03 March 2019

Build a Dumbarton Rail Tunnel

The Dumbarton water tunnel TBM,
being assembled for the start of its
five-mile drive under the Bay in 2011.
Boring a new tunnel under the Dumbarton corridor, through muddy soils right under a sensitive national wildlife refuge, seems like an impossibly difficult, risky and expensive undertaking in this day and age. But here's a little-known fact: it's already been done.

From 2011 to 2013, a 15-foot diameter tunnel boring machine (TBM) quietly bored a new five-mile tunnel under the Bay from Menlo Park to Newark. The $288 million project, the first tunnel ever bored under San Francisco Bay, is part of the Hetch Hetchy Water System and was built to contain a 9-foot diameter drinking water supply pipe that feeds San Francisco and the peninsula. The TBM that bored the tunnel was an EPB (Earth Pressure Balance) machine and advanced so quickly that it had to wait underground at the far end of its drive, while an access shaft was prepared so the machinery could be retrieved. There were few geotechnical surprises along the way, of the sort that can sometimes blow out tunneling budgets and schedules. The geological layers of clay, gravel and rock under the Bay along the Dumbarton corridor are now better known than they have ever been, and any "geotechnical risk" is effectively retired after the actual boring of an actual tunnel.

Of course, a rail tunnel would be larger and cost far more than the $288 million water tunnel. To safely carry train traffic at speeds of 125 to 150 mph, two parallel tunnel bores about 30 feet (10 meters) in diameter would be needed, connected by cross-passages about every 1000 feet and with a handful of ventilation and emergency evacuation shafts to the surface.

How Much Would a Dumbarton Rail Tunnel Cost?

The costing of bored rail tunnels is reasonably predictable, with models having been developed for example by the High Speed 2 project in the United Kingdom. The HS2 tunnel cost model can be applied to estimate the known cost of the Dumbarton water tunnel, as a sanity check. The model uses 2011 British pounds, which we convert to dollars using the exchange rate of $1.57 in 2011. The length of the water tunnel is about 8000 m, and it took about 100 weeks to drive and clear out (100 m/week drive and 400 m/week clear-out). Tunnel construction cost is scaled by bore diameter as indicated by section 4.2 chart G.1; the single-bore water tunnel has 23% of the perimeter of a twin-bore 9.6 m tunnel considered in the HS2 document. Disposal cost is scaled by bore area; the single-bore water tunnel has 11% of the area of a twin-bore 9.6 m tunnel. Note the water tunnel does not require portal or ventilation / evacuation facilities.

ItemDescriptionQuantityUnitRateCost ($M)
Purchase of TBMEPB Boring Machine1ea.$28M28
Support CostsFixed Costs (EPB Machine)1ea.$55M55

Time-related costs100weeks$1.7M/week170
Tunnel ConstructionEPB Tunnel (single bore)
Disposal of MaterialOff-site disposal8000m$800/m6.4


The HS2 model seems to predict the direct construction cost of the existing Dumbarton water tunnel reasonably accurately, landing within ~12% of its actual cost. Most of that difference can be ascribed to the much smaller boring machine, which the HS2 model cannot account for; the Dumbarton TBM cost about $10M.

Scaling It up for Trains

The unit costs from the HS2 model can be used directly to scale up to a Dumbarton twin-bore tunnel ready for high-speed electric trains. This tunnel will be a bit longer than the water tunnel, since unlike water, trains can't just climb vertically into and out of the tunnel. Assuming 2025 dollars, which are worth about 20% less due to inflation, you get the following direct construction costs:

ItemDescriptionQuantityUnitRateCost ($M)
Purchase of TBMEPB Boring Machine2ea.$35M70
Support CostsFixed Costs (EPB Machine)1ea.$69M69

Time-related costs120weeks$2.1M/week252
Tunnel ConstructionEPB Tunnel (twin bore)
Disposal of MaterialOff-site disposal10000m$9000/m90
Tunnel Portals
Tunnel ShaftsVentilation / Emergency3ea.$39M117
SystemsElectrical / Mechanical10000m$8000/m80


The basic construction bill comes to $1.2 billion in year-of-expenditure dollars for a state-of-the-art twin-bore electric rail tunnel built in the middle of the next decade. This figure is then burdened roughly as follows:
  • 3% environmental mitigation
  • 25% contingency
  • 6% engineering design
  • 3% program management
  • 4% construction management + 0.5% agency fee + 4% mobilization costs
These overhead rates compound with each other, combining to 53%. The expected all-up cost of a twin-bore Dumbarton tunnel is then about $1.8 billion.  Add to that the expense of removing the old bridge, estimated by Samtrans at $150M, and we reach almost $2 billion.

Why Tunnel?

As we are often reminded on the peninsula, a tunnel puts the trains out of sight and out of mind. In this case, it actually makes sense to build one because it crosses a terrain obstacle, San Francisco Bay. A new tunnel avoids visual and noise impacts, removes the blight of the old bridge, enables higher train speeds without endangering wildlife, and can be made more resilient to sea level rise than a new bridge. A new tunnel is not much more expensive than the options now being contemplated as part of the Samtrans Dumbarton Transportation Corridor Study, where it was summarily and improperly dismissed as too expensive, risky, burdensome and impactful (see Table 6-4). The tunnel option deserves a second and more serious look.

A Dumbarton tunnel could extend under University Ave and Willow Road in Menlo Park, grade separating both for a marginal cost that our model places at $132k per meter of twin tunnel (in 2025 dollars). The Samtrans study estimates each grade separation to cost about $200M (in 2017 dollars), so the two grade separations are worth about a mile of extra twin tunnel if you've already got TBMs in the ground. That's before the grade separations have to be rebuilt to accommodate sea level rise.

A Dumbarton tunnel would provide more cost certainty than a bridge. The last bridge the region built overran its cost estimates by several hundred percent, while the Dumbarton water tunnel was on time and on budget. Tunnel boring is a well-developed technology that is highly automated and doesn't use a lot of expensive construction labor. Some people are working on making it even more automated.

San Francisco to Tracy in 35 minutes
A Dumbarton tunnel could serve as a key component of a new regional rail link between the Bay Area and the Central Valley, putting San Jose much closer to Sacramento, and San Francisco under an hour from Stockton. It could eventually serve as the entry point of high-speed rail into the Bay Area, making faster trips from anywhere in the Bay Area to Sacramento and southern California. The performance simulation at right shows a high speed train passing through Tracy just 35 minutes after departing San Francisco Transbay, traveling along the Altamont SETEC alignment. This would vastly simplify the "blending" of Caltrain and high-speed rail since the latter would enter the peninsula rail corridor at its midpoint, sharing slow tracks for only half the distance of the existing plans and requiring fewer overtake maneuvers.

A new Altamont / Dumbarton high speed regional rail link could replace and combine the fragmented hodge-podge of projects and agencies variously pushing Altamont Commuter Express extensions, Valley Link, Livermore BART, a second BART Transbay Tube, the high-speed rail system, and whatever Cross Bay Transit Partners might come up with for Dumbarton, each of which nibble at different edges of the same basic problem: our regional mobility is inadequate and relentless traffic jams are crushing the souls of hundreds of thousands of people in the I-580, I-680, I-880, US-101 and CA-92 corridors.

The Dumbarton rail corridor needs to be thought of as so much more than a simple bay crossing that relieves traffic for people who work at Facebook. This is a one hundred year piece of infrastructure that can unclog an entire region, and it needs to be engineered for it. A tunnel for $2 billion (in 2025 dollars) is a sound and future-proof investment.


  1. A couple comments:
    1. It would be a mistake to rely heavily on UK modeling software to derive costs -- given all the cost blowouts they've been having lately. Granted those costs were not directly related to tunnel construction, but it is not as if Caltrain has shown any ability to deliver projects on-time either.

    2. Sorry, but the cost/rider calculation just does not pencil out for a Dumbarton commuter-rail crossing. I know it is fun to draw lines on a map, but there has to be some economic justification. Even HSR (if it ever happens) won't change that. A much better location for new conventional rail crossing is between Oakland-SF -- which as you know is under study -- and I think provides bigger bang for the buck. Politically there will not be support to build more than one transbay rail crossing.

    1. I would say that relying on cost modeling from the anglosphere is quite on point-- you wouldn't want my numbers to reflect what the Spaniards could do.

      I reject your point that there can be only one bored rail tunnel under the bay. This strange notion of scarcity comes from a place of fear that such a tunnel will cost tens of billions (hell, the DTX is already at six billion.) The BART people are already throwing around numbers like 12 to 15 billion, looking at East Side Access and Amtrak's Gateway Program.

      What I am saying, using a cost model from a country known for cost blowouts and having calibrated said model against the known cost of an actual example Dumbarton bored tunnel, is that a reasonable price for a twin-bore Dumbarton rail tunnel is TWO billion. The cost overruns on the Eastern span replacement of the Bay Bridge could have paid for it twice!

      A simple bored tunnel is not something that the local transportation industrial complex can lard up very much-- there is not much scope for scope creep and "signature" elements. Maybe that's why they don't want to consider it?

    2. Clem, two questions?

      Why are they using Eastside Access to estimate anything? Is BART trying to excavate a vast underground cavern under a current commuter rail terminal, that their sister railroad refused to share?

      Why not use a wider bore tunnel instead of a twin double bore?

  2. Capitol Hill to UW tunnel was 3.15 mi (5.07 km) and 300 ft deep at Volunteer Park. TBM had 21 ft (6 m) heads for twin-bore. In 2011 cost 1.9 billion.
    If I'm reading you correctly you're saying 31' at twice the stretch with about same price. Not so sure.

    1. Pretty sure that cost included two underground stations, so you really have to watch your apples and oranges. The stations are enormously costly compared to tunnel boring. These were the construction contract values:

      U220 - $309M - UW to Capitol Hill tunnel + UW station box
      U230 - $154M - Capitol Hill to Pine Street tunnel + CH station box
      U240 - $80M - Capitol Hill station fit out
      U250 - $142M - UW station fit out (a massive underground complex!)

      Alon Levy has written extensively about how US projects tend to blow out because of out-of-control station designs and costs.

      A Dumbarton tunnel is just a plain vanilla tunnel with no delicious toppings. The University Link project was a full sundae with all the fixings.

    2. You're right, my bad. Seems like a travesty spending that much on the worst station of the system. UW escalator ride is hellish and missing a connection to the UW underground parking was a major miss.

    3. That cost for the University Link tunnel includes two underground stations right? Stations sometimes account for the majority of the cost of bored tunnel projects, and the Dumbarton tunnel wouldn't need any.

    4. (Whoops, was looking at a stale page without the replies, feel free to delete the redundant comment.)

  3. If this tunnel would provide grade separation of University/Willow, the assumption would logically also include an underground Facebook station, yes?

    1. Oh no, an underground station is extremely undesirable, because not only would it be under the water table and have lots of flooding and buoyancy issues, but someone would immediately get the idea to build it with a mezzanine level. So no, no, no it would need to be outside the tunnel. If the tunnel portal is at Willow, the Facebook station platforms would need to be placed closer to Chilco.

      With rising sea levels, unless we dam the Golden Gate this entire area will be underwater and won't even need a station. At that point you'd just extend the tunnel westward until you reach dry land. Dumbarton is still the narrowest place to cross even with 10 feet of sea level rise. (Take a look!)

    2. There's no reason at all to be at-grade (and probably not even outside a bore) until east of Highway 101.

      And maybe not even than. Below-grade trenching (east of 101) all the way Dumbarton Junction and then all the way through Redwood City -- surfacing north of Cordilleras Creek, just into San Carlos -- is an argument that can be made.

      (FYI it's the only place on the Caltrain line south of 16th Street in SF that this argument can or should be made by anybody.)

    3. @Richard, I think you meant to write "Redwood Junction" instead of "Dumbarton Junction" and "until west of Hwy 101" instead of "east" in the prior two posts.

  4. Cross-passages can add more cost than one might imagine/fear.

    The soggy-landia Groene Hart tunnel is an interesting approach to this.

    1. Interesting, that they built a separation wall within the same single bore. But considering it to be a high speed tunnel, that might actually have been the most suitable solution at the time.

    2. Sounds like a job for Bertha!


    3. Thing is that this tunnel is considered "medium length". For long tunnels, it is pretty much state of the art to have two (single track) bores with connectors every few hundred meters, and some cross-overs in order to allow single tracking of only parts of the tunnel. In this configuration the other bore will act as emergency access to the one. The cross-overs are sealed with gates, which are opened only when needed. This is how, for example, the Gotthard Base tunnel is set up.

      Older configurations use a third, smaller, bore for emergency access. The Channel Tunnel is an example for that.

      Single bore with a large diameter does not really make sense, because there is way too much excavation material for the usable space. Of course, under some circumstances, that extra space can be used for example for high-voltage cables. For a road tunnel, that space is needed for ventilation and stuff.

    4. Isn't 27' x 2 a requirement? Bertha was 58'. Connect 3 short 2 mi tunnels.

    5. Clem's numbers seem to square up pretty well with MUNI's Central Subway tunneling costs.

    6. Here is how the big boys do this: https://www.tunneltalk.com/New-Products-Oct2015-Cross-passage-excavation-made-easy.php

  5. The western span of the Bay Bridge is 57 feet wide.
    The bridge is a total of about 5 miles long.
    The Yerba Buena tunnel is 76 feet wide.

    [the new eastern span is side-by-side lanes, 258 feet wide]

    How much would it have cost to build an "all new underwater tunnel Bay Bridge" using your cost estimates for 76 foot width (no stations necessary ...)? Would it have been cheaper than the retrofit bridge?

  6. What of the NFPA 130 Ventilation Zones that have been quite the controversy of late? Presumably it would be hard to have multiple ventilation zones under the bay. I don't think that cross passages count as ventilation zones (do they?). Probably segmenting the ventilation under the bay could only be accomplished by making the tunnels wider to accommodate extra air ducts.

    Avoiding this rule (which may be gratuitous compared with overseas regulations, but it is a rule nonetheless) seems like reason enough to avoid tunnels if at all possible - and in this case, it may be possible, given the precedent of the old bridge.

    1. NFPA 130 is a bigger deal when you have multi-track tunnels with trains running at slow speeds, where clearing a ventilation section takes longer than clearing a signal block. (Looking at you, DTX.)

      In the Dumbarton twin-bore tunnel described here, I included 3 ventilation shafts, nominally spaced 2500 m apart. Even if the trains only went 100 km/h, they would clear each ventilation section in at most 90 seconds, which is not likely to drive train headways.

      NFPA 130 is much less of a constraint in one-track-per-bore high speed tunnels. The higher the speeds the less it matters.

    2. How would you site these ventilation shafts? Presumably none over open water, but would you be building some of them in the sensitive wetlands that building a tunnel is intended to avoid? Maybe solvable but I have a feeling you may be understating the difficulty of a tunnel and overstating the difficulty of a bridge, since it wouldn't be perceived by neighbors as entirely "new" - since the bridge has always been there and there's always been the prospect of reactivation (even if, from a regulatory perspective, it must be treated as a greenfield project in some respects)

      Now, using the water line right of way from Willow to Filbert would be a good thing because it would allow a much higher speed transition from the Dumbarton line to the Niles subdivision (Without the zigzag of the existing corridor) but this would be possible regardless of whether Dumbarton is built as a bridge or a tunnel.

    3. ...I just have a hard time believing that a simple two track bridge here is going to be in the $many billions of dollars. In my home state of NC they just replaced the Bonner Bridge on the Outer Banks with a brand new 2.8 mile bridge with seven 300' wide spans for roughly $250 million. If the bridge is spec'd for freight, it will have to deal with somewhat bigger static and dynamic loads, but not $many billions more. Building viaducts with no signature span is cheap. Literally any contractor with any experience building a highway over a river could pull it off in their sleep. If the bridge structure is bid separately from the systems (as it should be) then the structure itself will be pretty cut and dry.

    4. "How would you site these ventilation shafts?"

      Comparatively simply, really. (Comparatively!)

      Start here and see if you can spot them, heading pretty much southwards, every 1.5 to 2 km.

      Then transpose to here (or, less optimistically, here and head east-north-eastwards and note that you hit well-sited and well-sized sites and construction/emergency-appropriate access roads every couple thousand yards all the way. (As a total aside, same deal if you connect instead to the interesting powerline ROW 1.5 south of the Newark Hetch Hetchy pipeline that Michael Kiesling identified 15+ years ago.)

  7. I am a fan of the Dumbarton Crossing for both HSR and as part of a regional rail network, but I have trouble believing a tunnel would be more cost effective than a new bridge. Although you point to the cost overruns of the new Bay Bridge versus the on-budget performance of the water tunnel, but a passenger rail tunnel is a far cry from a water tunnel. One could just as easily cherry pick the Al Zampa bridge at Carquenez ($240M in 2003 for a 3,400' suspension bridge) and the cost estimates for ARC or Gateway in NY (also water crossings with no stations in them) to argue that bridges are vastly cheaper. In fact, under virtually all conditions construction of a beam bridge is cheaper per unit length than any sort of tunnel. Considering that the length of the existing rail bridge is just under 2,500m, about a quarter the length of your proposed tunnel, and a new bridge will be significantly cheaper.

    Your reasons for preferring a tunnel do not measure up to the additional billions of dollars it would cost versus a bridge:
    -Mitigating the "visual and noise" impacts of a train line in the middle of water is a dangerous argument for someone who wants to heavily modify Caltrain and include HSR on the Peninsula. The visual and noise impacts from any of the grade crossing proposals you have covered ("its not a Berlin wall") are far greater than would be felt by the non-existent population in the middle of the Bay.
    -The blight of the old bridge is removed regardless of if the replacement is a tunnel or new bridge.
    -Speed is not really an issue, your example only shows 150 mph across the bay which is easily achieved on a bridge; in fact, most long tunnels (Gotthard, Seikan) have speed limits lower than the track on either side.
    -Endangering wildlife is another dangerous argument. The existing rail causeway to the old bridge already exists, so any environmental impacts to upgrading it and new tracks, etc. is minimal. Arguing otherwise gives ammunition to NIMBYs that could use it to block other needed improvements to Caltrain and other lines with arguably greater impacts. Would you have wanted to see Caltrain electrification blocked because of the endangered frog and snake living in the West of Bayshore property adjacent SFO that Caltrain tracks pass through?
    -Sea level rise is not really an issue. The bridge and causeway could be arbitrarily lifted 3-5' over the current track height at comparatively minimal cost to a tunnel that would be as long as a Geary subway.
    -The fact that current Dumbarton crossing options are ridiculously overpriced does not mean that the tunnel is a bargain. If your cost estimate is correct and we can reform local infrastructure practices to build a twin bore HSR tunnel at $320M/mi, then we can also get a simple concrete or steel beam bridge for a several tens of million dollars per mile. With a bridge the quarter of the length, it is the clear cost leader.

    1. The Gotthard Base Tunnel is certified for 250 km/h running, and Lötschberg as well (where they actually do it with the Class 503 Pendolini).

      The question with the bridge is whether a high bridge is needed to keep the bay navigable. But that would not be such a big issue, except for somewhat higher cost. Using Chinese style bridge element manufacturing would also reduce overall cost.

    2. If other recent projects (at Caltrain or in the Central Valley with HSR) are any guide, you can be sure that a new bridge will use the most labor intensive cast-in-place methods. It's about jobs for people who specialize in carpentry and rebar; prefab elements are frowned upon around here.

    3. Max, my understanding is that Gotthard is certified for 250 kph, but that they do not exceed 200 kph in service. My information could be inaccurate, and I would trust yours over mine.

      I am not sure how necessary navigation south of Dumbarton is; I cannot think of anything in Palo Alto, SJ, or Fremont to access and the bay in that area is only a few feet deep. In any event the Dumbarton road bridge is only 85 ft high with a 300 ft span, very modest from a construction standpoint. A movable bridge that rarely if ever opens wouldn't be much trouble. A fixed bridge at a low height with a one extra-long span that is lifted out of place once or twice a century for exceptional purposes is also an option. It denies the southern bay to sailing ships, but if the rail bridge deck is lifted 10-15' anyway for sea level rise there could be little to no impact on power craft or barges.

      Clem, if you are to assume that current contracting processes hold for a bridge then you also have to assume they will hold for a tunnel, and in that case your $2B estimate is wildly optimistic. A 10 km tunnel is only cheaper than a 2.5 km bridge if the tunnel is extremely efficient and the bridge is vastly overpriced. If both projects end up being overpriced because of the contracting culture, then the shorter bridge will be cheaper every time.

    4. In my original post I forgot to mention that a tunnel also incurs large recurring operations and maintenance costs that a bridge does not. Tunnels require ventilation, lighting, testing of life safety systems, repairing leaks, etc. Additionally, if major repair or replacement of either structure or tracks is required. That is more difficult and expensive for a tunnel versus a bridge as well.

      Tunnels are the most expensive type of right of way to construct and maintain. There are places where their use is justified or even required (dense urban areas, mountains, very long water crossings). Crossing a few kilometers of shallow water with no major shipping channel is not one of those places. Especially when a surface right of way already exists on both ends. The proper solution for Dumbarton is a new bridge.

    5. The reason why the speed in the Gotthard Base Tunnel is restricted to 200 km/h is capacity. With 250 km/h running, extra paths would be needed, and they would have to be taken from freight, which is not acceptable, as there are already only 5 (or 6) freight paths per hour… well, running a passenger train every 30 minutes eats 2 to 3 (freight) paths compared to run the two passenger trains in block distance. And don't forget, the main reason to be for the Gotthard Base Tunnel is to get trucks off the highways.

      Modern tunnels have ballastless tracks, which require very little maintenance. Up to a certain length, ventilation is also not necessary (with all electric operation). Lighting, yes, for emergencies. So, yes, there is maintenance, but overall cost are not excessive.

      About bridges: modern bridges are also very often made with ballastless tracks, also reducing maintenance. However, a movable bridge is really, really, only the very last resort, because it does, even when well implemented reduce the operation speed, and it will always be an effort to maintain. One aspect, however, which can bring the price of a bridge up is how deep one has to dig for a sufficiently stable foundation. And that could be an issue with the bay crossing.

    6. Max, thank you for the explanation re: Gotthard speed.

      I think you under-estimating tunnel maintenance requirements. The issue is not track, signals or catenary, since those exist regardless of the ROW (bridge, tunnel, etc.) All passenger tunnels except the very shortest require ventilation for air quality and the life safety/smoke control plan. Gotthard is all electric, but also has the most powerful ventilation system in the world. Clem's proposed tunnel is 10km, well beyond the length you cannot ventilate. Tunnels require a fire-alarm system, cameras, and two-way communication (call boxes or radio antennas). Areas of refuge and evacuation crossovers can require fire-proof doors and/or pressurization to keep smoke out. Tunnels require drainage, including pumps to get water back out of the tunnel. All of these systems require power, which means electric infrastructure beyond train power. Nowhere in the world are tunnel maintenance costs "not excessive" compared to the maintenance of open air track.

      There are also the operational and repair considerations. With a two track bridge/causeway you can add crossovers as often as needed to minimize single track sections during repair. With this twin bore tunnel any maintenance shutdown gives you a 10km single track significantly restricting capacity. You can build underground crossovers linking the twin bores, but mining them is slow and expensive (equivalent to adding a station box that Clem so strongly opposes). They are easily two or three orders of magnitude more expensive than a crossover on parallel track, and would drive Clem's optimistic costs way up. Similarly, with parallel track you can bring a work train alongside track needing repair; with a bridge you can bring a barge alongside, possibly without affecting train traffic if you are looking at the bridge structure only. With a tunnel, all material in or out has to fight for space in the tunnel, increasing time and cost. Virtually any work with personnel in the tunnel requires shutting down the line or implementing special controls. There are also occupational health considerations involving confined space and ventilation, such as dust if you are trying to sawcut concrete. The list goes on and on.

      Don't get me wrong, tunnels are amazing, and I can think of lots of Bay Area and California transportation projects where I would want to build tunnels despite all of these issues (DTX, Geary Subway, Van Ness/Mission subway, extend Twin Peaks tunnel to Daly City, extend Central Subway to Presidio, HSR tunnels to get across Altamont and Tejon, a second BART tube, ....). Clem described this tunnel as overcoming a "terrain obstacle." Mountains are a terrain obstacle. Deep rivers are terrain obstacles. Built up downtowns are terrain obstacles. The Bay at Dumbarton is just a shallow lake - less than a mile and a half wide, a few feet deep. A tunnel is not required to cross it, certainly not one four times longer than the actual water gap to cross.

      Regarding bridge foundations, to my knowledge there was no difficulty for any of the four bridges that have been built here (rail, road 1927, Hetch Hetchy above water portion, and road 1982). It is worth noting that the 1982 road bridge was built post-CEQA and had to address environmental concerns, and used technology similar to what would be used today (pre-stressed concrete). It cost $70M in 1982, approx. $185M today, with a seismic refit that cost $150M in 2010, good for another $180M today. This for a bridge that is 6.5% longer than the rail crossing, and twice as wide as what a two track structure would need. A baseline cost of $365M for a Dumbarton crossing is what Clem should be looking at, while finding somewhere beneficial to spend the $1.64B saved.

    7. Onux, I wanted to acknowledge that you make a strong case for a bridge.

    8. Good arguments, Onux, That's what a good discussion is about.

      For that bay crossing, a bridge appears to be the way of choice.

    9. Clem, I wanted to acknowledge that you make a strong case for almost everything on the Caltrain corridor, and for many things regarding CAHSR as well.

    10. Clem, I agree that your blog is fantastic and much of your information is pure lightning, especially when it brings the best of global practices in terms of project planning, scheduling, engineering, and vehicle design to the Caltrain corridor.

      This post is definitely not that. The whole idea of a tunnel seems predicated on avoiding a NIMBY battle that (by most accounts) did not materialize at the public meetings. Avoiding NIMBYs by building unnecessary tunnels is not a global best practice. It is *exactly* what causes the sort of unnecessary compromises and cost blowouts that are so prevalent in the US. There is also the issue of the wildlife refuge but again you're making that a bigger deal than it is. Most people seem to accept that this was a two track rail corridor and will once again be a two track rail corridor.

      I think it would be useful to post a "retraction" of sorts lest this blog post become ammunition for whatever of the small population of NIMBYs who might choose to dig in their heels over the idea of a tunnel. Just because a tunnel is probably possible, for reasonable costs (by tunnel standards) does not mean it is still the most practical alternative.

      Thank you Onux for this.

    11. Whoa there, I think you misunderstood me. Bridge and tunnel both have strong arguments in favor. No retraction is warranted.

      I still believe that a tunnel provides less room for cost blowouts than a bridge, and that the situation is not symmetrical. Boring tunnels is, by necessity of the confined space, highly automated and requires little construction labor. Building a bridge can also be streamlined by using prefabricated segments, but it doesn't have to be, and given the extortionary climate that our transportation-industrial complex operates under, you can be pretty sure that a bridge would involve the most cushy Project Labor Agreement, use the finest and most labor intensive cast-in-place construction techniques, feature some sort of "signature" architectural element, and provide the most abundant environmental mitigations. There is just no room for that bullshit in a tunnel.

    12. I disagree there is less room for cost blowouts in a tunnel or that a bridge must involve expensive elements. Your points of reference appear to be the efficient construction of the water tunnel and the cost overruns on the Bay Bridge. While both are local bay crossings, they are not the only or perhaps best examples.

      Regarding tunnels, it has been noted that TBMs are staffed with three times as many people in NYC as in Germany. Despite being “highly automated” you still have a labor-intensive result due to systemic factors. Furthermore, the actual boring is not the most expensive or high-labor part of a passenger tunnel. A tunnel may be more liable to overruns than a bridge in this regard. A bridge requires structure, track, catenary, and signals. A tunnel also requires ventilation, life safety, drainage, and non-traction power. Those additional systems are all opportunities for cushy PLAs and labor-intensive methods. There is also enormous risk for cost increase with a tunnel via additional underground construction, specifically underground crossovers (with nominal justification; a 10km without crossovers is long) or underground stations (the enticing “signature” element at Facebook or elsewhere).

      It should be noted in this respect that the water tunnel is not a transportation tunnel. It comes closest to being a project where the tunnel itself is the complete construction; it is just a tube to carry water. Not having to carry passengers it does not have ventilation, power, evacuation requirements, etc. It may not be the best point of reference.

      Bridges by contrast do not have to be over-expensive. I have mentioned the Al Zampa bridge in Carquinez which is a long-span high-clearance suspension bridge built relatively cheaply. The existing Dumbarton road bridge was the same, as was its retrofit. The cost of the Bay Bridge was harmed by interference for a “signature” span, but will a Dumbarton rail bridge have the same level of interest in “signature” elements as the second busiest bridge in the country did?

      In general, you are comparing apples and oranges when you look at the cost of a tunnel under a competent contracting regime and the cost of a bridge under the current state of Bay Area infrastructure construction. Current transportation agencies have experienced cost overruns or over-high base cost on all types of projects: bridges (Bay Bridge), tunnels (Central Subway, BART SJ extension), buildings (Transbay terminal), systems (CBOSS, Caltrain electrification). There is absolutely no reason to think that under the current system a Dumbarton tunnel would be any different. If you can reform the system to build a simple efficient tunnel (as you have priced) then that system will also be able to build a simple efficient bridge with prefabricated elements. But you can’t mix the systems to favor a tunnel. Anywhere you go in the world the unit cost of tunnels is higher than viaduct bridges or at-grade track, so at a same-system comparison a 10km tunnel should always be more expensive than a 2.5km bridge plus 7.5km of new track on an existing berm.

    13. @Onux, just a small clarification: the new bored SFPUC tunnel in the Dumbarton rail bridge corridor is walkable to allow for pipe imspections and repairs; it contains water pipes in air – not just water. If I recall correctly, it even contained a track during construction.

    14. "specifically underground crossovers (with nominal justification; a 10km without crossovers is long)"

      This is pro-level grasping at straws. Stop it! It makes your other points (which have arguable levels of validity) sound crazy.

    15. Mr. Mlynarik, exactly what is your point? Do you prefer a SETEC tunnel, do you support a bridge, or do you suggest something else? Or are you just here to be pedantic?

    16. @Reality Check, a temporary track to support removal of spoils from the TBM during construction is in no way comparable to in-service passenger rail. Similarly, the fact that the water tunnel can be walked (while normally having no one inside it) incurs none of the life safety and other systems that would be required for a tunnel that could have a thousand plus passengers at a time moving through it at high speed. The fact remains that the water tunnel is a water tunnel, not a passenger rail tunnel. This absolutely impacts costs.

      @Richard, please note I am in no way arguing for a tunnel with underground crossovers, I was just pointing out to Clem that Bay Area transportation agencies can find plenty of silly ways to drive tunnel costs far beyond what they should be, not just bridge costs.

    17. @Onux, yeah, I never said (or even implied) a temporary "miners" track ... or that the tunnel can be walked for pipe inspections ... was comparable to the requirements and associated costs of building a tunnel (or pair of tunnels) for higher/ish-speed passenger trains. And I don't think anyone that isn't ultra new here thought that, either.

      As mentioned, it was a small clarification since I didn't want anyone left thinking the tunnel was flooded and literally serving as a water pipe vs. housing water pipes.

    18. "plus 7.5km of new track on an existing berm." Good luck with that! In the wildlife refuge, unmaintained for half a century: piece of cake!

      Regardless of the uncontestable facts that America's world-leading-incompence purely-fraudulent-profit-lead transportation professionals will screw up and blow out any any all budgets for life safety, signalling, SCADA, etc, tunnel or bridge or straight-track-in-an-empty-field, I do think there's a very interesting civil engineering fact in the ground between Redwood City and Newark.

      Regardless of the considerable (in my estimation, and others') environmental, planning, mobilization, constructibility and operational advantages of going under rather than over this piece of the Bay, I don't think the advantage of taking a huge amount of potential fraud-delay-cost right off the table by the simplest and longest possible single EPB drive can be underestimated.

      There just can't be "special local needs" inside a big old bore. (Or two bores, but one large-diameter one internally vent/fire divided sure is appealing.) It's assembly-line work: not just the boring, mucking and lining, but also the slip-forming of the guideways, the track-laying, the traction, the ventilation, everything. For sure they will cluster-fuck the tunnel portals, just as they would (with hundreds of times the area scope!) bridge approaches, but think of it this way: the longer the tunnel, the more guaranteed-simple civil engineering lengthy bang you get for the fixed pain of being screwed at the portals.

      That and you completely eliminate (small emergency/ventilation vertical access points aside) all impacts -- environmental and human community -- along the lengthy approaches to any "cheap" new bridge. This ain't no Carquinez Bridge with your freeways already in place at both ends and your anchorages and tower foundations in rock in shallows and dry land.

      Hell, start/end the tunnel west of Marsh Road in Redwood City, well "inland" (not inland for long!) of the Bay, and just keep going until the last good place to start/extract the TBM. (Or don't extract it!) The further you go in known sediment the less pain per metre and less cost per metre, guaranteed.

      Yes, there will need to be emergency access pits (every couple km if Groene Hart Tunnel is anything to go by, or even the insane BART Lake Elizabeth business in Fremont) with permanent emergency-access-only surface route to a small above-ground structure, but again, fairly much assembly-line stuff with no scope for Local Design Elements or Commuter Parking Impacts or Children Exposed to Radiation Fields.

    19. @Richard, there are three errors in your argument:
      1. A bridge is not as difficult
      2. A tunnel is not as simple
      3. Even if 1 & 2 are false, the bridge is cheaper

      - Neither the existing bridge or berms are inside the wildlife refuge, per the official map. The ROW (150’ wide) is owned by SMCTD, and the refuge does not have an easement. The Dumbarton road bridge is similar (the refuge surrounds but does not include ROW) which did not prevent widening approaches in 2003 or retrofit in 2010.
      - The wildlife refuge is not a Wilderness or National Park. It is part of the Fish and Wildlife Service and allows duck hunting (some refuge!). CEQA does not prevent construction in sensitive areas, it requires study and mitigation. Re-constructing track on top of an existing berm requires no dumping or excavation of wetland, and thus least environmental impact.
      - Conversely, there are no community impacts along this route because no one lives next to the tracks.
      - Bridge construction can be just as automated. Viaducts with repeating precast elements are especially suited. Assembly line practices for laying track work as well on the surface as in a tunnel. Despite Clem’s statement regarding expensive cast-in-place concrete, precast was used for the new Bay Bridge, but the cost blowouts occurred at the self-anchored suspension span.
      - This IS the Carquenez bridge given that the berm and track do exist at both ends. There is no need for anchorages; unlike a suspension/arch bridges (which transfer loads from a long span to anchorages), a viaduct bridge transfers loads at each span to the columns they rest on. To end the bridge you just put in one last set of columns. At Dumbarton, where half the span has a depth of 15’ or less (most of that less than 6’), the columns can be driven piles or drilled displacement, used by the thousands in every mid to high rise foundation. They are much more and common than any sort of tunnel construction.

      - If I understand correctly, you believe that every few km (3-4 times for 10km, 4-5 to Willow Rd, and 5-7 to Marsh Rd) there will be an evacuation shaft dug, a building built, and a road linking them for emergency access. All will be new construction, and all in the wildlife refuge (which DOES have an easement over water tunnel ROW) or the Belle Haven neighborhood of Menlo Park. To argue that this “completely eliminates” environmental impacts is not logical. Digging up marshland for access shafts or paving it over for the access road is far more impactful that reactivating existing right of way.
      - Same for community impacts. To think that Menlo Park neighbors would easily accept digging shafts or a large portal in their “backyards” is not reasonable. Every access point becomes a location of “special local needs”. Look at what happened when they tried to affect a playground in Central Park while building the 63rd St Line back in the 70’s.
      - Tunneling is not immune to fraud-delay-cost. The Lake Elizabeth BART example (shorter tunnel, shallower water, a few miles away) directly contradicts your argument in this regard. If they can make that “insane”, they can screw up a major crossing like this.
      - Despite your claims of efficiency in the tunnels, I have already noted how TBMs in NY have three times the required staffing; inefficiency can absolutely happen inside the tunnel.

      3. Even if I am wrong about 1 and 2, the tunnel is still more expensive. I estimated bridge cost at $365M using the example of the Dumbarton bridge next door. The high end for greenfield HSR in Europe is $90M/mi, which would be $420M for the non-bridge portion (despite this cost including grading, cuts, and other things not needed here). Even if we DOUBLE both costs this comes to $1.57B, still $230M cheaper than Clem’s $1.8B estimate.

      More generically, you make the same mistake as Clem: all inefficient practices continue for a bridge, but for a tunnel (just here, just this once) everything is done efficiently. This is not a reasonable assumption.

    20. Instead of spit balling numbers here, why not look at the actual 2008 Pacheco vs Altamont study? The cost for a low bridge was estimated at $1.5 billion, and a high bridge at $2.7 billion. Clem will be happy to know his tunnel estimate of $2 billion was quite close to the amount computed in the study (however they propose tube instead of TBM).

      Some might argue the study is useless because the CHSRA had their thumbs of the scale for the Pacheco alignment. I thought the results were fairly reasonable, and didn't sugar-coat the Pacheco problems. In my view, the SF-Oak-Fremont-Livermore option in the study is looking better and better.

    21. I thought I'd throw in my 2-cents on this (very well written) blog thread:

      1: thank you for the very interesting debate on the merits of tunnel vs bridge. Regardless which side you fall on, IMHO both sides on this topic have made very reasoned, informed statements that allow the public to make informed decisions and input.

      2: (admittedly anecdotal) In 2009 I toured the construction of the new eastern span of the Bay Bridge while it was being build; the 'tour guide' was the spokesperson who most people associate with the construction of the span, Bart Ney. Caltrans and the construction companies involved in the building of the eastern span absolutely referred to the new span as a 'signature' bridge, with repeated references to Caltrans having its own 'signature' bridge (note that the GG bridge is not managed by Caltrans, noteworthy because Mr. Ney pointed to the GG bridge as another 'signature' bridge).

      3: (relevant fun fact) The new eastern span is a SAS bridge (Self-Anchoring Suspension). Most reading this blog have probably seen pictures of the GG and Western section of the Bay Bridge being built, where you see cables dangling in the air before the roadways were put in place. A SAS bridge can't be built that way: the roadway needs to be positioned before the cables are attached, which creates a circular dependency. So how did Caltrans resolve this? By (in Mr. Ney's own words) "building a bridge to build the bridge." That's right, Caltrans effectively built 2 bridges then tore down 2 bridges (the temp bridge and the old cantilever). Your tax dollars at work.

      4: I generally rail (pun intended) against scope-creep, but 1 advantage not mentioned for a bridge is that there's the potential for additional utility, in particular there's the potential to add support for non-automobile traffic such as bicycles and/or dedicated lanes for carpooling and/or buses.

    22. The Long Bridge Study in DC (admittedly, a much shorter span) wasted years studying scope creep (Adding streetcar tracks, adding carpool lanes, adding bike/ped paths) and decided to include bike/ped accommodations as part of its 'mitigations' however including them on the rail span itself would actully be more expensive and less feasible than building a dedicated passenger span. Not sure how that calculus would work out at Dumbarton, but it is a notable point of reference.

    23. Onux, Re "long single track in case of maintenance or irregularities": this is what schedule can look like on double track line with mixed traffic* and up to 12 km between stations: http://gvd.cz/czx/data/njr/pdf/L501_d.pdf
      Note that closure of one track (or turnout) for scheduled maintenance is done during weekends usually and incurs 10-20 minute delay.

      * locals: thin black, limited stop & intercity: thick black, freight thin & thick blue, train paths colliding with other train paths in red - i.e. local during weekdays and exress on weekend days

  8. When did the last train cross the bay at Dumbarton? For all of you (not Clem) who shrug off the environmental concerns, can you answer this question? 1982 was the year of the fire, but was freight using the line all the way to 1982? No upkeep on the embankments through the wetlands for about 40 years isn't exactly a turnkey project.

    1. @Michael, the Dumbarton rail bridge arson came about 16 years after the last freight across the bridge in May of 1982. The first report of a fire came in just before 7 pm on Saturday, January 3, 1998 — well after dark on a stormy, cold, rainy day:

      Dumbarton fire recalled 20 years later

      FIREFIGHTERS: Dumbarton rail bridge destroyed

      20 years ago today the oldest and first bridge across the San Francisco Bay caught fire

    2. Thanks for the correction/clarification.

    3. SMCo. TA bought the 11-mile Dumbarton line (Redwood Junction to the SP/UP Coast Line) from SP for $6.7m in 1994 for "future transportation purposes." SamTrans holds and maintains the ROW/title. In the months leading up to the arson, SamTrans planners started holding community outreach sessions in Menlo Park and other areas to present what were the first (failed) plans to fix up the line and bridge and start running (commuter) rail across it. A group of Menlo Park NIMBYs, living primarily in the "Suburban Park" (aka "Lorelei Manor") neighborhood was really, really upset about this. There were a few that went door to door and whipped up their neighbors into a classic reactionary NIMBY counter-campaign. They showed up at all meetings and droned, sometimes emotionally, on and on about how terrible it would be if trains, particularly diesels or freights, were to run right past the back of their homes and possibly derail ... and certainly ruin their quality of life and home values, etc. Passenger trains would ruin their privacy too. They trotted out examples of train derailments that had happened anywhere in North America, etc. They even tried to kill any political or financial support for such a crazy idea at the regional and state level by lobbying county supervisors, MTC commissioners and even state legislators.

      As soon as I read the news and circumstances of the wood trestle arson on a dark, wet and stormy night ... I immediately suspected that one or more of these residents either did it or put someone up to it, correctly thinking that that would either kill or indefinitely delay plans to run trains anywhere near the homes on the old tracks some swore their Realtors assured them would never see trains again.

    4. Just a question: were the arsonists ever found?

    5. @Max, no ... the arsonists were never caught.

      As the "Dumbarton fire recalled 20 years later" article I linked to in my earlier comment states:

      Looking back two decades, Schapelhouman recalled an hourslong fight from both land and sea as firefighters navigated unfavorable conditions to extinguish the flames on the railroad trestle. They were up against a fire that overwhelmed 1,766 feet of heavy timber soaked in a preservative and known carcinogen called Creosote, according to the district.

      “The oddity of having a railroad trestle on fire over water was unique and challenging and definitely frustrating,” Schapelhouman said, before noting his first reaction when he arrived on scene. “I couldn’t believe it. I thought, there’s no way this whole thing is on fire. But, in our business, you get a split second to be in shock and awe, then you’ve got to do something.”

      The cause of the fire has never been determined and it was eventually ruled as suspicious. Much of the evidence, including clues as to where the blaze first originated, was scorched before washing away into the Bay. Schapelhouman was working that night in 1998 and said he’s been reviewing old case files in preparation for the 100th anniversary of the fire district for which he’s worked for nearly 37 years.

      “We never told that story and we never released the pictures and part of that was because of the investigation,” Schapelhouman said before conceding what caused the Dumbarton fire may never be known but there is information about what occurred that rainy night.

    6. Hmmm… no… honi soit qui mal y pense…

  9. While rebuilding the Dumbarton corridor from RWC to Tracy does have merit, we need to accept that it's a huge uphill battle:
    1) Dumbarton Corridor - described above.
    2) Fremont Corridor - while 2 tracks - doesn't have much more RoW, so we have huge costs to get ~79mph passenger tracks.
    3) Sunol - We have a slow freight RoW, so we'll need new tunnels and associated costs + NIMBY for 2 79mph passenger tracks
    4) Pleasanton - Again, we have a narrow freight corridor, we're again have NIMBY + high costs of a 2-track 79 mph passenger corridor
    5) Altamont Pass - Need a tunnel, but at least not NIMBY.

    Now consider Pacheco Route to San Jose
    1) Merced to GIlroy (Pacheco land) - Expensive Tunnels, but little NIMBY
    2) Gilroy to South SJ - Wide RoW + 101 available, so adding 2 more tracks will fit. Less NIMBY than Pleasanton, Fremont or Menlo
    3) South SJ to Diridon - most challenging, but already have a decently fast freight corridor if UP accommodates.

    There's definitely value in Dumbarton corridor, but HSR has much less Nimby, wider & and straighter corridor there.

    Perhaps after ACE does some upgrades, and Capitol Corridor moves to new alignment, and Dumbarton service are all running, we'll have a candidate worth talking about.

    1. The best part about blog comments is commenters who read nothing, understand nothing, and repost nothing.
      And again.
      And again. And again. And again.

      Hey, speaking of which, time for adirondacker1200 to chime in!

    2. You should familiarize yourself with the SETEC alignment (start with the map). It uses the SFPUC right of way through Fremont, and yes, like Pacheco, requires some new tunnels. It does not go through Pleasanton or Livermore and does not use freight ROW; it uses utility ROW (high voltage transmission lines) through the Livermore Valley. It could connect directly to BART.

    3. Although the SETEC alignment has a lot going for it, I happen to think that not going through Pleasanton and Livermore is a bug, not a feature. The population of the Tri-Valley area is between ~250k to 360k depending on how far north you want to go towards Walnut Creek. Investing in a major infrastructure project while cutting this population off from commuter rail service to the Peninsula and SF is short sided. The TRANSDEF website has a picture with the caption "Follow the lights", but the SETEC alignment doesn't actually pass through the lights of Pleasanton and Livermore.

      There are NIMBY arguments against transportation infrastructure everywhere, but not everyone is a NIMBY. If we route all of our transportation away from anyone who might complain, we will end up with routes away from anyone period, and thus no ridership.

      Note, even if the main point of Altamont is HSR access to the valley, commuter ridership should not be discounted. Anywhere you go in the world daily commuter ridership is many multiples of daily inter-city/HSR ridership - even in places with fantastic HSR systems (i.e. Tokyo rail lines vs. Shinkansen, RER vs TGV, etc.). I-680 and the San Mateo bridge are packed everyday. Adding a rail corridor that parallels them without accessing the origins of those travelers should be questioned.

    4. @Onux, who told you the SETEC alignment precludes a Tri-Valley area station at places such at Mines or Tesla Road, where it is at-grade?

    5. " If we route all of our transportation away from anyone who might complain, we will end up with routes away from anyone period, and thus no ridership."

      California HSR's bat shit insane routings through the transit-oriented centres of Central Valley Cities, along "low-impact existing rail transportation corridors", and all trains via San José, Capital of Silicon Valley? Zero ridership.

      Caltrain's near-perfect routing along incredibly congested corridors with stations sited in existing TOD-tastic town centres? Pretty much zero ridership, by any realistic accounting, no prospect of non-negligible ridership under the insane proposed schedules and insanely high ongoing operating costs, and about zero return on many billions "invested".

      The problem isn't proximity to NIMBYs, it's grotesque unprofessionalism, rent-seeking, and fraud by the contracting mafiosi and their "public" agency enablers.

    6. I finally got a look at the SETEC alignment. I'll agree that it's a good find. However, I would like to see how it could help the ACE corridor. It seems to go around towns, BART, and existing ACE stations, so ACE would either see no improvement.

      On the other hand, if ACE were to switch to SETEC, it loses the built-up ridership at existing stations.

      Let's say we leave ACE as is and build SETEC as HSR only. Your tunneling costs are roughly same as Pacheco. Your NIMBY objections are similar. But you have a new complication. Which line do you buy from UP to serve SJ?

      Also, where exactly does SETEC transfer with BART? It doesn't seem to pass the Fremont line near one and runs way south of the Dublin Pleasanton line. You'd need to extend BART under Dublin / Pleasanton over NIMBY objections who already voted AGAINST a tunnel.

    7. @Reality Check, I never said that the SETEC alignment precludes a station at Mines or Tesla Rd, however they are surrounded by fields and vineyards, 2.5-3.5 mi from downtown Livermore, and 9+ miles from Pleasanton and Dublin - in the wrong direction to San Francisco. No one is going to drive or take a bus 9 mi away from where they want to be to get on a train and backtrack towards their destination. In other words, the SETEC alignment, although geographically located within the Tri-Valley, doesn't serve the *population* of the Tri-Valley. Commuter ridership at Mines Rd or Tesla Rd would be effectively nil.

      The existing Pleasanton and Livermore stations are not ideal (the Tri-Valley area is not densely populated and is spread out) but they are far more centrally located to jobs and people than anything east of Livermore. The UP route through this area is surprisingly straight, although unlikely to support the 160-200 mph speeds Clem's diagram shows SETEC achieving. The best argument I can see in favor of SETEC is that because of low density, commuter ridership from the area would be so low (despite ~1 hr single seat rides to downtown SF) that it wouldn't offset ridership loss on HSR due to longer Sac/LA trip times. I can't say for certain what the result would be, but it should be looked at before spending a few billion dollars on a new transportation line that parallels a populated corridor without providing any benefit to the day to day transportation needs of its residents.

    8. "On the other hand, if ACE were to switch to SETEC, it loses the built-up ridership at existing stations."

      Seriously, what ridership? We can imagine all sort of things, but look at the numbers.

      "Which line do you buy from UP to serve SJ?"

      That ship sailed in 1999 when Parsons Brickerhoff, and their fully-owned subsidiary DBA "Metropolitan Transportation Commission" and sundry cheaply-purchased penny-ante local city councillors, determined that the most profitable way to serve PB and industry allies was to extend BART in that transportation corridor. Rent-seeking and regulatory capture are overwhelmingly powerful ... and amazingly cheap to effect. Amazingly good investment for the private sector. Amazingly.

      They made their bed, we lie in it. Non-BART passenger rail between Oakland and San Jose is dead and irrelevant. (Again, look at the numbers.)

      "Also, where exactly does SETEC transfer with BART?"

      That's a legitimate and good question.

      "In other words, the SETEC alignment, although geographically located within the Tri-Valley, doesn't serve the *population* of the Tri-Valley"

      You know what? The population of the Tri-Valley has a nose-bleed-expensive massively-subsidized super-frequent-service BART extension. And freeways out the wazoo. And ACE, for whatever that's worth. And constant highway and roadway "improvements". "Express lanes"! HOV! The amount spent on subsidizing ranch subdivisions is already out of control. There's no case to be made.

      In an less shitty world -- one readily imaginable and constructable a couple brief decades ago -- HSR would have trench through "downtown" Livermore, there would have been a ridiculously nicely-sited BART/non-BART-rail/bus interchange at Stanley/Isabel, there could even have been another commuter stop in East Livermore, and there would have been a ridiculously nicely-sited BART/non-BART interchange north of Lake Elizabeth (1.5 mile, one-station, no-tunnel little BART extesion) in Fremont, and there would have been ridiculously good non-BART rail from Fremont to downtown SJ, with commuter stops along the way.

      All that was readily possible. (Sorry about bit-rotted partially-archived link. But so many many thanks to archive.org for doing the Lord's Work ... unlike everybody involved in transportation planning in the US, who just make the world a worse place.)

      The transit-industrial mafiosi decided against that, and we now deal with what we have.

      There's a ridiculous quantity and quality of rail and road transportation infrastructure already connecting the Tri-Valley sprawl to San Francisco Bay.

      Maybe Tracy-BART and Tracy-Redwood City are new things that can still be done in addition to the billions and billions and billions already thrown at and continuing to be thrown at Tri-Valley real estate subsidies.

    9. I don't understand all this stupid fascination with the SETEC alignment. On the Peninsula it would run above Hwy 101 terminating at SFO. In the East Bay (where half the Bay Area population resides) it proposes no stop at all -- just one long tunnel from Redwood City to the CV. If you are going to take that approach, then just hire Elon Musk to build his hyperloop.

    10. "On the Peninsula it would run above Hwy 101 terminating at SFO."

      What are you smoking? On the peninsula, a Dumbarton-Newark-Livermore-Tracy-... route would remove HSR (and any fast HSR-like inter-regionals) from the Caltrain ROW in Redwood City, enabling vastly superior Caltrain service with far lower impacts, while sharing Caltrain infrastructure in the most cost-effective and service-effective posssible fashion between Redwood City and San Francisco. Come on, man, you've been reading and writing about this stuff as long as I have. (Since 1995, at least.)

      "In the East Bay (where half the Bay Area population resides) it proposes no stop at all -- just one long tunnel from Redwood City to the CV."

      Uh, no.

      But if there's some sort of goal of HSR service to the Bay Area, you can either do something really realy shitty and expensive that pretty much terminally fucks over Caltrain service -- Pacheco -- or you can do what everybody else in the world does, and try to segregate services with very different average speeds as quickly as possible,

      Oh, and as for you and fellow croyanistas fascination with some sort of BART+HSR+gadgetbahn does-everything-for-everybody new tunnel from SF to ... [somewhere ... Alameda? Oakland? Connecting to WHAT?] -- that ship sank 15 years ago when the worst, no-though-service-ever Transbay Terminal rail disaster was rubber-stamped.

      The question to ask is: "Can anything be salvaged from how we've been screwed for the last 20 years by the transit-industrial mafia?"
      One answer is: "Continue as before!" MTC just loves New Bay Crossing studies, and has for decades. Let's study Dumbarton AND SF-Alameda. And why not SF-Farallons while we're at it. Caltrain just loves providing no service and spending billions on "state of good repair". BART just loves expanding outwards and killing alternatives.

    11. Well apparently I am the only one that actually read the SETEC plan. The NIMBY SETECs wanted HSR to go up Hwy 101 instead of Caltrain (it is right there section 2.8 Dumbarton Bridge – SFO Airport route via Highway 101). They propose no East Bay stations ("No new stations for minimum impact", page 18). As bad as MTC planning is, the SETEC stuff is even worse (which is no small accomplishment).

    12. OK you got me... the SETEC alignment, minus the 101 nonsense, plus a Dumbarton tunnel, plus a station or two in Fremont and the Livermore Valley with room for expresses to pass. It is not one continuous tunnel from Redwood City to Tracy. It is three relatively short tunnels through the hills as shown in my map.

      Recall the trigger for the independently-commissioned SETEC alignment was the CHSRA and PB engineering the maximally impactful Altamont alignment alternatives and holding barn-burner community meetings throughout the affected area to drum up opposition. They offered Altamont stakeholders a choice between a cr*p sandwich and a sh*t burger, while things along Pacheco were kept quiet. (CARRD made a great map visualization of where the community meetings were held). The SETEC thing was meant to prove the point that a good Altamont HSR alignment existed, and not to solve an actual regional transportation problem.

      So let's call it a SETEC-inspired alignment with significant modifications.

    13. @Onux: can you please clarify "wouldn't offset ridership loss on HSR due to longer Sac/LA trip times" ?

      What do Sac/LA trip times have to do with anything, since that leg of HSR is all in the Central Valley? I'm confused.

    14. @Clem, the clarification is that it was confusing wording on my part. It should have read "ridership loss due to longer SF-Sac & SF-LA trip times." I am not definitively stating that a Pleasanton/Livermore alignment is definitively superior to the SETEC portion between Fremont and Livermore; I acknowledge that going through those cities would take more time due to being longer and/or slower and that this would incrementally reduce HSR ridership. I just think that the amount of reduction should be evaluated against potential ridership gain due to picking a route that also services east bay commuting patterns. Commuter ridership within a metro area is always so much higher than intercity ridership between them.

      While I am a fan of Altamont, I also have to say that what @Drunk Engineer has noted makes me less a fan of SETEC. I can so see no possible reason to exclude a station in Fremont with a connection to the Capitol Corridor line that should some day be the basis of an East Bay Caltrain branch, even if Tri-Valley stations don't pan out.

      How was SETEC going to branch to San Jose? The "follow the light" picture in your TRANSDEF link shows it, but this is crayon with the Altamont path in that picture not matching the actual SETEC path. In none of the drawings could I find any branch or connection to existing rail lines heading south.

  10. Prediction- In ten years, we take BART to Pleasanton to get a train that will take us to Bakersfield. Something will be getting built between Bakersfield and LA, with Federal funds released in 2021.

    1. Maybe if Stormy Daniels builds a home in Palmdale Republicans will think it is a worthy place to visit. This would move it up to 2020.

  11. I wanted to share a sailing navigation map that might be of interest in this post. It shows depth of the bay at Dumbarton to be 40-50 feet.

    1. @Martin ... very cool map! Thank you.

      Clicking on the icon in the lower left corner of the map allows one to switch to a SonarChart(TM) view which includes higher resolution depth contour lines. The Dumbarton rail bridge swing span appears to be amidst the deepest area at around 47 feet. Surprisingly, this is just as deep as the deepest water (48 feet) under the Hwy 92 San Mateo-Hayward Bridge and about half as deep as BART's Transbay Tube corridor (~100 feet).

  12. Oops. I had the wrong thread before. These little tablets aren't the greatest for posting.

    Below assumes SETEC is palatable to prop 1 where LA-SJ is 2hr:10min and a 1 seat ride. Otherwise may need Pacheco as well.

    Completed Altamont SETEC alignment

    Also assumes:
    https://www.mercurynews.com/2018/05/24/bart-reject (Open in cognito)

    note: There are potentially 1.5 million people who could transfer from San Jouquins to stations located at Sacramento, Stockton and Modesto. There are 100s of thousands along ACE who could transfer at a Ulmar station. There are more than one million people located between Richmond and Castro Valley who could transfer from Capitol Corridor or BART to an Oakland HSR station.

    1. Can you please change the permissions of your map so the public can see it?

    2. Oh sorry, I'm a newbie at this. I just did a quick "stick figure" map. Give it a try now.

  13. Quick disclaimer. This is very crud; I just wanted to see if there was any merit to the route. Dublin to Castro City segment would be some combination of tunneling, viaducts and etc. Junction Station would be somewhere in Tracy or Ulmar.

  14. Regarding the south I think CAHSR should split into two groups, a CAHSR North and a CAHSR South, each representing one of the two systems. As stand alone entities, they would both be money makers; any ridership generated from connected North and South systems would be an additional bonus.

    Below a proposed South system: (a definite unsubsidized money maker):

    CAHSR South money maker

    I'm not a fan of the way the Vegas line is currently materializing. I'm concerned about non-state and non-US ownership (Virgin, Softbank and Brightline) especially if Rick Scott is involved. The most I would give them is from the border to Barstow and that's it. You never know if CAHSR will want to run competitive trains to Vegas. And Brightline isn't exactly known for true HSR, choosing slower diesel systems if at all possible.

  15. Another trestle fire... let's see how this unfolds as they investigate the cause.