MNRR Joint EMU Procurement with LIRR - Alt/Successor to EMU

I believe it's power constraints...

MattW wrote:

DutchRailnut wrote:

morris&essex4ever wrote:

khansingh wrote:Does this mean they've ruled out bi-levels?

Were bi-levels ever considered?

yes, MN can only go up, longer trains or more trains are out of the question. GCT is at capacity.

(Should I kick this question to the MNRR forum?)
What are the constraints on longer trains into GCT? Is it simply GCT platform length, or power supply issues elsewhere?

Platform length. GCT has a lot of platforms 10 cars or longer on the centermost groups of tracks on each level. But not nearly enough of them to satisfy future demand, and lengthening is impossible to do at the terminal in any meaningful way. Especially on the lower level, which has a bunch of platforms as short as 4-6 cars. New Haven Line EMU's are probably always going to have to be single-level because of the room taken up underneath by the multiple power inputs, so they are going to bogart more and more of the longest platforms in the future. For Hudson and Harlem EMU's plus the push-pulls there's only one way to substantially increase future capacity without excruciating costs or congestion...go up.

There's also the issue of a whole lot of Harlem intermediate stops having rather short platforms. Except for the stretch of 10-12 car platforms between Mt. Vernon West and N. White Plains, most of Harlem electric territory is 4-8 cars. Even if you beefed up the power draw the crush loads from consists substantially longer than the platforms starts dragging the dwell times longer and longer, and decaying the schedules. You would probably be looking at a price tag in the high 9 figures spread over decades...with a whole lot of local NIMBY sparring matches...to try to get most of those lengthened to 8-12 and keep the lengthening dwell times from front-of-train boarding from slowly choking the line to death. Going vertical with a goodly portion of the fleet saves that agony, and buys more decades of time to slowly overturn those stations on a more regular rotation of renovations. Hudson's in a little better shape with mostly 8-10 car platforms in electric territory. But those are still damn crowded trains that have to compete with New Haven for slots on the longer GCT platforms, so the future need is equally acute.

There are plenty of 10 car or more platforms in GCT, a few lower level platforms could be lengthened as they now extend via yard tracks.
service north of NWP is still restricted to 8 car max M-7/8 due to power constraints. other H&H tracks are not restricted but each every train set at one point goes to Put Jct.

as for New haven I would say they got to be careful till both cables are back, and I hope they force ConEd to put up a second permanent substation near Harrison, plenty of room on right of way.

The power and platforms seem like the obvious first step... And maybe long term signaling that could pack more trains closer together...

If you pack trains closer, even with shorter blocks, it will still slow down railroad.
In and around park ave the blocks are already half of what they should be, freight on MN is already limited to very slow speeds due to signal block length in entire system.
only place where big improvement could be made is NWP to Southeast where block length is such that only 6 minute headway can be obtained.

DutchRailnut wrote:If you pack trains closer, even with shorter blocks, it will still slow down railroad.
In and around park ave the blocks are already half of what they should be, freight on MN is already limited to very slow speeds due to signal block length in entire system.
only place where big improvement could be made is NWP to Southeast where block length is such that only 6 minute headway can be obtained.

Maybe they need to rethink using fixed blocks altogether and move to rolling block PTC.