Avelia Liberty/New Acela II's Speeds and Trip Times

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Ace

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What speeds and trip times will the Avelia Liberty/Acela II bring? The headline number in the articles about the new trainsets bill a top speed of 160 MPH, up from the current 150 MPH top speed in part of RI & MA but it doesn't tell us what improvement there would be elsewhere and the impact on trip times. For instance, will the 160 MPH speed apply to the fastest stretches south of NYC, namely Trenton to New Brunswick and Perryville to Wilmington where the current Acelas max out at 135 MPH? Could the new trainsets run faster at the slowest sections, e.g., running 40 MPH instead of 30 MPH.

The headlines all talk about the top speed of 160 MPH and the goal of 186 MPH pending track upgrades but there isn't much about the real world impact on travel times or on speeds south of NYC, which is where most Acela riders travel. I know Amtrak's goal is a 2 hour trip time between NYC and Washington but a lot of that will come from infrastructure upgrades. How much does the new trainset contribute towards that goal?

Anyone have any information or informed speculation about the above? Thanks.
 
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AFAIK, the only place where 160 will actually happen is the stretch near Providence. Someone can correct me if I’m wrong.

I wouldn’t expect 186 any time in the reasonable future... I think it’s (and 160 for that matter) just a flashy number for headlines.

I don’t think it’s completely correct to suggest most Acela riders are on NYC-DC. I think saying that the two legs are separate and there is little through traffic tells a more complete story.

NYC-DC is already close enough to a two hour stretch when they were running express trains. That section doesn’t need as much improvement as BOS-NYC, which I’m hoping the alleged improvements will shave off time. Even 20 minutes would make a big difference, but I doubt that will happen....
 

jis

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Eliminating the Elizabeth S curve would probably save more time than buying new equipment.
How much in your estimation will it cost to eliminate the Elizabeth S-Curve, and what is the likelihood of that happening?

Of course drilling a straight tunnel from New York to Washington would save even more time ;)

As they say, you fight a battle with the forces you have, not with the forces you wish you had.
 

crescent-zephyr

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How much in your estimation will it cost to eliminate the Elizabeth S-Curve, and what is the likelihood of that happening?

Of course drilling a straight tunnel from New York to Washington would save even more time ;)

As they say, you fight a battle with the forces you have, not with the forces you wish you had.
1 - do you think eliminating the S-curve would be more than 2 billion?

2- Eliminating an S-Curve somehow jumps to a comparison on drilling a 200+ mile tunnel?
 

Danib62

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The time savings of 160 mph to 150 mph are going to be negligible and I'd be surprised if they even bother updating the schedule. For example: the distance from Boston to NYP is 231 miles. If the train travelled at 150 MPH for the entire trip (something it doesn't even come close to doing) the trip would take 1:32:24. If you did the same trip at 160 MPH it would take 1:26:38 a time savings of a whopping 6 minutes.

Now add in how small the top speed stretches are and we're talking about incredibly meaningless time savings.

That said upgrading the slowest stretches from 30 to 40 would actually result in much greater time savings, though that isn't a rolling stock issue, that's a track issue and there's nothing about the new sets that would allow them to speed up service on those parts.
 

crescent-zephyr

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There are better places to spend money and get more for the dollar than the Elizabeth S curve.

Lots of low hanging fruit that I would wager come before which will improve travel times.
I’m sure. That’s one of the more famous places where all trains have to slow so that’s what came to my mind. Feel free to name some others!

The point is not the Elizabeth S-Curve, the point is the new train sets don’t really do much, but I’m sure they will be nice to ride. Hopefully.
 
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I’m sure. That’s one of the more famous places where all trains have to slow so that’s what came to my mind. Feel free to name some others!

The point is not the Elizabeth S-Curve, the point is the new train sets don’t really do much, but I’m sure they will be nice to ride. Hopefully.
Complete agreement!
The tilting capabilities of the new Acelas however intrigue me, and I would be curious if that would improve time over arbitrary top speeds.
 

jis

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The Acelas are allowed something like 80 mph, and ACS64 hauled Regionals are allowed 70mph on tracks 2 and 3 on the S Curve.

$2 Billion (just to pick a random number since I have no idea what the actual estimates are today for acquiring land in prime real estate territory, demolishing building and all that) will get them to go 30 mph faster over a mile or two miles plus reduce the amount of slow down and speedup, and save a minute or less overall.

The question to ask is whether there are better places to spend those $2 Billion to get more minutes of running time reduction. I think we may be missing the big picture for obsessing on the S Curve, perhaps because that is the only one we know about(?).

One would probably get more by changing the alignment of the bridge into Philly to flatten the Zoo curve, for which there is a proposal in the FRA Tier 1 study. When one is able to increase speed limits from 30mph to 50-60-70mph you get more minutes than 80 to 110.
 
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jis

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All those curves in North Philly must have more than an adverse impact than Elizabeth, which is a built up downtown, not miles of abandoned factories and brown fields.
More interesting possibilities are south of 30th St. in using the Eastwick alignment between Phil and Eddystone, which is much much straighter than the current NEC alignment between those two point. Part of the Eastwick alignment is currently used by SEPTA Airport service. This is proposed in the FRA Tier I EIS.
The tilting capabilities of the new Acelas however intrigue me, and I would be curious if that would improve time over arbitrary top speeds.
The current Acelas have tilting capability too, so that should not make a huge difference between the old and the new.

What will make a difference is the higher acceleration performance of the new sets. The NEC profile everywhere is such that one has to slow down and speed up a lot and the quicker that can be done the more time can be saved.
 
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I was under the impression that the 135 mph restriction NYC - DC was due to the 90 year old catenary structure. Replacing the existing PRR era catenary with constant tension should allow faster running as well as increasing reliability. I realize this has already begun in a few places between Newark and Trenton. Perhaps completing this work would be a more useful expenditure than straitening a few curves.
 

jis

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I was under the impression that the 135 mph restriction NYC - DC was due to the 90 year old catenary structure. Replacing the existing PRR era catenary with constant tension should allow faster running as well as increasing reliability. I realize this has already begun in a few places between Newark and Trenton. Perhaps completing this work would be a more useful expenditure than straitening a few curves.
There are only four or five stretches totaling maybe 50 miles where speeds higher than 125mph will be introduced progressively. Yes, it will require catenary upgrade beyond 135mph. Speeds higher than 135mph do not always mean it will be 160mph. Indeed even between Jersey Avenue and Trenton the entire length will not go to 160mph. There is a shallow curve that will hold speeds down in the middle, and also they failed to make the catenary constant tension all the way before running out of money. That will hold down speeds some too.

Straightening curves is an issue that is tackled in the FRA Tier 1 EIS for the NEC which has been completed. It is a rather thick document bound to put many to sleep. :) I have been quoting a few possibilities from it that are relatively less expensive. The document is not take all or nothing. It gives a good basis for making logical decisions on what to do next.
 

crescent-zephyr

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I was under the impression that the 135 mph restriction NYC - DC was due to the 90 year old catenary structure. Replacing the existing PRR era catenary with constant tension should allow faster running as well as increasing reliability. I realize this has already begun in a few places between Newark and Trenton. Perhaps completing this work would be a more useful expenditure than straitening a few curves.
Replacing the catenary will not increase the speeds of regional trains. “Straightening a few curves” would.
 

jis

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They are going to build new tunnels in Baltimore iirc. How much time savings would occur from that project?
That will be very significant since speed limits will go up considerably. That is actually a more or less fundable project now, out of the Infrastructure Bill.
 
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Ryan

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Relatively speaking, the tunnel is pretty short. Maybe a minute or two, tops.

Edit to add since Jishnu and I answered simultaneously: Agree that the speed increase is significant, but the distance relatively short and you're still on the approach to BAL so you're not going to realize that fully if you're stopping at BAL.
 

AmtrakBlue

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Relatively speaking, the tunnel is pretty short. Maybe a minute or two, tops.

Edit to add since Jishnu and I answered simultaneously: Agree that the speed increase is significant, but the distance relatively short and you're still on the approach to BAL so you're not going to realize that fully if you're stopping at BAL.
And all trains stop at BAL, correct? :)
 

jis

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I was looking for a good article on it and just found it:


Because the speed limit will go from 25mph or some such to 100mph, the article claims that running time will be reduced to 30 mins for BAL to WAS. If that is for Acelas that would be 3 minute saving. Anyway take a look at that article it is very informative.

If you wish to take a gander at the entire EIS, they are linked section by section at the bottom of the Amtrak page on the Frederick Douglas Tunnel:

 

crescent-zephyr

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Thanks for that link - page 15 of the Record of Decision quotes 2m31s in time savings for Amtrak and 1m49s for MARC trains (presumably because the latter stop at West Baltimore).
At a $4 billion price tag. Not saying that’s a bad thing... just pointing it out. Infrastructure costs money.
 

crescent-zephyr

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You're not paying $4B for 2 minutes of time savings, you're paying for two more tracks and a 140 year newer piece of infrastructure that isn't falling apart and causing major delays when it does.
That brings up an interesting point... what if the only benefit was the 2.5 minutes? What would that 2.5 minutes be worth to spend?
 

cirdan

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I’m sure. That’s one of the more famous places where all trains have to slow so that’s what came to my mind. Feel free to name some others!

The point is not the Elizabeth S-Curve, the point is the new train sets don’t really do much, but I’m sure they will be nice to ride. Hopefully.
There is an old railroader wisdom that says "if you want to go fast, don't go slow"

Going after slow sections delivers more in terms of overall time savings for the dollar than pushing top speeds up marginally in the few sections where they can be achieved.

I agree that it is wrong to single out the Elizabeth Curve in particular but there must be dozens of locations where speeds can be ramped up to 10 mph higher than today by relatively simple measures, sometimes as simple as catching up on deferred maintenance.
 
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