|Plan B: four doors per car.|
Based on a photo by Yevgeny Gromov
Then we need to be prepared for Caltrain Level Boarding Plan B.
By definition, Plan B will never be as good as Plan A. Plan A is a workable compromise solution that would enable a gradual transition to a fully compatible blended system where Caltrain and HSR can share the same station platform tracks with 100% level boarding.
Plan B is to join HSR in their choice of 51" platforms, however misguided it may be. The transition to 51" platforms, from today's 8" platform height, seems at first a much more complicated problem. But is it really? What if you did this to Caltrain's new EMUs?
The train depicted here has two sets of doors, one pair for 51" platforms located on the mid level at the ends of each car, and another pair (quite similar to the Bombardier cars, with two steps up from an 8" platform) on the lower level. This is only a minor tweak to Caltrain's plan, taking advantage of the vehicles to facilitate a gradual transition from today's 8" platforms to level boarding at 51". During the transition to level boarding, only one set of doors opens at each stop, depending on the platform height at that stop.
Because it is a very specific solution, it's easy to shoot full of holes. Plan B elicits a number of objections:
Extra doors take away seating space. Additional vestibule areas will consume the space for at least 16 seats per car, or about 12% of train's overall seating capacity. However, Caltrain already needs better standing areas to handle peak loads, and these vestibules could be a good way to comfortably accommodate standees. The loss of seating could also be compensated by going five-abreast in extra-wide trains.
Extra doors will cause breakdowns. While the overall reliability of a train certainly depends on how many doors it has, the failure rate of any given door is better measured in mean cycles between failures, rather than mean time between failures. There is not a single additional door cycle since only one pair of doors opens at any given stop, so breakdowns and maintenance expenses will certainly not double.
Wheelchairs need the ability to change levels. During the transition, when some platforms are at 8" and others at 51", wheelchairs may need to board and alight at two different heights. A large ADA-compliant bathroom may also need to be placed in the roomy lower level. This implies a requirement for a wheelchair lift inside at least one vehicle in the train. It would be a packaging challenge, but is certainly not unprecedented.
Bicyclists need to navigate interior steps. The large contiguous areas required for efficient bicycle storage (sorting bicycles by destination as is currently the practice) would most likely be located on the lower level. When boarding and alighting at a 51" platform, bicyclists would need to negotiate 3 steps inside the train, possibly while it is moving. This is certainly a challenge, but must be considered in the context of today's situation, where bicyclists have to maneuver inside a moving train to access a 40-bike storage area through a single 3-foot narrow entrance after climbing up four steep steps and turning the corner around a pole--sometimes in the middle of a Giants game crowd. Providing stair gutters in the bicycle car steps (which, by the way, would be longitudinal steps that could be built far less steep than those transverse gallery car steps) could make interior navigation far easier than it is today.
Extra doors will make the trains more expensive. There is no question that this extra complication will lead to extra expense, but the key question is how much? The extra pair of doors will be responsible for perhaps an extra 5% capital cost. On a half-billion-dollar fleet purchase, this amounts to $25 million, an amount that sounds enormous to anyone with a mortgage. But $25 million is a pittance in the context of the thousands of millions (billions!) required to build separate station infrastructure for Caltrain and HSR. The extra cost is a rounding error, and a good case can be made for HSR picking up the compatibility tab.
Trains are difficult to build with that many doors. Structurally speaking, each door opening compromises the strength of the car body structure, reducing its ability to withstand the enormous loads during a train wreck. The crashworthiness of rail cars is highly regulated by the FRA, and achieving compliance for a four-door car could be quite an engineering challenge. This is a question best left for car builders to answer.
So yes, admittedly, Plan B is sub-optimal for a number of reasons as described above. It is quite controversial even among Caltrain advocates, many of whom harbor a visceral dislike of 51" platforms. This dislike goes so far as to lead them to a very strange advocacy position: that Caltrain and HSR should have separate platforms!
As we have often discussed, separate platforms are an operational disaster waiting to happen at San Francisco Transbay, since every inbound Caltrain movement will conflict with every outbound HSR movement. This constraint will limit the capacity and future growth of the blended system. And it's not just a Transbay issue: separate HSR stations at Millbrae, the mid-peninsula, and San Jose will require billions of additional infrastructure spending that would not otherwise be necessary. Is that a better outcome than Plan B?
The Best of the Rest
Supposing Plan A fails and HSR insists on 51" platforms, then Plan B is the best of the rest. It is a simple plan, and a reasonable solution for not precluding common platforms in the future. Anyone who takes issue with it owes a detailed description of their own specific plan to make Caltrain and HSR more compatible.