# Tilting Trains and Technological Dead-Ends

The history of tilting trains is on my mind, because it’s easy to take a technological advance and declare it a solution to a problem without first producing it at scale. I know that 10 years ago I was a big fan of tilting trains in comments and early posts, based on both academic literature on the subject and existing practices. Unfortunately, this turned into a technological dead-end because the maintenance costs were too high, disproportionate to the real speed benefits, and further work has gone in different directions. I bring this up because it’s a good example of how even a solution that has been proven to work at scale can turn out to be a dead-end.

What is tilting?

It is a way of getting trains to run at higher cant deficiency.

What is cant deficiency?

Okay. Let’s derive this from physical first principles.

The lateral acceleration on a train going on a curve is given by the formula a = v^2/r. For example, if the speed is 180 km/h, which is 50 m/s, and the curve radius is 2,000 meters, then the acceleration is 50^2/2000 = 1.25 m/s^2.

Now, on pretty much any curve, a road or railway will be banked, with the outer side elevated above the inner side. On a railway this is not called banking, but rather superelevation or cant. That way, gravity countermands some of the centrifugal force felt by the train. The formula on standard-gauge track is that 150 mm of cant equal 1 m/s^2 of lateral acceleration. The cant is free speed – if the train is perfectly canted then there is no centrifugal force felt by the passengers or the train systems, and the balance between the force on the inner and outer rail is perfect, as if there is no curve at all.

The maximum superelevation on a railway is 200 mm, but it only exists on some Shinkansen lines. More typical of high-speed rail is 160-180 mm, and on conventional rail the range is more like 130-160; moreover, if trains are expected to run at low speed, for example if the line is dominated by slow freight traffic or sometimes even if the railroad just hasn’t bothered increasing the speed limit, cant will be even lower, down to 50-80 mm on many American examples. Therefore, on passenger trains, it is always desirable to run faster, that is to combine the cant with some lateral acceleration felt by the passengers. Wikipedia has a force diagram:

The resultant force, the downward-pointing green arrow, doesn’t point directly toward the train floor, because the train goes faster than the balance speed. This is fine – some lateral acceleration is acceptable. This can be expressed in units of acceleration, that is v^2/r with the contribution of cant netted out, but in regulations it’s instead expressed in theoretical additional superelevation required to balance, that is in mm (or inches, in the US). This is called cant deficiency, unbalanced superelevation, or underbalance, and follows the same 150 mm = 1 m/s^2 formula on standard-gauge track.

Note also that it is possible to have cant excess, that is negative cant deficiency. This occurs when the cant chosen for a curve is a compromise between faster and slower trains, and the slower trains are so much slower the direction of the net force is toward the inner rail and not the outer rail. This is a common occurrence when passenger and freight trains share a line owned by a passenger rail-centric authority (a freight rail-centric one will just set the cant for freight balance). It can also occur when local and express passenger trains share a line – there are some canted curves at stations in southeastern Connecticut on the Northeast Corridor.

The maximum cant deficiency is ordinarily in the 130-160 mm range, depending on the national regulations. So ordinarily, you add up the maximum cant and cant deficiency and get a lateral acceleration of about 2 m/s^2, which is what I base all of my regional rail timetables on.

You may also note that the net force vector is not just of different direction from the vertical relative to the carbody but also of slightly greater magnitude. This is an issue I cited as a problem for Hyperloop, which intends to use far higher cant than a regular train, but at the scale of a regular train, it is not relevant. The magnitude of a vector consisting of a 9.8 m/s^2 weight force and a 2 m/s^2 centrifugal force is 10 m/s^2.

Okay, so how does tilt interact with this?

To understand tilt, first we need to understand the issue of suspension.

A good example of suspension in action is American regulations on cant deficiency. As of the early 2010s, the FRA regulations depend on train testing, but are in practice, 6″, or about 150 mm. But previously the blanket rule was 3″, with 4-5″ allowed only by exception, mocked by 2000s-era advocates as “the magic high-speed rail waiver.” This is a matter of carbody suspension, which can be readily seen in the force diagram in the above secetion, in which the train rests on springs.

The issue with suspension is that, because the carbody is sprung, it is subject to centrifugal force, and will naturally suspend to the outside of the curve. In the following diagram, the train is moving away from the viewer and turning left, so the inside rail is on the left and the the outside rail is on the right:

The cant is 150 mm, and the cant deficiency is held to be 150 mm as well, but the carbody sways a few degrees (about 3) to the outside of the curve, which adds to the perceived lateral acceleration, increasing it from 1 m/s^2 to about 1.5. This is typical of a modern passenger train; the old FRA regulations on the matter were based on an experiment from the 1950s using New Haven Railroad trains with unusually soft suspension, tilting so far to the outside of the curve that even 3″ cant deficiency was enough to produce about 1.5 m/s^2 of lateral force felt by the passengers.

By the same token, a train with theoretically perfectly rigid suspension could have 225 mm of cant deficiency and satisfy regulators, but such a train doesn’t quite exist.

Here comes tilt. Tilt is a mechanism that shifts the springs so that the carbody leans not to the outside of the curve but to its inside. The Pendolino technology is theoretically capable of 300 mm of cant deficiency, and practically of 270. This does not mean passengers feel 1.8-2 m/s^2 of lateral acceleration; the train’s bogies feel that, but are designed to be capable of running safely, while the passengers feel far less. In fact the Pendolino had to limit the tilt just to make sure passengers would feel some lateral acceleration, because it was capable of reducing the carbody centrifugal force to zero and this led to motion sickness as passengers saw the horizon rise and fall without any centrifugal force giving motion cues.

Two lower cant deficiency-technology than Pendolino-style tilt are notable, as those are not technological dead-ends, and in fact remain in production. Those are the Talgo and the Shinkansen active suspension. The Talgo has no axles, and incorporates a gravity-based pendular system in which the train is sprung not from the bottom up but from the top down; this still isn’t enough to permit 225 mm of cant deficiency, but high-speed versions like the AVRIL permit 180, which is respectable. The Shinkansen active suspension is computer-controlled, like the Pendolino, but only tilts 2 degrees, allowing up to 180 mm of cant deficiency.

What is the use case of tilting, then?

Well, the speed is higher. How much higher the speed is depends on the underlying cant. The active tilt systems developed for the Pendolino, the Advanced Passenger Train, and ICE T are fundamentally designed for mixed-traffic lines. On those lines, there is no chance of superelevating the curves 200 mm – one freight locomotive at cant excess would demolish the inner track, and the freight loads would shift unacceptably toward the inner rail. A more realistic cant if there is much slow freight traffic is 80 mm, in which case the difference between 150 and 300 mm of cant deficiency corresponds to a speed ratio of $\sqrt{(80+300)/(80+150)} = 1.285$.

Note that the square root in the formula, coming from the fact that acceleration formula contains a square of the speed, means that the higher the cant, the less we care about cant deficiency. Moreover, at very high speed, 300 mm of cant deficiency, already problematic at medium speed (the Pendolino had to be derated to 270), is unstable when there is significant wind. Martin Lindahl’s thesis, the first link in the introduction, runs computer simulations at 350 km/h and finds that, with safety margins incorporated, the maximum feasible cant deficiency is 250 mm. On dedicated high-speed track, the speed ratio is then $\sqrt{(200+250)/(200+130)} = 1.168$, a more modest ratio than on mixed track.

The result is that for very high-speed rail applications, Pendolino-level tilting was never developed. The maximum cant deficiency on a production train capable of running at 300 km/h or faster is 9″ (230 mm) on the Avelia Liberty, a bespoke train that cost about double per car what 300 km/h trains cost in Europe. To speed up legacy Shinkansen lines, JR Central and JR East have developed active suspension, stretching the 2.5 km curves of the Tokaido Shinkansen from the 1950s and 60s to allow 285 km/h with the latest N700 trains, and allowing 360 km/h on the 4 km curves of the Tohoku Shinkansen.

What happened to the Pendolino?

The Pendolino and similar trains, such as the ICE T, have faced high maintenance costs. Active tilting taxes the train’s mechanics, and it’s inherently a compromise between maintenance costs and cant deficiency – this is why the Pendolino runs at 270 mm where it was originally capable of 300 mm. The Shinkansen’s active suspension is explicitly a compromise between costs and speed, tilted toward lower cant deficiency because the trains are used on high-superelevation lines. The Talgo’s passive tilt system is much easier to maintain, but also permits a smaller tilt angle.

The Pendolino itself is a fine product, with the tilt removed. Alstom uses it as its standard 250 km/h train, at lower cost than 350 km/h trains. It runs in China as CRH5, and Poland bought a non-tilting Pendolino fleet for its high-speed rail service.

Other medium-speed tilt trains still run, but the maintenance costs are high to the point that future orders are unlikely to include tilt. Germany has a handful of tilt trains included in the Deutschlandtakt, but the market for them is small. Sweden is happy with the X2000, but its next speedup of intercity rail will not involve tilting trains on mostly legacy track as Lindahl’s thesis investigated, but conventional non-tilting high-speed trains on new 320 km/h track to be built at a cost that is low by any global standard but still high for how small and sparsely-populated Sweden is.

In contrast, trainsets with 180 mm cant deficiency are still going strong. JR Central recently increased the maximum speed on the Tokaido Shinkansen from 270 to 285 km/h, and Talgo keeps churning out equipment and exports some of it outside Spain.

# Metro-North Doesn’t Know Best Industry Practices

Governor Ned Lamont’s plan for speeding up trains between New York, New Haven, and Hartford seems to have fallen by the wayside, but Metro-North and the Connecticut Department of Transportation are still planning for future investments. Several high-level officials met with the advocates from the Connecticut Commuter Rail Council, and the results are unimpressive – they have made false statements out of ignorance of not just best practices outside North America but also current federal regulations, including the recent FRA reform.

The meeting link is a video and does not have a searchable transcript, so I’m going to give approximate timestamps and ask that people bear with me. At several points, highly-paid officials make statements that are behind the times, unimaginative, or just plain incorrect. The offenders are Richard Andreski, the bureau chief of public transportation for CDOT, who according to Transparency.CT earns a total of $192,000 a year including fringe benefits, and Glen Hayden, Metro-North’s vice president of engineering, who according to See Through NY earns an annual base salary of$219,000.

20-25 minutes: there’s a discussion, starting a few minutes before this timestamp, about Metro-North’s future rolling stock procurement. In addition to 66 M8 electric multiple units (EMUs), the railroad is planning to buy 60 unpowered railcars. Grilled about why buy unpowered railcars rather than multiple units, such as diesel multiple units (DMUs), Andreski said a few questionable things. He acknowledged that multiple units accelerate faster than locomotive-hauled trains, but said that this was not needed on the lines in question, that is the unpowered Metro-North branch lines, Shore Line East, and the New Haven-Hartford line. In reality, the difference, on the order of 45 seconds per stop at a top speed of 120 km/h (55 seconds if the top speed is 144 km/h), and electrification both massively increases reliability and saves an additional 10 seconds per stop (or 30 if the top speed is 144).

More worryingly, Andreski talks about the need for flexibility and the installed base of diesel locomotives. He suggests unpowered cars are more compatible with what he calls the train of the future, which runs dual-mode. Dual-mode trains today are of low quality, and the innovation in the world focuses on single-mode electric trains, with a growing number of railroads electrifying as well as transitioning to multiple units. Metro-North itself is a predominantly EMU-based railroad – running more EMUs, especially on the already-wired Shore Line East, is more compatible with its existing infrastructure and maintenance regime than keeping low-performing diesel branches and running diesel under catenary on the trunk line.

1:14-1:17: Andreski states that the 60 unpowered single-level cars should cost about $250 million, slightly more than$4 million per car. When a reader of this blog noted that in the rest of the world, a 25-meter multiple-unit costs $2.5 million, Andreski responded, “this is not accurate.” The only trouble is, it is in fact accurate; follow links to contracts reported in Railway Gazette in the rolling stock cost section of this post. It is not clear whether Andreski is lying, ignorant, or in a way both, that is making a statement with reckless disregard for whether it is true. Hayden then chimes in, talking about FRA regulations, saying that they’re different from American ones, so European and Asian prices differ from American ones, seemingly indifferent to the fact that he just threw Andreski under the bus – Andreski said that multiple-units do not cost$2.5 million per car and if a public contract says they do then it’s omitting some extra costs. The only problem is, FRA regulations were recently revised to be in line with European ones, with specific eye toward permitting European trains to run on American tracks with minimal modifications, measured in tens of thousands of dollars of extra cost per car. In a followup conversation off-video, Hayden reiterated that position to longtime reader Roger Senserrich – he had no idea FRA regulations had been revised.

Hayden’s response also includes accessibility requirements. Those, too, are an excuse, albeit a slightly defensible one: European intercity trains, which are what American tourists are most likely to have experience with, are generally inaccessible without the aid of conductors and manual boarding plates. However, regional trains are increasingly fully accessible, at a variety of floor heights, and it’s always easier to raise the floor height to match the high platforms of the Northeast Corridor than to lower it to match those of low-platform networks like Switzerland’s.

1:45: asked about why Metro-North does not run EMUs on the wired Shore Line East, a third official passes the buck to Amtrak, saying that Amtrak is demanding additional tests and the line is Amtrak’s rather than Metro-North’s property. This is puzzling, as 1990s’ Amtrak planned around electrification of commuter rail service east of New Haven, to the point of constructing its substations with room for expansion if the MBTA were ever interested in running electric service on the Providence Line. It’s possible that Amtrak today is stalling for the sake of stalling, never mind that commuter rail electrification would reduce the speed difference with its intercity trains and thus make them easier to schedule and thus more reliable. But it’s equally possible that CDOT is being unreasonable; at this point I would not trust either side of any Amtrak-commuter rail dispute.

# FRA Reform is Here!

Six and a half years ago, the Federal Railroad Administration announced that it was going to revise its passenger train regulations. The old regulations required trains to be unusually heavy, wrecking the performance of nearly every piece of passenger rolling stock running in the United States. Even Canada was affected, as Transport Canada’s regulations mirrored those south of the border. The revision process came about for two reasons: first, the attempt to apply the old rules to the Acela trains created trains widely acknowledged to be lemons and hangar queens (only 16 out of 20 can operate at any given time; on the TGV the maximum uptime is 98%), and second, Caltrain commissioned studies that got it an FRA waiver, which showed that FRA regulations had practically no justification in terms of safety.

The new rules were supposed to be out in 2015, then 2016, then 2017. Then they got stuck in presidential administration turnover, in which, according to multiple second-hand sources, the incoming Republican administration did not know what to do with a new set of regulations that was judged to have negative cost to the industry as it would allow more and lower-cost equipment to run on US tracks. After this limbo, the new rules have finally been published.

What’s in the new regulations?

The document spells out the main point on pp. 13-20. The new rules are similar to the relevant Euronorm. There are still small changes to the seats, glazing, and emergency lighting, but not to the structure of the equipment. This means that unmodified European products will remain illegal on American tracks, unlike the situation in Canada, where the O-Train runs unmodified German trains using strict time separation from freight. However, trains manufactured for the needs of the American market using the same construction techniques already employed at the factories in France, Germany, Switzerland, and Sweden should not be a problem.

In contrast, the new rules are ignoring Japan. The FRA’s excuse is that high-speed trains in Japan run on completely dedicated tracks, without sharing them with slower trains. This is not completely true – the Mini-Shinkansen trains are built to the same standards as the Shinkansen, just slightly narrower to comply with the narrower clearances on the legacy lines, and then run through to legacy lines at lower speed. Moreover, the mainline legacy network in Japan is extremely safe, more so than the Western European mainline network.

On pp. 33-35, the document describes a commenter who most likely has read either my writings on FRA regulations or those of other people who made the same points in 2011-2, who asked for rules making it possible to import off-the-shelf equipment. The FRA response – that there is no true off-the-shelf equipment because trains are always made for a specific buyer – worries me. The response is strictly speaking true: with a handful of exceptions for piggybacks, including the O-Train, orders are always tailored to the buyer. However, in reality, this tailoring involves changes within certain parameters, such as train width, that differ greatly within Europe. Changes to parts that are uniform within Europe, such as the roofing, may lead to unforeseen complications. I don’t think the cost will be significant, but I can’t rule it out either, and I think the FRA should have been warier about this possibility.

# Train Weight and Safety

A recent New Jersey Transit train accident, in which one person was killed and more than a hundred was injured, has gotten people thinking about US rail safety again. New Jersey has the second lowest fuel tax in the US, and to avoid raising it, Governor Chris Christie cut the New Jersey Transit budget (see PDF-pp. 4-5 here); perhaps in reaction to the accident, Christie is announcing a long-in-the-making deal that would raise the state’s fuel tax. But while the political system has been discussing funding levels, transit advocates have been talking about regulations. The National Transportation Safety Board is investigating whether positive train control could have prevented the accident, which was caused by overspeed. And on Twitter, people are asking whether Federal Railroad Administration regulations helped protect the train from greater damage, or instead made the problem worse. It’s the last question that I want to address in this post.

FRA regulations mandate that US passenger trains be able to withstand considerable force without deformation, much more so than regulations outside North America. This has made American (and Canadian) passenger trains heavier than their counterparts in the rest of the world. This was a major topic of discussion on this blog in 2011-2: see posts here and here for an explanation of FRA regulations, and tables of comparative train weights here and here. As I discussed back then, FRA regulations do not prevent crumpling of passenger-occupied space better than European (UIC) regulations do in a collision between two trains, except at a narrow range of relative speeds, about 20-25 mph (30-40 km/h); see PDF-pp. 60-63 of a study by Caltrain, as part of its successful application for waivers from the most constraining FRA regulations. To the extent people think FRA regulations have any safety benefits, it is purely a stereotype that regulations are good, and that heavier vehicles are safer in crashes.

All of this is old discussions. I bring this up to talk about the issue of systemwide safety. Jacob Anbinder, accepting the wrong premise that FRA regulations have real safety benefits, suggested on Twitter that rail activists should perhaps accept lower levels of rail safety in order to encourage mode shift from much more dangerous cars toward transit. This is emphatically not what I mean: as I said on Twitter, the same policies and practices that lead to good train safety also lead to other good outcomes, such as punctuality. They may seem like a tradeoff locally within each country or region, but globally the correlation goes the other way.

In 2011, I compiled comparative rail safety statistics for the US (1 dead per 3.4 billion passenger-km), India (1 per 6.6 billion), China (1 per 55 billion), Japan (1 per 51 billion), South Korea (1 per 6.7 billion), and the EU (1 per 13 billion), based on Wikipedia’s lists of train accidents. The number for India is an underestimate, based on general reports of Mumbai rail passenger deaths, and I thought the same was true of China. Certainly after the Wenzhou accident, the rail activists in the developed world that I had been talking to stereotyped China as dangerous, opaque, uninterested in passengers’ welfare. Since then, China has had a multi-year track record without such accidents, at least not on its high-speed rail network. Through the end of 2015, China had 4.3 billion high-speed rail passengers, and by 2015 its ridership grew to be larger than the rest of the world combined. I do not have statistics for high-speed passenger-km, but overall, the average rail trip in China, where there’s almost no commuter rail, is about 500 km long. If this is also true of its high-speed rail network, then it’s had 2.15 trillion high-speed passenger-km, and 1 fatality per 54 billion. This is worse than the Shinkansen and TGV average of zero fatalities, but much better than the German average, which is weighed down by Eschede. (While people stereotype China as shoddy, nobody so stereotypes Germany despite the maintenance problems that led to the Eschede accident.)

I bring up China’s positive record for two reasons. First, because it is an example of how reality does not conform to popular stereotypes. Both within China and in the developed world, people believe China makes defective products, cheap in every sense of the term, and compromises safety; the reality is that, while that is true of China’s general environmental policy, it is not true of its rail network. And second, China does not have buff strength requirements for trains at all; like Japan, it focuses on collision avoidance, rather than on survivability.

The importance of the approaches used in Japan and on China’s high-speed rail network is that it provides safety on a systemwide level. By this I do not mean that it encourages a mode shift away from cars, where fatality rates are measured in 1 per hundreds of millions of passenger-km and not per tens of billions. Rather, I mean that the entire rail network is easier to run safely when the trains are lighter.

It is difficult to find exact formulas for the dependence of maintenance costs on train weight. A discussion on Skyscraper City, sourced to Bombardier, claims track wear grows as the cube of axle load. One experiment on the subject, at low speeds and low-to-moderate axle loads, finds a linear relationship in both axle load and speed. A larger study finds a relationship with exponents of 3-5 in both dynamic axle load and speed. The upshot is that at equal maintenance cost, lighter trains can be run faster, or, at equal speed, lighter trains make it easier to maintain the tracks.

The other issue is reliability. As I explained on Twitter, the same policies that promote greater safety also make the system more reliable, with fewer equipment failures, derailments, and slowdowns. On the LIRR, the heavy diesel locomotives have a mean distance between failures of 20,000-30,000 km, and the medium-weight EMUs 450,000 (see PDF-pp. 21-22 here). The EMUs that run on the LIRR (and on Metro-North), while heavier than they should be because of FRA requirements, are nonetheless pretty good rolling stock. But in Tokyo, one rolling stock manufacturer claims a mean distance between failures of 1.5 million km. While within Japan, the media responds to fatal accidents by questioning whether the railroads prioritize the timetable over safety, the reality is that the overarching focus on reliability that leads to low maintenance costs and high punctuality also provides safety.

In the US, especially outside the EMUs on the LIRR and Metro-North, the situation is the exact opposite. The mean distance between failures for the LIRR’s diesel locomotives is not unusually low: on the MBTA, the average is about 5,000 km, and even on the newest locomotives it’s only about 20,000 (State of the Commuter Rail System, PDF-pp. 8-9). The MBTA commuter rail system interacts with freight trains that hit high platforms if the boxcars’ doors are left open, which can happen if vandals or train hoppers open the doors; as far as I can tell, the oversize freight on the MBTA that prevents easy installation of high platforms systemwide is not actually oversize, but instead veers from the usual loading gauge due to such sloppiness.

Of course, given a fixed state of the infrastructure and the rolling stock, spending more money leads to more safety. This is why Christie’s budget cuts are important to publicize. Within each system, there are real tradeoffs between cost control and safety; to Christie, keeping taxes low is more important than smooth rail operations, and insofar as it is possible to attribute political blame for such low-probability events as fatal train accidents, Christie’s policies may be a contributing factor. My contention here is different: when choosing a regulatory regime and an overarching set of operating practices, any choice that centers high performance and high reliability at the expense of tradition will necessarily be safer. The US rail community has a collective choice between keeping doing what it’s doing and getting the same result, and transitioning operating practices to be closer to the positive results obtained in Japan; on safety, there is no tradeoff.

# NEC Future: Moving Sideways

The Northeast Corridor high-speed rail investment studies are moving forward, and four days ago the FRA released an early environmental impact study on the subject, as part of the NEC Future program. The study moves in part in the right direction, in that it considers many different segment-level improvements (for example, specific bypasses of curvy segments), but it still isn’t quite going in the right direction. It’s not a bad study in itself, but it does have a lot of drawbacks, and I would like to discuss the ultimate problems with its approach.

Overview

The EIS studies three alternatives, as well as an obligatory No Build option.

Alternative 1 includes minimal investment: capacity improvements already under consideration, including new Hudson tunnels; grade-separation of at-grade rail junctions, including Shell interlocking between the Metro-North New Haven Line to Grand Central and the NEC, which imposes a severe speed limit (30 mph, the worst outside major city stations) and a capacity constraint; and a limited I-95 bypass of the legacy NEC route in eastern Connecticut, to avoid the existing movable bridges. The bulk of the expense under this alternative, excluding the predominantly commuter-oriented new Hudson tunnels, involves replacing or bypassing obsolete or slow bridges with faster segments. I have advocated such an approach in certain cases for years, such as the Cos Cob Bridge; if anything, Alternative 1 does not do this enough, but I do appreciate that it uses this solution.

Alternative 2 constructs HSR along the NEC route, except for a major deviation to serve Hartford. It is also bundled with various bypasses and new stations elsewhere: under this alternative, Philadelphia and Baltimore get new stations, with extensive urban tunneling to reach those stations. Alternative 3 does the same, but considers more deviations, including a tunnel between Long Island and New Haven, and an inland route through Connecticut, closer to I-84 than to I-95 and the legacy NEC; it also constructs dedicated HSR tracks between New York and Washington.

The EIS does not include cost figures. It includes travel time figures on PDF-p. 51, which seem to be based on unfavorable assumptions: Alternative 2, called Run 5, does New York-Boston in 2:17 for trains making a few major-city intermediate stops; the Alternative 3 proposals vary widely depending on alignment, of which the fastest, the I-84 inland route, takes 1:51, again making intermediate stops.

The Good

First, the EIS includes service plan elements, stating the projected frequency of regional and express trains using the tracks. It also talks about clockface scheduling and proposes a pulse in Philadelphia, allowing timed transfers in all directions between local and express intercity trains as well as trains on the Keystone corridor. It goes further and discusses regional rail on the intercity tracks in the alternatives that include extensive new construction. In these ways, it focuses on regionwide rail integration far more than previous plans.

Second, in general, the correct way to think about NEC investment is component by component. The EIS gets closer to this ideal, by considering many different route combinations north of New York, and advancing several of them under the Alternative 3 umbrella.

And third, the concept of Alternative 1 is solid. In many cases, it is possible to bundle a trip time or capacity improvement into the replacement of an obsolete structure at very low additional cost. The example I keep coming back to is the Cos Cob Bridge, but it is equally true of the movable bridges east of New Haven. I also greatly appreciate that Alternative 1 recognizes the importance of grade-separating railroad junctions.

Ultimately, the EIS does not take the three good concepts – integrated service planning, component-by-component thinking, and bundling trip-time improvements when the marginal cost of doing so is low – to their full conclusion. Thus, there is no attempt at running intercity trains at high speed on shared track with commuter rail with timed overtakes, as I have proposed for both the inner New Haven Line and the Providence Line. On the contrary, the plan for capacity investment on the Providence Line includes extensive three-tracking, rather than limited, strategic four-track bypass segments. This cascades to the trip times, which are quite slow between New York and New Haven (1:08, for an average speed of 103 km/h), and a bit slower than they could be between Providence and Boston (24 minutes, whereas about 21 is possible with about zero investment into concrete).

The concepts of Alternatives 1, 2, and 3 represent bundles of levels of investment. This is the wrong approach. Alternatives 2 and 3 include new tunneled city-center stations in Baltimore and Philadelphia; but wouldn’t we want to consider city-center station tunnels in those two cities separately? It’s possible for one to turn out to be cost-effective but not the other. It’s possible for neither to be cost-effective, but for other improvements included in Alternative 2, such as curve modification around Metropark and Metuchen, to pencil out.

There’s far more interaction between different macro-level alignments, by which I mean such questions as “inland route or coastal route?” and “serve Hartford on the mainline or put it on a branch?”, than between such micro-level investments as individual curve modifications and urban tunnels. This means that instead of discrete alternatives, there should be one umbrella, taking in Alternative 2 and 3 variants, proposing all of those options as possibilities. A future study, with detailed cost figures, could then rank those options in terms of trip time saving per unit of cost, or in terms of social and financial ROI. This way, there would be concrete proposals for what a $5 billion plan, a$10 billion plan, a $20 billion plan, and so on would be. The Ugly Two elements in the study are inexcusable. First, the service plan description explicitly keeps Amtrak’s current separation of premium-fare Regionals and even-more-premium-fare Acelas. This is not how the rest of the world structures HSR: even when the HSR fares are substantially higher than the legacy rail fares, as in Spain, the fare per passenger-km is not very high, and is not targeted exclusively at business travelers. In France, the intercity fare (including TGVs, which are the bulk of French intercity traffic) was on average €0.112 per passenger-km in 2011. Premium service is provided on the same TGVs as standard service, in first-class cars. In contrast, Amtrak charges about$0.29 per passenger-km on the Regional and 0.53 on the Acela. And second, the investment alternatives appear to include more tunneling than is necessary. I will focus on the Hartford-Providence-Boston segment in Alternative 2, since it is less sensitive to assumptions on commuter rail track-sharing than the segments overlapping the New Haven Line. It is possible to go all the way from Hartford to the western margin of the Providence built-up area without any tunneling, and without outrageous bridging; see a past post of mine on the subject here, which concludes that it’s better to just go parallel to I-95 for trip time reasons. In Providence, tunnels are unavoidable, but can still be limited to short segments, mixed with elevated routes along pre-impacted freeway corridors. When I looked at it two years ago, I saw an alignment with just 2 km of tunnel, in Providence itself. In contrast, run A in figure 9 on PDF-p. 56 says that tunnels are about 27% of new construction between Hartford and Boston, which consists of, at a minimum, about 100 km of track between Hartford and Providence. Conclusion The EIS is a step in the right direction, insofar as it does consider issues of integrated service planning and prioritizing construction based on where it can be cheaply bundled into bridge replacement. However, it fails to consider cost limitations, as seen in the excessive tunneling proposed even in areas where high-speed tracks can run entirely above ground. It’s considering more options, which is good, but, Alternative 1, while representing a golden concept, is not sufficiently developed. What I would like to see from a study in this direction is a mixture of the following: • Discussion of how to avoid tunnels, including various tradeoffs that have to be made (for example, above-ground construction may require more takings). Generally, I want to see much less tunneling than is currently proposed. • A well-developed incremental option, similar to Alternative 1 but more extensive, including for example I-95 bypasses all the way from New Haven to Kingston and along strategic segments of the New Haven Line, such as in Port Chester and Greenwich. • Greater integration with regional rail; one litmus test is whether the Providence Line is proposed to be three-tracked for long stretches, or four-tracked at a key bypass station (the options are Sharon and the Route 128-Readville segment), and another is discussion of high-acceleration electric multiple units on the Providence Line and the Penn Line. • Unbundling of projects within each alignment – there is no need to, for example, consider the Philadelphia and Baltimore tunnels together (I also think neither is a good idea, but that’s a separate discussion). The view should be toward an optimal set of projects within each alignment, since macro-level decisions such as whether to serve Hartford are more political than micro-level ones of which curves to fix. This permits explicit discussions such as “would you be willing to spend2 billion and slow through-trains by 9 minutes to serve Hartford?”.

# Train Weights, Bilevel Version

My previous table of train weights covered single-level trains, with the exception of the ultralight (for a bilevel) TGV Duplex. By request, here is a similar version for bilevels. Note that very light trains such as the E231 or DB’s Class 423 are inherently single-level – though a bilevel Green Car trailer version of the E231 is quite light, even at 50% heavier than a single-level trailer.

Recall that Lng is length in meters, Wt is empty weight in (metric) tons, Width is in meters, Pow is maximum short-term power in megawatts, P/W is power-to-weight in kilowatts per ton, Ld is average load per axle in tons, and Wt/Lng is weight in tons per meter of train length.

 Train Lng Wt Width Pow P/W Ld Wt/lng E231 series Green Car 20 36 2.95 0 0 9 1.79 215 Series 200 368.5* 2.9 1.92 5.2 9.2 1.84 TGV Duplex 200 380 2.9 8.8 23.2 14.6 1.9 Bom. BiLevel Coach 26 50 3 0 0 12.5 1.91 KISS, Regional 150 297 2.8 6 20.2 12.4 1.97 KISS, Interregio 100 212 2.8 6 28.3 13.3 2.11 E4 Series 201 428 3.38 6.72 15.7 13.4 2.13 NS DD-AR (w/ mDDM) 100 221 2.8 2.4 10.86 13.8 2.21 GO Transit MPI hauling 12 Bom. BiLevel Coaches 332 734 3.24 3 4.1 14.1 2.21 Metra Highliner 26 59 3.2? ? ? 14.8 2.28 Caltrain Coradia 213 517 3.2? ? ? 16.2 2.43 X40 (Coradia, Sweden) 81.5 205 2.96 2.4 11.7 17.1 2.52 Caltrain MPI hauling 5 Bom. BiLevel Coaches 150.5 384 3.24 3 7.8 16 2.55 CityRail A-sets 78 201 3.04 ? ? 12.6 2.57 MI 2N 112 288 2.9 4.5 15.6 14.4 2.57 Colorado Railcar, bilevel 26 74 3.2? 0.96 13 18.5 2.86

*Caltrain claims the same weight – see pages 36 (which partially confuses the train with a heavier Shinkansen) and 45 of its document about bilevel EMUs. Japanese Wikipedia claims a much lower weight, coming from substituting 2 for the leading 3. Given everything else, the higher figure seems more likely (with thanks to Miles Bader for pointing the above link out).

The observation here is that FRA compliance no longer neatly separates trains. Part of it comes from the very heavy low-speed trains in France, of which the MI 2N is an example. I do not know whether this is caused by special regulations – on the one hand, the TGV reportedly has 500 tons of buff strength, but on the other hand, Sweden’s X40 is also quite heavy.

The reason for this is that while high buff strength adds weight, its effect is much larger on lightweight frames than on heavyweight frames. A train that is already heavy will become heavier if it is required to be FRA-compliant, but typically only by a few tons. New Jersey Transit’s ALP-46 locomotive is 7 tons heavier than the European locomotive it is based on, of which 4.5 come from FRA regulations. This applies equally well to low-power bilevels. Even lightweight, high-power products such as the KISS would be considered middleweight by single-level standards.

Observe, however, that to achieve acceptable average weight, FRA-compliant products have to sacrifice power (as is done in Toronto or on Caltrain) and also to have a heavy locomotive drag many relatively light coaches, raising axle load. For fast service, one must use a product like the Colorado Railcar, which is the heaviest train per unit of weight on both this table and the single-level table, and which also awkwardly is a high-level train with much greater height than permitted by any European loading gauge, avoiding the low-floor weight penalty.