• Acela II (Avelia Liberty): Design, Production, Delivery, Acceptance

  • Discussion related to Amtrak also known as the National Railroad Passenger Corp.
Discussion related to Amtrak also known as the National Railroad Passenger Corp.

Moderators: GirlOnTheTrain, mtuandrew, Tadman

  • 957 posts
  • 1
  • 57
  • 58
  • 59
  • 60
  • 61
  • 64
  by Arlington
 
Everyone who says the delay is overblown is correct. I wish RR.net had a "like" button.

On the "why didn't TCCI find this?" question, I suspect TCCI has modern constant-tension catenary like all TGV-heritage trains are all designed for (because nobody will build you NEC style constant geometry)

The Acela 2's pantograph apparently had trouble maintaining contact with NEC's constant geometry catenary. That's the kind of complex harmonic / double-pendulum kind of problem that you can only find by testing. And they found it. And it will take a little while to adjust the pantograph arms/springs/whatever and then re test.

I don't have a theory on the curves problem, but I can easily imagine that it'd be analogous to the catenary problem: only the NEC is built like the NEC.

Not a big deal. Not a reason to question retiring the Acela 1s (we had a whole thread on that). Not a reason to doubt the Acela 2
  by bostontrainguy
 
Matt Johnson wrote: Fri Jun 04, 2021 9:22 am
Rockingham Racer wrote: Fri Jun 04, 2021 5:09 am For one thing, the test track at TCCI in Pueblo is far different from the twisty, turny ROW east of New York. That said, they have not indicated where on the NEC the problems were occuring, have they?
With railfans flocking to Princeton Junction with their cameras for the night time test runs, there was video documentation of the train showing excessive arcing from the pantograph and failing to make the intended speed on some of the early runs. Which is surprising, because that's the constant tension catenary stretch.
Yes, I thought the same thing. What about Boston - New Haven? Is it also happening there?
  by Arlington
 
I read recently that the new CT catenary in NJ still had “leftover” elements that made it less global standard than TCCI and RI/MA are
  by west point
 
I await for Amtrak to fess up what the problem is maybe ? However the suspicion that there was some differences in what Amtrak was doing on the upgrade CAT sections had passed on to this poster several months ago. It is very difficult to work on any CAT on an active RR track. Especially on a 4 main track RR for the inside tracks. It took NJ Transit over a year even closing down Lackawanna on weekends.
  by John_Perkowski
 
Admin note

A caution: Discussions about the current fleet's disposition do not belong here. I reopened the thread on disposition.

Going forward, if you want to discuss disposition, and the thread isn't opened, ask first. Send a PM to one of the mods, Jeff Smith, Greg Primrose, or myself. If you don't, don't be surprised if your post disappears like a GG-1 hauled Congressional at speed.
  by Fan Railer
 
photobug56 wrote: Thu Jun 03, 2021 7:17 pm I do admit to being very puzzled. All this testing on the NE corridor with one of the 2 test trains, not a single hint of problems during the testing. One would think that if problems were found, that adjustments, fixes would have been made even if the set had to go to a yard or the factory for a month, then resume testing, but we never heard of that happening.
Just because it was never publicized doesn't mean there weren't problems throughout the testing period. Back when they began speed upgrade testing on October 27th, 2020, they were initially thinking they'd get up to the 165 mark after about a few days. On the first night, after only two trips, they discovered that the instrumented wheelset was damaged. It took them two weeks or so to source another wheelset, and so testing resumed on November 9th.

As test speeds gradually climbed higher from the 90 mph mark, the aforementioned issues with the pantographs was discovered (excessive pan bounce when operating in the rear-pan-up configuration, which is supposed to be the normal operating configuration), among other issues like ACSES/ATC. The issue was especially pronounced as speeds climbed higher than 140 mph, and would trigger protective functions on the train, such as tripping the MCB, etc., and so the train was basically stuck at that speed for a little while. Ultimately, they did not reach the 165 mark until Christmas Eve, and that was still in the forward-pan-up configuration, as the pantograph mods were not implemented until sometime in March of 2021. AFAIK, 165 mph in with the rear-pan-up configuration was finally achieved in April 2021 when the trainset was up in Rhode Island.

The mod applied to the pan consists of two small spoiler fins designed to induce lift (like a plane wing) at the higher speeds, which keeps the pan in contact with the wire more consistently when it encounters areas of poor wire geometry which induce oscillation in the pantograph height.
  by bostontrainguy
 
Fan Railer wrote: Mon Jun 14, 2021 10:26 am The mod applied to the pan consists of two small spoiler fins designed to induce lift (like a plane wing) at the higher speeds, which keeps the pan in contact with the wire more consistently when it encounters areas of poor wire geometry which induce oscillation in the pantograph height.
Well at least that sounds like a simple, quick and relatively inexpensive solution.
  by Fan Railer
 
photobug56 wrote: Mon Jun 14, 2021 2:21 pm So why a year delay in rollout?
If you'd read the article, it explains this. With the pan mod, the entire battery of speed tests must be repeated so that a new dynamic model can be generated throughout the operating speed range. This is why they're still testing almost every weeknight between HAM and COUNTY in NJ.

The year-long delay is cumulative; with the original in-service goal being 10/2021, as each new issue arises, between test instrumentation failure (whether due to rain damage or animal strikes), ATC issues, software issues, and the pan issue, time gets added on. A few weeks here and a month there, and there you go; you got at least a 9-month delay from the original goal.
  by ExCon90
 
bostontrainguy wrote: Mon Jun 14, 2021 10:55 am
Fan Railer wrote: Mon Jun 14, 2021 10:26 am The mod applied to the pan consists of two small spoiler fins designed to induce lift (like a plane wing) at the higher speeds, which keeps the pan in contact with the wire more consistently when it encounters areas of poor wire geometry which induce oscillation in the pantograph height.
Well at least that sounds like a simple, quick and relatively inexpensive solution.
Sounds like just what CTA did with the Skokie Swift when the same problem developed.
  by west point
 
The PAN problem is IMO going back to the old PRR variable tension setup. Since the tests were done in the fall , winter, & spring nothing has been tested on a really hot day when the wire will sag the most. Then what will happen ? I have no idea. Even if Amtrak test the AX-2 on the cheap constant tension there may be problems unknown. I have no idea what will happen? There may be issues in the 2 different upgrades that no one could have anticipated. That is what tests are all about.
  by west point
 
I really do not want to quibble over terms but it is not just wire but how it is hung and the supports on each track. PRR CAT was built to connect all 4 main track CAT together physically but not electrically whereas modern constant tension is built so there is no physical connection between tracks for the CAT . That PRR physical connection can make bounce much more easily to start..

Another problem is that the vertical poles to anchor the CAT by PRR are too far apart for constant tension. It is a 3 for 2 ratio but best way would be to just add a new pole between each existing pole. The reason that is not sufficient is that present PRR poles are rusting out at their base as they connect below ground level to support columns.
  by electricron
 
west point wrote: Tue Jun 15, 2021 12:00 am Another problem is that the vertical poles to anchor the CAT by PRR are too far apart for constant tension. It is a 3 for 2 ratio but best way would be to just add a new pole between each existing pole. The reason that is not sufficient is that present PRR poles are rusting out at their base as they connect below ground level to support columns.
Why not just replace the existing poles after installing the new ones in between, then all the poles will be new. Yes, it will cost twice as much, but all the poles should be good for another 100 years or more.

Any infrastructure, including railroads, are like yachts in that they are large holes in the water or earth that you keep sinking large amounts of money into. :-D
If you can not afford to maintain the infrastructure, maybe you should not had built it in the first place. :wink:
  by Ken W2KB
 
electricron wrote: Tue Jun 15, 2021 6:42 am
west point wrote: Tue Jun 15, 2021 12:00 am Another problem is that the vertical poles to anchor the CAT by PRR are too far apart for constant tension. It is a 3 for 2 ratio but best way would be to just add a new pole between each existing pole. The reason that is not sufficient is that present PRR poles are rusting out at their base as they connect below ground level to support columns.
Why not just replace the existing poles after installing the new ones in between, then all the poles will be new. Yes, it will cost twice as much, but all the poles should be good for another 100 years or more.

Any infrastructure, including railroads, are like yachts in that they are large holes in the water or earth that you keep sinking large amounts of money into. :-D
If you can not afford to maintain the infrastructure, maybe you should not had built it in the first place. :wink:
A substantial amount of the mileage in the New Jersey section of the Amtrak (PRR) mainline has the Amtrak 132kV single phase transmission lines, and above that, electric utility transmission overbuild (PSE&G 230kV) on the catenary poles. That extra railroad and public utility transmission greatly increases the complexity and cost of replacement.
  • 1
  • 57
  • 58
  • 59
  • 60
  • 61
  • 64