"the majority [of heat comes] from the train hitting the brakes as it pulls into the station, an intense friction that gives off an exorbitant amount of warm air."
I wonder if regenerative brakes can be installed (or are already installed...)
I wonder if regenerative brakes can be installed (or are already installed...)
https://en.wikipedia.org/wiki/Platform_screen_doors
Seems like they'd keep heat from the train from making its way onto the platform. And if platforms are air-conditioned, they'd keep that air from escaping into the tunnels.
And of course they can also help with safety.
Realistically by the time you are even close to half the 470 stations it will be late 2020's anyway. Then you can aim for full coverage as the stock is deprecated.
It is more likely the $1-2 million per station cost is not high priority as say CBTC which will improve revenue as it increases capacity.
The problem is also too large to segregate. We are talking about a third of the current fleet that is not compatible with new train door placements. Even after the oldest of these are retired with projected future train orders, it will be about a tenth of the fleet, larger than the entire Boston T rapid transit fleet.
You could either add extra platform doors or make platform doors that are wider than the train doors and open part way to match the train.
Unfortunately, if cars have different lengths, it increases permutations a lot. But you could handle even that by building a wall made entirely of doors (staggered on two door tracks), so the gap between any two doors can open up to any desired width.