28 July 2019

Emergency Exit Fail

Caltrain's new EMU train cars have an unusual configuration with two sets of doors. The lower level doors will be used at existing Caltrain stations, while the intermediate level doors (above the wheels at the ends of each car) are intended to be used at an undetermined date in the 2030s once these trains begin sharing stations with California high-speed rail, which will use high-floor trains and high platforms with boarding at about 50" above the rail. The California High-Speed Rail Authority, which Caltrain cryptically refers to as "external stakeholders," required this design feature as a condition of funding Caltrain's modernization to the tune of $750M, to maintain the option of sharing platforms at future HSR stations in San Francisco, Millbrae and San Jose.

The Original Plan

To maximize the short-term seating capacity of the new trains until the 2030s, Caltrain specified that the intermediate level should have temporary flip-up seats installed in front of the unused doors, five per door vestibule, with the seating blocking off the doors like this:
Configuration of intermediate level in A, B, C, E, and G cars
Because EMU cars are filled with electrical cabinets (labeled with yellow lightning bolts), the seating capacity of the train is reduced compared to a conventional train. This is the price you pay for not having a locomotive; all the bits that make the train go still need to find a place, which makes for a challenging packaging problem in a bi-level train. The reduced seating capacity of the train has been controversial and makes these temporary seats quite important. For each 7-car train, there are 70 of these intermediate level flip-up seats that make up a non-trivial 10% of the overall seating capacity of 667.

At some undetermined future date when the intermediate doors would be needed for compatibility with high platforms, the blue flip-up seating modules would be removed from the intermediate level.

A Regulatory Conundrum

In the design of any new train, federal safety regulations require that any passenger seating compartment be fitted with at least two emergency exit windows (for passenger egress) and two rescue access windows (for first responder ingress). The intermediate level counts as a passenger compartment because these flip-up seats are located within it. However, the intermediate level does not have what regulations consider to be a window; the only opening to the outside is through the doors. This set up a conflict with safety regulations.

In late 2017, Caltrain petitioned the Federal Railroad Administration for a waiver (docket FRA-2018-0003) by arguing that the emergency release feature of the doors would provide an equivalent level of safety, despite not meeting the letter of the regulation, allowing emergency access by climbing over the seat backs.

In June 2018, the FRA denied Caltrain's request because the flip-up seating installed longitudinally such that it blocks the doors could impede egress and access and therefore did not meet the intent of the regulation. The FRA stated that "the absence of need for these intermediate level doors to support current revenue boarding and alighting requirements does not negate the necessity for an unobstructed path in the event of an emergency." Curiously, this unobstructed path requirement applies only to doors, not to windows!

Implicitly, Solution A is to remove all seating from the intermediate level of the affected cars, which effectively sidesteps the emergency window requirement. But given that seating in Caltrain's EMUs is already quite limited, this solution seems like a non-starter as it would reduce seating capacity of a 7-car train by 9% from 667 seats to just 617 seats.
Solution A: not a passenger seating compartment
The FRA helpfully suggested some other possibilities.

Solution B: equip the intermediate level doors with a regulation-size emergency window of minimum dimensions 26" wide by 24" high. Unfortunately, that is too large for the dual-leaf design of the train doors; in other words, the window in each door leaf is too narrow to function as an emergency window.
Solution B: the minimum clear opening is too big for dual-leaf doors
Solution C: replace the intermediate level doors with a plug panel (essentially, a structural wall panel that does not function as a door) fitted with a regulation-size emergency window of minimum dimensions 26" wide by 24" high, until such time as the door-blocking seating is removed, the panel is removed, and the doors and platform bridge plates are re-installed.

Solution C: doors replaced by plug panels
Caltrain is now in the process of pursuing Solution C, plug panels. This change order is expected to cost about $4 million total up front, about $30000 per car, or $7000 per door. When intermediate-level doors are required a decade or more from now, a net sum of approximately another $10 million ($14 million future installation cost to be set aside, minus $4 million of door maintenance savings) would be needed to retrofit them. That is a LOT of money for a change that fundamentally reduces and complicates compatibility with HSR stations and platforms.

Other Solutions

There are other solutions that strike a better balance of functionality and simplicity without a seven-figure cost impact.

Solution D: short of removing all the seating from the intermediate level vestibule, the regulations require only one emergency window (instead of two) if there are four or fewer seats in the compartment. Removing seats from one side only and applying for a new waiver to allow unobstructed use of one of the doors in lieu of a single emergency window could work, addressing the FRA's stated concern with door obstruction. This would reduce seating capacity of a 7-car train by just 22 seats or 3% (5 seats lost in cars A and B, and 4 seats lost in cars C, E and G).
Solution D: reduced seating with unobstructed emergency access
Solution E: reconfigure the mounting bracket for the flip-up seating so that seats flip up and out of the way of the doors when not used, allowing the unimpeded use of both doors in lieu of emergency windows. This solution requires applying for a new waiver to allow the use of doors in lieu of emergency windows, but also addresses the FRA's stated concern with door obstruction. Placing the flip up seats in this manner would reduce the clear width of the door opening by a couple of inches on each side, from 51" to about 47", with no reduction to seating capacity.
Solution E: change flip-up seating orientation to provide unobstructed door access
(flip-up seats are shown in use; they fold flush against wall when not occupied)
Solution E would require no modifications whatsoever when the intermediate level doors are needed in the future, and could be implemented at all doors throughout the train including the lower level, adding seating capacity. Seats placed in doorways may sound like a bad idea, but in a crowded train, social signaling fairly quickly communicates to occupants of these seats that it's time to stand up and make way. This is the French "strapontin" seating in common use on some of the busiest rail lines in Paris:

Flip-up seats in a doorway of a brand new Bombardier EMU on Paris RER line D.
(foreground at left) credit: Wikipedia / KiHa 52
Indeed, the photo above, taken inside the same Bombardier EMU often vaunted in front of the Caltrain board by a certain member of the public as having so much more seating than Stadler's EMU, shows one of the secrets of achieving very high seating densities: flip-up seating in all doorways. The other three secrets are five-abreast seating, not having as much space dedicated to bikes, and lower acceleration performance that requires fewer electrical cabinets, leaving more space for seats. After adjusting for these four factors, it turns out that the Bombardier EMU provides no higher seating density than the Stadler EMU.

Ultimately, it is entirely possible that Caltrain simply does not wish to interface with high-speed rail in any station as a matter of policy, because it would require sharing and collaborating with another agency, and solving a somewhat complicated ADA compliance problem. Which agency would voluntarily bring that upon itself? Caltrain already took the HSR money, and installing plugs will "erase" the clunky and unpalatable concession they made in the name of compatibility, with the further bonus of not requiring another run at the FRA for a new waiver. The complicated ADA compliance issues associated with interior lifts are kicked as far down the road as possible!

No matter how you look at it, Caltrain's chosen approach is a ~$15 million mistake that reduces and complicates compatibility with HSR stations and platforms. There are cheaper, simpler and easier ways to achieve compliance with emergency window regulations. It's not too late to change course.