27 September 2012


Today another $40 million was pumped into Caltrain's CBOSS project, a unique reinvention of the wheel that is nearly certain to fail based on the past track record of similar projects in the Bay Area.

The cheerful press release contains the following gem:
The system, which costs $231 million, is fully interoperable with freight traffic using the Caltrain corridor and future High Speed Rail trains.
This one sentence could easily make one choke twice on the same pretzel.  First, the astronomical cost of more than $4 million per route mile is more than triple the world standard for similar projects.  Second, the claim of interoperability with HSR is an outright lie according to Caltrain's own contracting documents.

Interoperability, in this context, means spending additional millions to outfit each and every high-speed train in California (in a fleet that will dwarf Caltrain's) with CBOSS on-board signaling equipment.  Under this definition, CBOSS is no more interoperable with future "High Speed Rail trains" than it is interoperable with the red rail-cycle pictured above.


  1. Is CBOSS just a Caltrain marketing name for PTC similarly to how Audi uses Quattro for AWD? If not, can you do a quick comparison of how CBOSS differs from PTC? Are there "features" that Caltrain is asking that Metrolink down in LA found a way to do without?

    1. PTC (Positive Train Control) is a set of functions mandated by the federal government, not a product or an implementation of those functions. The three main functions are (1) to prevent train-to-train collisions, (2) to enforce speed limits, and (3) to protect way-side workers when they are present on or near the tracks.

      CBOSS is just one of many examples of PTC a implementation, although it is unique to the SF peninsula. While there were ambitions for it to have wider applicability, perhaps resulting in some economies of scale, this has not happened in practice and is unlikely to ever happen due to the great difficulty, cost, and risk of developing new safety-critical systems. The risk is very high that $231 million will be spent for a system that never quite works, doesn't fulfill its promise (to increase throughput), and is ultimately replaced with ERTMS.

    2. CLem is arguably not correct. "PTC" is simply a US regulatory term for what the resot of the English-speaking world calls "Automatic Train Protection". The US regulations for "PTC" also rquire enforcing temporary speed restrictions due to track work. World-wide, _the_ standard signalling system (including ATP) for new deployment is the European-sponsored ETCS system, publically standardized and availble from multiple vendors. Note in Europe, the cost of integrating earlier, now-obsoleted, national train-control systems can reach or exceed 30% of the cost of a new multi-system locomotive (Source: Bombardier TRAXX presentations, I can find the URL if pressed).

      All the major US freight railroads have formally adopted one or other variant of Wabtec's proprietary ETMS system. When people in the US talk about PTC, they sometimes really mean the Wabtec system. Caltrain embarked on CBOSS before those decisions were made. It's widely presumed that the vendor saw a potential market for which Caltrain would pay the development costs. With the adoption of Wabtec's technology, supposedly natively inter-operable variants, that market disappeared. No other customer on the planet has any interest in CBOSS.

      Clem is, if anything, understating the risks. And it'd be far cheaper to replace CBOSS with ETCS Level 2, than to pay integration costs and dual-equipment costs, to fit CBOSS into each end of every California HSR train-set.

      Meanwhile, Auckland, New Zealand, is installing a new signalling system as part of its regional commuter-rail electrification. The contract cost is about $90 million. Caltrain is paying two and a half times that.

    3. Aren't you guys also paying $80 million for electrification, with about the same route-length as Caltrain?

    4. Alon, that's for narrow gauge electrification, and in the southern hemisphere. We standard guage, northern hemisphere folks must pay $785 million for it.

    5. Hey Kiwi, when you write "it's widely presumed that the vendor saw a potential market for which Caltrain would pay the development costs" who is doing all this presuming, and how do you know?

    6. Possible systems:
      -ETCS, the world standard
      -ETMS, the US freight standard (from Wabtec, though there is definitely BNSF involvement in that design)
      -ACSES, the Amtrak northeast corridor standard
      -ITCS, the Amtrak Michigan standard

      I still cannot imagine why Caltrain thinks rolling its own is sane.

  2. Are there any features in CBOSS that are not accommodated in Wabtec ETMS? It might be somewhat defensible to have both ETMS and ETCS on the Caltrain corridor for interoperability of legacy equipment, but CBOSS sounds like a white elephant.

    1. Isn't CBOSS supposed to allow Caltrain to not lower crossing gates located at the far end of a station if the train is stopping there at the station?

    2. Yes and this only occurs at a handful of locations ... so hardly worth the cost and risk.

      The affected crossings with moderate to heavy traffic:

      Burlingame: Broadway NB (weekend service only)
      Redwood City: Broadway NB
      Menlo Park: Ravenswood SB
      Palo Alto: Alma NB
      Mountain View: Castro NB

    3. @Reality Check: That crossing count means around a $50 million per crossing premium for Proudly Designed in Northern California CBO$$ (just like iPhones!) over the non-vaporware real alternative of $100+ million cheaper, you know, working PTC.

      And another thing: can't nearly everybody grade separate for $50 million a crossing?

      Soooooo .... You have $250 million dollar burning a hole in your pockets, courtesy local, state and federal tax payers. Do you
      (A) Buy working PTC and build four or five grade separations
      (B) Buy non-working PTC and no grade separations

      I don't think anybody can argue that CBO$$, even in the very best case, won't deliver the worst possible result.

      Wow. Just wow.

    4. Even worse: this $50 million gate-crossing "premium" feature is of no benefit to Caltrain riders. It is only for the automobile drivers.

    5. Honestly, I'm pretty sure I could design an ETMS implementation which would allow for this. Just put a signal at the end of the platform, set it red for stopping trains, and ETMS guarantees that the train will stop at the red signal (that's the whole point of PTC...) so then you can program the crossing gates to not drop.

  3. Replacing CBOSS with ETMS - which is what is being installed on Metrolink makes a whole lot of sense. Going with ETCS is probably an even better idea, but neither really impose any extra costs on HSR in that HSR will likely want to run on ETMS track in Metrolink territory.

    It's worth noting that in the time that Caltrain has been jawboning about CBOSS, Metrolink was able to select ETMS (which is clearly the best choice for them since they have to share lots of track with lots of freight that also will use ETMS) and to start deploying it and will do so for lower cost.

  4. I cannot imagine how Caltrain is getting away with this CBOSS nonsense; I assume the people funding it did zero due diligence.

    As noted, Metrolink is installing a perfectly functional "freight" PTC system (ETMS) and they're about halfway done installing it.

    1. And gee, you have a point about something being "SPESHUL" about San Francisco. There are cost overruns and problems with lots of signal systems.

      But only BART designed a signal system which wasn't failsafe! Only BART then tried to build an overlay on its non-failsafe system (this failed, as you linked)! And Muni sure didn't manage to buy an improved signal system either!

      Maybe this really is just the "San Francisco political culture" documented here:
      and by many other articles by the same author.