01 December 2019

Three Next Steps

Caltrain's exhaustive business plan effort has resulted in a long range service vision for how to grow the railroad to the year 2040, recently adopted by the board as official policy. This is the mountain we wish to climb. How do we climb it? One step at a time. In fact, with electrified service now unlikely to begin before 2023, there is extra time to plan and execute three next steps.

Step One: Extend Platforms

The biggest short-term constraint to growing Caltrain capacity is  limited platform length. The new EMUs will be 685 feet long when extended to eight cars, too long for many existing platforms. The existing platform lengths are shown in the graphic at right (source), with the required extensions to 700 feet highlighted in orange. The diagram shows the year of construction of each platform, proving that Caltrain is a champion of platform construction, having poured about five linear miles of new platforms over the last two decades. The amount missing is about 3500 linear feet, or a bit over two years' worth of average platform production. There are a couple of tight spots boxed in by grade crossings, most notably Burlingame (767 feet between pedestrian crossings), but most locations have plenty of space.

Longer platforms enable the operation of 7-car diesel express trains, each with about 950 seats. While diesel trains don't feature prominently in future plans, they can still fill an important interim role once they become freed up by the arrival of the EMU fleet. The diesels can easily handle longer trains. It may not look good to continue belching diesel fumes, but it gets the job done at far lower emissions per passenger-mile than by forcing unmet demand to drive instead.

At the recent going rate of 7 to 10 thousand dollars per linear foot of platform, including all capital project overheads, the entire job should cost in the range of $25 - $35 million. For perspective, that's a percent or two of the modernization budget. This project is within reach of Caltrain's existing resources and is now official policy under section (1).E.ii of the service vision. There is no plausible excuse for not undertaking it immediately, to finish by 2023 concurrently with the start of electrified revenue service.

Step Two: Add 8th Car to EMU Fleet

The EMU order currently stands at 19 seven-car trains. The seventh car was ordered in a recent exercise of an option on the original contract, at an average price of $4.7 million per car. Assuming 10% price escalation, another 19 cars to extend this fleet to 8 cars would cost about $100M. This is a large sum, but one that could be scraped together over the next year or so if some high-speed rail funding gets re-allocated to interconnected "book end" projects.

The eighth car represents a significant step up in capacity: since it has no traction equipment cabinets, bike spaces or bathrooms, it has room for a whopping 132 seats, bringing seated capacity per EMU from 667 to 799, a 20% increase. So, for an extra 5% of the modernization budget, you buy an extra 20% capacity. This should be undertaken as soon as possible.

From an emissions point of view, ordering the eighth car is far preferable to ordering additional 7-car EMU formations to displace the diesel fleet sooner. Growing the fleet before fully replacing it provides a short-term peak-hour capacity boost that will remove traffic from roads and alleviate congestion, easily offsetting the emissions of the small remaining diesel-hauled fleet. Going all-electric sooner sounds "green" if you look at Caltrain in isolation, but keeping some diesels in the short term is greener when considering the overall transportation system of which Caltrain is a part, which is what ultimately matters for the air we breathe. Seven-car diesels can be used exclusively in express service, where fewer stops and starts (which are dreadfully slow with diesel) pose less of a time penalty.

There is the small wrinkle of where to park these longer trains when they are not in service. CEMOF, the maintenance facility in San Jose, currently stores two trains end-to-end on four 1200-foot sidings where two longer trains (EMU-8 at 685 ft, or diesel+7 at 664 ft) won't fit. This means at least four trains will need to be stored somewhere else, presumably at San Francisco or San Jose, as was the practice before CEMOF was built. In a real pinch, trains can be stored during the off-peak in the controlled sidings south of Redwood Junction, with certain shoulder-of-peak trains originating and terminating at Redwood City to avoid long deadhead moves.

Step Three: Accelerate Planning for Level Boarding

Level boarding (discussed extensively on this blog) decreases trip times, improves punctuality, increases crew productivity per hour of labor, and increases the frequency of service that can be provided by a train fleet of a given size. While Caltrain's embrace of the concept has been hesitant, it is now policy under the same section (1).E.ii of the service vision adopted by the board. The next step is to get serious about planning how to actually do it, because it is a far more complicated problem than it first appears.

Caltrain staff have decided to forgo boarding using the high-level doors, and recently issued a change order to have the EMU fleet delivered with these doors replaced by plug panels. Level boarding will happen with European-style 550 mm platforms, which can't be a bad thing, although accessibility requirements are more difficult to meet in the United States. The trick is then how to get there, and how to end up with a level boarding solution that doesn't require crew assistance whenever a person of reduced mobility needs to board or alight, in the current inefficient fashion of Northeastern railroads.

The trains will require a boarding step arrangement that deploys to serve either 8-inch legacy platforms (using a drop step mechanism) or to close the gap to newly raised 550 mm platforms, during an extended transition period where some stations may have been modified before others. Due to a lack of foresight on Caltrain's part, this capability is not available on the new EMUs as procured. The EMUs will need to be retrofitted with new three-position step modules (presumably engineered by Stadler's step supplier, Bode / Schaltbau) roughly like this:

The primary engineering challenge is to meet the ADA horizontal gap requirement in Position 2, which is 3 inches maximum (in current law) and is planned to be reduced to 2 inches. The step mechanism must also deploy to the correct height without crew intervention.

The platforms will need to be raised by a bit less than 14 inches, preferably without demolishing and starting over. One intriguing way to do this cheaply and with minimal service disruption would be to re-use the existing platforms as a slab foundation, with drainage, electrical grounding and bonding, and utilities staying as they are. The platforms would first be fitted with prefabricated adjustable edge modules. An adjustable platform edge that can be jacked to the correct height at initial installation and periodically adjusted during maintenance (e.g. after track tamping) is an unavoidable requirement of meeting the demanding ADA gap specifications for unassisted level boarding.

View of a single six-foot-long 550-mm platform edge module installed on a legacy 8” platform
After suitable modifications to platform amenities, the remaining area of the platform would be raised using lightweight expanded polystyrene fill (Geofoam) and modular pavers. The pavers cover the temporary boarding step that is integral to each edge module, which is no longer needed. The resiliency of the resulting platform structure enables periodic adjustment of the platform edge jackscrews to maintain compliance with the ADA gap criteria.

The modular construction technique with edge modules and pavers lends itself to rapid “blitz” construction schedules, since no platform concrete curing is necessary. After each night's construction, the platform can be left in a usable state for the next day's service, avoiding the logistical complications of closing entire platforms during construction.

Regardless of the technical solution ultimately adopted, level boarding starts with a robust planning process to define the problem and consider all the engineering approaches. This planning process is not expensive, and it needs to be funded and staffed now that level boarding is policy.

State of Good Design

Railroad operating departments work hard to achieve and maintain what is known in industry lingo as a state of good repair (SOGR). If that's all that Caltrain is going to do in the next decade, electrification will fall flat, like a sort of MBTA with pantographs on top. We have a chance to move beyond the narrow commuter-rail SOGR mindset, striving for something far bigger: a state of good design. The three next steps described here are a small way to get started right now on the way to the visionary service improvements described in Caltrain's business plan.