Acela 21 (Avelia Liberty) development, testing and deployment

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There has been posts that point out that the PRR sub grade is worn out. The solution? Undercutting which is very expensive and slow. Undercutting requires restoration of signaling once the undercutter has severed signal and other electrical and other items. Also if there are any left over pneumatic lines to switches?
 
Dragging this up..

Anyone hear anything about the first Production set being shipped out soon? I believe that the next TS was scheduled for September, but the Pandemic put a quick damper on that. I just know that it was pushed back to Feb/March time frame.
 
I feel this is the bigger issue. Maybe things will improve as engines become more efficient & lighter in the years to come.
Engines are as light as they can be to still perform satisfactorily with the trains they are assigned. Beyond a certain point, you begin to lose adhesive weight, and thus begin to limit the amount of tractive effort a locomotive can effectively apply to the rails, and thus lowering overall performance with heavy trains. You generally want 3x-3.5x as much total axle load for the rated starting tractive effort to ensure reliable performance.

For electrics, this is around 200k lbs on 4 axles w/ 72k lbs TE (this is already pushing the lower limit in my opinion; most of these electrics are very slippery on anything but dry rail), while diesels seem to hover around 270k lbs on 4 axles w/ 65k TE & ~4000 hp (you can't make diesels much lighter because of the presence of the prime mover and generator equipment; lighter diesels = smaller prime mover = less power). The MPExpress seems to be the outlier in the weight department, approaching 290k lbs on 4 axles, but they don't fit in Amtrak's clearance envelope for NYP anyway.
 
That is why when a rail operator is serious about high performance passenger service, they do not use loco hauled trains anymore, and opt for distributed power (EMU/DEMU) instead. They are less damaging to the track at speed and perform better.

Admittedly, US main line rail operators are still a few decades behind the rest of the world in discovering high performance (not necessarily high speed) passenger system operations.
 
the MPI engines are no longer in production
There you go spouting false information again... The product is still being offered as part of the Motive Power catalog
https://www.wabtec.com/products/5101/mp32-mp36-and-mp40-diesel-electric-commuter-locomotives
It is however unlikely that any future orders for the 36-40 versions would materialize for a number of different reasons, but that is not the equivalent of saying that they are "no longer in production". The MP54AC meets tier IV standards, and is probably the only viable passenger unit for MPI moving forward, outside of rebuilds.
 
TS2 is scheduled for positioning move to Boston tomorrow morning, 4/5/21, following 172 east out of PHL. It will stay up that way for the foreseeable future in order to conduct representative route testing between Providence and Westerly during the AM daylight hours.
 
Cool video.
Newby questions. Do they usually run with just one pantograph despite having two locomotives? Or is the front one just some sort of a cab car?
And it appears that the arc'ing that was going on in a relatively recent video is either much less noticeable or gone altogether.
The blue and white livery is growing on me. The horn still sounds oddly European but I am liking that more too.
 
Cool video.
Newby questions. Do they usually run with just one pantograph despite having two locomotives? Or is the front one just some sort of a cab car?
And it appears that the arc'ing that was going on in a relatively recent video is either much less noticeable or gone altogether.
The blue and white livery is growing on me. The horn still sounds oddly European but I am liking that more too.
It’s my understanding that they use just the rear pantograph 99% of the time. Both the front and back are power cars. They usually don’t turn Acelas so one power car takes the train north/east and the other takes it south/west.
 
I saw this question answered in reference to UK rail operations that, although either pantograph can be used, at higher speeds the rear pantograph causes lower physical resistance owing to the way they fold or retract. If you look at the video the pantograph is being "dragged" past the catenary as opposed to being "pushed". This sounds sensible but I'm no expert.
 
The Acela 21 sets have a high voltage bus connecting the two power heads so a single panto can supply power to both power heads. So in general practice for high speed runs at least they will normally use a single panto, usually the rear one.

The Acela 1s do not have the high voltage bus, so running with one panto means running with one power head and the other operating as an unpowered cab car, which is not ideal for high speed operation since that is when you need a bunch of the power.
 
For the purposes of testing, they are running with the same pan up, ie, they are not switching pans each time they change directions. The pantograph on Power Car #1 (PC adjacent to the First Class car) is the one that is equipped with the instrumentation, so that is the pan that is being used. This allows them to gather data on pantograph behavior for both directions of travel (leading pan up + trailing pan up). In service, the standard practice will be to operate with the rear pan up, but I suspect that due to faults, etc, we'll be seeing them running with the forward pan up a lot more often than would be expected.


 
Tilt VS No Tilt. Pay close attention to the lines on the coaches and the power cars.

Nice video! The difference in speed was surprising to me, but I'm not that familiar with HSR.

I will say, it really annoys me how the sides of the coaches point out and the sides of the power cars are flat.
 
Nice video! The difference in speed was surprising to me, but I'm not that familiar with HSR.

I will say, it really annoys me how the sides of the coaches point out and the sides of the power cars are flat.
The speed difference had nothing to do with the status of the tilt system here. The speed limit on the curve at this location is 130 mph for revenue Acelas with the tilt active. Last week, the test train was making 130 through here with the tilt deactivated. It just so happens in this specific clip, they likely got a cab downgrade from the Kingston distant signals, and so were on the brakes in the first clip.

The difference in profiles from the coaches and the power cars is literally due to the fact that the tilt system is only installed on the coaches. The coaches being tapered allows them to remain within the clearance envelope of the power cars when the coaches tilt and the power cars do not.

All that being said, here's the two-week compilation I have from testing up this way:


The train is scheduled to return to Philadelphia on Saturday, so keep an eye out for it.
 
The speed difference had nothing to do with the status of the tilt system here. The speed limit on the curve at this location is 130 mph for revenue Acelas with the tilt active. Last week, the test train was making 130 through here with the tilt deactivated. It just so happens in this specific clip, they likely got a cab downgrade from the Kingston distant signals, and so were on the brakes in the first clip.

The difference in profiles from the coaches and the power cars is literally due to the fact that the tilt system is only installed on the coaches. The coaches being tapered allows them to remain within the clearance envelope of the power cars when the coaches tilt and the power cars do not.

All that being said, here's the two-week compilation I have from testing up this way:


The train is scheduled to return to Philadelphia on Saturday, so keep an eye out for it.

Thanks for the information! I've been watching some of your recent Acela videos today as well
 
There has been posts that point out that the PRR sub grade is worn out. The solution? Undercutting which is very expensive and slow. Undercutting requires restoration of signaling once the undercutter has severed signal and other electrical and other items. Also if there are any left over pneumatic lines to switches?
Hmm, this explains why I have read about Amtrak putting some signal lines up on the overhead poles in places (the opposite of the usual trend); probably preparing for undercutting.
 
Now looking at Spring of 22 for revenue service:

The first of the 28 new Alstom trainsets had been expected to enter service this year, but the debut is now projected for spring 2022 as a result of modifications to the catenary system. The train’s pantograph would lose contact with the catenary wire and could not reach top speed, according to an official involved with the project. Modifications to solve the problem have required additional testing, computer modeling, and simulations. Those tests “have been an extended affair,” says Larry Biess, Amtrak assistant vice president of mechanical, adding several months to the timeline to deliver the equipment.
https://www.trains.com/trn/news-rev...ZRODIwag-8r3HXLV2SefG59TAXcuYWAawBsErn5bEAWwg
 
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