19 September 2023

First Look at Electric Service

Caltrain's proposed weekday peak service
Caltrain has started to pull back the curtain on their fall 2024 service pattern, when the electric fleet will (finally!) enter service.

The peak service pattern is depicted at right from a Caltrain slide, and looks like this in a string diagram from our trusty taktulator. The overall score for this timetable is a lukewarm 115 points relative to the benchmark score of 100 for the 2011 timetable, and it requires just 14 trains to operate, not counting spares.

The Good

  • Peak frequency will remain at four trains per hour per direction until ridership recovers more. This requires a waiver from the FTA, which originally made its funding contingent on operating six trains per peak hour per direction.
  • This enables operating with all-electric service in the portion of the corridor between San Francisco and San Jose, relegating the diesel fleet to where it belongs: not under the wire.
  • Stops are restored throughout the corridor, increasing service frequencies especially in Silicon Valley where the 2004 arrival of the Baby Bullet decimated ridership at skipped stops that nevertheless have healthy numbers of nearby jobs and residents.
  • Off-peak service is a subset of peak service, making for a regular and consistent half-hour "takt" throughout the entire day. This makes the timetable easy to use and memorize.
  • The Gilroy branch is served by a cross-platform transfer in San Jose, reflecting the results of a recent survey of its customers that revealed that a one-seat ride was their lowest priority.

The Bad

  • The Baby Bullet unfortunately survives as Express A, skipping perfectly worthy stops throughout Silicon Valley and tragically breaking the potential symmetry of the timetable. Express A should just be another Express B, giving evenly spaced 15-minute service from Redwood City to San Jose. This is very low hanging fruit that improves the timetable score from 115 to 118 points. The Baby Bullet pattern was a great idea for speeding up diesel runs, but in the new electric age, Caltrain should let it slip into history.
  • The "South County Connector" remains as diesel rail service. There is an opportunity for  enormous savings (and better service quality for riders) from selling off the entire diesel fleet and operating the Gilroy branch with much more frequent luxury buses. Operating and maintaining an excessively large electric + diesel fleet and wasting capital funds on the expensive but dubious idea of a BEMU distracts Caltrain from its core mission. If one believes in the idea of a fiscal cliff, then it's obvious that rubber tires can help Caltrain's balance sheet until the high-speed rail project electrifies the south county corridor.
The Implausible
  •  The proposed service pattern is built around a 75-minute all stops local trip between SF and SJ. This 75-minute figure is very impressive and would be a huge strength, if only it didn't border on the implausible. These are several issues with a 75-minute local run:
    • the trains have to accelerate very aggressively, something the equipment is admittedly capable of, but ouch, that electricity bill! Operating cost will depend not just on usage but also peak load, and high acceleration makes the peaks worse.
    • the timetable padding has to be shaved down significantly from today's comfortable margins
    • the station dwell time has to come down to a crisp BART-like duration of just 30 seconds. Without level boarding, this is unlikely to work reliably in daily service. The boarding step arrangement, door spacing and interior circulation of the new EMUs is identical to the Bombardier diesel sets, so it's hard to believe they would board any faster, before even considering the possibility of a crew interventions for wheelchair users.
    • There is nothing physically preventing a 75-minute trip, but if Caltrain can pull that off, what secret sauce of brief dwells have they been holding back from us all these years? Based on past operating practice, a more reasonable expectation would be an 86-minute trip. Let this serve as a prediction that Caltrain will find out the hard way that it really does have an urgent need for level boarding.

Taken together, there's a lot to like in this emerging service pattern, and a few tweaks can make it even more optimal. With freeway traffic getting steadily worse, the new service product will sell itself.

02 September 2023

Level Boarding: Still Not Getting It

The good news: Caltrain has initiated a small study effort to develop a level boarding roadmap, as part of its portfolio of capital projects.

The bad news: in the summary of this study, Caltrain shows no sign of grasping the purpose of level boarding. We might need to display it on a freeway billboard, like this:

Caltrain does a very nice job of explaining the benefits of electrification. Faster acceleration leads to shorter trip times, a strong message that they hammer often. On level boarding, however, the messaging is muddled. It's something-something about steps? Easier and more inclusive access?


It's about shorter trip times, just like electrification. While electrification saves time in motion, level boarding saves time at rest. The savings are big: cutting station dwell time from 45 seconds (typical for Caltrain today) to 30 seconds (typical for BART, which has level boarding) is worth almost as much "acceleration" as electrification. Electrifying without level boarding is half-baked, and Caltrain should be spending a lot more on level boarding than distractions like BEMUs. Please return to your core mission to quickly and efficiently get people where they are going.

About these numbers: the diesel trip time is for an all-stops local with 45 second station dwells and 15% padding. The EMU trip time has the same dwell and padding assumptions. The level boarding time assumes that station dwells drop to 30 seconds, and padding is cut down to 10%. The lower padding is appropriate because level boarding not only makes dwells shorter, but it makes dwells much more consistent and predictable, as discussed previously. If two wheelchair users need to board, it takes the same 30 seconds, not five minutes of staff assistance. Here are the detailed stop-by-stop stats and string diagrams if you want to tinker with assumptions.

04 June 2023

BEMU Obsession

Barry the BEMU,
Caltrain's new mascot

"Don't tell me what you value. Show me your budget—and I'll tell you what you value."

There's a new obsession gripping Caltrain: the Battery EMU, an electric train that can travel without overhead wires using electricity drawn from a large battery on board the train. The BEMU features prominently in Caltrain's recently approved two-year budget, which offers the best way to understand the agency's values. We find allocations for:

  • $80M for a single BEMU prototype train (at a $25M premium over a regular EMU)
  • $3.7M for in-house BEMU research and development
  • $2.5M for operations planning (including BEMU operations)
  • $1.1M to develop a 10-year capital improvement plan
  • $1 million to develop a roadmap for level boarding
  • $0.5 million to study future grade separations

The bottom of this list combines to roughly $5M of planning for Caltrain's entire future, a critically important activity to ensure its continued viability. The top two items in this list are almost $30M to pursue a BEMU obsession that will cost much, much more to scale up to anything resembling a viable service pattern. Going by these numbers, Caltrain values BEMUs about six times more than planning for its entire future!

Going Green by Blowing Green

Recently enacted California air quality mandates will make Caltrain's entire diesel locomotive fleet illegal to operate by 2030. This includes the nine locomotives now being refurbished at great expense and retained to operate diesel service to Gilroy (numbers 920 - 928).

If you start from the premise that rail service to Gilroy must be maintained and expanded at any and all costs (regardless of the much ballyhooed fiscal cliff) then a solution must be found to run trains beyond the end of the wires in San Jose, and soon.

Here is the range of available options, from cheapest and most reasonable to most risky and profligate:

  1. Most obviously, purchase the same diesel passenger locomotive that almost every passenger rail operator now uses in California: the Siemens Charger, used by Amtrak, ACE and Coaster. This is a modern low-emission model that will not be outlawed, requires no R&D, and costs about $8M each.
  2. Slightly more ambitious is to purchase an upcoming version of the same Charger locomotive that will have zero emission capability to operate through densely populated areas, thanks to a bank of batteries built into a permanently coupled passenger car. This is a model known as the ALC-42E and has been ordered in large quantities by Amtrak. As a bonus, it can draw power directly from overhead wires where available. This option requires no R&D and likely costs closer to $12M each.

  3. Yet another possibility, if one accepts the idea of a seamless cross-platform transfer at San Jose Diridon, is to serve the low-ridership Gilroy branch with smaller trains that do not interline onto the peninsula rail corridor. Stadler has an existing BEMU product known as the FLIRT Akku, developed for remote branch lines in Germany that have similar ridership profiles as Gilroy. This option requires little R&D (beyond overcoming American "not invented here" syndrome and shepherding the technology through FRA approval) and likely costs about $20M per train.

  4. By far the most risky and expensive option is to apply the Akku technology to the Caltrain version of the Stadler KISS, turning it into a supersized BEMU to serve Gilroy and points beyond (Salinas, anyone?) with massively oversized 650+ seat trains. This requires new research and development to add very large batteries (likely in excess of 1 MWh) that will be lugged around as giant dead weights whenever the train operates under the wire. Adding massive batteries to the KISS EMU defeats the very purpose of this vehicle: to move huge numbers of people quickly even with lots of station stops. Costing $85M for the first example and likely north of $60M for each follow-on, this BEMU can rightly be described as "the wrong tool for the job."

You'd need at least six trains to run anything resembling a reasonable service pattern, so multiply accordingly: Caltrain is contemplating the expenditure of about 1/3 billion dollars to keep the Gilroy branch steadfastly served by steel wheels on steel rails. We all love Gilroy, but at any cost?

the right tool for the job
(original by Grendelkhan)
Considering that the Gilroy branch generates very little ridership (about 1% of Caltrain's total ridership before the pandemic), a better interim solution, until the HSR project electrifies the tracks, is to transfer the Gilroy branch to a mature, affordable and environmentally friendly rubber wheel technology: the express bus. This would have the added benefit of allowing Caltrain to quickly rid itself of all of its polluting and failure-prone diesel equipment by 2025, with enormous savings in operating and maintenance costs just as the agency reaches its purported "fiscal cliff." Caltrain should go 100% electric now.

Consultant Featherbedding

The root of this insanity is understandable: Caltrain has for many years retained the services of in-house vehicle consultant LTK, tasked with supporting the highly complex procurement and regulatory approval of a new fleet of electric vehicles. Now that the Stadler contract will be winding down as this new fleet enters service, these people's jobs will be finished. They desperately need to justify their continued existence, and an open-ended research and development project to send oversized bilevel BEMUs all the way to Gilroy, Salinas and beyond is the perfectly timed green-washing opportunity.

Sadly, the BEMU is an expensive solution looking for a problem.

05 March 2023

The False Choice of Link21

Link21, the nascent megaproject to beef up the Bay Area's passenger rail network, features at its core a new underground transbay passenger rail crossing between Oakland and San Francisco. One of the major dilemmas facing this program is what kind of rail service to put in that new tunnel. The choice is posed between BART (understood as wide-gauge single-level rolling stock) and regional rail (understood as standard gauge FRA-compatible rolling stock). One or the other, but not both.

This is a false choice!

Yes, we can have both. They can share the same tunnels and tracks, if we can just get past the mental block of rigidly associating BART with broad gauge. It may seem mind-blowing, and require crayon colors that nobody has seen before, but BART can have a new standard gauge line. It's nothing unusual for transit systems to operate rolling stock with incompatible track gauges or structure gauges. Besides, BART already is our regional rail, despite any semantic distinctions we Americans reflexively attach to various sub-types of rail, real or imagined.

Where would this new standard gauge BART line go? From Oakland, it would continue south via existing and under-utilized standard gauge rail corridors to serve the (re-gauged) Dublin / Pleasanton branch, which could be further extended to serve the Altamont Pass (hello, Valley Link) and points beyond. Long-distance trains, provided they have a pantograph, could run through from the Central Valley straight into downtown San Francisco.

Link21 planners should stop promoting this specious choice between BART and regional rail. They don't need separate tunnels, and the dogmatic belief that they do will inevitably result in terrible planning decisions.

Small print regarding the graphic: the single tunnel bore (of two) is drawn rigorously to scale. The BART broad gauge version is 250 inches (almost 21 feet) in external diameter, taken from a VTA drawing. The regional rail version is 8 meters (a bit over 26 feet) to accommodate taller bi-level trains. The overhead conductor rail, of the same design used by Caltrain in its San Francisco tunnels, is 18 feet above the rail. The BART standard gauge train is a Stadler KISS with the same dimensions as Caltrain's, but a different color of paint as previously seen in this post.

Note an alternate configuration is also possible with a 40-foot external diameter single bore tunnel.

02 January 2023

Deadly Caltrain Underpasses

The recent storms demonstrate once again that Caltrain underpass flooding is a clear and present danger to the public. Deadly is no understatement: while only harrowing water rescues occurred in the 31 December 2022 atmospheric river, two people lost their lives in the flooded Hillcrest Boulevard underpass in Millbrae on 23 December 2021.

Poor "split" grade separation designs that only marginally lower the height of the tracks compared to fully elevated tracks are sure to kill again if Caltrain and surrounding communities continue to build more of them. (lookin' at you, Redwood City!)

Harbor Boulevard, Belmont
Ralston Avenue, Belmont (M.M. Parden photo)

42nd Ave, San Mateo (M. Sly photo)

Hillcrest Boulevard, Millbrae (December 2021)