Except that it's cheaper and easier to get rid of the slow spots. And, short of a totally devastating World War or alien invasion that demolishes most of Connecticut, I can't imagine that any new right of way can be built to replace the Shore Line.
North East Corridor (NEC) speeds, new stations and state of repair
- Thread starter Free Jaffa
- Start date
Help Support Amtrak Unlimited Discussion Forum:
this actually doesn’t check out.
It’s more economical and cheaper to increase slow than increase fast.
the difference between getting the Acela to 165 in a handful of select areas has little to no effect on trip times.
inceasing a spot from 30mph to 80mph makes much more of a difference.
Most top speeds around the world on great HSR services don’t actually top out much higher than an Acela. Indeed, only a handful of Shinkansen and TGV routes do (and Beijing to Shanghai in China). It’s their average speed that’s much better.
Last edited:
TheCrescent
OBS Chief
- Joined
- Jun 24, 2020
- Messages
- 562
While it may be cheaper to get rid of the slow spots, are they all being removed?
No.
Amtrak deals the cards that it has. There are and will be slow spots, and Amtrak can increase top speeds in some areas. So it removes slow spots when possible and increases top speeds when possible.
You’re gonna need to cite some stuff in order for me to be on board with your argument.
TheCrescent
OBS Chief
- Joined
- Jun 24, 2020
- Messages
- 562
No. I don’t do research for others unless I’m paid to do so or unless I’m a member of a volunteer organization that requires it.
So if they can't remove the slow spots, which is cheaper and easier to do, what makes you think that it's likely anyone will do what's needed to do to increase maximum speeds?
Like I said earlier, redoing or replacing the Shore Line through some of the most valuable real estate in America might require the devastation of a World War, an alien invasion, or a Godzilla rampage through Connecticut (that might make a good movie). OK, possibly also a change in our political culture that would increase the willingness to spend the terabucks (or maybe even petabucks) needed for such a public works project. Personally, I'd put my money on an alien invasion or a Godzilla rampage as being more likely.
mfastx
Service Attendant
This boggles my mind as well. I wonder if all four tracks will ever be in service concurrently in my lifetime lol.
Ahh, then we have proof by vehement assertion.
Straightening out ROW’s in some of the curviest parts of the NEC could cost upwards of 50 billion, and you still think cranking out a few upper end mph here and there is gonna help?
dlerach
Train Attendant
It always seemed an order of magnitude easier to improve the alignment of New Rochelle-Stamford than Stamford-New Haven. Norwalk and Bridgeport both have tremendously difficult curves that would require either tunneling, bypassing, or razing half of each city. The curve just east of Stamford to Darien is also basically impossible to improve without tunneling or razing the neighborhood of Noroton Heights.
New Rochelle-Stamford, on the other hand, presents fewer impediments. There are some curves that need straightening if operating speeds are going to dramatically increase (Harrison, Rye, Port Chester, Greenwich, Cos Cob), but the primary constraint on this section of the NEC is traffic density and congestion. Although traffic is very heavy west of Stamford, and Amtrak often finds itself following slow-moving commuter trains, the NYNH&H built this section of the alignment for 6 tracks instead of today’s 4, (the NYW&B took the space for those two tracks between Larchmont and Port Chester during its period of operation). Since then, the construction of the Connecticut Turnpike/I-95 has encroached on the right-of-way in some areas, but to my eye it is still possible to add two additional tracks with only a bit of imagination and perhaps some minimal takings.
Giving Amtrak two independent tracks west of Stamford would *dramatically* improve reliability and running times, as well as increase capacity for Metro North. Most importantly though, allocating Metro North tracks 1-4 and Amtrak 5-6 could eliminate the need for a flyover at Shell Interlocking, one of the most challenging chokepoints on the whole NEC. Tracks 5-6 could instead shift to the middle of the r-o-w with a flying junction between Port Chester and Greenwich, where there is much more open space.
That just leaves the constraining curves. They could all be reduced to 1° with only one major deviation from the alignment, though they would require takings. 1° curves would allow Northeast Regionals to travel 110 mph and Acela trains to travel 125 mph:
1. Harrison needs its S-curve eased, which would require relocating the Rye Racket Club and taking 1-2 rows of houses on the southwest side of town.
2. The Rye and Port Chester curves are sharp and run through highly-built downtowns, but I-95 offers an almost perfect bypass here (curving onto I-95, though, would require demolishing about 12 houses and placing two tracks of the railroad on an expensive viaduct.)
3. Greenwich’s station lies on an S-curve, which can be corrected again by exiting I-95 with a flying junction onto the current r-o-w just east of the Greenwich station. This requires demolishing the office building directly south of the station.
4. The Cos Cob Bridge currently lies between two sharp curves. Replacing the troublesome bridge with a fixed span on a broad curve would allow 110/125 mph operation.
These improvements are tremendously expensive, yes, but together with minimal improvements to the Hell Gate line, they would allow Amtrak to provide true high speed rail on some 35 miles of railroad with the only speed limit remaining between Penn Station and Stamford the Hell Gate Bridge.
New Rochelle-Stamford, on the other hand, presents fewer impediments. There are some curves that need straightening if operating speeds are going to dramatically increase (Harrison, Rye, Port Chester, Greenwich, Cos Cob), but the primary constraint on this section of the NEC is traffic density and congestion. Although traffic is very heavy west of Stamford, and Amtrak often finds itself following slow-moving commuter trains, the NYNH&H built this section of the alignment for 6 tracks instead of today’s 4, (the NYW&B took the space for those two tracks between Larchmont and Port Chester during its period of operation). Since then, the construction of the Connecticut Turnpike/I-95 has encroached on the right-of-way in some areas, but to my eye it is still possible to add two additional tracks with only a bit of imagination and perhaps some minimal takings.
Giving Amtrak two independent tracks west of Stamford would *dramatically* improve reliability and running times, as well as increase capacity for Metro North. Most importantly though, allocating Metro North tracks 1-4 and Amtrak 5-6 could eliminate the need for a flyover at Shell Interlocking, one of the most challenging chokepoints on the whole NEC. Tracks 5-6 could instead shift to the middle of the r-o-w with a flying junction between Port Chester and Greenwich, where there is much more open space.
That just leaves the constraining curves. They could all be reduced to 1° with only one major deviation from the alignment, though they would require takings. 1° curves would allow Northeast Regionals to travel 110 mph and Acela trains to travel 125 mph:
1. Harrison needs its S-curve eased, which would require relocating the Rye Racket Club and taking 1-2 rows of houses on the southwest side of town.
2. The Rye and Port Chester curves are sharp and run through highly-built downtowns, but I-95 offers an almost perfect bypass here (curving onto I-95, though, would require demolishing about 12 houses and placing two tracks of the railroad on an expensive viaduct.)
3. Greenwich’s station lies on an S-curve, which can be corrected again by exiting I-95 with a flying junction onto the current r-o-w just east of the Greenwich station. This requires demolishing the office building directly south of the station.
4. The Cos Cob Bridge currently lies between two sharp curves. Replacing the troublesome bridge with a fixed span on a broad curve would allow 110/125 mph operation.
These improvements are tremendously expensive, yes, but together with minimal improvements to the Hell Gate line, they would allow Amtrak to provide true high speed rail on some 35 miles of railroad with the only speed limit remaining between Penn Station and Stamford the Hell Gate Bridge.
west point
Engineer
What would it cost to straighten the NEC from North PHL to past Frankford Junction? IMO that would have the best benefit per passenger minutes as that is a very heavy number oof passengers.
George Harris
Engineer
To cut through all the arm-waving about speed limits and restrictions:
The length of a segment permitting a higher than current maximum speed for the railroad is effectively reduced by the length of track needed for acceleration at the beginning of the segment and the length of track needed for deceleration/braking in approach to the end of the higher speed segment. For a low speed restriction, the reverse is true, in that the effective length of the restriction is increased by the need to slow down for it and speed up from it.
Plus, consider the seconds per mile at 125 mph is 28.8 seconds and for 150 mph is 24 seconds, so each mile you increase saves you 4.8 seconds. BUT, wait a minute, you really can't do that good as when you get to the start of this super high speed section, you have to accelerate to it and then brake to the lower speed at the end of it. And, you have to do these while the full train length is within the higher speed segment. So, if we ignore train length, if the higher speed section is 10 miles long and you take 1/2 mile to accelerate and 1/2 mile to brake, you have reduced run time by something like 45.8 seconds, that is less than one minute, and increased energy consumption significantly to do so. (Aerodynamic train resistance, with is the main component of running resistance at high speed is proportional to the square of the speed. In other words, aerodynamic at 150 mph is 1.44 times the aerodynamic resistance at 125 mph. Thus, for a 20% increase in speed you have a 44% increase in resistance, then add in acceleration energy, which even if partially balanced with use of regenerative brakes, you have an overall increased energy consumption for this near insignificant improvement in run time.)
No let's look at a one mile 30 mph segment that for the same money we can get up to the full 125 mph limit. One mile at 30 mph is 120 seconds. Let's say it takes the same 1/2 mile each end for acceleration and braking, which is probably about right on the braking end and probably short on the acceleration end, you have for this one mile speed restriction two miles that take 166.5 seconds versus 57.6 seconds if the restriction did not exist, so you have reduced run time by 108.9 seconds, in other words, nearly two minutes and by eliminating the braking/acceleration probably reduced overall energy consumption along with it. By the way, unless this is a straight track restriction such as a bridge, but improvements on curves, you would probably have some small reduction in length of line as well.
If my objective is to give the politicians something to brag about, then spend it on the speed limit increase. If my objective is to improve run time then spend it on increasing speed in low speed areas.
Nuff said.
The length of a segment permitting a higher than current maximum speed for the railroad is effectively reduced by the length of track needed for acceleration at the beginning of the segment and the length of track needed for deceleration/braking in approach to the end of the higher speed segment. For a low speed restriction, the reverse is true, in that the effective length of the restriction is increased by the need to slow down for it and speed up from it.
Plus, consider the seconds per mile at 125 mph is 28.8 seconds and for 150 mph is 24 seconds, so each mile you increase saves you 4.8 seconds. BUT, wait a minute, you really can't do that good as when you get to the start of this super high speed section, you have to accelerate to it and then brake to the lower speed at the end of it. And, you have to do these while the full train length is within the higher speed segment. So, if we ignore train length, if the higher speed section is 10 miles long and you take 1/2 mile to accelerate and 1/2 mile to brake, you have reduced run time by something like 45.8 seconds, that is less than one minute, and increased energy consumption significantly to do so. (Aerodynamic train resistance, with is the main component of running resistance at high speed is proportional to the square of the speed. In other words, aerodynamic at 150 mph is 1.44 times the aerodynamic resistance at 125 mph. Thus, for a 20% increase in speed you have a 44% increase in resistance, then add in acceleration energy, which even if partially balanced with use of regenerative brakes, you have an overall increased energy consumption for this near insignificant improvement in run time.)
No let's look at a one mile 30 mph segment that for the same money we can get up to the full 125 mph limit. One mile at 30 mph is 120 seconds. Let's say it takes the same 1/2 mile each end for acceleration and braking, which is probably about right on the braking end and probably short on the acceleration end, you have for this one mile speed restriction two miles that take 166.5 seconds versus 57.6 seconds if the restriction did not exist, so you have reduced run time by 108.9 seconds, in other words, nearly two minutes and by eliminating the braking/acceleration probably reduced overall energy consumption along with it. By the way, unless this is a straight track restriction such as a bridge, but improvements on curves, you would probably have some small reduction in length of line as well.
If my objective is to give the politicians something to brag about, then spend it on the speed limit increase. If my objective is to improve run time then spend it on increasing speed in low speed areas.
Nuff said.
TheCrescent
OBS Chief
- Joined
- Jun 24, 2020
- Messages
- 562
Yes, improving speeds in a few stretches to 160 mph may shave a few minutes off total trip times. That helps, particularly when spending billions to straighten curves isn’t going to happen.
As we all know, in some places, modernizing track and catenary just to bring them up to 2020 standards and to increase capacity means that the additional cost to permit 160 mph operation is quite low- e.g., New Jersey track around Princeton. If necessary updates are already being done, why not spend a bit more to get speeds up to 160?
please just refer to George Harris’ post
Wires are not the thing preventing higher speeds around Princeton junction. Tracks have concrete ties and are pretty up to date too.
Last edited:
George Harris
Engineer
(In answer to a comment/question concerning NY to NH catenary
Thank you. I have not kept up with things in the northeast as much as I did in the past. As a response to someone who made the comment about the constant tension catenary also being used in light rail: Yes. The whole "constant tension" concept simplifies so many things in the operation and maintenance of overhead electrification it comes under "Why didn't we start doing this years ago?" heading. It is to my mind, at least, the only way to go in overhead electrification in almost all, like 99,9%+ of electrifications.
TheCrescent
OBS Chief
- Joined
- Jun 24, 2020
- Messages
- 562
I’ve read it.
None of us on this board (as far as I know) is a decision maker about where to spend funds for infrastructure upgrades.
I’m well aware that eliminating slow spots may be more cost-effective and more effective overall in raising average trip times.
But unless and until Amtrak gets sufficient funding to allocate as it thinks best to improve trip times overall, it has limited funds and funding for specific projects.
If all Amtrak has is funding to increase a speed even on a short stretch to 160 mph, but it doesn’t have funding to eliminate a slow stretch, then I for one would be an absolute fool to decline to work to increase the speed to 160.
As is often said, don’t let the perfect be the enemy of the good. If all Amtrak can do is increase a maximum speed to 160, do it, even if slow stretches cannot be eliminated.
Ok, so I don't really understand your point.
We both want to improve trip times on the BOS-NYP (and overall) sections of the Acela route.
It has now been established that the most effective way to do this, both cost-wise and speed wise, is the improve slow sections; yet you are claiming that we should use the most expensive and least effective way of lowering trip times: increasing top speeds. You say there is some amorphous reason than Amtrak ought to do this, without any citations.
If anything, I'd invert your argument: lets not let perfect (increasing top speeds), be the enemy of the good (slashing trip times economically).
----
for what its worth, I do believe Amtrak is increasing top speeds where it makes sense (Rhode Island).
Last edited:
TheCrescent
OBS Chief
- Joined
- Jun 24, 2020
- Messages
- 562
My point is this:
Take whatever funds are available and make whatever improvements to infrastructure can be done to improve trip times.
If all that can be done is to improve maximum speeds on short stretches, do it!
Amtrak doesn’t have unlimited funds or unlimited control over what projects can be funded. Just use whatever funds can be obtained for whatever projects can be funded.
jis
Permanent Way Inspector
Staff member
Administator
Moderator
AU Supporting Member
Gathering Team Member
I would just gently add a little color to how project funding is decided on the NEC. It is not decided by Amtrak alone. That used to be the case before Congress created the North East Corridor Commission. It is decided by the North East Corridor Commission which is in charge of managing all funding of NEC projects by Congressional decree. It gets funding from the Feds and the States and in consultation with all stake holders, decides on project priorities. There is an enormous list of projects described in excruciating detail, that is publicly available with tentative cost estimates to feed into this decision making process. Of course if Congress designated a specific pot of money for a specific project then it is the Commission's job to make sure that Congress' wish is carried out
TheCrescent
OBS Chief
- Joined
- Jun 24, 2020
- Messages
- 562
Great post, jis. As anyone who has even a cursory familiarity with how government works knows quite well that legislatures and executives certainly don’t necessarily spend money based on the best use of money, based on objective criteria; they spend it for a range of reasons unrelated to what’s the best use of funds. Thus government spending on railroad infrastructure may have nothing to do with what’s the most cost-effective way to improve the railroad. So Amtrak should take the funds that it can get, for the projects that it can get funded. Even if an outcome in an ideal world would be different.
George Harris
Engineer
I think you are missing the major point I was trying to make: Improving maximum speeds on short sections" gets you next door to nothing.
If I were to redo my little calcs above using 160 mph instead of 150, then for 160 versus 125 you gain 63 whole seconds in TEN MILES if the speed limit before was 125 mph, and you have an increased power consumption of about 60% per mile to do this. In other words, if you want to save 10 minutes, you have got to have 100 miles of track that is already good for 125 mph that you can raise to 160 mph, and that had better be a near to continuous 100 miles. Also, if you have curves that are good for 125 mph and no more, they would still be good for 125 mph and no more unless you can modify those curves. Dlerach mentioned 1 degree curves as being good for 125 mph under the Acela: Based on the old SE = 0.0007 V^2 D formula, this would indicate a balancing superelevation of 10.93 inches, which is extremely high, so I am not sure that is correct. The usual maximum superelevation is 4 inches on lines carrying high freight cars such as piggyback or double stacks, and 6 inches on lines that either are passenger only or limited to passengers and low center of gravity freight equipment and loads, so, if given 6 inches actual, this leaves an unbalance of near 5 inches. The usual is 3 inches, but with tilting equipment you can do more, so let's assume the Acela can handle 5 inches of unbalance. Churning the SE formula around, this says that for 160 mph operation you must have curves of not greater than 0 degrees 36 minutes. Again, we are dealing with not the direct ratio of speeds but of speed squared. (A one degree curve, chord definition, has a radius of 5,729.51 feet, and a 0d 36m curve has a radius of 9,549.25 feet. Degree of curve is defined as the change in direction over a chord distance of 100 feet.)
I am saying all this to say that realistically if you want to increase run time, you deal with the slow areas, and then maybe think about raising the speed limit. To quote an article on this subject that was in the Railway Gazette International quite a few years ago, "The best way to go fast is to avoid going slow."
Yes, I realize that politicians tend to live in fantasyland on many things and one is virtually everything involving railroads, but none the less we had better be able to understand what the realities are and not go into swooning fits believing what they tell us. The CAHSR is an outstanding of a very good and essentially necessary system that has been turned into a boondoggle by political manipulations. There is a saying that you probably dare not say out loud in current conditions, which is the first exercise in developing any major facility is shoot all the involved politicians.
Last edited:
TheCrescent
OBS Chief
- Joined
- Jun 24, 2020
- Messages
- 562
No, I’m not missing your point. I understand your point.
Sorry, but expanding MN trackage from 4 to 6 is a non-starter. First, you would need to rebuild every station from Portchester to New Rochelle. Second, there are many encroachments into the original 6 track space by buildings and bridges.
The improvements from New Rochelle to NYP for west side access will improve the running time on that stretch of rail.
joelkfla
Engineer
I gave a "like" for the 1st 4 sentences. The rest was over my head!
west point
Engineer
Mr. Harris is correct. If Amtrak could bet almost all slow curve sections up to 110 - 120 MPH then NYP <> WASH times could be under 2 hours. With rush hour Acela-2 service ever 1/2 hour and other times 1 hour wonder how many more passengers would ride? Of course it means fix the CAT to constant tension and 120 foot hanger spacing
Latest posts
-
-
-
-
Connecticut Inland Route and Albany - Boston Corridor (Compass Service)- Latest: AmtrakMaineiac
-
-
