NEC Speeds

[Anonymous]

I understand that the top speed of an Acela on the NEC is 150 mph.  What is the top speed of a regional train? Also, what would be the top speed of a commuter train, i.e. a New Jersey Transit train?

[conrailman]

Another  Amtrak trains can go up to 125 mph and NJ can  go 90  to 110 mph.

[henry6]

But high speed commuter trains with short distances between stations is nonesense.  Commuter train time is consumed in slowing down for frequent stops, dwell times of one to 5 minutes per station, then slow acceleration often not achieving equipment speed if not track speed before the next station stop.  So what if it can go to a zillion miles an hour if the ability to achieve it is either not there or so costly it is not feasable?  Capacity has to be achieved in ways other than just speed.  More tracks, better acceleration and deceleration, shorter dwell times, better or more minute traffic control(shorter blocks, GPS spacing, etc.), maybe more high level platforms (but the important ones have been done, especially all along the Corridor).  AMtrak is not saddled with commuter stops and starts and can better achieve the higher speeds with economy and reason.

 

[blue streak 1]

Sam1

I understand that the top speed of an Acela on the NEC is 150 mph.  What is the top speed of a regional train? Also, what would be the top speed of a commuter train, i.e. a New Jersey Transit train?

NEC speeds  are a mixture at present. Acela can only do 150 MPH for a short distance in CT / RI. South of NYP the speed limit for Acelas and HHPs are 135 MPH but that is only for a steady Ambient temp within a narrow range.  Temp extremes will reduce speeds in unknown increments.

This is all because of the variable tension PRR CAT NYP - WASH.  Constant tension CAT will start being installed on 26 miles from north of Trenton to south of Trenton.  This new CAT is supposed to be rated for 160 MPH.  Many times Amtrak issues a 90 MPH heat order on MARC and Amtrak as the CAT is considered worse Wilmington - WASH

For NJ transit the new ALP-45s ( electric ) and ALP-46s are rated for 125 MPH.  Many NJ  Transit trips during rush hours go non stop Newark - Trenton thus the need for higher NJT speeds to keep that section fluid. The last time I rode EMUs they seemed to be limited to 100 MPH ?? But the EMUs have good acceleration for the locals and are usuallly on the outside tracks. Some turn back EMUs will go opposite direction non stop.

[oltmannd]

blue streak 1

 

Sam1:

 

I understand that the top speed of an Acela on the NEC is 150 mph.  What is the top speed of a regional train? Also, what would be the top speed of a commuter train, i.e. a New Jersey Transit train?

 

 

NEC speeds  are a mixture at present. Acela can only do 150 MPH for a short distance in CT / RI. South of NYP the speed limit for Acelas and HHPs are 135 MPH but that is only for a steady Ambient temp within a narrow range.  Temp extremes will reduce speeds in unknown increments.

This is all because of the variable tension PRR CAT NYP - WASH.  Constant tension CAT will start being installed on 26 miles from north of Trenton to south of Trenton.  This new CAT is supposed to be rated for 160 MPH.  Many times Amtrak issues a 90 MPH heat order on MARC and Amtrak as the CAT is considered worse Wilmington - WASH

For NJ transit the new ALP-45s ( electric ) and ALP-46s are rated for 125 MPH.  Many NJ  Transit trips during rush hours go non stop Newark - Trenton thus the need for higher NJT speeds to keep that section fluid. The last time I rode EMUs they seemed to be limited to 100 MPH ?? But the EMUs have good acceleration for the locals and are usuallly on the outside tracks. Some turn back EMUs will go opposite direction non stop.

I think I read somewhere the AC Arrows are only good for 80 mph, which matches my experience riding them.  Rode a train of mixed vintage Comets with an ALP45, also 80 mph.  But the new bi-levels are good for 100-110, I think.

[blue streak 1]

quote user="oltmannd"]

I think I read somewhere the AC Arrows are only good for 80 mph, which matches my experience riding them.  Rode a train of mixed vintage Comets with an ALP45, also 80 mph.  But the new bi-levels are good for 100-110, I think.

[/quote]

Don: can not answer that.  A copy of Amtrak's ETT might be revealing. Could be why they are on Boontown and shore line service mostly.  I do know that all NJ equipment ordered in last few years ( when exactly ?? ) is specified at `125 MPH.

Although SEPTA did not order any equipment for a long time the Silverliner - 5s were built for 125 MPH.  Probably eventually south of PHL ?? and maybe Harrisburg line.  As you know Silverliners - 2s & 3s are being retired but not all 4s  as the 5s order is not yet enough. 5s and 4s can operate together but Septa does not plan to do so unless it is to rescue broken down train. 

Another factor for EMUs are how many in consist.  The number of PANs contacting the CAT were limited to 3  ( 6 cars )  for metroliners for many year. I heard that NJ Transit has speed limits if there is over a certain number of PANs Anyone know ??  again Amtrak ETT would be very helpful to confirm or deny..

All these restrictions due to the condition of the PRR CAT south of NYP. MARC is fortunate that their electric motors are rated the same speeds as Amtraks' motors and Acela as well. Several of our posters have critized the Constant tension CAT upgrades but these restrictions on other equipment has consequences as well especially in very cold or very hot weather. 

[oltmannd]

Somewhere in these forums, there was a discussion of the AC conversion of the Arrows and why they are only good for 80 mph.  I don't recall the reason.  Was surprised that my Comet train was only operated at 80 mph max.  It was a weekday off-peak train. Would have thought 100 mph would have been the norm.  Maybe it's more about energy and schedule keeping?

[timz]

blue streak 1

all NJ equipment ordered in last few years ( when exactly ?? ) is specified at `125 MPH.

I guess you mean they told the manufacturers to design the new equipment so it could do 125, someday. But does NJT allow any of its trains to exceed 100 as of now? New equipment or old?

[henry6]

There are allowable speeds over 100 mph allowed on the Corridor west of New Brunswick.

[RayG8]

TRAINS published the speed limits on the NEC a couple of months ago. ACELA is only good for 150 in a few short stretches, I think the longest one is about 10 miles through RI south of Wickford.

[Mario_v]

Been seing Amtrak & NJT public TTs and have reached some conclusions :

- Even in non stop trains (there are some peak time services on NJT's 'Northwest Corridor' that are mostly non stop from Newark to Trenton), commuters are preety slow (are there any specific limitations on the 'slow' lines? ). Maybe that ccorresponds to an imposed speed limit;

- Schedules seem to have quite a bubch of buikt in pading, in both cases. The only ones that are quite fast are Acelas, and only between NYP & WAS. Bt even with all the tilting technology these trains are only marginally fater than their Metroliner ancestors. Here's a shining example: In Amtrak's 1984 schedule there were some Metroliners doing NY - WAS in 2 hours 49 minutes. Today, Acelas do 2 hours 45. Maybe the extra 10 Mph speed limit and the ability to go thru curves faster isn't being used.

Well, maybe all the padding seems to excessive to me, since I'm from Europe and therefore I'm used to have fast trains with far less padding. Normally in Europe padding is added like this : fast priority trains (High speed or Intercity/Eurocity): between 3 and 4 minutes per 100 km (62 miles). Other trains get 5 minutes. In the last segment between the last stop and the terminal station, some extra 2 or 3 minutes are added to recover for some eventual delays, despite the padding added to the schedule. Now imagine that Amtrak would apply this kind of padding technique. Probably conventional trains woukd be doing somenthing like 3 hours 05 or 3 hours 10 between NYP & WAS (Acelas can stay as they arem, or eventually could do 2 hours 40). Between NYP & BOS Acelas could be doing 3 hours 15, and conventional trains 3 hours 50 in a 'meomory' schedule.

As far as commuters are concerned, normally, here in Europe, stops are reduced to the bare minimum : half a minute, but over there in the US I believe things are way too different from here.

And since I'm maybe writing too much, one thing I cannot undestand is the fact of long distance trains (Silver Service, Florida ...)being suite slow between NYP and WAS. Is that because of old baggage cars being used (limited to 90 mph ?)