Northwestern Pacific Railroad Network

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KPIX is reporting a meeting tonight in Marin to discuss whether to renovate this old NWP tunnel.  No plans for rail but being a bicycle rider I can attest to the value of having that tunnel available in the the old RoW, now the bicycle path out of Sausalito.

This is not tonite's video but still interesting:

We recently had the post of the video of the last train leaving Sausalito.  Now where is that Sterling Hayden coach which passed thru this tunnel on its way to a new home?

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Comment by Dave S. on October 3, 2017 at 2:21pm

In the report page A3 (linked below) three bore holes were drilled on Chapman Dr., just off of Camino Alto/Corte Madera Ave:

One thing that nobody ever mentions when talking about the Alto Tunnel is that with the great Southern Marin floods of 1982 there was a major slide here.  The ground in the left-third of this photo slid away and took all the phone lines between Mill Valley and Corte Madera with it.  [I was actually talking to somebody on the phone when this happened at around 02:00 AM.  There was a great blue flash in the sky and our conversation got cut off.  I still had phone service, just couldn't call south of the 924 exchange.]

Anyway, what I always believed is that the Alto Tunnel, which is about 225 feet below, gave way causing this major slide.  Yes, 225 feet is quite a distance, but it just seemed too coincidental:  Alto is directly below here.  However, working against this theory is figure B-1 (PDF page 39) of the report which indicates that 600 feet of the tunnel length below this area is intact or inferred intact.  Amazing to me that the northern half of the tunnel, the wettest half, is the most intact.

Comment by Dave S. on October 1, 2017 at 4:59pm

See p. 20 for an overview of the cost estimate to rehabilitate this tunnel for recreational use.  Spoiler alert:  they peg the figure at $47M.  Based on the cost to rehabilitate the Cal. Park Hill tunnel, about $33M, I have my doubts about this Alto figure.  Consider that Cal. Park was nearly intact when it was rebuilt, much shorter, but a larger bore since it was sized for double-track.  However, original cost estimates to re-open Cal. Park were way lower (about $8M, if I recall correctly) than the final bill, an effect common with most public works projects.  (Don't get me started on the East span of the Bay Bridge!)

Alto Tunnel Investigation & Cost Estimate Update – 2017

Alto Tunnel Study Page -- Walk Bike Marin

Comment by Daniel Stege on September 28, 2017 at 7:48pm

Thank you for keeping it real.

Comment by Dave S. on September 28, 2017 at 4:46pm

As long as no public money is spent on this very expensive project, I'm OK with the Marin Bicycle Coalition funding it on their own.  I would imagine at least $100M to reopen and bring that tunnel up to today's standards.

Now if every MBC member sold their Trek Madone 9.9 bicycles and got $10k each for them ($12k list) and contributed all that money to this cause, they would still need 10 thousand members to do this, which of course they don't have so this won't happen.

I'm not sure why these guys obsess so much on this tunnel.  I agree that Camino Alto is dangerous for bicyclists, but there are two alternate routes, one with slightly less hill climbing, and another (by 101) involving much less hill climbing.

It would probably be cheaper to widen Camino Alto than reopening the Alto tunnel, but I don't think these guys worry about cost because they think they can get public funds to cover it.  They should worry about the as yet unfulfilled bike paths promised by SMART.

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