08 September 2018

Still Dithering on Level Boarding

EMU low door configuration
Recent documents seeking regulatory relief from certain FRA requirements for Caltrain's new EMU fleet reveal details of the interface between the train and a station platform.

The lower doors of the EMUs will feature a deploying step at 15 inches (measured above the top of the rail), halfway between the 8-inch platform and the 22-inch train floor. The resulting step arrangement, when deployed, is similar to the existing Bombardier cars, although the floor height of the Bombardiers is 3 inches higher.

So far, so good.

A closer examination of the step mechanism (see Stadler engineering drawing, as submitted to FRA) shows that the step module retracts upward from its 15 inch deployed height, using a cam mechanism, and stows with the step tread 2.5 inches below the door sill. This makes the step unusable for an ADA-compliant level boarding interface, where it might have been configured to close the gap with a 22" platform, at the same height as the train floor. Recall that ADA regulations for unassisted level boarding require a platform gap less than 3 inches, with vertical discontinuity less than 5/8".

One faction of Caltrain staff evidently envisions level boarding using the low doors of the new EMUs, but the engineering drawing proves this is out of the question without a complete redesign and replacement of the door step mechanism. Even then, there are serious questions about the feasibility of a gradual transition to level boarding where the train fleet must serve a slowly evolving mix of 8-inch and raised level platforms.

As per usual with level boarding, the end goal is clear, but getting there is the hard part and often involves lots of hand waving.

Consultant Still Doesn't Get It

Not only is the lower level door step mechanism unsuited for future level boarding, but Caltrain's vehicle engineering consultant, LTK Engineering Services, states that low platforms will be used indefinitely. On page 1 (PDF page 5) of the recent FRA waiver application, we read:
Initially, Caltrain will utilize only the lower level doors to serve their existing 8-inch platforms. Once CHSRA service begins in the corridor, there will be a station or two that will have high level platforms and will be served by the Caltrain EMUs via the intermediate level doors. Other Caltrain stations will remain low level and will be served by the lower level doors.
No! Continued use of 8-inch platforms means long dwell times and time-consuming conductor-assisted boarding for persons of reduced mobility using a manually emplaced bridge plate. This antiquated state of affairs cannot be allowed to persist. Blithely ignoring the minutes that can be saved while the train is at rest is unacceptable, especially after spending two billion dollars to save minutes while the train is in motion.

It is time to adopt a policy on level boarding, and to push Caltrain's staff and consultants to reach agreement on the technical approach to get there. Here we are in 2018 and there is still obvious disagreement about whether to implement level boarding at all (a no-brainer if you look at the big picture) and at what height, using what doors on the new EMU fleet. Stop dithering and do it!

Footnote: there are multiple waiver petitions relating to EMU design details.
FRA-2009-0124 Tier I Alternative Vehicle Technology crashworthiness (approved)
FRA-2017-0104 Position of bathroom car emergency exit window (approved)
FRA-2018-0003 Use of upper doors in lieu of emergency exit windows (denied)
FRA-2018-0067 Emergency brake handles, grab irons and steps, clearances (pending)

25 August 2018

Over-Promising on Electrification

Numerous recent Caltrain materials include the following quantitative claims (see slide at right) about the service benefits of the electrification project:
  1. A baby bullet train making 5-6 stops will make the SF - SJ trip in 45 minutes, down from 60 minutes today.
  2. A train making the SF - SJ trip in 60 minutes will be able to stop 13 times, up from 6 stops today.
Both of these claims are greatly inflated. They are easy to verify using a computer program known as a train performance calculator, which numerically integrates the differential equations of motion of a train based on the known characteristics of the track (vertical profile, curve, speed limits, station stops, etc.) and of the train (power, weight, tractive effort, drag, etc.) Physics and math can predict timetable performance quite accurately.

Myth #1: the 45-minute Baby Bullet express

Today's diesel performance
(pure run time, no padding)
Here is what a typical baby bullet run looks like today, with an MP-36 diesel locomotive, six Bombardier coaches, and a load of 600 passengers. There are five stops in this example, each lasting (very optimistically, as riders will attest) just 60 seconds. The pure run time from San Jose to San Francisco 4th and King is 52:22 under ideal conditions, without any margin or padding that is added to a real timetable; compare to the weekday northbound timetable at 64 to 67 minutes, or up to 25% longer (!) than the pure run time. Note that the weekday timetable has been extensively padded lately due to crowding; in 2012, the same run was timetabled at 59 minutes with 12% padding.

Tomorrow's EMU performance
(pure run time, no padding)
All other things being equal, let's substitute an EMU train for our slow diesel. The same run drops to 48:15, just four minutes quicker. This isn't surprising: baby bullet trains spend most of their time cruising near the speed limit, where the faster acceleration of EMUs doesn't provide a benefit. With all other things being equal (including crowding and long dwell times--why would electrification resolve these?) we can expect the timetable for our five-stop baby bullet to drop by the same four minutes, or 60 to 63 minutes. That is a full 15 to 18 minutes slower than claimed by Caltrain! Even if you remove the copious 5-8 minutes of extra padding present in today's timetable and compare to the 2012 timetable, we're still 10 minutes slower than claimed, at 55 minutes.

EMU performance at 110 mph
(pure run time, no padding)
How could you possibly get to 45 minutes? One approach is to raise the speed limit to 110 mph, which is planned in the long term but clearly outside of the scope of the electrification project. Changing only that variable, and slowing down as needed where curves limit the speed to below 110 mph, our EMU now makes the same San Jose to San Francisco run in 41:32, almost seven minutes faster. However, we're still 7 to 10 minutes slower than Caltrain's 45-minute claim, or 2 minutes slower when using 12% padding. Again, the reasons for having such enormous amounts of timetable padding will not suddenly disappear after electrification!

The best way to get there is with level boarding, which alleviates Caltrain's crippling dwell time problem. Level boarding has two benefits: the primary benefit is in the form of reduced dwell time during each stop, and the secondary benefit is in the smaller amount of timetable padding that is needed, thanks to the improved schedule adherence that is possible when the occasional wheelchair lift deployment no longer threatens to inject random three-minute delays. Padding could conceivably be cut to 7%, and dwell time to 30 seconds. No new simulation runs are required-- our five-stop 79 mph EMU makes it in (48:15 - 2:30)*1.07 = 49 minutes on the timetable; the 110 mph EMU makes it in (41:32 - 2:30)*1.07 = 42 minutes.

Caltrain's claim of a 45-minute baby bullet is readily attainable only after three major improvements are made. These are not included in the scope of the electrification project and are currently unfunded:
  1. Conversion of the baby bullet fleet from diesel to EMU
  2. Implementation of system-wide level boarding
  3. Curve realignment, track upgrades and grade crossing safety upgrades for 110 mph
To promise a 45-minute baby bullet run in the short term is at best misleading and at worst a flat-out lie. Once the electrification project is complete, we can expect approximately zero improvement in baby bullet performance, with timetabled runs in the range of 64 to 67 minutes. If the initial slight increase in capacity of the electrification project relieves crowding (but will it, enough to offset the performance loss from dragging a seventh Bombardier car?) then we could return to the 2012 timetable performance of 59 minutes.

Myth #2: the one-hour, 13-stop limited

Let us assume for the moment that padding returns to the 2012 level of about 12%. Assuming 60-second dwells and a 79 mph speed limit, how many intermediate stops can a limited train make between San Jose and San Francisco before the timetable hits one hour?  Subtracting 12% pad from one hour, we need to make a pure run time of 53:34.

With today's diesel bullet performance, Caltrain's claim of six stops in one hour checks out reasonably closely at 54:57 or just over one hour including padding, i.e. close enough. Let's change the assumptions, one by one:

Simulation CasePure Run TimeTimetable
Case A, Diesel, dwell 60, 6 stops, 12% pad0:54:571:01:33
Case B, EMU, dwell 60, 6 stops, 12% pad0:50:100:56:11
Case C, EMU, dwell 60, 7 stops, 12% pad0:52:040:58:19
Case D, EMU, dwell 60, 8 stops, 12% pad0:53:581:00:27
Case E, EMU, dwell 30, 8 stops, 7% pad (level boarding)0:49:580:53:28
Case F, EMU, dwell 30, 9 stops, 7% pad (level boarding)0:51:220:54:58
Case G, EMU, dwell 30, 10 stops, 7% pad (level boarding)0:52:460:56:28
Case H, EMU, dwell 30, 11 stops, 7% pad (level boarding)0:54:100:57:57
Case I, EMU, dwell 30, 12 stops, 7% pad (level boarding)0:55:340:59:27
Case J, EMU, dwell 30, 13 stops, 7% pad (level boarding)0:56:581:00:57
Case K, EMU, dwell 30, 13 stops, 7% pad (level boarding), 110 mph0:53:080:56:51

Simulation Case K
(pure run time, no padding)
Case D shows that the maximum number of stops permissible under post-electrification conditions is at most 8, just two more stops than today, and not 13 as claimed by Caltrain. Only after level boarding does the number of stops increase to 13 as shown by Case J, but once again, level boarding is not included in the scope of the basic electrification project. Case K illustrates the diminishing returns from increasing the speed limit to 110 mph; the more stops a train makes, the less benefit there is from the higher allowable speed. Case K (see diagram at right) shows the train almost constantly accelerating and braking, which is not how one would choose to operate given the cost of electricity in the real world.

The takeaway message to Caltrain is this: don't over-promise and under-deliver on the modernization project. Your electrification project reduces time in motion and establishes a foundation for further improvements, but is not sufficient by itself. To deliver the service benefits promised in your public presentations, you absolutely need level boarding to reduce time at rest.

(do I sound like a broken record?)

11 August 2018

New SF Caltrain Terminus Opens at 0 tph

Zero trains per hour (tph) is the inaugural Caltrain service level at San Francisco's new Transit Center, which opened to the public today after a decade of construction. The grand opening of the center, with its expansive $400 million basement featuring ghost tracks, ghost platforms and a ghost passenger concourse will no doubt crystallize the increasingly urgent transportation need for the downtown extension (DTX) of the peninsula rail corridor. Only then will train service increase beyond the current level of zero tph.

Huge opening day crowds at the Transbay Transit Center. Photo by Adrian Brandt.
Why build DTX?

Simple. Within a half mile radius of the Transit Center, there are more jobs than within a half mile radius of every station along the peninsula rail corridor from San Francisco 4th and King all the way to Gilroy, COMBINED! Even before high speed rail shows up, this is a piece of infrastructure that makes perfect sense. Or does it?

An epic opportunity for transit funding extortion

The clear (and, as of today's opening, agonizingly present) need for the DTX sets up a deliciously fat and juicy prey for the transportation-industrial complex, which you can think of as a hungry snake. Here we are, in a strong economy, in one of the richest cities on Earth, facing a specific and obvious transportation need: they can name just about any price. The latest estimate for the biggest meal that the snake can swallow is six billion dollars, and that's only the start. Scope creep, dizzying amounts of contingency cushioning, and construction change orders are sure to drive it far higher. Civil engineering megafirms, labor unions, and complacent and poorly coordinated government agencies are salivating at the prospect of feasting on the DTX. The bigger it gets, the more sated and comfortable everyone will be, with the notable exception of the suckers who pay taxes and ride trains.

The DTX project needs a major cost cutting exercise

"It is difficult to get a man to understand something, when his salary depends on his not understanding it." This insight by Upton Sinclair applies to any attempt to reduce the scope or optimize the cost effectiveness of the DTX project. There isn't and probably won't be a true will to do it, but in a pretend world where the interests of taxpayers and riders came first, where might you start cutting scope?
  1. Delete the Pennsylvania Avenue tunnel extension. There is a perfectly serviceable tunnel already available. Engineering acumen should be brought to bear to overcome the (otherwise delightfully profitable) constraints of building a new trenched grade separation by figuring out how to shore up I-280 during excavation; how to cross the SFPUC's giant new sewer; how to duck under 16th street using a steeper 2.5% grade than the train people would prefer; and how to build temporary "shoo-fly" tracks under I-280 during construction now that the area is hemmed in by fresh UCSF construction. The usual paint-by-numbers engineering that deploys freight train design standards as "constraints" shows this to be categorically impossible, but is it really? Sharpen your pencils.
  2. Delete the mezzanine level at 4th and Townsend. Station mezzanines are a knee-jerk (and delightfully profitable) design feature of every recent piece of rail infrastructure in the United States. Wedged above the tracks, underneath, in the sky or in a cavern, mezzanines tend to sprout everywhere. In this case, a mezzanine makes passenger access more circuitous and pushes the track level much deeper, increasing the depth of excavation. The mezzanine and station become an enclosed underground space, triggering an avalanche of fire safety requirements that greatly increase cost and complexity, with all manner of vent structures and evacuation shafts. The right answer is simple, direct and free-flowing access from platform to street, and an open station ceiling that vents to the street through a slot built into a raised median on Townsend Street-- as wide as necessary to treat the structure as an open station under fire safety regulations.
  3. Daylight as much of the shallow Townsend Street portion of the alignment as possible, with a central median vent slot (just like in Los Angeles on the Alameda Corridor, where three of the nation's busiest diesel freight tracks are concealed beneath the street with a vent slot as narrow as six feet). This configuration has the potential to simplify the engineering considerations and costs related to fire safety, and even improves rail operations: without the onerous fire safety requirement of having only one train at a time occupy each tunnel ventilation section, operation of the entire DTX becomes less constrained.
  4. Slim down the three-track tunnel, another one of Sinclair's salary considerations, to two tracks instead of the planned three. The Rail Alignments and Benefits (RAB) operations analysis, carried out by a premier Swiss rail operations consultancy, concludes on page C-68 that "Under normal conditions, only two tracks are required in the tunnel leading up to the TTC to operate the analyzed service plans. More detailed analysis is recommended to identify the most effective approach to provide infrastructure redundancy (e.g. the proposed third tunnel track) to help mitigate the potential effects of major service disruptions." The clear implication here, artfully worded so as not to upset Sinclair's salary men, is that a third track is not necessarily the best or only approach to achieve infrastructure redundancy.
  5. Add three 400-meter underground storage tracks, feeding in towards the Transit Center instead of the peninsula, along the northwest edge of the existing 4th and King station footprint. The fire safety requirements for this underground infrastructure would be less stringent because it would not be occupied by passengers. With beefy foundation columns bored down to bedrock to straddle this yard, the entire footprint of the site can still be redeveloped above grade, safeguarding San Francisco's desire to use "value capture" from this increasingly coveted parcel to finance DTX construction. The resulting train storage capacity is far more conveniently located than the remote yard sites currently proposed at Oakdale or Bayshore, reducing long-term operating costs. Even skyscrapers can be built on top of train storage: see Hudson Yards.
  6. Rationalize the Transit Center approach tracks to speed up train movements. The throat of the station has been identified as a key bottleneck for train movements (see RAB operations analysis page C-96, "Key Findings of Conceptual Planning"--and recall that you read it here first). An optimal layout has been identified that better enables concurrent arrivals and departures of two trains (see page C-117 of same). Precious seconds saved in the station approach can increase the traffic capacity of the DTX and make it more resilient to disruptions.
  7. Don't use exotic and expensive tunneling methods when their sole purpose is to keep businesses along the DTX route healthy during construction, by avoiding cheap but disruptive cut-and-cover methods. The intent is noble, and the recent impact of Central Subway construction in Chinatown is painful and fresh in our minds, but this sort of thing rarely pencils out for anyone but Sinclair's salary men.
Only after a draconian cost cutting exercise might it begin to make sense to build the DTX. At a price point of six billion dollars for a couple of miles of tunnel, we regretfully should keep service levels at zero trains per hour.

03 May 2018

Fleet of the Future

Not bad in blue, huh? This parody of the fragmented state of Bay Area transit is based on an image by Stadler Rail. There should be plenty in this image to offend almost everyone!

24 February 2018

The End of CBOSS

The rosy view, from 2011
Caltrain's troubled positive train control solution, known as CBOSS, has now been completely abandoned, to be replaced by the de-facto standard freight PTC technology known as I-ETMS. That's mostly good news, since Caltrain will no longer be stranded with a globally unique PTC system. I-ETMS is being deployed by numerous other commuter rail operators in the U.S., allowing some economies of scale and standardization.

Notwithstanding, CBOSS easily rates as the most spectacular contract failure and biggest lawsuit in Caltrain's entire history, since the Peninsula Corridor Joint Powers Board was formed in 1985.

Project expenditure history, by fiscal quarter. Fluctuations in
recent quarters are unexplained, presumably related
to termination of the Parsons contract in 2017 Q2.
Gap reflects two missing quarterly reports.
The sums expended are staggering, especially when considering that just 52 route-miles are to be fitted with PTC. To date, according to the latest quarterly capital projects report, Caltrain has expended $201 million out of $240 million budgeted for the project.

The March 2018 board packet includes a new item awarding a $49.5 million contract to Wabtec to deploy I-ETMS on the peninsula rail corridor, presumably re-using some of the hardware and communications infrastructure already installed under the CBOSS contract. The "owner's cost," borne by Caltrain to cover program management and testing, has averaged $1.2 million/month over the past five years, and should stretch well into 2019 until PTC is fully deployed and activated. (Note the December 2018 statutory deadline only requires a "revenue service demonstration" over a limited portion of the corridor). Caltrain staff estimates that owner's costs will grow the I-ETMS deployment to $59.5 million, pushing the PTC project total to at least $261 million. The board packet hints at additional future program costs, beyond the $59.5 million "switching cost" from CBOSS to I-ETMS.

How much money did Caltrain waste on CBOSS?

To estimate how much money Caltrain wasted on CBOSS, we can examine the PTC project finances of other commuter rail systems deploying I-ETMS, but without the wasteful detour into research and development of globally unique alternative solutions. These PTC-related expenses are variously reported to each operator's board of directors, in press releases, or to the FRA.

OperatorCityRoute Miles EquippedVehicles EquippedPTC Cost
MetrolinkLos Angeles249112$216M
CoasterSan Diego6017$87M
ACESan Jose06$10M

A linear regression analysis on three variables (cost per route mile, cost per vehicle, and a fixed cost allowance for control facilities) for these five commuter rail I-ETMS installations reveals that equipping one route mile of track costs on average $0.36M, equipping one locomotive or cab car costs $1.0M, and the fixed cost is $21M. These are simplistic approximations, but they do give a reasonable ballpark estimate for the underlying cost of a commuter rail I-ETMS deployment.

We then apply these estimated regression factors to Caltrain. With 52 route miles and 67 vehicles, the cost of I-ETMS deployment for Caltrain, had this solution been pursued from the beginning, would have been approximately 52 x 0.36 + 67 x 1 + 21 = $107M. This tells us two things.

First, we can infer from the $59.5M switching cost to I-ETMS that 107 - 60 = approximately $50M or just one quarter of the CBOSS sunk cost (including the fiber communications backbone and a subset of the control facilities and wayside/vehicle hardware) is salvageable for I-ETMS.

Second, since the total cost of Caltrain's PTC project is expected to reach at least $261M, we can infer that Caltrain wasted 261 - 107 = approximately $150 million on the egregious failure that was CBOSS.

$150 million flushed down the toilet. Heckuva job, Caltrain!

19 January 2018

CalMod 2.0: Three Things to Watch

UPDATE, from Caltrain TIRCP funding application
  • CalMod 2.0 is now formally known as EEP or Electrification Expansion Program
  • 100% state-funded through cap and trade program (TIRCP)
  • Consists almost entirely of option buys of 96 EMU cars for $600M
  • 17 x 8-car EMU fleet planned for start of electric service (if $$ awarded)
  • No 4-car EMUs (this is super important for future off-peak service)
  • No third bike cars.  Extra money for station bike parking
  • No level boarding.  Can kicked down road
  • Broadband internet on the EMUs at start of electric service, for a cool $14M
  • Diesel bullets redeployed to SJ - Gilroy - Salinas in unspecified future project

Caltrain was recently reported to be seeking another $630 million grant from California's cap and trade program to eliminate diesel trains entirely and to increase the passenger capacity of the new EMUs a decade earlier than previously envisioned. A previous board agenda alluded to a $756 million program known as CalMod 2.0, consisting of:
  • Full conversion to 100% EMU + capacity increase ($440M)
  • Broadband ($30M)
  • Maintenance facility improvements ($36M)
  • Level boarding and platform extensions ($250M)
While the amount reported in the press doesn't match the CalMod 2.0 tally, there may be other funding sources on tap and we are probably looking at the same package of improvements. The EMU fleet expansion is an exercise of the fully priced option for 96 additional EMU cars under the existing contract with Stadler.

There will be three important issues to keep an eye on:

1) Level Boarding

Level boarding is the logical next step after electrification, and a perfect complement: where electrification reduces time in motion, level boarding reduces time at rest. Every second of trip time saved is equally valuable, which is why cutting station dwell times is enormously important.

Not all level boarding solutions are created equal, and it's not enough for the height of the platform to equal the height of the train floor. To enable dense "blended" traffic on the peninsula corridor, what Caltrain needs is unassisted level boarding where persons of reduced mobility can board without the help of a conductor across an ADA-compliant gap. That means NO bridge plates, NO exterior lifts, and NO conductor assistance.

While the new EMUs will have the ability to dock at 51" platforms, staff and consultants evidently do not agree on a path forward towards system-wide level boarding. With a nine-figure amount being contemplated for platform extensions and level boarding under CalMod 2.0, the approach and transition strategy needs to be straightened out, and soon, to avoid enormous "do over" costs. And we should not let Caltrain claim that platform extensions for 8-car trains will cost a lot: the real price tag for that is in the range of $25 million.

2) Short EMUs for Frequent Off-Peak Service

Base order (blue) and option order
(orange) show fleet composition
for 100% electric service
The sort of service that Caltrain wants to run in the future, currently being discussed in the context of a nascent business plan, will determine the specific composition of the 96-car option order, i.e. how many of what EMU car type to buy. The wrong fleet decision could very well preclude service patterns that may be deemed preferable once the business plan effort concludes, which is why CalMod 2.0 needs to be carefully considered not to overtake or conflict with the business plan effort. That being said, you don't need an army of consultants to figure out what fleet Caltrain will need.

Use case #1: during rush hour, to run a 70 minute SF Transbay - South San Jose schedule at 6 tph per direction with 20 minute turns at each end, you need (70+20)/60 * 6 * 2 = 18 trains in service, plus one extra train available at each end of the line to protect against cascading delays, or 20 trains available for service. Allowing for a couple of trains to be down for maintenance, we need 22 trains total @ 8 cars each.

Use case #2: off-peak service running at 80 minutes SF Transbay - South San Jose at 3 tph per direction with 20 minute turns at each end, you need (80+20)/60 * 3 * 2 = 10 trains in service, plus one extra train at each end, or 12 trains available for service. Throwing in another two trains down for maintenance,  we need 14 trains total. Because it's very expensive to haul around empty seats, these must be short 4-car trains.

Supporting both of these use cases within the overall size of the Stadler order (96 cars base order + 96 cars option) requires the option order to consist primarily of 4-car EMUs, as shown in the figure at right. At peak times, 4-car EMUs would operate in pairs, mixing with the rest of the 8-car subfleet. If needed in the long term, EMUs could be extended to 12 cars by coupling 8 + 4 cars.

3) Just Say No to a Third Bike Car

Bringing a bike on Caltrain is one of the finest ways to commute; your author has done it hundreds of times. The bikes-on-board community is already gearing up to pressure Caltrain into adding a third bike car to the future 8-car EMUs, deeming the two bike cars in the base order 6-car EMUs to be inadequate. The typical argument goes that any bike "bumped" is a paying customer left behind, which is a logical argument when spare capacity is available. However, with trains at standing room only peak loads (by design!) there are plenty of potential non-bike passengers left behind. They are not "bumped" in the literal sense, since they don't even show up at the train station. Here's why: when the cost of enduring a crowded train trip becomes unbearable, the invisible hand of supply and demand pushes more and more potential riders to drive instead.

Under SRO conditions, every free bike space on the train displaces a paying passenger, a sort of "reverse bumping" effect that explains quite elegantly why, for example, the Paris RER does not and should not have dedicated bike cars. Caltrain has gone quite far enough in providing free bike space on board, and should not have a third bike car in 8-car EMUs, in everyone's interest of maximizing peak passenger capacity. In the long term, bike commuters will benefit more from world-class bike parking.