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Hotfoot for the Iron Horse PUBLIC ACCESS

Attempts are Under Way to Bring U.S. Rail Service into the 21St Century.

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Contributing Editor.

Mechanical Engineering 122(06), 46-52 (Jun 01, 2000) (7 pages) doi:10.1115/1.2000-JUN-1

Attempts are under way to bring US rail service into the 21st century. A range of initiatives that may spark further advances in the US rail system are under way in the United States and abroad. Amtrak’s new Acela Express is scheduled to go into service this summer in the Northeast Corridor. It is expected to achieve a speed of 150 mph. Freshly arrived at Philadelphia’s Penn Coach Yards, the Acela Express power car is unwrapped and inspected. The covering of the nose has been pushed up, revealing the engine underneath. Amtrak, which hopes its new high-speed service will finally nudge it into the black, has ambitious plans to start high-speed services in other areas of the country. The US Department of Transportation has designated several corridors where economic factors and local political support seem to indicate a chance of success.

The era of high-speed rail transportation may be decades old in Japan and Europe, but only this year, with the imminent debut of Amtrak’s Acela Express service, is this innovation due to arrive in the United States, or at least the Northeast Corridor. Even then, the fastest trains, which will go about 150 mph, will be no match for the TGV (train à grande vitesse) and its cousins in Europe, which can have speeds on the order of 200 mph, but which require dedicated ultrastraight track to be laid expressly for the trains of great speed. Clearly, there is some catching up yet to be done. A range of initiatives that may spark further advances in the U.S. rail system are under way in the United States and abroad.

Amtrak's new Acela Express is scheduled to go into service this summer in the Northeast Corridor. It is expected to achieve a speed of 150 mph.

Grahic Jump LocationAmtrak's new Acela Express is scheduled to go into service this summer in the Northeast Corridor. It is expected to achieve a speed of 150 mph.

The lines of development being pursued in the railroad industry fall under two main headings: high-speed rail, based on traditional “steel-on-steel” technologies, and maglev, which is short for magnetic levitation. The U.S. Government is currently funding research into both fields under a 1998 law known as the Transportation Equity Act for the 21st Century, or TEA-21 for short. This includes $22 to $25 million per year in “real money”—authorized and appropriated—for work on next-generation high-speed rail.

“The most likely way to see high-speed rail is by upgrading existing routes to make possible higher speeds and service levels,” said Robert J. McCown, director of technology development programs in the Office of Railroad Development at the Federal Railroad Administration in Washington. In the early 1990s, there were plans in Texas and Florida to bring about TGV-type highspeed service, which involved laying the dedicated, ultrastraight track that such trains require, but those initiatives were abandoned as uneconomical. For the foreseeable future, it seems, high-speed rail in the United States will have to make do with the same old tracks that everybody else—including commuter and freight service—uses. This rules out TGVs, but a lot still can be done with an upgrade.

Some of the increase in speed realized by the new Acela Express, in fact, comes from completing the electrification of the track. Until this year, trains had to switch to diesel locomotives for the stretch from New Haven, Conn., to Boston. Already Amtrak’s Metroliner service in the Northeast Corridor reaches speeds up to 120 mph, and electrification and other track improvements on that line have allowed Amtrak to introduce an upgraded service, with refurbished versions of its regular cars traveling at speeds of 110 to 125 mph, which it calls Acela Regional. This is not regarded as being high-speed rail, properly speaking; the term “accelerail” is sometimes used for this sort of service. But in other parts of the country, such speeds might well qualify as high-speed rail. Certainly, a jump in speed from 80 mph to 120 mph is no trifle.

Amtrak, which hopes its new high-speed service will finally nudge it into the black, has ambitious plans to start high-speed services in other areas of the country. The U.S. Department of Transportation has designated several corridors where economic factors and local political support seem to indicate a chance of success. These include Los Angeles to San Diego, as well as the San Joaquin Valley from Bakersfield to Oakland, in California; several Midwest corridors emanating from Chicago, notably ones to St. Louis and Detroit, but also to Cincinnati, Cleveland, Milwaukee, Omaha, St. Paul, Minn., and Carbondale, 111.; a Pacific Northwest Corridor including Portland, Ore., Seattle, and Vancouver, B.C.; a Southeast Corridor from Washington to Charlotte, N.C., and a Gulf Coast Corridor between Atlanta and New Orleans. In many cases, said McCown, the states have formed coalitions to sponsor efforts to bring these services to their areas. These projects follow the same model as the Northeast Corridor, using the old tracks, shared with freight trains. Electrification of these tracks, however, is generally considered impractical.

Freshly arrived at Philadelphia's Penn Coach Yards, the Acela Express power car is unwrapped and inspected. The covering of the nose has been pushed up, revealing the engine underneath.

Grahic Jump LocationFreshly arrived at Philadelphia's Penn Coach Yards, the Acela Express power car is unwrapped and inspected. The covering of the nose has been pushed up, revealing the engine underneath.

McCown identified four areas important to this effort in which work was progressing: motive power, train control systems, grade crossing hazards, and tracks and structures. To deal with the problem of motive power where electricity is not provided, two new systems are in the works.

The Federal Railroad Administration, or FRA, is in a public-private partnership with a U.S. subsidiary of Bombardier Inc. of Montreal to develop and demonstrate a high-speed nonelectric locomotive (NEL) powered by a 5,000-hp turbine. According to Daniel Palardy, project and engineering manager for Bombardier Transportation on this program, the locomotive is the fossil fuel version of the Acela Express power car, designed and built by a consortium of Bombardier and Alstom of Paris. Alstom is also cooperating with Bombardier on the NEL prototype. The NEL has the same platform, the same trucks, the same basic structure (including crashworthiness components), and a similar exterior, and will be capable of achieving the same 150-mph top speed, even on nonelectrified track. The small size and weight of the turbine (compared with a diesel engine) helps to keep the weight down, which will result in lower track maintenance costs. The power from the turbine output feeds into a gearbox that provides it to two ac alternators, which in turn feed into the electric traction system. A high-speed generator being developed under another FRA program may be installed and tested in the prototype locomotive in a later phase.

To make high-speed rail possible in areas where rail tracks are not electrified, Bombardier has designed the NEL, a fossil-fuel version of Amtrak’s Acela.

Grahic Jump LocationTo make high-speed rail possible in areas where rail tracks are not electrified, Bombardier has designed the NEL, a fossil-fuel version of Amtrak’s Acela.

A lot of effort has gone into designing the NEL to operate at high cant deficiency (up to 9 inches compared with only 3 to 4 inches for most North American locomotives) and to impart low dynamic vertical forces to the rail. High cant deficiency capability permits operation at higher speeds through curves. For high-speed service, standard track would need to be upgraded, but until that happens, the locomotive could still be used at less exciting speeds on lower-speed track. This means, Palardy noted, that if you want to run a service that connects with, say, the Northeast Corridor, you could come in at lower speed and once on the corridor go as fast as an electric train. The prototype is now being built and should be ready for initial static testing by this summer.

To store energy for extra power needs, the Advanced Locomotive Propulsion System being developed at the University of Texas uses a large flywheel, seen here in a sectional view.

Grahic Jump LocationTo store energy for extra power needs, the Advanced Locomotive Propulsion System being developed at the University of Texas uses a large flywheel, seen here in a sectional view.

Farther in the future is the Advanced Locomotive Propulsion System, or ALPS, being developed at the Center for Electromechanics at the University of Texas in Austin. This system also uses a 5,000-hp gas turbine, but here it is directly coupled to a high-speed (15,000rpm) generator. In addition, there is a very large energy-storage flywheel connected to a high-speed motor/ generator. John Herbst, the project manager, explained that if the locomotive needs extra power, say to accelerate or to climb a hill, it can pull an additional 3,000 hp from the flywheel for three minutes. When the engine needs to slow down, it feeds power from the traction motors back to the flywheel. The flywheel also levels out the load on the turbine to reduce thermal cycling and extend turbine maintenance intervals.

The turbine-driven generator feeds ac power, rectified to dc, into a dc bus. This is connected to a set of bidirectional power converters. One of these provides variable-frequency ac to the traction motors on the axles—a configuration similar to that of a diesel electric locomotive. Another bidirectional power converter is connected to the flywheel-driven motor/generator to allow power transfer to and from the dc bus. Size, weight, fuel, and maintenance economies are said to be impressive, and the engine should be capable of 150 mph.

Train control, the second of McCown’s priority areas, includes radio-based train control, automatic location systems, onboard computers, digital data train-to-ground radio links, and ground systems.

Roy Allen, president of Transportation Technology Center Inc., which operates a test facility in Pueblo, Colo., pointed out that trains are currently controlled through a signaling system, with the trains being detected by electric circuits in the rails. The interval between signals is known as a “block,” and in some areas these blocks can be several miles long. Since only one train is allowed to be in a block at a time, this imposes a considerable constraint on the railroads capacity.

McCown said that “all the major North American railroads are participating with the FRA in a joint project to hammer out industry interoperability standards that will govern how the railroads will work with each other in deploying train control technologies. The approach will have to be modular, allowing each railroad to select the level of train control function it needs for its operating circumstances. Without this modular approach, the result would only be more confusion.”

He set forth two general approaches that might be made to train control, noting that other systems are also possible. In both, the train would carry an onboard differential global positioning system receiver and a computer. One system, currently being demonstrated in Michigan, involves gathering up all the signal system information and broadcasting it to the train, where the computer, which knows the train’s location from GPS, decides on its own what to do without central control.

The ALPS generator is to be cooled by an oil/air heat exchanger, to be mounted in the roof cowling, supplying about 2,000 scfm of flow at 3.8 psig.

Grahic Jump LocationThe ALPS generator is to be cooled by an oil/air heat exchanger, to be mounted in the roof cowling, supplying about 2,000 scfm of flow at 3.8 psig.

In the other system, the train would radio its location to a central control center. The center would send back instructions as to how far and how fast the tram should go, which would be relayed to the engineer. If the instructions were violated, the computer would stop the train. Such a system is now being designed and constructed in Illinois under the auspices of the railroad-FRA joint project. Full-scale commercial operation is slated for the end of 2002.

As for McCown’s last two areas of concern—eliminating grade crossings and ameliorating track and structures—they are less susceptible to snazzy, high-tech solutions. They are still important, since the faster the train, the better the track needs to be. The Federal Railroad Administration defines different classes of track—Acela is class 8, Metroliner is class 6, freight lines can go as low as class 4. The higher the number, the tighter the tolerances, and the higher the speed permitted.

In the ALPS system, power from a turbine-driven generator goes to bidirectional power converters that can feed it to traction motors or to the flywheel.

Grahic Jump LocationIn the ALPS system, power from a turbine-driven generator goes to bidirectional power converters that can feed it to traction motors or to the flywheel.

Much of the testing of new train designs before they are put into service takes place at the Transportation Technology Center in Pueblo, Colo., 50 square miles of prairie with 48 miles of track. The site is owned by the FRA and operated by the center, which is affiliated with the Association of American Railroads. According to Roy Allen, the center’s president, the only comparable facilities are in Beijing and Moscow. It was here that the new Acela trains were recently put through their paces to get them ready for service.

ALPS engineer Scott Pish, a member of the assembly team, poses with components of the high-speed generator during its final assembly.

Grahic Jump LocationALPS engineer Scott Pish, a member of the assembly team, poses with components of the high-speed generator during its final assembly.

Currently, the center is running tests on a Japanese train that is able to adjust its wheels to run on tracks with different gauges. This is rarely a problem in the United States, where the only narrow-gauge lines are a couple of scenic tourist railways, but in Japan, the bullet trains operate on a different gauge from standard trains, so a transfer between lines means getting off the train. Allen explained that on the gauge-changing train, each wheel on the power car has an independent suspension and traction motors. When changing gauges, the weight of the axle is carried on linear bearings running down the side of the tracks.

Many of the prospective maglev systems being designed in the United States make use of the Transrapid technology that has been developed in Germany over the last several decades.

Grahic Jump LocationMany of the prospective maglev systems being designed in the United States make use of the Transrapid technology that has been developed in Germany over the last several decades.

Since most members of its parent association are freight railroads, much of the center’s work is on matters of interest to freight carriers, such as gauge tolerances and track profiles. High speed is rarely a priority for freight railroads. Allen C. Bieber, a senior engineer for locomotive design with General Electric Corp. in Erie, Pa., pointed out that with trains of perhaps 150 cars, moving very fast is unrealistic.

The need to control trains of such enormous length led to the development of an electronically controlled pneumatic brake, for which some of the testing was done at the center in Pueblo. Allen explained that since air brakes were invented by George Westinghouse in the 19th century, they have used air pressure both to put the brakes on and to carry the signal. As a result, the signal can propagate only at the speed of sound, and on a 120- or 150-car freight train that can mean a delay of several seconds as the cars bunch together. The electronically controlled pneumatic brakes will still use air as the energy medium, but the signal will be carried by either a cable or by radio; both are being tested.

Another technology being worked on is wayside detection. David Cackovic, director of engineering services at the Transportation Technology Center, explained that trackside acoustic sensors can be used to ascertain the condition of bearings and detect potential problems before trouble develops. The infrared sensors commonly used detect heat; by the time the bearings are giving off heat, though, they are already breaking down. Various parts of the bearing have acoustic signatures, said Cackovic, and with modern computational techniques a clear picture of a bearing’s condition can be teased out.

A Transrapid vehicle negotiates a bendable switch. Arms that wrap under the guideway hold magnets that are attached to rails on that guideway, lifting the train.

Grahic Jump LocationA Transrapid vehicle negotiates a bendable switch. Arms that wrap under the guideway hold magnets that are attached to rails on that guideway, lifting the train.

Maglev trains ride on a cushion of magnetic force that keeps the train body from touching the rads or guideway, and motive power can also be supplied through the system. The early work on this technology was done in the United States, notably by James Powell and Gordon Dan-by, who received a patent in 1968. But “the Americans essentially gave up in the mid-’70s” when funding disappeared, observed Arnold Kupferman, who oversees the maglev program at the Federal Railroad Administration in Washington. Since the mid-1970s, the main impetus has been overseas, and Germany and Japan have both been testing maglev systems for many years. Financing remains a daunting hurdle, however. Just a few months ago, Germany decided not to go ahead with building what had been planned as the first intercity maglev line, between Hamburg and Berlin, although other possible routes remain under consideration. In Japan, too, maglev is still at the testing stage.

In Germany, the Transrapid system has been carrying passengers on a 31.5-km test loop for years. It was certified as operationally ready in 1991.

Grahic Jump LocationIn Germany, the Transrapid system has been carrying passengers on a 31.5-km test loop for years. It was certified as operationally ready in 1991.

However, the TEA-21 legislation did provide funding for preconstruction planning for maglev demonstration projects—$55 million over three years—along with authorization to spend $950 million to construct an actual working system. According to Kupferman, “We’ve got seven projects doing preconstruction planning now. We’ll narrow the field to two or three in September, and finally select one for funding.”

The planning has been going on for a year or so, but the obstacles are severe. Maglevs are not cheap to build—$25 million to $50 million per mile seems to be the going rate—and half of the $950 million has to be matched by the community involved (all seven projects are being carried out by local or state bodies). And that money is only authorized, not yet appropriated, so in the end, local dignitaries will have to persuade Congress to turn over almost a billion dollars of real money, which could prove to be a tall order.

Even so, this money is not enough to finance a major intercity connection, and the seven projects are mostly of the airport-link variety, since the project selected will be expected to earn back more than its operating costs each year. The projects in question are centered around Pittsburgh, Baltimore/Washington, Las Vegas, New Orleans, Los Angeles, and the Cape Canaveral region in Florida. The seventh project would construct the first 40 miles of a planned 110-mile route between Atlanta and Chattanooga, Tenn.

The most popular technology among these contenders is the German Transrapid system, which works on the principle of magnetic attraction. The cars have arms that wrap around the bottom of the guideway. On these arms are electromagnets that are attracted to ferromagnetic rails on the underside of the guideway, thus lifting the vehicles and levitating them above the guideway surface. A further set of lateral magnets holds the vehicle in place above the guideway. Magnetic rails act something like the stator of an electric motor that has been unrolled and stretched along the guideway. As the electromagnetic field travels down the guideway, it pulls the vehicle along with it. Energy transmission is by electromagnetic induction. The Germans designed their system to operate up to 280 mph, but speeds of 300 mph and more are said to be practical possibilities.

There are several other competing maglev systems, however. The Japanese have continued work along the lines pioneered by Powell and Danby. Their technology operates on the basis of magnetic repulsion. Superconducting magnets on the train induce a current within coils on the sides of the U-shaped guideway, which then act as electromagnets that push the cars away, causing them to float above the guideway. But the superconductors involved need to be kept at cryogenic temperatures. Still, the system has carried passengers at speeds exceeding 340 mph.

A Japanese experimental maglev vehicle, the MLX01, slides down one of the test tracks operated by Railway Technical Research Institute.

Grahic Jump LocationA Japanese experimental maglev vehicle, the MLX01, slides down one of the test tracks operated by Railway Technical Research Institute.

Powell and Danby have not abandoned their interest in maglev, either. The two men formed the Maglev 2000 of Florida Corp., operating out of Titusville, to further develop magnetic-repulsion transportation systems. This company is behind a project in the Cape Canaveral area that is one of the seven to have received preliminary funding from the Feds. According to Charlie Smith, program manager for Maglev 2000, over the past 12 years the company has come up with several vital improvements on the Japanese system, with a view to making maglev more cost-effective for use in the United States.

One new development is an electronic switch that will enable the vehicles to switch off the main line electronically at high speed, with no moving parts involved. Another is a lower-cost guideway configuration. The narrow-beam guideway is just that, a concrete beam with coils attached to its sides; the train car wraps around it. The coils are of aluminum, wound into rectangular panels about 3 by 6 feet in extent and encapsulated in polymer concrete. This arrangement is not only cheaper to build (perhaps as little as $10 million to $12 million a mile over smooth terrain, according to Smith), but the 6- to 8-inch gap that results between car and guideway gives the cars great stability, and hence a large cushion for weight. This should make it easy to use the system for freight service. There is even talk that mining operations might eventually use it for transporting ore.

Maglev 2000 is currently constructing a 1,000-foot demonstration line, and eventually plans a 20-mile line from Port Canaveral, a busy cruise port, to the Kennedy Space Center on Cape Canaveral and on across the Banana and Indian Rivers to the airport at Titusville. Even if the federal financing falls through, noted Smith, “Our technology does seem to be attractive to private investors.”

A system recently developed at Lawrence Livermore National Laboratory, called Inductrack, uses a Halbach array of magnetic bars and shows promise, but is still in the experimental stage. There is a separate program aimed at developing low-speed maglev for urban transit purposes, operated by the Federal Transit Administration and funded even more parsimoniously than intercity maglev.

Some who are connected with the conventional railroad industry question whether maglev systems can be economically practical anytime soon, and indeed, plans to build such systems seem to be repeatedly defeated by cost considerations. But, as Kupferman pointed out, “This is the first new mode of transportation since the airplane. We’ve been fooling around with railroads since 1830; now they’re up to 200 mph or so. The Wright Brothers certainly never envisioned a 737. With maglev, we’re starting out at 280 miles per hour. Who knows what we’ll be able to do 50 years from now? Unless we take the first steps, we’ll never find out.”

Copyright © 2000 by ASME
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