• NJT 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

  by amtrakowitz
 
Nasadowsk wrote: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
How many of these EMU-operated services extend to 60 miles in length or longer? Passengers either on or off the NEC would not put up with anything like a Deutsche Bahn "Regio"-style EMU for going from New York to Trenton (even the versions that hit 100 mph like Class 426).
  by DutchRailnut
 
since same commuters now ride the MLV's on some trains its irrelevant on what they will tolerate.
betya the 2x2 seating is big incentive for them.
  by Jtgshu
 
Arrow 3s can still go 100 and actually even faster than that, but they are limited by timetable instructions to 80mph. In late 2003 timeframe, they were suddenly raised to 90mph, but then dropped back down to 80 about 3 weeks later. There is nothing that would prevent them from being raised tomorrow. I doubt it would happen, but they are NOT governed at 80. I have no idea what the governor is set on on them, or even if they have one, I have no idea.
  by amtrakowitz
 
The Arrow IIIs vibrated badly at and above 90 mph immediately post-rebuild. Was anything done to alleviate this? Something tells me the answer would be in the negative. That's aside from NJT not including "long doors" and automatic variable-tap transformers in that rebuild despite the fact that both were available pre-rebuild (Comet IIIs and the first batch of ALP-44s had arrived the year before said rebuild).
  by Jtgshu
 
while im not certain how true it is, and I might have something mixed up, but IIRC they DID fix the problems, which I believe came from hollow axle shafts. I think they replaced all of them with solid axle shafts, however, the problem was with the now one unpowered truck, the remaining powered axles were suffering from overheating and stress/heat cracks from working harder at the higher speeds. So the decision was made to lower them to 80mph. When they were raised to 90 for that short time, I noticed no difference in ride or excessive vibration, other than a random car or pair that just had a bad ride to begin with.

The rebuild on the A3s was pretty much entirely propulsion related. They kept many of their original features/characteristics, including the long doors and transformers which required the manual change. they were freshened up on the inside, but all new door systems for long doors were not in the plans. Keep in mind that at the time, 1992/93, while there were plans for Midtown Direct and I think at that point construction started already, they already had that service covered with the ALPs and Comets. Also, the rules for operating with end doors open and traps up weren't changed yet, so it was common and easy to run with the end doors open and the traps up, like have been done seemingly since the beginning of railroading. Why redesign a piece of equipment that has what works very well already? Rebuilding the Comet 2 end doors in the 2001/02/03 rebuild to match the rest of the Comet fleet made sense, but it wouldn't make sense to have rebuild the A3s with long doors, at the time and the way things were operated then.

Even with the manual change now on the A3s, its not a big deal - if they need more MUs on the Hoboken side, they change them over when they come in for their 92 day inspection, which at any time, there are like 15-20 of them in the shop at any one time getting done anyway, so its not a huge deal. No they can't run on the Coast Line any longer or on Midtown Direct, but again, in the early 1990s when the rebuild was being planned and was going on, that wasnt' an issue.
  by Matthew Mitchell
 
Patrick Boylan wrote:If it's to be conversions then what does "new vehicles" mean?
I can't figure the arithmetic. "$1,400,000, plus five percent for contingencies, for a total contract authorization of $5,208,000"
$1,400,000, and $1,400,000 don't go evenly into $5,208,000. So how many multi level MU's are we supposed to get?
It's an add-on to a previous engineering contract. Presumably, the previous contract (which I assume was for engineering the ML coaches) was for 3.8 million or so.

As for your second question: this isn't the contract for building the cars, so we don't know yet.
  by Nasadowsk
 
Jtgshu wrote: while im not certain how true it is, and I might have something mixed up, but IIRC they DID fix the problems, which I believe came from hollow axle shafts.
I believe the hollow axles were removed in the 80's around the same time SEPTA dumped theirs.
  by amtrakowitz
 
Jtgshu wrote:
amtrakowitz wrote:
Jtgshu wrote:Arrow 3s can still go 100 and actually even faster than that, but they are limited by timetable instructions to 80mph. In late 2003 timeframe, they were suddenly raised to 90mph, but then dropped back down to 80 about 3 weeks later. There is nothing that would prevent them from being raised tomorrow. I doubt it would happen, but they are NOT governed at 80. I have no idea what the governor is set on on them, or even if they have one, I have no idea.
The Arrow IIIs vibrated badly at and above 90 mph immediately post-rebuild. Was anything done to alleviate this? Something tells me the answer would be in the negative. That's aside from NJT not including "long doors" and automatic variable-tap transformers in that rebuild despite the fact that both were available pre-rebuild (Comet IIIs and the first batch of ALP-44s had arrived the year before said rebuild).
While I'm not certain how true it is, and I might have something mixed up, but IIRC they DID fix the problems, which I believe came from hollow axle shafts. I think they replaced all of them with solid axle shafts, however, the problem was with the now one unpowered truck, the remaining powered axles were suffering from overheating and stress/heat cracks from working harder at the higher speeds. So the decision was made to lower them to 80 mph. When they were raised to 90 for that short time, I noticed no difference in ride or excessive vibration, other than a random car or pair that just had a bad ride to begin with
? Why should the new AC motors have become stressed from such operating conditions? And why would an unpowered truck be such a problem when other MUs, both historically and contemporarily, operated with a single powered truck?
Jtgshu wrote:The rebuild on the A3s was pretty much entirely propulsion related. They kept many of their original features/characteristics, including the (short) doors and transformers which required the manual change. they were freshened up on the inside, but all new door systems for long doors were not in the plans. Keep in mind that at the time, 1992/93, while there were plans for Midtown Direct and I think at that point construction started already, they already had that service covered with the ALPs and Comets. Also, the rules for operating with end doors open and traps up weren't changed yet, so it was common and easy to run with the end doors open and the traps up, like have been done seemingly since the beginning of railroading. Why redesign a piece of equipment that has what works very well already? Rebuilding the Comet 2 end doors in the 2001/02/03 rebuild to match the rest of the Comet fleet made sense, but it wouldn't make sense to have rebuild the A3s with long doors, at the time and the way things were operated then
The Comet IVs arrived on NJT in 1996, six years after the Comet III. The "long door" concept was already proven with the Comet III. Are explicit operating rules that much more important than actual safety, especially relating to running at high speeds during rush hour when passengers would occupy the end vestibules by necessity?
Jtgshu wrote:Even with the manual change now on the A3s, its not a big deal - if they need more MUs on the Hoboken side, they change them over when they come in for their 92 day inspection, which at any time, there are like 15-20 of them in the shop at any one time getting done anyway, so its not a huge deal. No they can't run on the Coast Line any longer or on Midtown Direct, but again, in the early 1990s when the rebuild was being planned and was going on, that wasn't an issue
How was it not an issue when the ALP-44s had been bought with this very on-the-fly transformer-tap-changing capability? Never mind the Kearny Connecting having been opened in 1996, only six years after the big rebuild that was minus the very features that would make them ideal for Midtown Direct. Looks more like a deliberate move to make Arrow IIIs less flexible. Another "quirk" of the DeLibero era?
  by Ken S.
 
Had the plan been to rebuild the Arrow IIs for Midtown Direct service before someone found out just how bad their condition was?
  by Nasadowsk
 
amtrakowitz wrote: ? Why should the new AC motors have become stressed from such operating conditions? And why would an unpowered truck be such a problem when other MUs, both historically and contemporarily, operated with a single powered truck?
Because you've got 6 motors pulling the load 8 pulled before. Overpowering motors isn't uncommon with AC drives - I actually know one water treatment plant where the pumps simply cannot be run at 60hz under all conditions because they'll overload if they do, thus they're limited to 58.5 or so. I wouldn't at all be surprised (and for the record, I don't have the whole story, I suspect few do) if that's what's going on with the Arrows - the inverters are somewhat larger than the motors (likely) and will gladly overload the motors to get to 60Hz, thus an operating restriction...
  by DutchRailnut
 
as for hollow Axles I believe all were taken out of service including MNCR's M-2's in mid 80's.
On MNCR the wheels were actually comming off, due to over greasing of bearings.
The axles overheated and with added heat from braking would let go of bond between wheel and axle during station stops as axle cooled faster than wheel.
on acceleration the axle would slip in wheel and wear to point of wheel comming off.
MNCR replaced all hollow axles for solid once, resulting in much higher unsprung weight and associated rail wear.

as for unpowered truck having problems, my guess is:
it is because on that truck you got airbrakes only and no dynamics.
Since the truck was not like a coach with higher brake capacity, it took a lot more wear than the power trucks, which have dynamic brake from max speed to about 15 mph.
again just a guess.
  by Jtgshu
 
It wasn't in NJTs plan to run MUs via Kearny Jct no matter how ever right or wrong that assumption was looking back. Lets not forget the EXPLOSIVE growth that NJT has seen since the mid 90s in ridership. They sure didn't predict it, and no one else did either.

They felt that the MUs were fine being rebuilt as they were, with the doors and traps, and manual change transformers. Like I said, they had the brand new ALP44s and Comets then which could handle the voltage change. That was the equipment for Midtown Direct. That was the "go anywhere" equipment, and the MUs were left for the trains that they have historically ran over since lord knows when, MUs into Hoboken and MUs from Trenton/South Amboy (later Long Branch) to NY.

yes, the long doors were/are safer, but keep in mind how the lines were set up. The NEC was/is almost all High Level (where most ran and still do run) and the Coast Line had/has some low level stops, but the ridership was less. The MandE had/has shorter trains, so it really wasn't an issue with crew members keeping and eye on passengers and most folks knew at the time to stay in the car until the train stops (thats what the sign on the aisle door STILL stays....but no one reads it anyway).

But it doesn't matter what I or anyone else says anyway, Amtrakowitz will still continue to beat the same drums that he always has.....and the real reason or at least a reasonable explanation will never satisfy, and there will always be a question to the answer to the question.

Round and round and round we go.

Looking back, was NJT correct? That can be debated til the cows come home, but they sure did something right as they are still running 20 years after rebuild and a good number of them are getting a little bit more life breathed into them until their replacements come in whatever form they might take. But they are still the workhorse of the entire passenger car roster. Not bad for 35 year old cars, and who knows how many millions of miles and trips and at this point billions of passengers they have moved.
  by Silverliner II
 
Jersey_Mike wrote:and while the Arrow III's retained their grids after the rebuild, dynamic brake energy is first dumped into HEP. This strategy saves about 10-15% in energy costs.
The Arrow III's did not have dynamic brakes before their 1993-1996 rebuild... those came new with the rebuild.

I would gather that these MU's would obviously be equipped with conventional couplers and all necessary air/HEP/MU connections to be able to operate with current multilevel trailers. Personally, I find it a good idea. A few friends and I actually had speculated "what if they had a Comet V modified as an MU that could work with the trailers" when they first came out. And then we shook our heads "Naaaaaah, they'd never do that..."

Well whaddya know....

Friday night and the lights are low.....
  by 25Hz
 
So, the arrows are geared for 100 yet they keep to the schedule just fine. No reason not to gear the MLV-MU's to 100 if they have 4 powered axles. Their weight is actually a good thing, will give lots of traction and dynamic brake effect. The tricky part i guess is making sure the electronics package doesn't blow itself up trying to get the heavy cars moving.


http://www.youtube.com/watch?v=Bhp5i1EITxc

http://www.youtube.com/watch?v=BgaU5D3vM90
  by kilroy
 
and most folks knew at the time to stay in the car until the train stops (thats what the sign on the aisle door STILL stays....but no one reads it anyway).
Yeah and walked right off the bridge and into the river....

I stll can't belive the guy did that and that was before smartphones.
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