Ghost Tunnel ~ Saturday, September 06, 2014

From CalTrain, between Bayshore and South SF stations, coming around the point by Brisbane, I've noticed an abandoned tunnel portal. You can see it in this Bing Maps birds-eye view. The story is that this was originally part of the SP peninsula bayshore line, but when the 101 freeway was built, the railway was moved out of its way and now goes around a hill it used to go under.

I went poking around to get a better view than from a passing train. The site is at the back of an industrial park and is not too hard to get close to, though I had to stand on the fender of a parked truck to get a good view over a fence.

It made me curious whether the other end still exists or has been buried under the 101. Here's a series of views from a Historical Topographical Map online collection from UC Berkeley (this site is an awesome resource--I wish this sort of thing was available for the whole country).

1896: before the Bayshore Cutoff was built. South San Francisco is a little village by a lagoon.

1915: Tracks up the bay shore, right on the water a lot of the way, and there's the tunnel.

1947: That red line is not the modern Freeway, just the Bayshore Drive that's still there.

1956: The freeway and relocated tracks are under construction.

1968: Basically like today; the freeway is there, and the tracks are moved, but the tunnel is still shown. The south portal is still there. Interesting!

1973: Not much change since 68, but the USGS seems to have forgotten about the tunnel!

Taking another look at Bing Maps facing where the tunnel should go, I can't see any sign of it. Actually, the modern lay of the land seems to be a bit different than the old top maps suggest, or even modern ones.

1995

The maps make the freeway look like an elevated structure, but I think actually the whole area underneath, where the missing portal would have been, has been filled in. Also note the little bit of hillside east of Bayshort Drive--it seems to have gone through a small cut, but this just isn't there now. Maybe the stub piece of hill was leveled to make fill for the new freeway.