I’d think, in order to hit full speed even with a limited stop or express train, you’d still have speed issues coming up on a metro area. You can’t just blow through Philly at 160 even if you hadn’t planned on stopping there.
You can but the track has to be built for it. Japan has stations that are passed at 320km/h (200mph). You need minimum four tracks (two platforms, two passing) and curves/gradients suitable for the speed, along with noise mitigations as necessary.
If you’re trying to re-use tracks and stations built in the 1800s that’s possibly less feasible.
In an ideal world you’d have bypasses or tunnels to help them keep up speed, but that all depends on land allocation and investment. If you’re stuck with old windy narrow tracks then yes youre going to be limited.
Trains like shinkansen can go very fast through dense urban areas, i think mostly in tunnels - but also because they spend a lot to straighten the routes. Obviously there are still some slow sections, but they minimize it by design - and probably a willingness to bulldoze historical land ownership.
I guess in Philly the route probably winds around a bit.
https://www.openrailwaymap.org/
It looks like all lines funnel through a couple of very tight curves around the centre. That looks like quite a sensitive choke point.
But apart from that section it looks like the acela limit is over 100mph for quite a lot of the urban area around Philly, which isn’t too bad. Its not like its crawling around at 60mph for half the distance.
There’s another interesting looking slow chicane in Wilmington. In that case there’s what looks like an ideal bypass line already there for any express. It runs through a massive siding (freight maybe?) that is limited to 10-30mph. Looks like a no brainer to me, strengthen those bridges and run any express through that. plenty of dead space around there to reconfigure just one level crossing i think to worry about. most of it is 3-4 tracks already judging by google map.
I heard that US freight and passenger rail don’t like to share and enjoy though so probably that’s a non starter.
The speed with high speed rail is usually made between cities, less so in dense areas. But that doesnt mean there is no gains to be made by improving track and running at say 130-160 km/h (80-100 mph)
To my knowledge these trains can alao accelerate quite fast because they are electric trains.
The express service is still considerably limited in the DC to Boston because it’s like 40% metro and still has to slow down. You have DC, Philly, NY, and Boston all with substantial suburban infrastructure and it adds up.
In the best of situations on express it’s hard to justify express acella unless you are really cash strapped.
Not really for Acela. The NE Corridor is fully grade separated for most parts and four cities chosen are far enough apart to make use of the train’s top speed.
It makes use of the trains top speed for less than 50 miles of the route. It’s basically only infrastructure: tight curves, ancient bridges and tunnels, too many choke points. It may be grade separated but you still can’t blast through towns at full speed. It’s limited by freight trains. It’s even limited by shipping, because of drawbridges.
Edit - Here’s a partial map illustrating speed increases for some planned infrastructure projects
As the comment you’ve replied to says, they are limited by the line speed and their design, and design speed, is effectively the same as the latest TGV.
You’re not understanding the difference between the line speed and the train’s design speed. The train is capable of comparable speeds, significantly higher than the track speed
Its literally the same trainset by the same manufacturer as the TGV, hence the comparison. The highest track speed on the northeast corridor is 160 MPH, which is why they’re calling it a 160 MPH train.
The problem is the infrastructure not the train. Its a good train.
No, it is not the same train. The Acela II has a technical top speed of 189MPH. It might be built by the same company (Alstom), but it is no TGV. One of the differences is that the Acela has less motor units than the TGV.
Yes… The point is the maximum design speeds of both are very similar.
Yes TGVs run operationally at much higher speeds than the Acela II but that is due to infrastructure, not the train itself. The train itself, independent of track constraints, is capable of similar speeds. I don’t think there’s much more worth saying on the matter.
Even if same train, it is not run under the same regulations. The US FRA regulations really kneecap the operational speeds:
For the track between New Haven and Boston, [Acela] has a waiver for operation at 7 inches of unbalanced superelevation. This means, that the [tilting] Acela is allowed to use the same curve speed as non-tilting TGVs (or multiple units) in France. The “Acela Express” looses about half an hour between New York and Boston, compared to best practice in tilting train usage. (It also looses at least half an hour, compared to the calculations of US railroad engineers in the 1960s.)
Note that the above was written about Acela 1. The Acela 2 is supposedly lighter weight, so in theory FRA might allow higher speeds (though I have yet to see any progress there).
The tracks are the limiting factor. The acela trains are basically the TGV. They could go the same speed with better infrastructure.
The tracks and I’m sure the distances between stops. Hard to hit full speed when you already have to plan to slow down for the next stop.
Part of handling that is having both local and limited-stop services (which they likely already do) and a good local/commuter train network.
I’d think, in order to hit full speed even with a limited stop or express train, you’d still have speed issues coming up on a metro area. You can’t just blow through Philly at 160 even if you hadn’t planned on stopping there.
You can but the track has to be built for it. Japan has stations that are passed at 320km/h (200mph). You need minimum four tracks (two platforms, two passing) and curves/gradients suitable for the speed, along with noise mitigations as necessary.
If you’re trying to re-use tracks and stations built in the 1800s that’s possibly less feasible.
In an ideal world you’d have bypasses or tunnels to help them keep up speed, but that all depends on land allocation and investment. If you’re stuck with old windy narrow tracks then yes youre going to be limited.
Trains like shinkansen can go very fast through dense urban areas, i think mostly in tunnels - but also because they spend a lot to straighten the routes. Obviously there are still some slow sections, but they minimize it by design - and probably a willingness to bulldoze historical land ownership.
I guess in Philly the route probably winds around a bit. https://www.openrailwaymap.org/ It looks like all lines funnel through a couple of very tight curves around the centre. That looks like quite a sensitive choke point.
But apart from that section it looks like the acela limit is over 100mph for quite a lot of the urban area around Philly, which isn’t too bad. Its not like its crawling around at 60mph for half the distance.
There’s another interesting looking slow chicane in Wilmington. In that case there’s what looks like an ideal bypass line already there for any express. It runs through a massive siding (freight maybe?) that is limited to 10-30mph. Looks like a no brainer to me, strengthen those bridges and run any express through that. plenty of dead space around there to reconfigure just one level crossing i think to worry about. most of it is 3-4 tracks already judging by google map.
I heard that US freight and passenger rail don’t like to share and enjoy though so probably that’s a non starter.
The speed with high speed rail is usually made between cities, less so in dense areas. But that doesnt mean there is no gains to be made by improving track and running at say 130-160 km/h (80-100 mph)
To my knowledge these trains can alao accelerate quite fast because they are electric trains.
The express service is still considerably limited in the DC to Boston because it’s like 40% metro and still has to slow down. You have DC, Philly, NY, and Boston all with substantial suburban infrastructure and it adds up.
In the best of situations on express it’s hard to justify express acella unless you are really cash strapped.
Not really for Acela. The NE Corridor is fully grade separated for most parts and four cities chosen are far enough apart to make use of the train’s top speed.
It makes use of the trains top speed for less than 50 miles of the route. It’s basically only infrastructure: tight curves, ancient bridges and tunnels, too many choke points. It may be grade separated but you still can’t blast through towns at full speed. It’s limited by freight trains. It’s even limited by shipping, because of drawbridges.
Edit - Here’s a partial map illustrating speed increases for some planned infrastructure projects
The Acela trains are far from being on par with French TGV, German ICE, or Japanese Shinkansen.
For a European, this is just a medium speed train.
As the comment you’ve replied to says, they are limited by the line speed and their design, and design speed, is effectively the same as the latest TGV.
TGVs at “normal speed” go at 320km/h or 200MPH. They can go up to 350MPH.
The Acela with its 160MPH top speed does not come close.
You’re not understanding the difference between the line speed and the train’s design speed. The train is capable of comparable speeds, significantly higher than the track speed
It is not. The technical top speed of the Acela II is less than 190MPH due to technical restrictions, and it has less engine units than a TGV.
From the comment that started this thread:
No, we all understood this the entire time.
Its literally the same trainset by the same manufacturer as the TGV, hence the comparison. The highest track speed on the northeast corridor is 160 MPH, which is why they’re calling it a 160 MPH train.
The problem is the infrastructure not the train. Its a good train.
No, it is not the same train. The Acela II has a technical top speed of 189MPH. It might be built by the same company (Alstom), but it is no TGV. One of the differences is that the Acela has less motor units than the TGV.
Sounds pretty comparable to 200 mph (320 km/h) to me…
The 200MPH is not the top speed. It is the operational speed. High speed trains in Europe regularly travel at speeds exceeding 300km/h.
Yes… The point is the maximum design speeds of both are very similar.
Yes TGVs run operationally at much higher speeds than the Acela II but that is due to infrastructure, not the train itself. The train itself, independent of track constraints, is capable of similar speeds. I don’t think there’s much more worth saying on the matter.
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Even if same train, it is not run under the same regulations. The US FRA regulations really kneecap the operational speeds:
Source: https://zierke.com/shasta_route/pages/15regulation.html
Note that the above was written about Acela 1. The Acela 2 is supposedly lighter weight, so in theory FRA might allow higher speeds (though I have yet to see any progress there).