• 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

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  by bdawe
 
Matt Johnson wrote: Fri May 22, 2020 6:02 pm Interesting that only the lead loco has the pan raised.
I've read that in places that multiple pans cause wave issues in the wire at speed? Given that these are fixed consists, presumably power runs through the whole set?
  by RRspatch
 
bdawe wrote: Fri May 22, 2020 8:13 pm
Matt Johnson wrote: Fri May 22, 2020 6:02 pm Interesting that only the lead loco has the pan raised.
I've read that in places that multiple pans cause wave issues in the wire at speed? Given that these are fixed consists, presumably power runs through the whole set?
If you look at videos of the French TGV on an LGV you will notice only the pan on the rear unit is raised. Running along the roof of the train is a 25Kv 50Hz cable bringing power to the lead power car. This of course is done by SNCF to prevent bow waves in the catenary. Looking at pictures of the ACELA II I don't see anything that would look like a high voltage buss cable. I seriously doubt 480 volts being sent back from the lead unit is enough to power the rear unit as well as power the rest of the train. I figure the train will operate with pants up on both ends in NEC service.

Now if there is no way to send power back or forwards through the train the interesting part here is that the train got up to 165 MPH with only the lead unit on line. I assume they're using sand bags or some other weight to simulate a full passenger load. The question I guess would be how long did it take to get up to that speed with only one unit on line?
  by hxa
 
RRspatch wrote: Sat May 23, 2020 12:59 am
bdawe wrote: Fri May 22, 2020 8:13 pm
Matt Johnson wrote: Fri May 22, 2020 6:02 pm Interesting that only the lead loco has the pan raised.
I've read that in places that multiple pans cause wave issues in the wire at speed? Given that these are fixed consists, presumably power runs through the whole set?
If you look at videos of the French TGV on an LGV you will notice only the pan on the rear unit is raised. Running along the roof of the train is a 25Kv 50Hz cable bringing power to the lead power car. This of course is done by SNCF to prevent bow waves in the catenary. Looking at pictures of the ACELA II I don't see anything that would look like a high voltage buss cable. I seriously doubt 480 volts being sent back from the lead unit is enough to power the rear unit as well as power the rest of the train. I figure the train will operate with pants up on both ends in NEC service.
What about delivering that power via a through, 2000 to 4000 V intermediate DC link?
  by west point
 
Did someone post that the FRA will not allow a bus running across the whole train ? If that is so maybe that is why each car does not have traction motor like some in Europe do ?
  by gokeefe
 
I was wondering about that too but figured this probably wasn't true given some of the equipment operated by the MTA and (I think) SEPTA and NJT.

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  by MattW
 
I believe the FRA allows jumpers between married pairs. Beyond that, I know of no equipment in this country that transmits power between more than two cars.
  by NeedhamLine
 
Looking at the construction photographs, there appears to be the standard TGV-style high voltage line running between and above the cars - it's just that it is shrouded on this design so less obvious than on single-level TGV cars (where it is more or less exposed) - so I would expect that these would run with a single pantograph. See here: https://earlrichardson.com/recent-projects/alstom/49

Given the size of the insulators used, doubt that this would be for HEP-type voltage.
  by Tadman
 
west point wrote: Sat May 23, 2020 11:39 am Did someone post that the FRA will not allow a bus running across the whole train ? If that is so maybe that is why each car does not have traction motor like some in Europe do ?
MattW wrote:I believe the FRA allows jumpers between married pairs. Beyond that, I know of no equipment in this country that transmits power between more than two cars.
This is my understanding, although I have not read the specific rule related to this issue. HEP can cross field-operated couplings, traction power can only cross semi-permanent couplings. See M8, geep-slugs, Arrows, etc... all have traction power crossing a coupling that can only be undone by shop forces.

I was a bit surprised when Metra and South Shore ordered the gallery EMU a few years ago and didn't marry the pairs, as the pantograph hump takes up a few rows of seats.
  by WhartonAndNorthern
 
Is anyone hearing any chatter that the FRA won't allow new A2s to run faster than A1 speed until ALL A1s have been retired? Of course that also assumes that there's any track upgraded to >150 mph standards. If you've heard something about this and have a concrete source (like chapter and verse from the Federal Register) let me know. The rumor source is not very credible but occasionally pans out. I'd like to be able to debunk this (hard to prove a negative I know).
  by bdawe
 
WhartonAndNorthern wrote: Tue May 26, 2020 4:24 pm Is anyone hearing any chatter that the FRA won't allow new A2s to run faster than A1 speed until ALL A1s have been retired? Of course that also assumes that there's any track upgraded to >150 mph standards. If you've heard something about this and have a concrete source (like chapter and verse from the Federal Register) let me know. The rumor source is not very credible but occasionally pans out. I'd like to be able to debunk this (hard to prove a negative I know).
What's the reasoning? That A1 bankvaults are too dangerous to comingle at spead?
  by WhartonAndNorthern
 
bdawe wrote: Tue May 26, 2020 5:09 pm What's the reasoning? That A1 bankvaults are too dangerous to comingle at spead?
That's what I want to know. Aren't they certified to the same Tier 2 standards? Aren't Amtrak and the commuter railroads used to having different equipment that has different timetable speeds? Adding an H-bag drops the speed of a Regional, etc.
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