• #14 Orange Line Cars 1400-1551 (From Red/Orange Procurement discussion)

  • 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: CRail, sery2831

  by octr202
 
T hints that Orange Line cars may return to service in the next few weeks:

https://commonwealthmagazine.org/transp ... ng-tested/
  by TurningOfTheWheel
 
The new cars likely have a higher peak current flow than the existing ones (more power for acceleration/regen), so the T may be waiting to complete the electrical substation refurbishments before releasing all of the new fleet onto the line.*

*Complete guess on my part!
  by CRail
 
New equipment also puts power back into the overhead when it's in regenerative braking rather than just burn it off in grids, so a train slowing down can help power a train starting up. They're actually more efficient than the older cars. To your point, however, to run a mix of trains that consume more power on takeoff with ones that don't give power back when braking is likely to put additional strain on the substations.
  by TurningOfTheWheel
 
CRail wrote: Mon Dec 27, 2021 7:16 pm New equipment also puts power back into the overhead when it's in regenerative braking rather than just burn it off in grids, so a train slowing down can help power a train starting up. They're actually more efficient than the older cars. To your point, however, to run a mix of trains that consume more power on takeoff with ones that don't give power back when braking is likely to put additional strain on the substations.
The strain on the system was more of my point. There will be more current flowing through the rails if the new cars are both drawing more power at acceleration and putting (some of) it back into the system on deceleration (hence my reference to "regen", sorry if that was unclear).
  by CRail
 
The capacity issue is in what the power station can put out, not in what can flow through the infrastructure. Having regenerative braking put power back into the overhead (third rail, conduit, w/e...) puts less of a strain on the system, not more.
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