Friday, March 29, 2013

Summit Tunnel

South portal of Summit Tunnel, entering
Burns Creek basin, c. 1882.
Summit Tunnel, often also called Wrights Tunnel, was a major undertaking made by the South Pacific Coast Railroad beginning in 1878. Located at the top of Los Gatos Creek, 889 feet above sea level, construction was troubled by the fact that the tunnel ran directly over two fault lines, the more dangerous of which was San Andreas Fault. The tunnel, which was originally known as Tunnel #3 then renamed Tunnel #2 before it ever opened, was over a mile long (6,200 ft.) and ended up above Burns Creek, a tributary of Soquel Creek, north of Highland, a village that would soon develop into Laurel. Because of the fault line, natural gas regularly leaked into the tunnel. During construction, a massive explosion crippled the tunnel and killed over thirty Chinese workers. The largest of the leaks was found and sealed but small leaks continued to seep into the tunnel during its entire time of operation. It is said that a small flame was left burning at all times to keep the gas levels down. Construction of the tunnel was completed in May 1880. 

Construction of northern end of Summit Tunnel, c. 1879.
The broad-gauging of the Mountain Route was first foreseen by the Southern Pacific Railroad soon after it took over operation of the line in 1889. Summit Tunnel was targeted as the first tunnel to be widened to support the larger trains and construction on the tunnel and its northern portal was completed in 1893. With the new construction, a large and somewhat elegant water diversion was built to the right of the north portal, parts of which still survive today.


Reconstruction of the north portal, 1892-1893.
Nearly completed northern portal, 1893.
Little changed after the widening and expansion. The tracks north of Los Gatos were still not broad-gauged and the new tunnel remained an anomaly, with the other tunnels retaining their wooden original portals. Although there are no photos of the portal, it seems likely that even the south portal of Summit Tunnel was not upgraded. In 1903, the Cats Canyon tunnel was daylighted and Summit Tunnel was formally renamed Tunnel #1.

1893 Summit Tunnel north portal with a track inspector on his tricycle. Tracks still appear to be narrow-gauged.

In April 1906, the San Francisco Earthquake utterly devastated the tunnel, cutting off service over the mountain. The 1893 portal was repaired but the narrow-gauge tracks were pulled up and replaced with new broad-gauge tracks.
Repairmen inside the Summit Tunnel, probably after the 1906 Earthquake.
The south portal was completely replaced in 1908 and a brick roof was installed that went 300 ft. deep into the tunnel from the south to help protect the tunnel in case of a natural gas explosion. That portion of the tunnel still exists today, as does the portal itself.

The south portal of Summit Tunnel after 1908.
For the next thirty-two years, the town of Wrights declined slowly but surely. The tunnel remained in almost daily use, however, with Suntan Specials cruising every Sunday during the summer and freight and commuter trains using the tunnel at least twice of day even during the rest of the year. But a destructive winter in 1939-1940 sealed the fate of the tunnel. 


Summit Tunnel north portal in the autumn of 1937. (Courtesy Bruce McGregor)
Summit Tunnel north portal in April 1940 after abandonment papers had been filed. (Courtesy Bruce McGregor)
The entire Mountain Route was abandoned due to repair and maintenance costs. In April 1942, the tunnel was dynamited at the entrances by H.A. Christie's railroad salvage company. On the north side, the dynamite was placed roughly 100 feet inside the tunnel since the forward portion was hard concrete. On the southern end, the dynamite was 300 feet inside due to a brick ceiling. Both ends can be navigated today on foot.


The eerie view inside Summit Tunnel's south portal looking south toward Laurel. Taken by
Bruce McGregor in 1967, this tunnel has changed little since it was abandoned in 1940.
Tracks have been removed and the roof has been destroyed about 150 feet behind the
photographer, but otherwise this portion of the tunnel remains completely in tact.
The heavily graffitied inside of the Summit Tunnel's north portal today. The rubble pile is directly behind me.
Access to the northern portal of Summit Tunnel is relatively easy. It can be found at the bottom of Wright Station Road just before the bridge. Look for the mailboxes, jump the fence, then turn left. The tunnel's just a bit into the overgrowth. 


The north portal of Summit Tunnel today (Photo courtesy Brian Liddicot)
The southern portal has been almost completely overtaken by the surrounding foliage due to a natural spring that has degraded the cement over the past seventy years. While large portions of the portal survive, sediment has raised the floor level and collapsed the entrance. Large portions of cement lay scattered around, while the once majestic cement waterfall sits broken and unused to the right.


Here is a perspective shot of the collapsed north portal of Summit Tunnel. It is still quite high, but the floor has definitely move upward toward the ceiling over the past seventy years.
The now-unused spillway beside the tunnel entrance, covered in moss and lichen and in pieces.
Access to the Summit Tunnel's southern portal is a much more difficult feat. It is located down a long and steep path off of Troy Road near Summit Road. While it can also be accessed via a long private driveway in Laurel Canyon (the driveway was once the right-of-way), this method is much more difficult. The Troy Road approach pops you right on top of the southern portal, and then you can climb your way around to the entrance via a wrap-around trail.


Standing on top of the portal, looking down.
As previously mentioned, the southern portal and 300 feet of the tunnel itself still survives in nearly pristine condition, giving an eerie feeling of what it was like traveling a mile underground without natural (or artificial originally) light. 


Summit Tunnel's south portal today. Overgrown but otherwise intact.
Summit Tunnel's south portal from the inside showing the brick ceiling and
the distant glow of the entrance to the portal.
Rumors and legend has it that the tunnel was only blasted at the entrance and that the interior is still mostly intact, though heavy levels of methane have leaked from the original cracks of 130 years ago. The tunnel may have been briefly opened and even explored following the 1989 Loma Prieta Earthquake, though actual proof of such an exploration is difficult to find and Rick Hamman reports that while the plan was created, it was never implemented. Regardless, it is extremely like that this tunnel could be serviceable again given the correct circumstances. The right-of-way to and from the tunnel is largely reparable, further giving hope to this unlikely cause.

4 comments:

  1. Let me know the next time you want to go look at any tunnels. This stuff is fascinating to me.

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  2. About 1992, a group of 5 friends and I hiked the old SPC and extensively explored the right of way, including the south end of the summit tunnel. I will never forget walking to the debris pile and having one of the gang suddenly point out a natural gas bubbler. Just as he did that, one of the other guys said "This is so cool, calls for a cigarette!" and we heard the lid on his Zippo pop open.

    Don't know if there was enough gas to cause an explosion, but we all grabbed him mid spark, just in case.

    Same trip, we met a local "farmer" near the Glenwood Tunnel who kindly advised us, with aid from 2 rottweilers and a double barrel 12 gauge, that he wasn't thrilled with us hiking near his "garden".

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  3. Yes, I am glad that the current owners in that area are not quite so violent, though they still do own large dogs. Glenwood Tunnel's north portal is on public land (water district) while it's south portal is not owned at all. Neither should be defensible with a gun then or now.

    Regarding the bubbler, I didn't see any nor did we ever smell natural gas there, which was a good thing. Still, did you happen to take any photographs of the hike back then or could you describe the bubbler? I'd like to know what to look for when I head back there.

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  4. Natural gas is very hard to notice if you're not looking for it -- it has no odor or appearance. The rotten eggs smell is added to commercial supplies, but you'd get no such warning from a natural supply like this.

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