• MLV EMU Procurement

  • Discussion related to New Jersey Transit rail and light rail operations.
Discussion related to New Jersey Transit rail and light rail operations.

Moderators: lensovet, nick11a, Kaback9

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  by DutchRailnut
 
Having EMU's geared for 90 mph makes way more sense than having them geared for 110 or 125 Mph.
on EMU's the advantage is getting in and out of stations fast, which can only be done with correct gearing or immense amounts of power.
Running 35 mph faster between stations would not gain you much if it takes you twice as long to get to the max speed.
  by amtrakowitz
 
Amtrak still needs sets that can keep the schedule on Thanksgiving Day specials though, i.e. when it comes time to borrow same.
  by Matt Johnson
 
morris&essex4ever wrote:
amtrakowitz wrote:I didn't mention Trenton Expresses. The 47-mph average speed was for Trenton Locals, which were more prevalent in the past than expresses. And what expresses there were did have a faster average speed than nowadays, frankly.
Did they really?
Having ridden an express train between Newark and Princeton Junction a number of times, my experience is that there's a bit of padding. If we ran at track speed the whole way we'd get into PJ a little early. Throw in a delay or two, maybe a couple of track switches and some restricted speed running, and they can still sometimes make that schedule.
  by DutchRailnut
 
amtrakowitz wrote:Amtrak still needs sets that can keep the schedule on Thanksgiving Day specials though, i.e. when it comes time to borrow same.

Amtrak has had no trouble borrowing 80 mph NJT MU sets before, so 90 mph would be improvement ;-)
  by 25Hz
 
Since the max speed of the outer tracks is 110 they should be geared for at least that. It would be foolish not to take advantage of getting the slowest rolling stock out of the way to make a tighter schedule. Lets face it, there's no way even properly rebuilt arrows are going 110.

90 may be EMU start-stop favorable, but right now everything is 100 mph capable aside from the arrows, and everything is designed for faster aside from maybe the PL42's. I think the PL42's max out at 105 if i remember reading their njt spec sheet from several years ago. Plus some of them will be used on nyp-nwk-pjct super-expresses.

Plus there's the upcoming amtrak "speedway" upgrades for a large chunk of the NEC in NJ.

In any case, if you're going to reinvent the wheel, why not make it one that goes faster? ;)
  by DutchRailnut
 
cause your not re inventing the wheel, by gearing the cars for 110 you would need nearly 50% more power than same equipment at 90 mph, and no room on ML power car to put that kind of power.
It will still have hard time getting to 110 mph and on average only do 45 to 60 mph by gearing it at 90 and attaining 90 you will have a faster train.
  by Nasadowsk
 
Dutch is right - if you look at EMUs around the world, they all max out at 80 - 100, and most are on the 'slow' side. But they accelerate quickly to that speed.

Off the NEC, 110mph is worthless anyway. It's better to design for acceleration than top speed. That's what EMUs are best at anyway.
  by Fan Railer
 
What they need in the future is a CVT type gear transmission for railways applications. Might not be feasible at the moment, but if someone, or some company could find the right design and the combinations of materials that could withstand the forces that would be going through the gearbox, then it would be a major improvement in terms of being able to balance high acceleration with a higher operating speed.
  by 25Hz
 
I still think 90 is too slow. On a 12 car train you have plenty of braking ability, and maybe instead of:

a-b-b-a-a-b-b-a-a-b-b-a
you could do
a-a-b-a-a-b-b-a-a-a-b-a

This way you have maximum acceleration with minimal seat loss.

It also makes no sense to have these power cars towing around coaches that can go faster than the power car.

One of the ways to increase capacity without increasing tunnels or tracks is to speed the trains up.
  by Jtgshu
 
A large portion of the NEC is only 90mph on the outer tracks for NJT equipment. Its 90 all the way to County on track 4, and 90 east of Lincoln on track 1. Even if it was 100 inbetween the "middle zone" stops, (Metro-Jersey Ave) trains aren't going to get much faster than that anyway before having to slow down. You could do it, but it would be a minimal distance before having to put the brakes on, which would have to be further back than it is now because the speeds are higher.

Sure it would help expresses, but the signal progressions to slow down for crossing back over would really eat up and time savings.

If the NEC had the capacity where trains weren't catching up to each other or being held out for overtakings places or held outside of stations for another train to make a stop, where max speed would really be the only limit to how fast to get from A to B, id say go for it, but because of reality and how things really work out there, it makes no sense to sacrifice other areas of performance for a relatively few trains to enjoy these benefits.

Its the same thing as to why the Geeps are geared for 100mph. Thats all well and good that they can do that, but they would be so much faster if they were limited to 80mph as they would perform much better at slower speeds where they are operating 95 percent of the time. So what if the trailers can go 100 or faster. The ALPs can/maybe will be able to go faster, so its not like that allowed higher speed is going to go to waste.

Anyway, I think we would find that the MUs would be mroe for the Hoboken side rather than the Newark side. Im sure there would still be some on the Newark side, but they are still very ideal on the MandE and Gladstone Branch. If that were the case, then more than 90mph would really be a waste.

Im still trying to figure out why/how PL42s came into this discussion?

And the a-b-b-a-a-b-b-a (etc) made me think of "Dancing Queen"......thanks.........now that stupid song is in my head.........
  by 25Hz
 
Just saying that all of the new equipment is 100 mph, and would be except these. Makes no sense to order a crazy batch of never before tried equipment and then limit their speed just because of some technical theory. The arrows are geared for 100 aren't they? They seem to do fine.

Not my fault you have visions of trainsets dancing in your head! :p
  by ryanov
 
25Hz wrote:Looking at that photo & taking what you said JT i think i solved most of the problems... You'd only lose 16 seats (8 of which are often unoccupied due to ergonomics)
That's not really true. The seats are nowhere near as close together as they are on the flippable-seat cars so people do sit there.
DutchRailnut wrote:Amtrak has had no trouble borrowing 80 mph NJT MU sets before, so 90 mph would be improvement ;-)
They may not have, but I rode on one of those sets for the nearly 5 hour trip from Washington, DC and I call tell you they should have had plenty of trouble.
  by mtuandrew
 
Fan Railer wrote:What they need in the future is a CVT type gear transmission for railways applications. Might not be feasible at the moment, but if someone, or some company could find the right design and the combinations of materials that could withstand the forces that would be going through the gearbox, then it would be a major improvement in terms of being able to balance high acceleration with a higher operating speed.
I've wondered about that, since you'd get the benefits of low-speed torque and high-speed power without enormous motors or complex electronics. For that matter, I know the French made many monomotor electric locomotives in the 1960s with two speeds (freight and passenger), though you had to stop and manually switch the output. Maybe computer synchronization would allow that switch to happen at speed, like some of the modern clutchless manual automotive transmissions.
  by 25Hz
 
ryanov wrote:
25Hz wrote:Looking at that photo & taking what you said JT i think i solved most of the problems... You'd only lose 16 seats (8 of which are often unoccupied due to ergonomics)
That's not really true. The seats are nowhere near as close together as they are on the flippable-seat cars so people do sit there.
I'm aware of seat using habits, having ridden about 700 NEC peak hour crush loaded trains and off peak, evening & weekend & holiday trains over the span of 11 years. ;)

Typically 2 or 3 people sit there, if they are short enough with not too much stuff 4 can fit. If i sit there no one can sit across from me. The lack of an armrest makes sitting in the inner seat by the stairs tricky on very crowded trains, especially if you are carrying anything.

On other lines the seating habits may be different.
  by Nasadowsk
 
25Hz wrote: Makes no sense to order a crazy batch of never before tried equipment and then limit their speed just because of some technical theory.
Yes, let's not let reality get in the way of our fantasies...
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