125MPH on New Haven Line?

I've read about the poor condition of bridges on the New Haven line. Does anyone know what else is stopping Amtrak from running trains at 125/150MPH on this line? Is there anything about the alignment that makes it unsuitable to run trains at these speeds or is it just poor infrastructure?

Thanks,

FRN9 wrote:I've read about the poor condition of bridges on the New Haven line. Does anyone know what else is stopping Amtrak from running trains at 125/150MPH on this line? Is there anything about the alignment that makes it unsuitable to run trains at these speeds or is it just poor infrastructure?

Thanks,

Curves, hyper-dense traffic and a signal system optimized for 90 MPH commuter rail and not 125+ MPH intercity, no tilt allowed for the Acelas.


There's not a whole lot that can be done for most of this. It's just too hard to do dispatching that can be everything to everyone on the busiest end-to-end commuter rail line in North America. They might be able to buy some extra flexibility if they execute the PTC installation absolutely spot-on with not one hair of inefficiency. Enabling Acela tilt is feasible if Amtrak spends the $$$ to do it, but Metro North obviously won't be paying for any of that and it will be slow going given the need to keep all tracks in service while they optimize those curves for tilt. However, all of this takes a very far back seat to the bridges, catenary renewal, and service/reliability improvements. Making the service more reliable to all users is going to do far and away the most good for everyone. And likewise Amtrak can minimize whatever drag effect from 90 MPH and stiff congestion New Rochelle-New Haven the more it improves its infrastructure south of Penn to remove those bottlenecks and open more 125 MPH territory for the Regionals and 150+ territory for the Acelas.


Have to look at the whole NEC for answers. Simply looking at MNRR territory in isolation and asking why can't they do this or that doesn't give an accurate picture of what aggregate/systemic improvements are possible across the corridor. They've got $10 billion in other performance-enhancing things they need to do on the official NEC Infrastructure Plan to optimize the Amtrak-owned track to its fullest potential and catch up on basic bread-and-butter state of repair on the New Haven Line before they've settled up enough else that the 90 MPH Metro North speed limit imposes any top-priority performance constraint. We're a looooooooooooooooong ways a way from existentially having to come to grips with that with everything else that can improve Amtrak's NEC performance.

Amtrak Acelas are allowed to use tilt mechanism on MNR, the restriction was lifted a while ago. There are Manu curves on the New Haven and the heavy traffic that both prevent very high speeds.

the difference in time for express between current speed and 110 mph minus curve and bridge restrictions was only 4.6 minutes from New Rochelle to Division post.
Hardly worth the upgrading of interlockings and signal system.
The New Haven line was built for 70/75 mph and with all commuter trains in its way, even if speed were 110 mph the Acela could hardly ever get over 70 mph anyway.

In another thread we've discussed the importance of raising average speeds. Going from 90 to 110 or 125 does far less for your average speed than getting the really slow spots up to reasonable speeds. I don't know enough about the New Haven route to state that there is/isn't such slow areas, but if there were, it would be a far better use of money than boosting top speeds over 100.

Tadman wrote:In another thread we've discussed the importance of raising average speeds. Going from 90 to 110 or 125 does far less for your average speed than getting the really slow spots up to reasonable speeds. I don't know enough about the New Haven route to state that there is/isn't such slow areas, but if there were, it would be a far better use of money than boosting top speeds over 100.

Couldn't agree more.

What makes the New Haven Line busier than the NJT section of the NEC?

Are there spots where it is not 4 tracked? What if all of the Amtrak stations had two island platforms and 2 bypass tracks added (like EWR airport rail station)?

FRN9 wrote:Are there spots where it is not 4 tracked?

Devon (junction with the Waterbury Line, a/k/a the Naugatuck) to just short of West Haven was three-tracked at some point in the 1980's, although room for the 4th main track remains under the catenary structures and on the bridges.

FRN9 wrote:What if all of the Amtrak stations had two island platforms and 2 bypass tracks added (like EWR airport rail station)?

There are only 4 Amtrak stations in MNRR territory - New Rochelle, Stamford, Bridgeport and New Haven. New Rochelle has one island platform, one wall platform and one bypass track. Stamford has two islands with one bypass track. New Haven, as one of the busiest stations in New England, has 8 platform tracks on 4 island platforms, plus a bypass and yard trackage. That leaves Bridgeport, with two wall platforms-- but Bridgeport station is on a viaduct and located right between a moveable bridge and the sharpest curve on the line, so even if you could install a bypass (not likely) you're not going to save much time.

The existing New Haven Line will NEVER, EVER be a high speed railroad as it is presently made up. It just isn't possible with lots of curves, restrictive bridges and commuter train traffic. The present signal system would not be able to handle higher speeds and major changes to this signal system would reduce capacity and that too is a NO NO. While the freight trains might be gone this line is handling the highest volume of traffic that it ever has since it was built. Capacity could be somewhat increased by building by-passes from the worst restrictive spots but this would come at a huge cost. All to save maybe 5 minutes running time. The line needs up-grading to a point where we would have a system that can run day after day without some sort of a problem. Many existing bridges are so old and so deteriorated that a total replacement is the only solution. The fourth track needs to be restored between Devon and Woodmont. Looking back the non-stop running time between Grand Central Terminal and New Haven of 1 hour and 18 minutes to 1 hour and 22 minutes is gone for good and not going to return, the railroad as it is presently constituted can not handle this any more.
Noel Weaver

Operational capacity (the number of trains you can fit through a segment), not speed, is the name of the game for the New Haven Line, as the vast majority of passengers carried are commuters, not intercity travelers. When speeds are raised, operational capacity takes a hit because stopping distance increases disproportionally greater than the increase in speed. When stopping distances increase, the number of trains you can put through a segment goes down, and that hurts everybody. That's why increasing speeds to get a 4 minute travel time reduction is probably not going to happen with the current New Haven Line layout.

Too many sharp curves and close clearances. The NH Line's speeds are pretty much maxed out. The only speed increases are going back to 90 MPH from east of New Rochelle to just west of Harrison and possibly just east of Milford to New Haven (excepting the curve at West Haven). There will be no speed upgrades until the PTC system is fully implemented.

Clean Cab wrote:Too many sharp curves and close clearances. The NH Line's speeds are pretty much maxed out. The only speed increases are going back to 90 MPH from east of New Rochelle to just west of Harrison and possibly just east of Milford to New Haven (excepting the curve at West Haven). There will be no speed upgrades until the PTC system is fully implemented.

There is no reason the New Haven Line could not be upgraded to an 80mph standard instead of the 60-75mph it currently runs at, however at the end of the day the State of Connecticut is the one that owns the line and signs off on all capitol improvements or service upgrades.

upgrading to 80 mph would gain you 2 minutes ?? hardly worth the cost.

In about 1965 I got a cab ride RT between NY (Penn Station) and NHV in an EP-5, north on a mail train and returning on SENATOR #173. Although the timetable had a max. speed of 70 MPH, there were places where we did 80 (the jets accelerated very fast - better than GG1's in my opinion). The major differences between then and now are (1.) freights and not as many commuter trains as today and (2.) the moveable bridges at Cos Cob, Saga and Devon did not have speed restrictions as they do today - the restrictions were imposed during the PC days and never upgraded.
Prior to PC, COLONIAL #171 used to leave NHV at 10:54 am and arrive Penn Station at 12:25 pm; there were times when I've seen the train make up 5 min. There were intermediate stops at Bridgeport and Stamford. I've never seen a recent Amtrak regional train make a 1'31" NHV-NY run with two intermediate stops.

Andy

There is one thing they could do to increase capacity and thereby bump up the average speed-- add a 5th main track between New Rochelle and Port Chester. The ROW and catenary structures through there are 6 tracks wide after all. It wouldn't be cheap- the stations would all have to be rebuilt and you'd have build parking structures to replace lot space lost in Rye, Harrison, etc. But unlike some other things (straightening Jenkins Curve, tunneling under Norwalk Harbor, etc.) it seems do-able.

That space formerly occupied by NYW&B tracks through Larchmont of which you speak has been occupied by I-95 since 1954. There is no room for a 5th track in that area.