When first advertised, this active-tilt system was supposed to be so marvelous that it would allow trains to take curves at between 100 and 125 mph, while keeping passenger comfort at a maximum. (I believe that trains can stay on the rails while rounding curves of certain radii at these speeds, but the passengers would be thrown to one side of the train when the centripetal forces kicked in, not to mention being made extremely ill by the G-forces.)

However that objective, along with the apparent public acceptance of the even higher Acela Express fare structure, could have been accomplished with conventional cars incorporating Acela Express' "smart" interior design features (i.e. they were not designed to emulate a 737's interior as were Amfleets)and hauled with existing locomotives. Maximum speed would have been 135; Boston-NY would been scheduled at 3'55" NY-Was 2'45".

The existing Acela Express equipment should simply have waited until there was infrastructure in place to support "speeds of" instead of "speeds up to" 150.

Talk about how to have saved us taxpayers a few $$$$$$!!!

Well, what's more foolish is putting a train with high capabilities on an infrastructure that can't support them. What you end up with is a train that looks good but does everything the other trains do (this refers to the Cascades Talgos as much as the Acela Express, of course).

quote:

---

Originally posted by irishchieftain:
Getting back to Acela Express, though: You'll never see them going faster than 90 mph on the CDOT/MTA-controlled part of the Northeast Corridor.

---

Well, I've heard maybe 110 mph in the future, but we'll see. Even 90 isn't so bad...the important thing is managing the traffic flow so that the trains can get from New Rochelle to New Haven on time, regardless of what speed they travel at!

quote:

---

In addition, the CDOT has banned the use of active-tilt on their part of the NEC because the Acela Express cars were built with two inches of excess clearance on each side (which makes CDOT fearful that a tilting train will sideswipe a train on an adjacent track)—Amtrak knew this when going in to get these trainsets built.

---

I've been wondering, are Metro North's tracks actually closer together than on the rest of the NEC?

quote:

---

Best chance to see high-speed running outside the current areas, i.e. in the future, should be (I don't say "will be" because I've lost faith) the former PRR NY-Washington. (And, of course, these trainsets will never reach 170 mph, which they're reputedly capable of achieving, thanks to the FRA.)

---

Best place for 150 mph, IMO, is from New Brunswick through Princeton Junction to Trenton, NJ. There are, I believe, two minor 130 mph curves between New Brunswick and Trenton, but other than that it's dead straight track. That's where I think the Acela Express should definitely be allowed 150 mph, and Amtrak needs to make replacing that old variable tension catenary a priority!

As far as the train being capable of 170 mph, of course it can go faster than it does in revenue service! It's officially rated for 165 mph (10% above its max revenue speed), and I think you'll find that most trains have some margin specified. (The TGV's, for example, are capable of more than 186 mph.) I'll settle for more 150 mph running!

quote:

---

Originally posted by vthokie:
Best place for 150 mph, IMO, is from New Brunswick through Princeton Junction to Trenton, NJ. There are, I believe, two minor 130 mph curves between New Brunswick and Trenton, but other than that it's dead straight track. That's where I think the Acela Express should definitely be allowed 150 mph, and Amtrak needs to make replacing that old variable tension catenary a priority!

[This message has been edited by vthokie (edited 05-05-2002).]

---

1) The tilting mechanism is purely for passenger comfort. It has nothing whatever to do with how fast the train can run (the power cars don't tilt).

2) Amtrak asked the FRA for permission to run with nine inches of "cant deficiency" (nine inches over balancing speed, which is the speed where outward tilt exactly equals the superelevation of the high rail). Due to continuing unsolved problems with the tracking of the trucks (they "hunt" unpredictably on curves), FRA limited the train to (IIRC) 7 inches north of NYP and 6 inches south. This holds down maximum curve speeds, and FRA people tell me the hunting problem is unlikely to ever be corrected.

3) For the same reason, FRA limits the maximum speed of the train in *any* curve to 130 mph.

4) Even if the train were to perform to specifications, 150 mph would be permitted on only 45 miles of track between NYP and WAS.

quote:

---

Originally posted by rresor:

1) The tilting mechanism is purely for passenger comfort. It has nothing whatever to do with how fast the train can run (the power cars don't tilt).

---

Yes, I'm aware of that. Which leads me to another question...if the X2000's flexible axle mounts on the trucks were the key to actually taking curves at higher speeds, how was the Acela supposed to have the same capability with conventional trucks?

quote:

---

5) My April 2001 timetable gives a speed of 65 for Acela Express through the Elizabeth reverse curve, vs. 55 for Amfleet. So there's a little difference.

---

Well, guess that answers the question!

Looks like your timetable lied...and assuming that the AE ever does that speed around the curve, how is that a significant improvement over the conventional trains? Like I said, the AE does not do 65 through Elizabeth Reverse Curve, bottom line. Conventional trucks still have high capability to keep the train on the track through curves, still and all...but since this is still a big issue, why did Amtrak use a technology supposedly from yesteryear on a "train of the future"???

The TGV's, for example, are capable of more than 186 mph

Much more...they do 190 mph in regular service nowadays, and the test train that ran at 327 mph is well documented...

Even if the train were to perform to specifications, 150 mph would be permitted on only 45 miles of track between NYP and WAS

Which 45 miles? And what are they scared of? The whole Acela Express project sounds lamer and lamer with each retelling. It's a lot more than 45 miles between NY and Washington...besides, how much trackage can the AEM-7s with Amfleets get up to 125 mph on??? That ought to tell you just where the Acela Express can do its vaunted 150 mph.

Due to continuing unsolved problems with the tracking of the trucks (they "hunt" unpredictably on curves)

Hmm?? And I thought that this problem was fixed and all, what with the various reports on Railroad.net to the affirmative. So the Acela Express is just the new E-60, then, but just not as bad...? It's a sad state of affairs when a B-B locomotive hunts; really lackadaisical design, I would say. (Although, come to think of it, it looked to me like an HHP-8 I was observing passing through Linden, NJ today pulling 10 Amfleet I cars was indeed hunting just a little.) Can Amtrak do anything right???

The tilting mechanism is purely for passenger comfort

Ad nauseam; this is about the umpteenth time I've heard that. However, on the same note, the passenger comfort was supposed to be maintained at higher speeds through curves than conventional equipment. Active-tilt becomes quite redundant when you run the train at the same speed through the curve as conventional railcars. Correct?

the priority is replacing all the substations that feed the catenary

I would like to think that auditors KPMG will be insistent in the inclusion of all liabilities, including capitalized leaase obligations.

Remember; read the Footnotes!!!

"First curve west of MP 14 (that would be the Elizabeth reverse curve):

Track 1 55
Track 2 65
Track 3 65
Track 4 55

"Curve east of Elmora": 55 all four tracks

BUT, speed on tracks 2 & 3 in first curve is same for Acela Express and other trains.

The 45 miles in question are between New Brunswick & Trenton and between Perryville and "Gunpow" interlocking.

It's 225 miles from NYP to WAS.

I agree with you; Acela Express was a fraud from the beginning.

OK...well, that puts it in black-and-white. Well, to re-iterate one of my other queries, on how much of the 225 miles is 125-mph running permitted for AEM-7/Amfleet trains (or the second coming of the "Metroliner", if you like)? Are there any milepost markers where the Acela Express is permitted either 140 or 145 mph beyond the delineated 150-mph territory? Well...all of this is spitting in the wind, in light of the defrauding of the US that the Acela Express project turned out to be.

Where Acela Express can achieve 150 mph depends on three things:

1) ACSES (Advanced Civil Speed Enforcement System) installed and working
2) Constant-tension catenary (without that, max is 135 for both Acela Express and Metroliner consists)
3) Track geometry (AE is restricted to 130 mph at present on ANY curve by the FRA).

Nevertheless, Amtrak's "Year 2010 Plan" shows no more than 45 miles of 150 mph operation (with some curve restrictions) even when the three conditions above are achieved.