I was doing that tourist thing in Mystic, Connecticut of seaport fame when the railroad crossing gates activated. I pulled into the parking lot of the Mystic Amtrak station so as to watch the train -- I thought it might stop at the station -- but it was an express train and an Acela consist. Didn't position myself to get any photos, but at least I got to see an Acela for the first time.
The train raises a number of questions. The first thing I noticed was that there was a long wait once the crossing gates were down for the train to come by, and this was Amtrak's fastest train. I am sure that experts have looked at this from every angle, and far be it for railfans to suggest whether the gates should be down less time. For the gates down so long without a train raises the temptation to (illegally) run the gates. For the gates down a shorter time, there is a bigger chance of someone getting "caught" in the crossing. There are engineering "trades" for everything, and I am curious regarding how the gate dwell time is decided. The train didn't go past the station all that fast, by the way.
One reason the Acela didn't zip past Mystic at 100-per is that the station is on a reasonably sharp curve, and you could really see the Acela lean into that curve. Now I know that part of the lean is whatever super elevation is on the track, and the remainder of the lean is the hydraulic banking system, but this raises a couple more questions.
We have had tilting trains before going through Mystic, which it seems has a sharp curve in a location accessible to photos, i.e. the train station, and express trains not stopping. The Pullman Standard Train-X equipment in the late 50's on the New Haven followed by the TurboTrain on Penn Central in the early 70's had passive tilt, the LRC was tested on this route by Amtrak, the active-tilt Acela currently runs on the Shore Line, and there has been non-tilting "conventional" equipment.
I know that most photographers want to get a "picture of the train", and there are some standard camera angles many people use. But I have seen some photos of the European Pendolino and British Advanced Passenger Train and the Swedish X-2000 tilting. But how come I have never seen a picture showing how the Train-X, Turbo-Train, Talgo, or Acela leans into a curve from any stateside photographer? I guess I could have taken such a picture, but I didn't hang around Mystic Amtrak station to get a chance to set up such a shot. Properly taken, such pictures could document the amount of super elevation and amount of suspension tilt, and besides the kewl factor, such pictures could chronicle the operation of these high-tech trains.
A second question is, remind me why Amtrak is running Acela trainsets on the Shore Line and why the bazillion dollars was spent on the very nicely maintained and modern double-track overhead wire beyond New Haven? I can understand the use of Acela sets on the NY-DC run owing to the fast running, if not true HSR, that can be achieved. But even with the tilt, it didn't seem that the Acela consist went by the station all that fast.
Is the answer to my question the value of the one-seat express train ride from Boston all the way to DC? Is there a lot of customer demand for that? Does the Acela with its electric high-horsepower and active tilt provide substantial speed-up on the Boston-NY segment? I once heard that Amtrak tried out the Acela predecessor in the form of the LRC, and it seemed that tilt equipment didn't provide much of an edge over good ol' Amfleet, which is a kind of "poor man's tilt train" in that Amfleet doesn't lean out of curves as much and allows good curve speed on the Shore Line. Given the twisting, winding, scenic Shore Line, is the Acela giving any quantifiable benefit in timing on that run?
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
I definitely do not have the technical answers but these factors may be relevant:
1. Acela travels between Boston and New York in about three and a half hours an improvement of half an hour over previous trains (and 45 minutes quicker than Northeast Regionals between new York and Boston).
2. Between New York and Boston the Acela Express has up to a 37% share of the combined train and air market.
3. Tilting enables passengers to ride more comfortably on curved sections of track faster than would otherwise be possible, by leaning into the bend. Metro-North Railroad restricts tilting on the segment of track north of New York owned by them. While the system was originally designed for a 6.8° tilt, the cars were redesigned 4 inches wider to accommodate wider seats and aisles that reduced allowable tilt to a more modest 4.2° to fit within the clearance constraints of the existing tracks.
C&NW, CA&E, MILW, CGW and IC fan
If you had been at the Kingston RI station, you might have observed the Acela passing through at 150 mph. The only part of the NEC where the Acela currently runs at 150 mph is in RI and MA. The Regionals hit 125 mph on those same segments, because they are now powered by electric locomotives from New Haven to Boston.
Yes, much of the Shore Line East route is still slow, though the Acela and Regionals do hit 100 mph on portions of it. By electrifying the NEC from New Haven to Boston, Amtrak did away with a large number of daily engine changes and now has improved trip times for both classes of service, the Acela and the NE Regionals.
As for the gate timing, it should be a quad gate at Mystic as there are now 11 remaining grade crossings on the NEC, all in the stretch from just west of New London to Mystic. All of them, other than the crossings in New London near the station (where the trains are going slow anyway), should have quad gates to prevent people from attempting to drive around the gates. If people in Mystic are unhappy with how long the gates are down, I'm sure Amtrak would be happy to dust off the NECIP plans for separating the grade crossing next to the Mystic train station that was rejected by the locals back then. Of course, Amtrak would ask the locals and CT DOT to pick up much of the tab for the bridge that was to provide the grade separation west of the current grade crossing.
With regards to photos of the Acela tilting, there are many such photos on the net.
One question to answer first: do the Acela power cars tilt at all?
The X2000 power car didn't, and it was allowed higher speeds around PRR curves than Acela is.
As for the question of value of the ride, the answer is in the figures: people do pay to ride and traffic has increased so that trains have been added. Also, if it didn't make money, attract a goodly number of passengers, in the time it has been in service, it would have been abandoned by now.
As for the grade crossing time....I wonder if it is set for the trains stopping distance as much as its arrival at the crossing.
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Presumably the up to a 37% share of the combined train and air market came from a Wikipedia posting, which references a March 21, 2008 WIRED article. The quote from the article; "An Amtrak rep says Acela’s market share on the busy route grew from 36 percent in 2006 to 41 per cent last year." It does not say that the Acela's have a 37 or 41 per cent of the Boston to New York end point market.
Coupled with the map presented, I suspect the claim the market is the total market between Boston and New York, which amongst other stops would include Providence and New Haven. Both of these stops are significant markets for the train, but they are not significant air markets to and from New York. This is especially true for New Haven.
Amtrak is cherry picking market data to toute the impact of its trains on NEC travel. Amongst other things it overlooks buses, which I suspect are a significant presence in the NEC. Reportedly Megabus is doing well in the New York to Washington market. Equally important, although I have not been able to find the numbers for the NEC, I wonder what per cent of the intercity travel market Amtrak enjoys when automobiles are thrown into the equation. The travel market is not just trains and planes.
Wikipedia along with several other sources claim that the Acela is profitable. That is incorrect. Based on Amtrak's numbers, which by the way have not been presented for more than a year because Amtrak is supposedly trying to figure out how to roll depreciation, interest, and unallocated costs into its route costs, the Acela is not profitable when the capital costs, which are substantial, are rolled into the equation.
Why electrify the Shore Line? No alternative with a reasonable timeline, I suspect. If you wanted to do the "inland" route via Springfield, you wind up having to deal with Conrail over how, who and where east of Springfield. If you try to resurrect the old NH "airline", you'd wind up in NIMBY-land in short order. Just doing catenary and raising speed on the Shoreline waded pretty deeply into the NIMBY swamp (NIMBY-land? NIMBY swamp? I need to keep my metaphors straight!).
The route really isn't THAT bad. There is a lot of straight, fast running east of Mystic. The intolerable cruelty is west of NH. 90 mph and no tilt is a schedule killer. Every other problem with the NEC north end pales in comparison to this.
The little bit of tilt that Acela is allowed probably isn't worth what it cost, but that's due in part to "he said/she said" inexcusable problem of the 4" too wide equipment.
If I were the king of Amtrak and I was given a mandate to improve the NEC running times, my wish list would probably be:
1. Move track centers on curves 4" and push for more underbalance from FRA to get Acelas going "full tilt"....NOW!
2. Constant tension cat on south end - as fast as I could steal the money.
3. New HSR alignment Shell to NH. First step, guestimate the $$$ and find the funding. Nobody will really pay any attention to lines on a map until you have the bulldozer idling.
I'd also start looking very closely at ripping out the coded track circuit based signal system (ACSES) and replacing it with freight industry standard PTC equipment and develop floating blocks to increase capacity on the line and reduce delays.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
With respect to crossing gates, I was there at Amtrak Station, Mystic, CT only to watch one train. From the angle of having pulled into the station parking lot, I saw only one gate arm protecting the side of the crossing I was on. It could have been one of those "barrier" gates that resists vehicles from crashing through, but if it were a "quad" gate that blocked off both entry and exit from the crossing, I think I would have noticed that and remarked upon it.
Does anyone even use a "quad" gate that blocks both sides to prevent "gate running." As I said, everything has engineering trades, and a quad gate could potentially trap someone inside the crossing, and you can think of the law suits.
As to the long gate dwell time, I am not complaining about it as I wanted to watch the train, and I don't know of anyone who lives there complaining about it. I was simply pointing out that the dwell time is one of the engineering design parameters affecting safety that also has a tradeoff associated with it. The dwell time seemed long enough, and the train speed slow enough, that if there was some kind of detection system that the engine driver could stop a train in time to avoid a crash. But as Mystic Station is on a rather sharp curve, the driver probably doesn't have a clear sight line and would have to rely on some remote detection. Or maybe the long dwell time is a safety feature in that if someone gets stuck on the crossing, they have time to evacuate their vehicle and live, even if a crash is not avoided?
As to photos of the Acela tilting, I see lots of photos of the Acela on the Web, but I can't turn up any face-on shots of Acela on a curve that clearly shows the combined track super elevation and train banking system tilt. When I searched Google for "Acela Tilt Photos", one of the first sites to turn up was right here. Funny thing that Google, you ask a question and it points you to the Web board where you asked that same question.
Yes, there are pictures of the Acela on curves and pictures from different angles, but pictures highlighting such technical features of trains tend to be rare or non-existent. The tilt feature of TurboTrain on this same route was touted, but try finding a photo showing it (yes, I have Jason Shron's book). I am also suggesting that Mystic, CT Amtrak Station would be a safe and legal place to get such a photo (of Acela -- TurboTrain returned to that Big Coach Yard in the Sky).
With respect to whether the locomotives or "power cars" tilt, I wasn't set up to snap a photo (sorry), but it appeared that the whole train leaned into that curve the same amount. Again, it is sometimes a large level of superelevation that can give the same effect, and that is why I asked about how much the Acelas tilt. The amount of lean was not as extreme as I have seen in photos of X-2000 or Pendolino, but it looked like a lot. Yes, the locomotive doesn't have to tilt (LRC locos were that way), but it seems that these do.
Again, with respect to tilt and whether it is a matter of "passenger comfort", there is a safety component too. The amount of underbalance, that is, going around the curve faster than the superelevation amount, is ultimately limited by either the train tipping (which had happened in Australia on a narrow-gauge -- 3.5 foot gauge -- tilt train exceeding a speed restriction), or the train putting too much force on the outside rail, but the passenger comfort limit is usually reached first, hence the use of tilt trains. But it is more than simply whining passengers complaining about their comfort just as the grade crossing safety equation is more than town residents complaining about wait times at grade crossings.
The FRA has rules on the amount of underbalance felt by the passengers, and it is a safety issue concerning allowing passengers to walk about the train and passengers not being seat belted. The FRA rules allows 3 inches of underbalance on "conventional" trains, 4 inches on Amfleet with its reduced outward lean, and Don Oltmann once weighed in that Amfleet got a waiver on the Shore Line to operate at 6 inches. If Amfleet is allowed 6 inches of underbalance, and I read on another Web thread that Acela is limited to 6 inches because apart from limiting the tilt for sideswipe worries, the design limit of 9 inches of underbalance didn't work out on Acela because there is an increased derailment risk owing to technical aspects of the truck's tracking characteristics during tests.
Given the solution of using dual-mode locomotives, the small apparent design edge of Acela over Amfleet, the numerous speed restrictions on the Shore Line, and Boston-NY being a "thinner" segment than NY-DC, I think at least asking whether the New-Haven to Boston electrification was a good purchase decision is worthy of some discussion pro and con. Even if more money for Amtrak capital improvements (or catching up on deferred maintenance) is to be had, money spent in one place is not available to be spent some other worthy place.
Center city to center city Boston to NY and NY to Boston all three are probably about the same elapsed time with Acela maybe having the time edge and the bus the price edge. But bus has the most problems of lost time because of highway congestion especially at the two ends thus not meeting its schedule and not being as reliable. After Acela, Northeast Regional trains are not that much slower. The trains offer metro stops in CT with MNRR connections to GCT; I'm not sure of bus accomodation, and planes better not. Buses do have a closer to home pick up in Boston...more community or suburban points, which trains do not. All three (or four) services price themselves for their percieved market and all seem to be thusly successful. Rail does have room for expansion of services with more trains to be added as well as more cars on the Regionals. Planes and buses are more restricted as airways are croweded and while more buses can be added (sections of runs?) congestion can conusme them. More highways cannot be built. But faster tracks with faster train can.
Paul, the Acela power cars do not tilt, only the passenger cars do. An "active" tilt system is employed. The amount of tilt is determined by onboard electronics. Of course, the entire train leans into the superelevated curve. The active tilt is turned off while on MNRR territory.
According to the Amtrak ETT, the public crossing at MP 132.3, Broadway Extension, is a "smart crossing" with 4 quadrant gates and a vehicle detection system is installed, interconnected with the cab signal system and can downgrade the cab signals if a vehicle is stopped on the crossing.
Paul MilenkovicDon Oltmann once weighed in that Amfleet got a waiver on the Shore Line to operate at 6 inches.
In the process of looking for Amtrak's latest operating data on the NEC, i came across this. Probably debatable truth in the view of some posters, but ya never can tell:
"According to U.S. Department of Energy data, Amtrak is almost 14 percent more efficient than domestic airline travel and 31 percent more efficient than auto travel on a per-passenger-mile basis."
Figures listed are from 2009 and refer to BTUs used per passenger mile.
Energy Efficiency Data Source: U.S. Department of Energy Oak Ridge National Laboratory Data on Fuel Efficiency - Transportation Energy Data Book (Edition 30), Table 2.12
From the April performance report:
"Year-to-date ridership between Boston and Newark is down significantly (-31%) as a result of JetBlue beginning service in this market in May 2011, and the subsequent drop in prices on the existing market’s carriers. Acela ridership in the endpoint markets of NY-DC (+3%) and NY-Boston (+3%) performed slightly better than the rest of the route in April FY12."
"Northeast Regional travel in the endpoint market of NY-Boston (+18%) was strong in March. However, the southend endpoint market of NY-DC was +1% vs last April. The top markets through New York including Boston-Philadelphia (+81%) and Philadelphia-Providence (+92%) were up significantly due to a drop in airline service."
[Specific data on route operating expense versus operating revenue still not available due to financial system conversion]
Paul Milenkovic Given the solution of using dual-mode locomotives, the small apparent design edge of Acela over Amfleet, the numerous speed restrictions on the Shore Line, and Boston-NY being a "thinner" segment than NY-DC, I think at least asking whether the New-Haven to Boston electrification was a good purchase decision is worthy of some discussion pro and con. Even if more money for Amtrak capital improvements (or catching up on deferred maintenance) is to be had, money spent in one place is not available to be spent some other worthy place.
Paul: The speed restrictions are definitely a problem. MN RR is certainly a culprit. Maybe once all the substandard bridges are replaced a long term program of maybe 5 -10 miles every 3 - 4 years to eliminate all speed restrictions in a segment would be appropriate ??
blue streak 1 Paul: The speed restrictions are definitely a problem. MN RR is certainly a culprit. Maybe once all the substandard bridges are replaced a long term program of maybe 5 -10 miles every 3 - 4 years to eliminate all speed restrictions in a segment would be appropriate ??
The speed restrictions in CT are due to the many curves of the tracks, the bottlenecks, the tight spacing of the tracks on the New Haven Line portion, and many other factors. The bridges, especially the many movable bridges, are only part of it. To "eliminate all speed restrictions" on the New Haven line and Shore Line East would require straightening out the ROW, which would require massive and hugely expensive taking of private property. Which is politically impossible. The best that can be done is selected curve reductions or straightening of the route in short segments where it can be done. Another alternative in eastern CT is to resurrect the idea of a bypass or realignment of the NEC to follow the I-95 ROW from the CT River to west of Mystic and then reconnect to the current NEC before Westerly or elsewhere in RI.
The 2010 Next Gen NEC concept document route skipped the New Haven Line entirely with a proposed new route through the middle of CT - north from NYC, then through Danbury, Hartford, and through NE CT. This was a first draft concept proposal, not an engineering study. The problem is that selecting an entirely new route through CT will take 20 years of feasibility, engineering, environmental studies with numerous contentious public meetings.
There are improvements in the plans for CT. The Niantic River replacement bridge should go into service this fall which will allow for 90 mph speeds across the bridge segment rather than the 60 mph for the current bridge. The replacement of the catenary on the New Haven Line is projected to be done by 2017. The 2010 NEC Master Infrastructure Plan called for NYP-BOS trip times of 3 hours and 8 minutes by 2030 with a mostly conservative list of projects.
New versions of the NEC Master Plan and the Next Gen NEC documents are supposed to be released soon. We will see if the planners are willing to fight for additional speed improvement projects in CT.
A lot of people look at flat maps of the East and New England and literally or physically draw straight lines from place to place. What they don't realize is that while not 5000+ ft high Rockey Mountains, even the frequent 100 foot high coastal area and up to 2, 3, and sometimes 4 thousand ft. high hills are packed together so that valleys are often tight and twisting. CT is a great example of almost this entire description except the hills aren't much over 2000 feet but the narrow valleys seperating them are virtual curves and over short distances 360 degrees is possible. Add to that that when the railroads were built, property acquisitions for ROW's added to the curvatures. To go back almost 200 years to "straighten" things out is not only politically impossible but also probably civilly impossible' and perhaps even physically, and definitey financially, impossible. The answers to progress and speed will have to be found in the track and the trains rather than in the terrain.
Alan FThe speed restrictions in CT are due to the many curves of the tracks, the bottlenecks, the tight spacing of the tracks on the New Haven Line portion, and many other factors.
I think the primary reason for the many turns on the NH Shore route is because the original engineering placed it very close to the coast, but had it swinging inland, to avoid inlets or cross them at a narrower point then going straight, and then back close again. That route does so a lot, but not primarily to avoid hills.
timz Paul Milenkovic: Don Oltmann once weighed in that Amfleet got a waiver on the Shore Line to operate at 6 inches. No idea what waiver they have, but can anyone name a curve on the NEC where Amfleet is allowed a speed that would demand 6 inches unbalance?
Paul Milenkovic: Don Oltmann once weighed in that Amfleet got a waiver on the Shore Line to operate at 6 inches.
No idea what waiver they have, but can anyone name a curve on the NEC where Amfleet is allowed a speed that would demand 6 inches unbalance?
I think Paul might have misunderstood what I said a while back...or I said it poorly. The six inches is the max superelevation of the track allowed. Amtrak has lots of 6" superelevation, but anything over 4" is very rare in the freight world. Four inches will get you balance at 60 mph on a two degree curve.
oltmannd timz: Paul Milenkovic: Don Oltmann once weighed in that Amfleet got a waiver on the Shore Line to operate at 6 inches. No idea what waiver they have, but can anyone name a curve on the NEC where Amfleet is allowed a speed that would demand 6 inches unbalance? I think Paul might have misunderstood what I said a while back...or I said it poorly. The six inches is the max superelevation of the track allowed. Amtrak has lots of 6" superelevation, but anything over 4" is very rare in the freight world. Four inches will get you balance at 60 mph on a two degree curve.
timz: Paul Milenkovic: Don Oltmann once weighed in that Amfleet got a waiver on the Shore Line to operate at 6 inches. No idea what waiver they have, but can anyone name a curve on the NEC where Amfleet is allowed a speed that would demand 6 inches unbalance?
Sorry Don, you are among the most technically savy persons around here and any technical detail I remember for someplace I assume to have come from you.
Yes, there is the superelevation and then there is the "unbalance" or the "cant deficiency." Both can be measured in units of inches, and doing a simple calculation on a calculator with trig functions, inches of superelevation on standard gauge of 4'8 1/2" is about the same as angle in degrees. Also, to an initial rough approximation without getting into all of the trig functions, the superelevation and the cant deficiency in either degrees or inches add.
For example, if the track is banked (superelevated) by 6" and if the Acela is permitted 7" of cant deficiency in rounding a curve, you have a total of 6+7 = 13 inches to plug into formulas for how fast you can go around the curve. If the Acela tilts no more than 4 degrees, that 4 degrees roughly takes 4" off the 7" cant deficiency to leave 3" in the calculation of how much force is experienced by the passengers (about the same as a conventional non-tilting train operating at 3" cant deficiency).
There are a lot of places where this is discussed so I am not including a bibliography here, but it seems the Acela was once qualified for 9" of cant deficiency, but they trimmed this back to 7" -- this has nothing to do with the tilt and everything to do with whether the power cars (locomotives) that weigh 200,000 lb a piece would put too much sideways force on the rails. I also hear that the Acela is limited to 4-deg tilt, some people say the engine driver has to flip a switch to disable even that much tilt on Metro North, others say the tilt is disabled over the entire Shore Line to Boston, the one photo of an Acela leaning into a curve at Elizabeth, NJ suggests to me that the lean is all the large amount of superelevation Don is talking about and that the tilt is disabled everywhere.
I have heard that Amfleet has been OK'd for 6" cant deficiency and I read elsewhere that Amfleet operates at up to 5" cant deficiency on the Shore Line. I also read that VIA has given up on maintaining the active tilt on the LRC and those cars operate tilt free.
As to the suggestion that the railfan community could supply photos and the counter that the photos are out there and I need to look them up, the few photos I have seen suggest that the NEC uses the fully allowed 6" of superelevation, which is a lot to us Midwest flatlanders who only see freight tracks. That amount of superelevation will produce a noticable lean into the turn when viewing trains or in pictures. The other thing is that from my train model experience in building tilting trains for exhibition, the lean on the nose of something like an Acela power car is much more visually striking, and it will be hard to tell of the following trains cars are leaning more.
On the other hand, the TurboTrain power cars carried passengers and they had the same (passive) tilt system as the intermediate cars. I haven't seen a TurboTrain photo showing evidence of the passive tilt adding to the superelevation lean, and the same holds true for Acela.
Paul Milenkovicthe one photo of an Acela leaning into a curve at Elizabeth, NJ suggests to me that the lean is all the large amount of superelevation Don is talking about and that the tilt is disabled everywhere.
Paul MilenkovicI have heard that Amfleet has been OK'd for 6" cant deficiency and I read elsewhere that Amfleet operates at up to 5" cant deficiency on the Shore Line.
Last I looked Amfleet was allowed 100 mph around the curve at 41.9064N 71.3109W
http://maps.google.com/maps?q=41.9064+n+71.3109+w&hl=en&sll=37.0625,-95.677068&sspn=38.41771,56.513672&t=h&z=16
which is a 1 deg 30 min. Anyone beat that one?
timz Paul Milenkovic: the one photo of an Acela leaning into a curve at Elizabeth, NJ suggests to me that the lean is all the large amount of superelevation Don is talking about and that the tilt is disabled everywhere. Ignore that suggestion. Paul Milenkovic: I have heard that Amfleet has been OK'd for 6" cant deficiency and I read elsewhere that Amfleet operates at up to 5" cant deficiency on the Shore Line. I bet no one can find a curve where Amfleet is allowed 6" deficiency. Five inches isn't out of the question; does anyone know of such a curve? Last I looked Amfleet was allowed 100 mph around the curve at 41.9064N 71.3109W http://maps.google.com/maps?q=41.9064+n+71.3109+w&hl=en&sll=37.0625,-95.677068&sspn=38.41771,56.513672&t=h&z=16 which is a 1 deg 30 min. Anyone beat that one?
Paul Milenkovic: the one photo of an Acela leaning into a curve at Elizabeth, NJ suggests to me that the lean is all the large amount of superelevation Don is talking about and that the tilt is disabled everywhere.
Paul Milenkovic: I have heard that Amfleet has been OK'd for 6" cant deficiency and I read elsewhere that Amfleet operates at up to 5" cant deficiency on the Shore Line.
Ignore the suggestion? Who am I going to believe, you or my lying eyes?
I print the photo and I take out a ruler. It is pretty straightforward to measure the tilt of the power car relative to the crossties. The word-on-the-street they tell me is that the power car doesn't tilt. It is harder to see the tilt on the coaches. In fact, there is a picture out on the Web of one of the Advanced Passenger Train prototypes where the tilt on one of the coaches failed, and you really have to study the picture to see it out-of-line with the other coaches. On the other hand, there are features on the coaches, the rooftop blisters come to mind, that may allow judging the amount of tilt.
For example, how about this picture http://www.rrpicturearchives.net/showPicture.aspx?id=599324 from south of NYC. The power car is really leaning into that curve, but you can compare that lean against this wooden crossing planking on an adjacent track, and this picture confirms that the power cars are not tilting, either because the tilt was turned off or because the power cars never had the tilt linkage. You can't see the roof blisters on the coaches too well, and it is hard to compare the car sides as the power car appears to have slab sides whereas the coaches have that faceted sides like on the LRC's. But no way those coaches are tilting as much as 4 degrees in that photo.
I also did a quick calculation on 100 MPH on a 1.5-deg (1 deg 30 min) curve and came up with an equivalent lateral acceleration of 10.17" of cant. As from the photos and the heavy lean of the crossties, I believe that the superelevation is 6", which means that Amfleet is allowed 4" of unbalance on that curve (the .17 is attributed to all of the rounding and approximations I am making). That is consistent with CFR Title 49 -- Transportation, Sec. 213.57 Curves; elevation and speed limitations. That Federal regulation limits "conventional" equipment to 3" cant deficiency whereas "trains demonstrated to have minimal adverse suspension roll" (i.e. Amfleet with the Pioneer III truck) is allowed a full 4".
Again, there are multiple factors imposing limits on the cant deficiency, and a train tipping over only happened (once -- Lady: do these big jets crash very often? Airline agent: no, only once) in Australia with a Hitachi tilt train on narrow gauge (3.5 foot). Before the train tips over you run into problems of the locomotive spreading the rails or sufficient side forces to climb the rails, and before that you run into "passenger comfort", which is really passenger safety so someone doesn't fall down and break a hip getting up out of their seat. I am aware that someone may have tested an Amfleet at 6" unbalance out in Pueblo, CO to see that it doesn't jump the tracks; that doesn't mean Amtrak runs that fast or even is allowed to run them that way. But a lot of "the guys" (in the railfan community) seem to think Amfleet is allowed 5", which as you say, could be checked by calculation of curves against their posted speed limit.
So what is Acela allowed on that curve, faster than 100 MPH?
There is a lot that we argue about here, about we scrapped steam too soon, be need to spend more money on HSR, long-distance trains, etc. that will never be resolved. Whether Amfleet is allowed essentially the same curve speeds as Acela, whether the Acela tilt is even in use or not, all of these questions could be answered from info railfans could access along with a few properly chosen photographs. Inquiring minds need to know, and whether tilt trains are even practical is an important public policy question.
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