FP10 wrote:Just from being in there I would say the air quality at Back Bay is far worse then the Harvard "yellow train" tunnel. Ive spent a decent amount of time waiting in there and haven't noticed any obvious diesel fumes. Then again the real problem is CO2, which of course is odorless so that may still be an issue. Perhaps the tunnel is constructed in such a way that it naturally ventilates?CO2 is harmless, CO is deadly.
The heavy research of a Seashore member (retired news media tech) revealed that the 3 trackless lines survived not because of any environmental pull by Cambridge, Watertown, or even Belmont, but because of the tunnel. According to his findings, the theory in place is called the piston effect. A vehicle traveling through the tunnel forces air out in front of it and in behind it, similar to a piston in its chamber (this is also very evident in the rail subways). A diesel bus will pollute the air that it's pulling in, but a trackless trolley will force out that pollution while pulling in clean air behind it. Naturally this doesn't eliminate all of the pollutants, but it certainly cuts down. To this we owe the survival of the tracklesses. On a second note, I believe from what I've been told that there is some sort of ventilation in the tunnel now, although I have never seen it.
RailBus63 wrote:I understand that in theory, but in practice it forces a large number of riders to walk a longer distance to a substandard waiting area, which can get very crowded and often forces passengers to stand close to the curb as multiple coaches pass by (none of them going the posted 10 mph speed limit). It's obvious that no one in MBTA management or customer service has ever been a regular 77 rider.The waiting area is no shallower than the rest of the berths in the tunnel, and it's certainly larger than that where the 2 most popular routes from the station pick up (Watertown/Waverly). Making passengers walk a couple hundred extra feet is not detrimental, and is not an issue worthy of creating serious operational difficulties to correct. Again, I often ride the service in question and board at that exact location, which I've done for decades, and never have I been significantly dissatisfied with the set up. If the station is that much of a problem, more passengers would transfer at Porter.
Moderator: Massachusetts Bay Transportation Authority, Brightline Trains
Avatar:3679A (since wrecked)/3623B (now in service as 3636B).
Avatar:3679A (since wrecked)/3623B (now in service as 3636B).