Chapter 2 HIGH-SPEED RAIL TECHNOLOGIES AND FOREIGN EXPERIENCE Contents Summary . 15 Equipment and Track Options.. 15 Propulsion System Options . 16 Foreign Experience . 17 Discussion . 18 Conventional Equipment on Existing Track.. 18 New Equipment on Existing Track . 20 State-of-the-Art Equipment on New Track . 21 List of Tables Table No. Page 2. SNCF 125-mph Trains. 18 3. HST Comparison of Trip Times . 20 4. Ridership: Shinkansen, 1965-70, 1975-80 . 21 5. Trip Times on Shinkansen . 23 6. Proportion of Tunnels and Viaducts . 23 7. TGV: Comparison of Trip Times . 26 List of Figures Figure No. Page 1. Rail Travel: Tokyo-Osaka . 22 2. Japanese National Railways Standard Gage (Shinkansen) Lines . 23 3. SNCF-TCV Line Between Paris-Lyon . , 23 Chapter 2 HIGH-SPEED RAIL TECHNOLOGIES AND FOREIGN EXPERIENCE In this assessment, a high-speed passenger rail This chapter examines the high-speed rail opera- system is defined as one that can attain speeds of tions of foreign countries and, on the basis of that 125 mph or more. With the exception of the analysis, describes the technology options for Northeast Corridor (NEC) in the United States high-speed rail service, and the various conditions where trains now achieve speeds of 120 mph on that may make one option more attractive than some parts of its right-of-way, all development the others. and use of these systems has occurred abroad. SUMMARY The technological options for high-speed rail freight shares the high-speed route with the pas- service include combinations of equipment, track, senger trains. Frequencies of service are contingent and power systems. Two of the equipment and on coordination with freight and commuter serv- track options—conventional equipment on up- ices and are adversely affected when the speeds graded track, and state-of-the-art equipment on of each service differ widely. new track or on partly new track—are now em- New technology applied to vehicles and signal ployed in the regular high-speed passenger rail and control systems make faster trips possible on service offered by Great Britain, Japan, and existing track. At speeds of more than 125 mph, France. Advanced technology (tilt-body equip- however, automatic speed controls are desirable ment) on existing track is being actively pursued as are technologies that reduce weight and by Britain and Canada, but is not yet fully pressure on the track. Where speeds are limited developed or implemented. The final equipment, by curves, the use of tilt-body vehicles (if further track, and power option—the ultra-high-speed developed) might improve trip times. Above 125 mode, magnetic levitation (maglev)—is still in the mph, complete grade separation is essential, and, developmental stage in West Germany and Japan. on the high-speed sections, tracks cannot be Of the propulsion system options, either diesel or shared with other types of trains. electric are used on all state-of-the-art trains. A brief discussion of each of these technology op- State-of-the-Art Equipment, Partly tions is presented below. or Totally New Track (France, Japan) Equipment and Track Options Where speeds substantially above 125 mph are desired, dedicated track becomes essential. The Improved Conventional Equipment Run On equipment must be designed to new and more Upgraded Existing Track (Great Britain, stringent specifications to keep the ride quality United States, Canada) and the forces exerted on the track within the proper limits. Lightweight materials, new and so- This least-cost option uses conventional equip- phisticated signaling, and train control systems ment at a maximum speed of 125 mph on existing track shared with freight and/or commuter trains. are required, and radii of curves must be in- Foreign experience, particularly in Great Britain, creased. For relatively small changes in elevation shows that such equipment can run comfortably en route, heavier gradients can be used to reduce and safely at speeds of 125 mph. Grade crossings the need for expensive viaducts and cuts. usually are eliminated on high-speed sections. This option technically allows for design speeds Stringent safety precautions are required where up to 200 mph on new track between cities, 15 25-413 0 - 84 - 6 16 ● U.S. Passenger Rail Technologies though lower speeds typically are used in revenue possible to use at least twice as much power con- service. The French avoided the major capital ex- tinuously as a diesel locomotive, with a signifi- penditure of new track into city centers at the cost cantly higher short-term power output and accel- of lower speeds (125 mph maximum) at each end eration rate, as well as improved braking. How- of the trip. The Japanese, because of overcapac- ever, the necessary overhead power supply instal- ity on existing lines and unsuitable track gage, lations and substations are very expensive, and constructed totally new track for their bullet train. existing signaling systems usually require renewal to prevent magnetic interference from the trac- Very High-Speed New Modes—Maglev tion system. Replacement of signaling systems also (Developmental: West Germany, Japan) is required to accommodate safe train spacing at higher speeds. To transfer the amount of power Maglev is the only new surface mode for high- needed, high voltage systems are a necessity, speed intercity transport still in the development usually by means of an overhead power supply. stages. Speeds in excess of 250 mph are possible Whatever traction is used, as speed increases, using such systems. The Japanese have tested an unsprung axle load* must be kept to lower values experimental vehicle at 320 mph. The West Ger- to avoid too great an impact on the track and mans are beginning final testing of their maglev vehicle. Unsprung axle load can be reduced by vehicles this year. Theoretical operating costs for suspending heavy electric motors on the truck a maglev system have been projected to be lower above the primary springs or on the vehicle body than those of a conventional new high-speed rail- itself with flexible drive. Total weight on each axle way corridor, however, verification of operating also is important and must be reduced as speed costs under conditions that fairly reflect revenue increases to ensure good ride quality. service await test results. Maglev would be competitive with air travel Gas Turbine Power from station to station on routes characterized by While gas turbine power units offer the advan- high population densities at one or both ends, tages of rapid power buildup and are very light- “travel affinity” between the cities, and long weight, the escalating fuel costs in the 1970’s and distances between stops. the engine’s lower efficiency except at full power led to the virtual abandonment of this technolo- Propulsion System Options gy. ** Turbotrains, which use gas turbine engines, Diesel Power are run routinely from Buffalo to New York. The diesel power unit carries its own primary Linear Motors power supply (the diesel engine) with fuel for 1,000 miles or more. It uses an onboard generator To date, electric propulsion has used rotary to provide electric power to motors that drive the motors carried on the train. With linear motors, axles of the power car and to provide heating, the magnetic parts of the conventional rotating cooling, ventilation, and lighting. Although lim- motor are replaced by a passive element on the ited in size and weight, the diesel-powered train vehicle and an active element in the track that in- is very flexible and can be moved around the sys- teract to accelerate, maintain speed, or decelerate tem as traffic needs dictate. Nevertheless, a design the train. Problems of power transmission and speed much higher than 125 mph is regarded as wheel to rail adhesion may be reduced by linear impractical by engineers because of power con- induction motors (LIMs). The first commercial in- straints inherent in diesel traction. stallations of LIMs (noncontact propulsion) for Electric Power ● Unsprung axle load is the weight not supported by springs, and therefore in immediate contact with track structure. This type of Electric locomotives basically are simpler, contact will result in higher impact loads for the same weight because of the absence of a cushioning effect of the springs. lighter in weight per horsepower, and cheaper to ● *However, the French National Railways (SNCF) still operates maintain than diesel locomotives. They make it a few trains at 100 mph maximum speed. Ch. 2—High-Speed Rail Technologies and Foreign Experience ● 17 revenue operation are under construction now as though it was recently increased to approximately low-speed transit lines in Toronto, Vancouver, 170 mph. and Detroit. Great Britain uses conventional equipment Maglev vehicles use linear motors for noncon- (diesel- and electric-powered lightweight trains) tacting propulsion. A variety of such motor types on existing track at maximum speeds of 125 mph. have been developed and tested with maglev ve- The British decided not to build new track because hicles; however, only the linear synchronous of projected high costs and probable opposition motor (LSM) currently is being developed for on environmental grounds. Great Britain and high-speed applications. While the principle of Canada also are developing separate versions of linear motors is simple, maglev requires a sophis- tilt-body equipment, designed to improve train ticated power conditioning and distribution sys- speeds on curves through the use of tilt mecha- tem to control the proper amount and frequency nisms. Viable commercial application of tilt-body of electrical power for propulsion. equipment is still in question. Comparison of various propulsion system op- Japan’s Shinkansen bullet train system uses tions, indicates that diesel power is flexible and state-of-the-art equipment on completely new does not require a large capital expenditure for track.