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Discussion relating to the operations of MTA MetroNorth Railroad including west of Hudson operations and discussion of CtDOT sponsored rail operations such as Shore Line East and the Springfield to New Haven Hartford Line

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 #1536646  by UpperHarlemLine4ever
 
Have noticed 10 and 12 M3 trains on the Harlem line but never more than 8 car M7 trains. Heard that the substations have to be upgraded. Is that the case?
 #1536660  by DutchRailnut
 
correct the M-7's have much higher Horsepower than M-3 (1036 vs 660)
not sure how much was upgraded, but for example near Bronxville there was a trailer type emergency substation for years it would need total replacement.

north of Virginia Road sub stations as build were only for 6 car M-3 trains , later upgraded and voltage raised to be able to run 8 car trains.

below Woodlawn there was some spare capacity and some M-8 trains are run with 10-12 cars (same 1036 hp)
 #1536702  by RearOfSignal
 
On one occasion we ran a 10 car M7 consist to NWP during the evening rush. Had to do a double-take on that one. We usually ran with 10 M3s, so when I saw M7s I thought we would have people sitting in the luggage racks, but was pleasantly surprised to see we somehow had 10 cars.

It was common to move around much longer consists in the yard. Because of large gaps in the 3rd rail on tracks 24 and 25 in Harmon yard leading into the coach shop we would switch out as many as 14 cars of M7s in one cut (Though most of those cars were off the 3rd rail on those tracks). Now that the electric car shop has opened up and the spot tracks have moved to tracks 40 and 41 there isn’t a need to run such long consists, plus there is a more elaborate bug and 3rd rail system leading into the new shop building.
 #1537420  by SeanW
 
RearOfSignal wrote: Sat Mar 14, 2020 6:47 pm On one occasion we ran a 10 car M7 consist to NWP during the evening rush. Had to do a double-take on that one. We usually ran with 10 M3s, so when I saw M7s I thought we would have people sitting in the luggage racks, but was pleasantly surprised to see we somehow had 10 cars.

It was common to move around much longer consists in the yard. Because of large gaps in the 3rd rail on tracks 24 and 25 in Harmon yard leading into the coach shop we would switch out as many as 14 cars of M7s in one cut (Though most of those cars were off the 3rd rail on those tracks). Now that the electric car shop has opened up and the spot tracks have moved to tracks 40 and 41 there isn’t a need to run such long consists, plus there is a more elaborate bug and 3rd rail system leading into the new shop building.
Good to know. But what specifically is a "bug" in this context?
 #1537424  by DutchRailnut
 
keep in mind with yard moves, a AC traction train is not even close to drawing max power.
 #1537427  by dieciduej
 
SeanW wrote: Sun Mar 22, 2020 2:41 pm Good to know. But what specifically is a "bug" in this context?
You can think of it as an extension cord for the 3rd rail power. There are no 3rd rails within a shop facility, henceforth the cars are unpowered. The "bug" is a device that, at least for the MBTA in Boston, that slip on to the contact shoe of a train so that it can be moved into the shop and around the shop. Once the car is in the correct position for working on the bug is disconnected. At that point the car is powered via another extension cord to power the internal systems, lights, HVAC, electronics and so on. I hope that answered your question.

JoeD
 #1537688  by Railhead
 
I never really thought about the power output of the substation as a limitation to train length
Does one substation supply power to all the tracks in one section ? ( four track zone one substation supplies the power to the third rail for all four tracks)
How many train sets do they allow in that section at once ?
If you had four train sets, one on each track, at one time that would require a lot more power then just one train set
Is it based on the timetable or just the maximum number of trains that can be expected in that area at one time
 #1537691  by Backshophoss
 
Each new generation of the M series EMU draws a hair more power than earlier generation,the kicker is the substations were designed
around the M-1's power draw at the time the NW to B North 3rd rail extension on the Harlem line.
The substations were upgraded during the construction of the extension to handle the M-3's,up to 4 pairs(8 cars).
Not sure of the current limit of M-7's or M-8's headed to Brewster.
 #1537725  by RearOfSignal
 
There is no specific limit to trains in a section under normal circumstances. Even if there are several trains in a section, particularly in two track territory like the upper Harlem, the signal system will reduce the speed of the trains, thus reducing the of load the trains are drawing from the traction power system.

The train schedule for certain areas, such as the upper Harlem are designed to space trains so as not to draw too much power. Even still in recent years MNR has bee working to address these problems by upgrading the traction power system in a few places throughout the railroad.