, would be extremely interesting to note.

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