The T isn't going to block its only path to One-Person Train Ops on the last line that doesn't yet employ it by kneecapping themselves with a permanent operating kludge. That's cutting off your nose to spite your face. PoP implemented fully lets them get rid of the trailing operator and take advantage of the born OPTO capability that's been built into every car they've ordered since 1986 but never used anywhere except non-revenue moves. They can enormously expand service on a smaller staff by doing that and improve their farebox recovery by a big measure. I don't want to hear one peep about cushy union jobs in the rapid transit div. ever again if we're so hot to de-loop the Central Subway that workplace efficiency is the barter we're permanently giving up. Understand what the forever-and-ever implication is there.Correct me if I'm wrong, there is one operator for each trolley car and no plans to change that. Each operator simply needs to go to the other end of the car they are operating. And when type 10s are here, which is what this is planning for, a lot more trains will run as single type 10s or 9/10 combos which the same each operator moving to the end of their car would apply.
Also...major correction here. . .
Type 10's are going to run as two-car trains most of the time per the GLT horse's mouth as told to the FCMB. Consist sizes are not going to change with the new fleet, making the pursuit of Green Line OPTO ever more a high existential priority. The T is not--and, as we'll see, cannot--make this purchase with a goal of dividing their consist lengths in half. It will be running stretched pairs with double the capacity--2 'supercars' equaling the seating/standee capacity of a 4-car Type 7/8/9 train--as an ironclad prerequisite for all the other big improvements they're doing. Because some of those improvements have other tradeoffs that need to be traded back into balance. The next-gen signal system with auto speed/stop enforcement and computer-primary dispatching won't be able to space trains as closely as today's human-operated single-file. The only way to maintain and ultimately increase Central Subway bandwidth with smidge longer spacing is by aggressively attacking dwell times (and their drag effect on schedules) with more doors, seating, and aisle space per train. This works hand-in-hand with surface PoP and transit priority to solve the "garbage in, garbage out" problem of bunching where branches meet at Kenmore and Copley, so total throughput can be backfilled with more slots at less padding and many fewer canceled trips from late/bunched prior headways aborting the next headway from schedule correction. X feet further spacing on the single-file by not having the human always touching the throttle conversely ends up counterintuitively increasing throughput by being able to slash back schedule padding to the bone. But you need the extra seating capacity to go that hyper-aggressive at the slack padding, so it can't be done by laterally trading over to singlets everywhere but the peakiest-of-peak.
None of it works if train capacity stays near-static to today; the onboard threshold has to get busted through to a whole new level to make this new GLT ops paradigm work. It ends up being a step backwards when the train spacing has to increase and fleet management ends up too target-fixated on minimum-most cars/seating to physically do the job. Supersizing slashes the dwells and (more than) makes up the difference. Therefore, all peak-period trains on all branches will eventually be 2-car 'supertrains' once the backlog of platforms are lengthened. And tame the backlog they must...because this isn't going to work as well as intended if the B and C are malingering for 10 years behind schedule on platform lengthenings.
It also means...yeah, OPTO is also not optional for GLT once they get their PoP game honed enough to leave the rear car's cabin vacant. They need that in order to muscle the human resources around efficiently in this whole new way of doing things.
The only time singlets are going to dominate the service ranks are on the far off-peak when dwells are a total non-factor and headways are usually longer making the train spacing balancing act ^^above^^ moot. Neato...the night shift will cost an insignificant few bucks less to operate. But far off-peak is also when short-turning goes quiet, so running singlets does nothing for speeding up in-car end changes. Everything's running to the ends of branches, little to nothing is turning at loops or crossovers, and they have all the time in the world to do it because headways are throttled-back. Singlet supertrains aren't going to buy us any tangible flex where we need it most. Any time headways are running at full-throttle but loads are not, like the mid-afternoon a couple hours before the peak shift...you're probably still going to see that 2-car service baseline set by the new default train spacing. Short-turn augmentation, on the other hand, is almost entirely a peak-period thing when absolutely everything will be running at 2-car...so we still have to mind our future considerations before getting all demolition-happy with the loops and downtown turnbacks. An end change move time of day when shortie patterns are online is going to be in an OPTO universe where walking outside the train is the only way it can be physically done.
They're putting on such an enormous PR front to explain this to the public because the reasons for supercars require more explanation than just face value. "Divide cars by 2 = SAVINGS!" is what the public's going to assume on-spec. It's not an accurate assumption at all, and not even one-tenth the story of how freaking BIG a sea change GLT is seeking in the operating rules of the Green Line as we've ever known it. The entire service balance is going to be completely different after this, and the supertrains are merely one cog in a whole bunch of other interdependent stuff trading off amongst each other to achieve that new and better service balance. You can't get the full picture of what they're going for by looking at just one cog in a contextual vacuum. If "more singlets = progress" is your first takeaway...STOP...Google for the last GLT public meeting slides...and re-educate. That ain't even the half of it.