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  • Discussion relating to commuter rail, light rail, and subway operations of the MBTA.
Discussion relating to commuter rail, light rail, and subway operations of the MBTA.

Moderators: sery2831, CRail

 #1627630  by MBTA3247
 
diburning wrote: Wed Aug 16, 2023 7:51 am
jwhite07 wrote: Mon Aug 14, 2023 5:40 amdiburning - B Line splitting trains just before Lake Street? I can't understand that one. Maybe some kind of operational restriction against coupled trains running through the yard or around the loop? Do they re-couple them into trains at the loading platform heading inbound or somewhere else?
No operational restriction on pairs going through the loop. They park them in the yard uncoupled as well, so that might be why? To not have to uncouple on curved track? What I described only appears to occur on Saturday/Sunday evenings with two-car trains.
What you've neglected to mention, is what happens to each car after they uncouple? Are they both sent into the yard? Or does one go into the yard and one go around the loop to make a single-car trip downtown? Or something else?
 #1627634  by ExCon90
 
The next--to-last suggestion seems the most likely possibility if it consistently happens around the end of the peak and not at other times.
 #1627638  by typesix
 
The trains are split before Lake st later at night so Type 7s are stored and Type 8s will be used as singles in service. They are split before the yard for convenience. Type 7s are no longer allowed in service as singles because of their high floors.
 #1627643  by jwhite07
 
That makes sense. Allows for less staffing late at night too... once upon a time ridership was consistently high all day every day and they could rarely do that, apparently now they can.
 #1627645  by diburning
 
MBTA3247 wrote: Thu Aug 17, 2023 7:32 pm
diburning wrote: Wed Aug 16, 2023 7:51 am
jwhite07 wrote: Mon Aug 14, 2023 5:40 amdiburning - B Line splitting trains just before Lake Street? I can't understand that one. Maybe some kind of operational restriction against coupled trains running through the yard or around the loop? Do they re-couple them into trains at the loading platform heading inbound or somewhere else?
No operational restriction on pairs going through the loop. They park them in the yard uncoupled as well, so that might be why? To not have to uncouple on curved track? What I described only appears to occur on Saturday/Sunday evenings with two-car trains.
What you've neglected to mention, is what happens to each car after they uncouple? Are they both sent into the yard? Or does one go into the yard and one go around the loop to make a single-car trip downtown? Or something else?
They both go into the yard. Some of them may loop, but there's usually more trains arriving than trains departing.
 #1627851  by HenryAlan
 
caduceus wrote: Sun Aug 13, 2023 4:08 pm I remember them joining two green line cars - I think both Type 7s - at the inbound side of North Station Elevated, probably in the 2003-2004 timeframe. Why they weren't joined out of Lechmere to begin with I don't know.
I remember a few times in the late 80s or early 90s, being on a train that was split at Gov't Center, with one car being sent back toward Park, while the other continued toward Lechmere. I doubt it was scheduled that way, but it certainly happened from time to time.
 #1627867  by Disney Guy
 
Two separate cars coupled together at (the old) North Station inbound.

1. If they were both going to the same destination then a no-brainer to, if possible, couple them together just for coming together, which would reduce subway congestion.
2. An operator was going to swing off and the other operator gets in the front car with the rear car empty/emptied.
3. The second car developed an almost incapacitating defect and the operator of the first told to wait up for it at the next station (here, North Station) to drag it home.

"" train that was split at Gov't Center, with one car being sent back toward Park, while the other continued toward ""

Handling a westbound gap in service (or sudden crowd) without creating a gap in northbound service. Due to street traffic delays I am not surprised that fancy footwork is needed in the central subway every now and then to smooth out gaps in service.

Some additional complexity for such things as (back then) only the E line normally serving Lechmere and a big delay on Huntington Ave. Then commandeer all or half of, say, a B train to go to Lechmere but the operator has to be qualified for and have shift time to do that and maybe also do Heath St.

The same kind of run as directed can be done on the SL1-SL2-SL3 Silver Line routes but it is not quite as complicated since the three routes have the same downtown terminus.\
 #1628171  by CRail
 
Closed for housekeeping. Way to many nesting quotes and way off topic.