Discussion related to commuter rail and transit operators in California past and present including Los Angeles Metrolink and Metro Subway and Light Rail, San Diego Coaster, Sprinter and MTS Trolley, Altamont Commuter Express (Stockton), Caltrain and MUNI (San Francisco), Sacramento RTD Light Rail, and others...

Moderator: lensovet

  by lpetrich
 
2nd Transbay Tube needed to help keep BART on track - SFGate proposed by Zakhary Mallett, a member of BART's Board of Directors.

A breakdown or other technical problem in one of the tracks of the existing tube can force BART to run single-track under the Bay.

ZM mentioned these proposals:

More BART tracks under downtown Market Street, SF. These would have to be under the existing ones, something that will likely require deep tunnel boring. The article mentioned the tracks running alongside the existing ones in west Oakland and under the Bay, and from Civic Center, continuing underneath Fulton St. and then south under 19th St. to Daly City.

Mission St. and 3rd St. Both proposals include a tunnel under Geary St. and Geary Blvd. to west SF, and a transbay tunnel to Alameda Island. From there, it either goes to the Oakland Wye or Fruitvale station.

I'd place my bet on the 3rd St. one, because that expands the range of BART's service area in downtown SF. But Folsom St. would also be good.
  by lpetrich
 
Prospects for 2nd BART tube gain momentum, but wait could be long - SFGate
But despite the surge of interest, a new tube won’t arrive as quickly as anyone would like. It would take many years — perhaps 30 or more — to build political support, satisfy environmental concerns, decide where it should go, come up with many billions of dollars, and finally, build the new line. ...

A second tube would give BART, and its 400,000 daily riders, some relief. It would create a way to get around broken-down trains or other troubles in the tube. It could allow the transit system to run round-the-clock service, now precluded by maintenance needs.

Most important, it would increase the capacity of the system, which is becoming increasingly stressed by ridership that has grown much faster than BART anticipated. ...

A new tube, at this point, is an unfocused vision, far in the distance. A study of a new tube isn’t likely to start until at least 2017, when a recently initiated study of transit capacity in the Bay Area transit core — essentially the Transbay Tube, Bay Bridge and Market Street subway — is completed.
It would likely cost around $10 - $12 billion.
  by lpetrich
 
This is nearly a year ago, but I found it as I was searching for other BART stuff: BART gets serious about a 2nd East Bay-S.F. Transbay Tube - SFChronicle.com
It would be the biggest Bay Area infrastructure project, probably, since the BART system was built more than 50 years ago, and it would cost twice as much as the new Bay Bridge, from $12 billion to $15 billion at a minimum.
It would go between Alameda Island and South of Market in SF, either Mission St. or AT&T Park. At the Alameda end, it would connect to the existing East Bay lines, while I don't know if it would do that at the SF end.
  by lpetrich
 
Seems like we have some updates, courtesy of Link21 Program | Link21

The Link21 planners seem like they are very early in planning, and they mainly state a lot of broad goals. But I've found a few things on what they have decided so far.

In Infrastructure | Link21 I find "The Key to Connection Is a New Transbay Passenger Rail Crossing". They have decided on making it a tunnel rather than a bridge, because a bridge must be very high to allow ships to pass under it.

Also discusses:
  • Benicia-Martinez Rail Bridge - has a center span that is lifted for ships, impairing its reliability
  • Richmond to Martinez Shoreline - very scenic, but very slow and close to sea level
  • Jack London At-Grade Tracks - slow, congested
  • The Oakland Wye - "All BART lines go through the Wye, a low-speed pinch point for the system."
  • Downtown Extension and Salesforce Transit Center - connect it to a new transbay tunnel?
Another thread: BART, Amtrak exploring possible joint transbay crossing - RAILROAD.NET - over in the Amtrak forum (2019 and earlier)
  by lpetrich
 
Train Technology | Link21 - the study's authors recognize that the Bay Area has two incompatible types of regional-scale rail systems: BART and all the others ("Regional Rail"). After noting propulsion and rail-gauge differences, the page states "There are also many structural, vehicle weight, and regulatory differences between the two systems."

Light-rail systems are an additional type, but they are relatively short-distance.

This poses a serious difficulty for an additional transbay tube. Will it be BART-only? Regional-rail-only? For both BART and regional rail?

If it is BART-only or BART+RR, then that raises the issue of how it is to connect to the East Bay BART lines. Avoiding the Oakland Wye would be good to do, but that raises the question of what line to connect to? The Fremont Line? The Richmond Line? The Concord Line? Just south of MacArthur?
  by lensovet
 
Well and if it goes to the new transbay terminal, where does it go after that?

Also I don't understand how Amtrak could use this without new equipment. There is no electrified Amtrak service in California.
  by west point
 
Caltrain will eventually be using Transbay date sometime. So, no problem there as could be thru service but who knows. Equipment? Same answer these new tubes will be at least 15 years in the future. Too many variables.

Less we forget . If the tracks are shared gauge then very possible that CA HSR would use the tubes to continue from Transbay to Oakland and beyond. In fact on further consideration more likely CA HSR would use the tubes rather than Amtrak.
  by lensovet
 
west point wrote: Sun Apr 03, 2022 2:16 am Caltrain will eventually be using Transbay date sometime. So, no problem there as could be thru service but who knows. Equipment? Same answer these new tubes will be at least 15 years in the future. Too many variables.

Less we forget . If the tracks are shared gauge then very possible that CA HSR would use the tubes to continue from Transbay to Oakland and beyond. In fact on further consideration more likely CA HSR would use the tubes rather than Amtrak.
I'm confused, what does Caltrain have to do with BART?

CA HSR can't even build a straight section through the central valley on time, how on earth are they going to now electrify tracks and apparently run through service?
  by lpetrich
 
west point wrote: Sun Apr 03, 2022 2:16 am Less we forget . If the tracks are shared gauge then very possible that CA HSR would use the tubes to continue from Transbay to Oakland and beyond. In fact on further consideration more likely CA HSR would use the tubes rather than Amtrak.
Shared gauge with BART???
  by lpetrich
 
First look at BART's 2nd Transbay Tube renderings - KTVU Fox 2

Check ‘Em Out! We Have Our First Renderings of the Second Transbay Tube - "A longtime BART fan fantasy is coming to life, as a second Transbay Tube gets its first proposed public renderings, though there are a couple proposals, and it probably won’t be operating until 2040 at the earliest."

I looked in Link21 Program | Link21 and I could not find any reference to those plans, and likewise for Projects - Capitol Corridor and Projects & Plans | bart.gov. Those two sites linked to the Link21 site.

The new transbay tube will include a second crossing for BART and a crossing for regional rail (Caltrain, Capitol Corridor, etc.)

The renderings show two configurations for the new transbay tube: two separate tubes, one each for BART and RR, and a combined tube for both. Each of the separate tubes will likely be like the existing BART transbay tube, a pair of single-track tubes. The combined tube will have likely have four single-track tubes, two each for BART and RR.

The BART line will branch off a little south of MacArthur, and will have a possible downtown-Oakland station, a Jack London Square station with a relocated RR station, a possible Alameda station, and a Salesforce / Transbay Transit Center (TBT) station, with an option to continue westward. BART may also get a San Antonio station between Lake Merritt and Fruitvale stations.

The RR line will get a station at the West Oakland BART station and one at the TBT.

For separate tubes, BART may get stations at Mission Bay and at 4th and King, while for shared tubes, RR may get a station shared with BART in Alameda.
  by west point
 
Any project will require at least 2 separate tubes. They would have a escape route between the tubes about every 800 feet. That because of national fire codes. Forget number.
  by lpetrich
 
west point wrote: Mon Sep 26, 2022 2:25 am Any project will require at least 2 separate tubes. They would have a escape route between the tubes about every 800 feet. That because of national fire codes. Forget number.
That's a rather nitpicky design detail, and it does not affect the essential content of what I posted.