27 November 2016

What Level Boarding?

Caltrain disagrees with itself regarding which exact platform height to adopt for level boarding. Is it 50 inches or is it 25 inches? You be the judge. Consider the evidence:

Exhibit A: the Electric Multiple Unit conformed contract documents specify that the new level boarding platform height will be 50 inches:
Section 2.2.1.1 Future Level Boarding 
CHSRA trains will run over the same alignment and stop at some of the same stations as JPB trains. The bi-level EMU must therefore have the same interface with the infrastructure as the future High Speed Rail cars, including clearance envelope, and platform boarding height. 
JPB plans to raise platform heights to approximately 50.5-50.75” ATOR (to interface with a vehicle threshold height of 51” ATOR), initially at San Francisco, Millbrae, and San Jose stations. Other station platforms on the JPB system may ultimately be raised to the same level. These requirements will likely require two sets of doors – one at high level and one at a lower level. 
(...) 
To facilitate the scenario where all platforms are raised to the ~50.5” ATOR level, it must be possible for JPB to easily de-activate the lower level doors and add additional passenger seating in the lower level vestibule area. 
Section 3.3.3 Threshold Height / Platform Interface 
EMUs shall be compatible with JPB’s existing platform height (8 inches ATOR) and existing mini-highs (22 inches ATOR). In addition, EMUs must be compatible with JPB’s future level boarding platform height of approximately 50.5 to 50.75 inches  ATOR.   Each car shall be capable of serving both platform heights during the transition from the existing platform height to the future platform height.

Exhibit B: slides from a November 22, 2016 study session of the Mountain View Transit Center master plan, held to solicit input from the city council. In this document, we find out on page 14 that Caltrain plans to adopt a new level boarding platform height of 25 inches:
Design platforms for future level boarding operations, which will begin after the Caltrain fleet is converted from diesel to electric trains. Level boarding at a 25” height (versus the current 8” height) will shorten boarding time for all passengers and meet Americans with Disabilities Act requirements. 

Exhibit Cslides from an October 18, 2016 meeting of the Citizen Working Group advising San Francisco's RAB (Railyard Alternatives and I-280 Boulevard) feasibility study. On slide 11, we learn that Caltrain plans to adopt not one, but two level boarding platform heights. Platforms at 4th/King will be rebuilt to 25 inches, while platforms at Transbay will be built to 50 inches:
For 4th/King it is likely that Caltrain and HSR will operate at different platform heights 
• HSR will operate at 50-inches, Caltrain at 8-inches top of Rail (TOR). Therefore, there will be dedicated platforms for Caltrain and HSR at 4th/King 
Caltrain may change height of their platforms at some time to 25-inches from TOR but still will be different than HSR 
All platforms at TTC to be constructed at 50-inches. Caltrain will use 2nd set of doors at TTC and utilize any platform/track at TTC
This sort of inconsistency would be amusing if level boarding wasn't the most important modernization step that Caltrain must take after the electrification program is completed... and if the EMUs that Caltrain just ordered from Stadler could actually serve a 25" high platform.

The Stadler EMUs won't work with 25 inch platforms

Barring a contract change order and significant technical modifications, the EMUs as specified by Caltrain and as recently ordered from Stadler will not be capable of boarding or alighting passengers at a 25 inch platform.

First, there's the little issue that the floor height of the lower level of the new EMU was not specified in Caltrain's contractual documents. Stadler went with the standard 22" (550 mm) above the rail, according to their specs. Stepping down from a 25" platform into a 22" rail vehicle is frowned upon by regulators. But leave that aside and imagine the trains actually had a 25" floor level that matched a 25" platform.

Unless every single Caltrain platform were to be raised overnight from 8" to 25", a logistical feat that is exceedingly unlikely to be within Caltrain's financial means or capital project planning ability, the conversion to 25" level boarding will necessarily entail a transition period during which EMUs will serve an evolving mix of 8" and 25" platforms. This has technical implications described in the EMU contract documents:
For compatibility with the existing platform height, vehicles will require an intermediate step between the platform height and the lower level boarding threshold height, at approximately 16 inches ATOR.  This intermediate step must be either removable or retractable to support conversion to a high-door-only modification once all JPB platforms have been raised to 50.5 to 50.75”. The vertical face of this intermediate step will be located at approximately 61 inches from car centerline. In addition, a ramp or bridge plate must be provided to interface with JPB’s current mini-high platforms to load wheelchair passengers.  The ramp or bridge plate must comply with 49 CFR 38.95. The entire platform interface system must also be usable during the transition from the current platform height to the level boarding platform height. 
This "intermediate step" is identical to the step arrangement currently found on Caltrain's Bombardier bilevel cars. As long as the intermediate step is present (at 16 inches above top of rail and 61 inches from car center line), here's what the situation looks like at a "level boarding" 25 inch platform, during the transition period:

This is a fatal flaw. A level boarding solution must be structurally and operationally feasible, which this 9" deep by 16" wide gap is not.  This is not a simple matter of welding some plates over the step wells, since the intermediate step would remain in use throughout the transition period, likely several years.

The end goal must be unassisted level boarding at every station, fully compliant with the ADA gap specification of 49 CFR 38.93(d)(1).  Manually operated bridge plates are not okay; conductor-assisted level boarding won't cut it for a punctual and reliable blended system where HSR and Caltrain must share primarily two tracks.  This means Caltrain should either drop any talk of 25" platforms, or modify the EMU contract post haste with the same retractable bridge plates at the low doors as will be fitted to the 50" high doors.

Level boarding requires a carefully engineered solution and a crisp strategic plan for how to get there. The documents cited above suggest that Caltrain still needs to get it together.

20 September 2016

EMU Brochure

Credit: Stadler Rail Group
This week is InnoTrans 2016, the world's biggest rail industry trade show, held in Berlin, Germany. Stadler has a big presence there, and rolled out an updated website and downloadable brochures. Among them is a preliminary brochure for Caltrain's new KISS EMU, affording the first public glimpse into design details of Caltrain's new fleet.

Key Specs

The Stadler KISS (recently re-branded KISS160) as configured for Caltrain is a high-performance train that will have no issues sharing the corridor with high-speed rail.
  • Power: 6000 kW (8000+ hp)
  • Acceleration: 1 m/s2 from 540 kN (implying a loaded mass of 540 metric tons)
  • Braking: rated at 8000 kW, with most of the energy fed back into the electric grid
  • Vehicle width: 3 meters (comfortably inside US loading gauge)
  • Maximum speed: 110 mph
  • Straight sides, taking full advantage of US loading gauge, unlike European KISS
Train Layout

The six-car EMU shown in the brochure features dual boarding height doors throughout, to share platforms with high-speed rail and to enable Caltrain to transition gradually to gap-free level boarding, to cut down dwell times for the blended system.  The train consists of the following:


ParameterCar 1Car 2Car 3Car 4Car 5Car 6Total
Car typeCabMiddleMiddleMiddleMiddleCab-
Number of powered axles24040212
Seats, lower level3823638638149
Seats, upper level525260526052328
Seats, intermediate level10+21010+161010+1610+296
Seats, total102859210092102573
Bike spaces--40-40-80
Bathroom-1----1

As delivered, the upper level boarding doors are sealed and 5 seats are configured longitudinally in each vestibule on the intermediate level, accounting for 10 seats per car. These seats will be temporarily removed during the transition to level boarding with high platforms (when both sets of doors must be cleared of seats), diminishing seating capacity by roughly 10%. Once Caltrain achieves 100% level boarding, that seating can be restored on the lower level of each car.

The layout for all six cars can be viewed by zooming into the original PDF brochure, or more conveniently as individual graphics extracted below.


Accessibility

The seating diagrams reveal that the ADA bathroom displaces 15 seats.

Interestingly, the Stadler diagrams show two wheelchair spaces on the lower level of every car, which appears to imply that ADA wheelchair lifts would be provided in every car to cross between the lower and intermediate levels of each car.

Future Capacity

Caltrain's order from Stadler includes options for another 96 cars, which are planned to be exercised to expand the fleet to 24 trains and lengthen all trains to 8 cars or about 200 m long.

With the seating layout and train car dimensions defined, it is possible to predict the seating capacity of an 8-car train. The basic 6-car train already has all the traction equipment, so the two extra cars would likely be trailer cars similar to cars 3 and 5 above, except without the bike storage area on the lower level. Each of these extra cars would have 60 seats on the upper level, 46 seats on the lower level, and 26 seats on the intermediate level, for a total of 264 added seats. This would bring each train's ultimate capacity to 837 seats and 80 bikes, with plenty of additional space for standees.

31 July 2016

Future Proofing Hillsdale

The next big grade separation project on the peninsula rail corridor will be at 25th Ave in San Mateo, a logical next step in the decades-long process to grade separate the corridor.  This grade separation will establish a 6.5-mile stretch of 100% grade separated right of way, laying the groundwork for a future four-track mid-line overtake facility that will allow express trains to overtake slower commuter trains under the "blended system" jointly planned by Caltrain and the HSR authority.

Preliminary rendering of new
Hillsdale station with island platform
The latest plans presented to the Caltrain board of directors show a split-grade elevated solution, built sufficiently wide for four tracks but initially only fitted with two tracks spaced on approximately 48-foot centers.  The Hillsdale station is moved north by a quarter mile to straddle 28th Ave, and fitted with a central island platform sized approximately 36 x 700 feet and built 8 inches above the rails.

Vertical circulation to this island platform is provided at the north end (two stairways connecting to the sidewalks on each side of the new 28th Ave underpass) and the south end of the station (a new pedestrian tunnel with one stairway and one wheelchair ramp).  In cross section, the new Hillsdale might look like this:

Of course, the accelerated schedule for its completion is closely linked to electrification, so quite soon thereafter it might look like this, with mixed diesel and EMU service.  Note that per Caltrain plans, the overhead contact system is 22 feet above the rails. plenty to clear even the tallest freight cars.
It's not too difficult to guess what happens when the blended system overtake tracks are built: the new platform and all associated vertical circulation (stairs and ramp) will be demolished, to be replaced by a pair of new express tracks right down the middle of the corridor.  A first phase of this "New New Hillsdale" station would like this, hopefully with level boarding platforms.  Note the new portal configuration of the overhead electrification, to span across four tracks and two platforms without placing poles close to the edge of the new platforms:
After demolition of the "New Hillsdale" island platform, the original 48-foot track centers allow for two additional overtake tracks and a central fence (track spacing 15 + 18 + 15 feet) to prevent passengers from crossing between the two new side platforms of the "New New Hillsdale."  Including stairs, the "New New" station is 106 feet wide and looks as much as possible like any station on Amtrak's Northeast Corridor.  It could almost be mistaken for Princeton Junction:
While it's a fine idea to build the new grade separation sufficiently wide for four tracks, demolishing the "New Hillsdale" station only to replace it so soon with a "New New Hillsdale" seems terribly wasteful. Perhaps this is another case of "why build it right when you can build it twice?" Surely there is a better way.

Rebuilding Hillsdale Once and for All

There's a much better way to build the New Hillsdale once and for all.  It initially looks like this:
Note the central island platform is a full-height level boarding platform, disguised for now as an 8-inch platform by raising the track bed by 51 - 8 = 43 inches using a thicker-than-usual layer of ballast. The final footprint of this station, which will ultimately have the HSR overtake tracks on the outside, is less than 100 feet wide at the platform. The footprint will never change; all the concrete has been poured and not another cubic yard is needed in the future. Soon after electrification, mixed EMU and diesel service would look like this:
The overhead contact system is built in its final configuration 22 feet above the eventual height of the tracks; because the tracks are raised by 43 inches, the vertical clearance is temporarily reduced to 18' 5" which still safely accommodates Plate F freight cars, the tallest that have historically been used in this part of the corridor.  Therefore, there is no constraint to freight service.  This electrification will never change, with all the portals in their final configuration.

When all the diesels are gone and it's time to transition to level boarding, a track maintenance project takes place over a weekend.  43 inches of ballast are removed from under the tracks, using standard track maintenance machines.  The rails are never even disconnected.  (Not to be too flippant, this is still a major track maintenance operation that would require sophisticated planning and modern high-capacity machinery; but it is certainly within the realm of what Caltrain has done before.) Minor lateral adjustments are made to track and overhead contact system alignment, yielding this for the Monday morning rush:
Not a single cubic yard of concrete is required either to convert to level boarding, or to add the overtake tracks once HSR service begins on the peninsula.  The final blended system configuration is ultimately this:
Built once, and built right!

That FSSF Thing

Placing the express overtake tracks on the outside, in a fast-slow-slow-fast or FSSF configuration, as opposed to the traditional slow-fast-fast-slow or SFFS configuration inspired by road design, is a key architectural decision for the blended system.  The forces of traditionalism will argue strongly for SFFS because that's how it's "always" done, yielding nice straight express tracks down the middle of the corridor-- but clear exceptions to this "rule" exist, with examples of FSSF corridors in these videos from Sweden (with 125 mph express trains!) and Australia.

The fatal operational flaw of traditional SFFS corridors is that when a track must be taken out of service, either accidentally or intentionally for maintenance, commuter trains either must cut across the express tracks (fouling express traffic) to reach the opposite platform, or use super awkward bridge plates to board from the fouled express track.  In contrast, an FSSF island platform is operationally flexible: the train simply crosses over to the opposite side of the island, without ever getting in the way of express traffic.  For the peninsula "blended system" where Caltrain and HSR share the corridor, the operational headaches of SFFS could prove unworkable in the long run as the rail corridor is maintained.

One argument systematically trotted out against FSSF is this: wowing express trains around the outside of every island platform will make for a slalom "barf ride" that will give HSR passengers motion sickness, if not downright whiplash.  This argument intuitively rings true, but turns out to be patently false when you run the numbers.  In reality, an express train blasting around the Hillsdale island platform at 125 mph will do so on curves with a radius greater than four miles, requiring just 2 inches of superelevation to be rendered imperceptible to passengers.

Download FSSF island platform plans
for every station on the Caltrain corridor
(3.3 MB PDF, see page 9 for Hillsdale)
Another argument leveled against FSSF is that the island platform arrangement requires additional right of way compared to a traditional SFFS outside platform arrangement.  The footprint of a FSSF station can be made nearly as compact as a SFFS station, especially if the central island platform (shown in the above diagrams at 33 feet wide) is slightly tapered at its ends, yielding an imperceptibly curved platform that is for all practical engineering purposes the same thing as a tangent (straight) platform. In any case, the available right of way at the Hillsdale location is a generous 150 feet wide, making such footprint considerations moot.

The Takeaways
  • DON'T rebuilt infrastructure multiple times.
  • DO build it once and build it right, in its final configuration
  • DON'T build station platforms that are not compatible with level boarding, where this can be avoided.
  • DO create the Caltrain engineering standards for level boarding.
  • DO build the new Hillsdale station with a level boarding platform, years before the transition to level boarding occurs, by temporarily raising the track bed to make the platform only 8" tall.
  • DO build the new Hillsdale station as an island platform, even after high-speed overtake tracks are added
  • DO put the high speed tracks on the outside, in the FSSF configuration, for operational flexibility.

25 July 2016

Steaming Pile of CBOSS

CBOSS, the Communications Based Overlay Signal System, is a Positive Train Control (PTC) system being developed by Caltrain to prevent human error from killing or maiming passengers or rail workers.  It is a deeply troubled project.  Caltrain recently requested a peer review of the project from APTA, the American Public Transportation Association, whose subject matter experts were given access to personnel and documents.

Download the final report from the peer review here (500 kB PDF).

It's fair to say our worst fears have come true:
  • the project manager does not have the requisite technical experience
  • there is no project schedule, and October 2016 is just another month on the calendar
  • inter-operability requirements and test methods are not defined or agreed upon
  • configuration management is not just out of control, but completely lacking as a process
  • software and network security is an afterthought
  • animosities between project management and the contractor are impeding the resolution of technical issues
  • operator training has not started, and the materials for such do not yet exist
  • weekly top-level status meetings between Caltrain management, the program management consultant, and the contractor had not been occurring
The list of documents reviewed by the panel in Appendix C would make a juicy FOIA request.

A little bird overheard some discussions that do not appear in the APTA final report, because the report is intended to provide only constructive criticism to help Caltrain out of this mess.  It's even uglier than you could have imagined:
  • Parsons Transportation Group (PTG), Caltrain's prime contractor, does not have the right skills mix to manage complex system integration on 13 different subcontracts
  • PTG is fearful that the commercial terms of the CBOSS contract expose them to legal action by Caltrain, contributing to the lack of transparency
  • Subcontractor General Electric (now Alstom) discovered that simply re-using the existing ITCS product wasn't going to work.  The inter-operable version of the product is incurring massive increases of scope that were not accounted for in the original contract
  • Because of the extent of the changes made to ITCS, the FRA is requiring the same certification and type approval process as for a new PTC system, undermining Caltrain's claim to reusing an off-the-shelf technology
  • The FRA has taken the position that Caltrain is really installing two PTC systems, requiring full testing of both I-ITCS and IETMS (the system that will be used by Union Pacific freight trains on the peninsula corridor)
  • Inter-operability means not only allowing IETMS equipment to operate in CBOSS territory, but also allowing CBOSS equipment to operate in IETMS territory, something that Union Pacific has been concerned about testing thoroughly
  • Poor coordination for accessing an operating railroad for system installation and testing has been and continues to be a bottleneck
  • Additional funding is going to be needed, but nobody knows how much more
  • A change of contract operator (currently Transit America Services, Inc, soon coming up for re-bid) would introduce significant program execution risk
  • Getting all the CBOSS-equipped trains into revenue service could take up to 5 months
The already egregious sum of $231 million to cover a measly 51 route-miles with PTC is about to increase significantly, something you would never guess from the latest CBOSS update provided to Caltrain's laissez-faire board of directors.
Fast forwarding to whatever year it eventually takes place, the RSD (Revenue Service Demonstration) will consist of flipping the "on" switch and transforming rush hour into an epic cascade of software glitches reminiscent of the 1998 MUNI Meltdown.  On that day, we will all know that this CBOSS turkey has finally come home to roost, as was foretold way back in 2009.

10 July 2016

The Capacity Problem

These days, Caltrain is breaking a ridership record nearly every month.  Rush hour trains are running with standing-room-only crush loads, measured by Caltrain's statistics as a percentage of seating capacity.  The most recent ridership counts (tallied during the low-ridership season in the first quarter of 2016) showed several trains running at 125% of seated capacity, even after the addition of a sixth car.  Capacity, or the lack of it, is becoming a problem and Caltrain will need to do more about it before 2020.

A montage of what a Caltrain EMU
by Stadler might look like,
based on a photo by Yevgeny Gromov
The recent award of electrification contracts, including an order for sixteen new six-car EMU trains from rail vehicle manufacturer Stadler, has brought this issue to the forefront.  Caltrain's Chief Operating Officer for Rail, Michelle Bouchard, had to concede in front of the Caltrain board of directors that the new EMUs would initially have a lower seat count than the diesel trains they will replace. The argument was that increased capacity could be achieved by increasing train frequency from 5 to 6 trains per peak hour per direction, and ultimately by lengthening the EMUs from 6 cars to 8 cars, something that can be done to an EMU without loss of performance or track capacity, unlike a diesel train.

Here are some thoughts about the capacity problem.

Capacity is measured in people, not seats.  Measuring passenger load factors as a percentage of seated capacity works well for airplanes, but doesn't quite do the trick for a transportation mode where passengers routinely stand.  The design of a train, including the number of seats, the interior layout, and accommodations for standees (handrails, poles, straps, etc.) has an enormous effect on the level of comfort experienced by passengers when the car operates at "125% seated capacity."  In rail vehicle A, filled with seats and with few places to stand, 125% feels uncomfortably crowded.  In rail vehicle B, with a lower seat count and large areas where passengers can comfortably stand, 125% of seated capacity feels just fine. A better metric of the true capacity of a rail vehicle is the number of seats plus some number of standees per unit of usable floor area (typically 4 standees per square meter); with such a metric, "100% capacity" feels like the same crowding regardless of train design.

Load factors over 100% seated capacity are desirable.  While this may be news to the person crushed between two sweaty people in the vestibule of a rush hour train, sizing the train fleet so that everyone can get a seat during the peak leads to a lot of empty seats running around the system or idling in yards during off-peak hours. This can be mitigated by changing the length of train consists (like BART), but unless trains are designed for this to begin with, it can't be done in daily practice.  Caltrain's new fleet of EMUs will not be easily reconfigurable unless two EMUs are coupled together; plans for this are not evident in the train configurations discussed in the EMU Request for Proposals (6 cars and 8 cars).  With fixed train consists, there is necessarily a sweet spot where a balance is achieved between two undesirable conditions: too many bums and not enough seats during the peak, and too many seats and not enough bums off-peak.  That sweet spot will mean peak load factors should very well be over 100% when measured as a fraction of seating capacity.

LIRR M-7 rail car with 5-abreast,
by Lexcie via Wikimedia Commons
Middle seats are seats, too.  The idea of 3+2 seating (five abreast) is usually batted away with a summary argument that passengers don't like middle seats, but it undeniably results in more seating capacity.  The question is, do passengers dislike middle seats more than they dislike standing? Commuter railroads on the East Coast seem to know the answer: the Long Island Rail Road M-7, the Metro North M-8, and the SEPTA Silverliner V, (to cite only the most modern examples) all feature 3+2 seating areas.  If providing seated capacity is so important, and if load factors are going to be measured as a percentage of seated capacity, then that middle seat is worth an easy 25% additional capacity.  The Caltrain EMU contract could be changed to require 3+2 seating; Stadler has already built a 3+2 bi-level EMU for a Russian client.

Fewer seats can actually increase passenger capacity.  If Caltrain stays with 2+2 seating and a lower seat count, the additional space for standees can provide greater passenger capacity if standees are properly accommodated.  The new EMUs should be configured with poles, handrails, grab handles or straps as necessary to allow standees to travel comfortably when no seats are available.  During the platform height transition period when Caltrain will be operating dual boarding heights (two sets of doors), the number of seats will temporarily drop after seats are removed from the high door boarding vestibules.  This may increase the load factor when measured as a percentage of seated capacity, but it will actually increase passenger capacity by opening up more room for standees.  Comfort may suffer, but only temporarily.

Caltrain should find a way to buy 8 car trains right away.  If some trains are already running at 125% seated capacity in 2016 during the winter low season, they are probably running at 150% seated capacity during the summer.  Seasonal load factor will go even higher if ridership continues to increase between now and 2020 when the new EMUs arrive.  By then, even with the entire Caltrain diesel fleet at six cars per train, the system will likely be bursting at the seams.  The step change in service quality thanks to the new EMU fleet will trigger another ridership increase.  Taking into consideration those three factors (high season peak, continued ridership escalation and better EMU service), it seems likely that six-car EMUs will be overcrowded from day one.  If Caltrain can scrape together another ~$150 million (another 7% of the total tab for modernization) to exercise an option on the Stadler contract, all EMUs can enter service in 2020 as 8-car trains.  Short platforms can be dealt with by prohibiting boarding and alighting from the front or rear cars at the few stations that cannot berth a 200-meter train.  An eight-car Stadler KISS with 2+2 seating will accommodate about 750 seated passengers and another 1000 standees.