MAGLEV Worldwide Status and Technical Review

Transcription

1 1 Électrotechnique du Futur 14&15 décembre 2011, Belfort MAGLEV Worldwide Status and Technical Review Alain CASSAT, Vincent BOURQUIN BCD Engineering, Sàrl Place de l Europe 8 CH-1003 Lausanne, Suisse alain.bcde@bcde.ch, Vincent.bourquin@bcde.ch Table des matières 1. Introduction Objectives High Speed Ground Transportation Ground Level versus Tunnels High Speed Trains State of the Art Interoperability High-speed trains and lines Propulsion Track Energy Transfer Operational control From Railway to Maglev Function Equivalences Maglev Technologies Basic Concepts Superconductivity Low Temperature Superconductive Coils High Temperature Superconducting (HTS) Magnets Vehicle Introduction German and China Transrapid JR-Maglev (MLX) Swissmetro Project Italian UAQ 4 Project Inductrack Project Cobra Project Japan HSST Korean Incheaon Maglev Infrastructure Track Transrapid JR-Maglev (MLX) Swissmetro Project Inductrack Project... 22

2 Urban Maglev Propulsion High Speed Maglev Low Speed Maglev Transrapid JR-Maglev (MLX) Swissmetro Project Italian UAQ 4 Project Inductrack Project Cobra Project Japan HSST and Korean Incheon Maglev Levitation and lateral guidance Transrapid JR-Maglev (MLX) Swissmetro Italian UAQ 4 Project Inductrack Project Cobra Project Japan HSST and Korean Incheon Maglev Transfer of Energy to the Vehicle Introduction Transrapid JR-Maglev (MLX) Swissmetro Italian UAQ 4 Project Inductrack Project Cobra Project Japan HSST and Korean Incheon Maglev Power Supply Transrapid JR-Maglev (MLX) Swissmetro Italian UAQ 4 Project Inductrack Project Cobra Project Japan HSST and Korean Incheon Maglev Operational control Comparison between high-speed rail and maglev Resistance to motion Infrastructure Tunnel infrastructure and tunnel passing Integration aspects Audible Noise Energy consumption Emissions Costs Performance Maglev World Wide Projects Europa Germany System Italy Project Spain Project... 44

3 Switzerland Swissmetro Maglev Project Switzerland SwissRapide Express Project South Korea Incheon International Airport System China Japan MLX JR-Maglev HSST USA Maglev MagneMotion American Maglev Technology Transrapid Technology General Atomics Indutrack II South America - Brazil Cobra Conclusions High Speed - Industrial Achievement Urban Maglev- Low Speed - Industrial Achievement Markets Sustainable development Maglev Accidents APPENDIX I - Transports without Wheel and Rail - Brief Historic Glossary References... 53

4 4 MAGLEV Worldwide Status and Technical Review Alain CASSAT, Vincent BOURQUIN BCD Engineering, Sàrl Place de l Europe 8 CH-1003 Lausanne, Suisse alain.bcde@bcde.ch, Vincent.bourquin@bcde.ch ABSTRACT This paper presents technology aspects and choices relative to worldwide MAGLEV projects such as the German and Chinese Transrapid, the Japanese MLX and HSST, the Korean Tube Train, the USA Inductrack, the Brazilian Cobra and the Swissmetro. Propulsion, magnetic levitation and guidance, transfer of energy to the vehicle are investigated KEYWORDS Inductrack, Linear Motor, Magnetic Guidance, Magnetic Levitation, MAGLEV, MLX, Swissmetro, Transrapid. 1. Introduction 1.1 Objectives The objectives of this paper are to present an overview of actual worldwide developments in the field of Maglev and cover some technical key issues related to them. The actual status of the art is presented. This paper presents a synthesis of the Maglev technologies and projects. In this paper, it is considered Maglev systems, referring to industrial or commercial Maglev and Maglev projects, referring to studies, R&D developments, which have not reached, at that time, an industrial or commercial level. The content of this paper is the following: In the next part of this introductory chapter, the main aspects regarding transport requirements are reviewed. In the second chapter, the state-of-the-art of high-speed railway systems is briefly reviewed as it is the main reference today in terms of guided ground mass transport systems and technologies with numerous successful implantations worldwide at low, medium and high-speed. In the third chapter, some basic differences between railway and maglev systems are reviewed, indicating the differences and similarities on how both systems materialize the functions required to achieve the movement and control the forces to maintain the trajectories of the track. In the fourth chapter, the state-of-the-art of maglev technologies and systems is extensively reviewed, with detailed presentation of the principles, technologies and equipment used in the different concepts to fulfill the main functional requirements (vehicle, track, propulsion, levitation, energy transfer, power supply and operational control). In the fifth chapter, a comparison is undertaken between maglev and railway system on specific topics, such as aerodynamics, total cost of ownership and implantation acceptance. In the sixth chapter, a review of the implantation project for the main existing maglev systems and concepts is presented. Inputs of this paper are issued of many publications, keynotes and conferences given in references. Consequently, some texts, figures and pictures are issued from these references and should not be considered in this paper as here mentioned authors original work. 1.2 High Speed Ground Transportation Our modern societies require a growing mobility to sustain their economical, political and societal development. This exceptional growth in mobility is difficult to predict and was essentially underestimated in the past two decades. There is therefore a strong need of new infrastructures at the urban, suburban and interurban level, as well as at the international level to develop exchanges within and between networks of cities and regions. As indicated by Schäfer (ref. 25), «during the past 50 years, global average per capita income has increased slightly more than threefold, and world population has more than doubled. This combined growth, by a factor of 7.4, has translated into a nearly proportional increase in passenger mobility.»

5 5 In the same time, the need to fulfill sustainable objectives necessitates to improve transport in a drastic way with regards to environmental impacts, societal effects (noise, pollution, congestion) and economical cost (in particular in terms of beneficial operations and infrastructure amortization, which necessitates the reduction of operational and maintenance costs). Lopez-Ruiz (ref. 29) indicates that in 2050, France and other industrialized countries should decrease their CO2 emissions of 75% compared to today s values. Absorbing increased mobility, reducing environmental impacts and increasing sustainability of transport are the three challenges of future transport. This can only be feasible with the invention of new sustainable innovative transport systems and services. Schäfer (ref. 25) indicates a growing mobility that may rise by a factor of two in Western Europe in The World citizens travel approximately 48 billion km per year today; by 2050, that figure may grow to over 240 billion km, 5 times more than today. The transport was traditionally sorted into three categories of solutions: 1) Ground transportation, essentially rail and road transportation today, at the surface or underground; 2) Water transportation, essentially maritime or fluvial transportation today; 3) Air transportation. These classes have emerged from the differences in system engineering for each category necessitating the gathering and organization of a specific network of technical disciplines to master different categories of problems. The political organization has followed the same division. However, the speed is a better metrics to define the categories of systems. The following speed categories are usually defined: low speed for personal mover or surface public transport : up to 100 km/h; medium speed for urban or suburban transport: km/h on dedicated infrastructure, essentially ground transportation; high speed ( km/h) railway, maglev and airplanes; super speed ( km/h) systems, essentially airplanes and maglev, even though a few railway systems has demonstrated that they could reach this speed category. Schäfer (ref. 25) has also shown that high-speed and super-speed systems need to be considered in the same category than airplanes and that this niche will significantly increase its market share by The French AGV (automotrice à grande vitesse, Fig. 1) has reached the official top speed of km/h, on April 3, The top speed was reached at kilometer point 191 near the village of Le Chemin, where the most favorable track profile exists. The AGV is specified to achieve a commercial speed of 350 km/h for a load of 17 tons per wheel axle. This technical achievement shows the expertise of the high-speed railway industry, but the main operational problem at high-speed is to maintain the total cost of ownership sufficiently low to maintain attractiveness to compete with lowcost airlines. High-speed railway needs an intensive maintenance effort and expensive infrastructure. The maximum operating velocity of railways may attain 400 km/h, but is limited with rail-wheel contact (and its impact on wear and track maintenance) and power collection (catenary) for traction, which imposes technical limits to lead to acceptable operating and maintenance costs with the present technologies. Figure 1: The French AGV (automotrice à grande vitesse); source AGV Le 21ème siècle à très grande vitesse, Alstom. West Europe is investing in the creation of a high-speed rail network to improve the competitiveness of high-speed railway through a network effect. This work is supported by a strong interoperability effort from rail suppliers and operators. In Asia, Japan has achieved a highly profitable and dense high-speed rail network. South Korea and Taïwan have implemented main lines through the country and China is also working to establish high-speed link between their main cities. The distances in this country are such that the highest possible speed provides significant advantages, but in the same time, the maintenance costs and the safety are predominant factors that need to be mastered. In America, the development of cars and airplane has put aside the development of the railway, even though this country has been a pioneer in the history of rail. A lot of projects have been prepared, but the road to implantation is fastidious.

6 6 It is in this general context that the maglev technology is trying to find an industrial, societal and political path to its implantation. Since the second half of the 19th century, researchers and designers focused on ground transportations without rail and wheel. Different concepts were proposed, as presented in Appendix I. Today mainly, Magnetic Levitated (MAGLEV) systems are considered as industrial solutions. Both industrial Maglev for low speed ( 150 km/h) as Urban Maglev and high speed ( 400 km/h) Maglev are seen on the worldwide market. Various solutions are considered mainly depending on the speed of the transportation system and on the mechanical air gap between the vehicle and the track. Super-speed maglev systems are limited to two industrial types: the German and Chinese Transrapid systems: the superconducting JR type (Japan MLX). 1.3 Ground Level versus Tunnels New transport capacities are required between fast growing cities and highly populated areas. The combination of natural obstacles, protected areas, environmental constraints and populated area with a not in my backyard attitude makes the implantation of transport lines on the surface extremely difficult, it possible at all. The curvilinear lengths of the lines are increased to avoid obstacles and the use of tunnels is more and more necessary and widespread. Even, stations are placed often outside the cities. This fact applies to both maglev and railway. From their initial design, Maglev systems working with attraction levitation principle (such has Transrapid and Linimo) have been designed for open air operations on a viaduct. This elevated guide way gives a limited advantage in terms of integration compared to railway system. The start of the Japan urban maglev Linimo line is in a tunnel. The Munich project of Transrapid was planned with tunnels in both ends. For low-speed underground metro, the use of linear motor with a classical wheel-rail system to guide and support the coaches, instead of conventional rotary motor associated to a gear and a wheel, allows for a significant reduction of the frontal area of the vehicle. The corresponding cost saving of the civil engineering infrastructure of tunnels makes the use of the linear motor attractive. Such metros are currently used in many Japan metro lines. An additional benefit is the wear reduction on rails and wheels since acceleration and braking are undertaken by electromagnetic force in the linear motor and not at the rail-wheel interface. Figure 2 shows the gain in tunnel diameter versus conventional solution. Figure 2: Cross section of linear subway car and conventional subway car; metro linear motor; source: Prof. Koseki. At high-speed, Transrapid avoids tunnels in which its operational speed needs to be reduced. The Japanese high-speed Maglev MLX has been designed for tunnel operation: research on aerodynamics in tunnels at high-speed (over 500 km/h) has lead design team to equip the vehicle with long nose, small vehicle frontal cross-sections, high crosssectional area of the tunnel and special infrastructure at tunnel ends to handle aerodynamic problems such as the sonic boom. The cost for passing tunnel is high and has a strong impact on the design of the system. Speed, ambient pressure, vehicle and tunnel sections are strongly related through the aerodynamic matters. For both railways and maglev, the passing of tunnels has a key impact on the design of the vehicles and the cost of the infrastructure.

7 7 In the open air, the increase in speed increase wear and maintenance in the same time as operating costs as the aerodynamic resistance increases with approximately the square of the speed. The installed power and the track requirements are also factors increasing investment costs. The total cost of ownership is increased and must be compensated by a better attractiveness for airplane or car users to reach profitable operation. The only approach to decrease the total cost of ownership of a high-speed system is to combine tunnel and reduced ambient pressure. Though the principle was presented in an article in the Scientific American written by an anonymous author in the very beginning of the 20 th century (ref. 35), several projects have been developed since. The Swissmetro project is an intensively worked system being developed in the last 40 years by industry, universities and engineers. The demonstration was made that: 1. The total cost of ownership is decreased by three factors: a. The reduction of the line length by having the possibility to draw the most direct route between two points (as long as geology permits it). b. The industrialization of the tunnel construction. c. The reduction of operation and maintenance costs, through lower consumption (the power to maintain the reduced pressure is much less than the gain in aerodynamic resistance), automated control, a higher stability and stiffness of the infrastructure and, the maglev characteristics. 2. The fully underground solution simplifies the implantation and the social acceptance of the line. It reduces to zero the noise emission, which is normally associated with high-speed transport. It suppresses any visual intrusion in landscapes. 3. It also provides a safe and protected environment against theft of copper and terrorist action. 4. Existing state-of-the-art technologies and processes make the project feasible and ready to reach an industrial integration and a first implantation. If the cost of a high-speed railway line (250 km/h) can be as low as 10 M /km in good conditions, it can reach M /km in Switzerland with 64% of the line being in tunnels for new lines on the Swiss Plateau (see Trottet, ref 30). Figure 3.a shows how the investment cost for the track is increasing with the growing proportion of tunnels along the line. An underground solution as Swissmetro is shown as more attractive as this proportion reaches 30-35% for a railway line or 10-15% for a highway. Modern tunnels are now built for higher speed on new lines and therefore, the track investment costs is even higher as presented in the figure, as presented in the above mentioned example. a) b) Figure 3: a) Investment costs relative to tunnel proportion for railway, highway and Swissmetro (Values in CHF 1998, 1 CHF was 0.75 at that time); source Swissmetro, EPFL. b): Relative energy consumption versus partial pressure (Swissmetro). When considering the operational costs, it can be seen in fig. 3.b, that there is a minimum value depending on different parameters (tunnel diameter, speed, blockage ratio or ratio of the vehicle cross-sectional area versus tunnel crosssectional area). They can be significantly reduced compared to an atmospheric pressure situation. The graph is presented on a wet tunnel hypothesis, leading to a huge expense as the saturated pressure of water is reached. Swissmetro has developed a dry tunnel infrastructure that improves the presented figure. To date, the KRRI (Korean Railway Research Institute) has launched a similar project in South Korea. In Japan, after preliminary research and analysis, a joint research team has been launched in 2010 between the Japan Society of Civil Engineering, Institute of Electrical Engineers of Japan and the Japan Society for Mechanical Engineers to investigate an ultra-high speed train

8 8 running in a tunnel with reduced pressure. In USA, ET3 (ref. 31) is based on small vehicles travelling in small and evacuated tubes that can be on the surface. 2. High Speed Trains State of the Art 2.1 Interoperability Interoperability and safety are key European developments to achieve a trans-european railway network. Since the creation of railway lines and network, the technical strategy, the specifications and the implantation was undertaken by national railway companies. Differences in gauge widths, electrification standards and safety and signalling systems have naturally grown different from one network to the other, and, when national standardization was achieved, differences from one country to the other still exists. Interoperability is managed at the European level by the Directive 96/48/CE of 23 juillet 1996 and concern only high-speed lines and trains. 2.2 High-speed trains and lines The first High-speed trains has been developed in Japan and set in operation on the Tokaido high-speed line between Tokyo and Osaka in This line is still the most heavily travelled high-speed line in the world with 138 million people transported in The Japan Shinkansen network carrying 322 million passengers per year, which makes the Japan network the most used one, even though, with km of lines, it is the third high-speed railway in the planet. The trains in Japan have integrated the most advanced technologies to achieve a high level of comfort, reducing noise for inhabitants, maintain a dense traffic operation with a high punctuality and a high-level of safety in an adverse environment in matter of earthquake. The most visible technologies on Shinkansen trains (Fig. 4) are the technologies integrated for aerodynamics purposes, such as aerodynamic brakes, noise protection over the bogie, streamlined shapes for low aerodynamic resistance and special nose shape for sonic boom avoidance and side-wind stability. Figure 4: Japan E-954 (JR-East) new Shinkansen Operation speed 360 km/h in 2011, Vmax=389km/h at the test run in 2005; source JR-East. Figure 5: The French AGV (automotrice à grande vitesse); source Alstom. The second country operating high-speed trains is France with the successful TGV first in 1981 between Paris and Lyon. Rapidly, France has become a reference in terms of speed, both operational speed which are today set at

9 9 350 km/h or record speed as mentioned earlier. France has at present km of lines, which is the fourth biggest high-speed network in the world. Figure 5 shows the new AGV. Germany has developed its High-speed ICE technology step-by-step to reach a fully interoperable train, the ICE-3. Germany has a network of km of line, immediately following France. Germany is also delivering the first highspeed trains to Russia (Siemens Velaro) operated between Moscow and St-Petersburg. Italy has developed the ETR high-speed train family operated on the 923 km of Diretissima high-speed lines. Spain, which started high-speed operation with trains between Sevilla and Madrid in 1992 with the French TGV technology, has now the second network in the world with km of line and its own high-speed Talgo trains. Finally, China has made the most impressive progress having today the longest high-speed rail network with km of network out of which km are capable of speed of 350 km/h. Korea has also started with the French technology and has now its own high-speed trains KTR. Over the year, the trains have integrated numerous technologies and improvements to increase passenger comfort and ride quality, safety and noise emissions. For example, modern trains are now pressurized to avoid aural discomfort to passenger, which was a major source of complaints for passengers in the 1990s. 2.3 Propulsion New generations of high-speed trains tend to avoid having the propulsion concentrated at the beginning and at the end of the train. Thus the propulsion is divided along the train permitting to have smaller motors and a better repartition of the masses. This approach is implemented in the new French AGV (Fig. 6), but it can be seen also in Korean and Japan new high-speed trains. Furthermore, BLDC synchronous motor with permanent magnets (Fig. 7) is the modern solutions for the propulsion. High efficiency (>97%) is achieved for a ratio of less than 1 kg/kw. Figure 6: The French AGV (automotrice à grande vitesse); source Alstom and Prof. M. Debrune. Power: 800 kw; Mass: 768 kg; Max. torque: 4200 Nm; Max. speed: 4570 rpm; Max. current: 280 A; Max U phase to phase: 2800 V. 2.4 Track Figure 7: The French AGV: BLDC synchronous motor with PM - bogie; source Alstom and Prof. M. Debrune. The tracks have different gauges. Historically, more than 32 gages have been used ranging from 380 mm to mm (even mm in Russia for ship transport). Today the standard for railway is the mm, which corresponds to the distance between the two rails. To give examples of the magnitude of some exceptions: Spain and Portugal uses mm; Brazil, Australia and North Ireland are using mm, Russia and the countries issued from USSR are using mm.

10 10 The track is also dimensioned for a given speed: the higher the speed, the higher the requirements and the more expensive is the track. Track and trains are interacting with each other in a complex way and details play a critical role in interoperability. The tendency in Europe in the last decade was to separate infrastructure and vehicles for organizational reasons and to allow companies to operate trains that can freely travel on the European rail network. This separation has made the optimization between infrastructure and trains highly difficult, in particular with respect to maintenance (which is significant on high-speed rail network). Maintenance is a major problem which necessity arises from the dynamics of the train-track interaction. For example in Switzerland, the maintenance has been underestimated in the process of speeding up the network and requires now compensation by the government. Ballasted track are a standard since decades. But the use of slab-track (Germany and the Netherlands) or hybrid (slab-track with reduced concrete volume filled with ballast for cost reasons as can be observed in Italy on the Firenze Arezzo line) allows reducing the maintenance requirements. In tunnels, where the maintenance is prohibitive and dangerous, slab-track is essentially used. 2.5 Energy Transfer A pantograph collecting current on a catenary by contact is the traditional method to operate the transfer of energy from the infrastructure to an electric moving train. The complex composition of friction and current transfer at the interface between the pantograph and the catenary makes the catenary an important wear part of the system as it is submitted to two important wear mechanism (mechanical abrasion and electrical arching). Recently, the high price of the copper has motivated robbers to steal it from catenaries along railway lines, provoking additional operational breakdown indirectly due to the energy transfer system. Regarding interoperability, the electrification of the railway has led to differences in the voltage and the frequency from one rail network to another (Fig. 8). The following figure shows the difference in electrification standards in Europe, where 5 different voltage levels are available. The trains have accommodated this by the use of modern transformers allowing the operation from one electric network to another. 2.6 Operational control Figure 8: Electrification of European railway. In Europe, the ERTMS («European Rail Traffic Management System») is a key project being implemented in Europe to make rail transport safer and more competitive, but also to enable trains to cross national borders. The Directorates- General of Mobility and Transport of the European Commission extensively describes it (Ref. 28). ERTMS features two basic components: GSM-R, which is a radio communication system based on GSM standard and using frequencies specifically dedicated to railways. This system transfers voice and data information between the trackside and the vehicle.

11 11 ETCS (European Train Control System). A train-based computer, the Eurocab, compares the speed of the train as transmitted by the track with the maximum permitted speed and slows down the train automatically in case of excess. The implementation is planned in three stages or levels: o ETCS level 1: The permitted speed is sent through standard beacon (Eurobalises) located along the track. o ETCS level 2: The permitted speed is sent through GSM-R and it is no longer necessary to retain trackside signals. This reduces significantly investments and maintenance. The position of the train is still located by trackside equipment. The first commercial implantation of ERTMS level 2 occurred in November 2003 in Switzerland. o ETCS level 3: The train itself sends its rear end position, allowing to have a better accuracy and therefore optimize the line capacity and further reduce the trackside equipment. A third layer related to traffic management is currently entering a demonstration phase along the North-South corridor of the trans-european network (Rotterdam Milano) in the framework of the Europtirail pilot project. It must be noted that ERTMS does not allow driverless operation of trains. In this area, only slow-speed urban railways with a protected infrastructure (typically tunnels or elevated guide ways) are operated in an automated mode without drivers (wheel on rail or tyre on rail systems). 3. From Railway to Maglev Function Equivalences The differences between railway and maglev can be easily described when considering the transfer of loads and forces from the coaches to the ground. The essential differences are in the way the vehicle will interact with the guide way. The following key functions are necessary to consider (Fig. 9): Vertical and lateral guidance: o o Suspension: o o Railway: a standard railway wheel-rail ensures both lateral and vertical guidance as presented in Fig. 9 (bottom right). The system is very sensitive to geometry precision, but has a fundamental advantage: a low resistance, particularly at low-speed (and particularly much lower when compared to tyres-road rolling resistance). The force transmitted through the contact area can reach kn/cm2, which needs then to be distributed by the track through a succession of components (rail, sleepers, ballast) to the soft ground. Maglev: levitation assures vertical guidance and lateral guidance is provided also by different methods without contact described later in this article. All the methods require a linear guideway supporting track-based equipment. As an example, the Transrapid geometry for these functions is presented in Fig. 9 (top and bottom left). It can be seen that the levitation system, working by attraction requires that a part of the vehicle needs to be placed under the track to apply a vertical force. The layout of the JR-maglev is different as this superconducting system does interact with the side structures for levitation and guiding purposes as can be seen in Fig 13. Thanks to the possibility to distribute forces (for certain categories of maglev, such as Transrapid), the pressure at the vehicleinfrastructure interface is considerably reduced compared to railway to an order of 10 N/cm^2, which is several orders of magnitude less. This loading difference can reduce the weight and the proportion of the required track infrastructure for maglev systems. Railway: a suspension is required to filter the dynamic forces occurring at the rail-wheel interface as the rail imposes a change in the trajectory due to a curve or to deflections (inaccuracy of the alignment). Two levels of suspension are required. Maglev: maglev systems can integrate one level of suspension in the control of the levitation (electronic suspension), which leads to a considerable simplification of the mechanical arrangement of the vehicle. This is done by the JR-Maglev on which large airgaps are present and also on lowspeed maglev since the low-speed allows this integration even with small airgap. With an airgap of mm and the necessary inaccuracy of a guideway submitted to various temperature effects (solar radiation, water evaporation, etc.), deflections and vibrations, Transrapid still needs two levels of suspension. Swissmetro used a combination of high-precision and highly stiff guideway due to the protected and stable environment on one side and an increased air gap of 20 mm to remove one level of suspension. Propulsion:

12 12 o o Railway: a torque is applied to the wheel and is transmitted to the rail through the contact area between the wheel and the rail. The propulsion force transmission by this mechanism requires a sliding movement on one part of this area (on the full area when we reached slipping conditions). This sliding movement generates wear. The force transmission is dependent on the load applied on the wheel. The propulsion force is generated from the vehicle to the infrastructure, which requires the transmission of the propulsion power to the vehicle. Maglev: the propulsion force is without contact. This is achieved by a linear motor creating an electromagnetic force creating no mechanical movement and no wear. For low-speed maglev, the active part of the motor is placed inside the vehicle and the power is picked up by the energy transfer system. For high-speed maglevs (JR-Maglev and Transrapid), the active part of the motor is placed on the infrastructure. This simplifies the contactless power transfer to the vehicle. Transfer of energy to the vehicle: o o Power supply: Railway: as described earlier, a contact of a train-based pantograph on a catenary supplies the energy required for the train systems and the propulsion, the latter being the highest share. Maglev: for low-speed application (such as HSST), a contact of a slider over a conductive bar pick up the power required for the vehicle, the levitation and the propulsion. For high-speed system, contactless systems are preferred and will be fully described below. If this is an area of intensive research, present industrial solutions are usually available only at a certain speed, which requires, at low speed, an on board generator (JR-Maglev) or batteries (Transrapid). Some successful tests were also conducted using inductive energy transfer. For both systems, the power supply is not a problem as the existing electrical network is sufficiently developed to integrate both railway and maglev systems. Communication and operational control: The differences are essentially in the operational control, which allows the maglev systems to be fully automated. The communication technology could be interoperable, but the information content is different. Depending on the technical equipment, the engineering of the vehicle/train can be based on two different approaches: 1. Concentrated load transmission (classical approach): in railway, the coaches are installed on bogies that are responsible for the trajectory following, in particular of the propulsion, suspension and guidance functions. The arrangement of the TGV (which was also a part of the numerous innovations of the British APT Advanced Passenger Train) is particularly efficient with bogie at the junction of two coaches. The same philosophy has been chosen for JR-Maglev which is based on bogies on which one can find the same functions as present on a railway bogie (see Fig. 13), the bogie have a metallic colour on the lower side of the vehicle). The forces to and from the coaches are concentrated at the position of the bogie (essentially one bogie per coach) to be transmitted to and from the infrastructure. 2. Distributed load transmission: Both Transrapid and HSST are based on a coach on which several bogies are mechanically connected with degrees of freedom to cope with curves (see fig 12 for the Transrapid and Fig. 19 for the HSST-Linimo). The concept used on Swissmetro was to suppress bogie as high radius of curvature are easier to define underground and makes the ride much more comfortable. A specific articulated connection between coaches has been developed to integrate the required degree of freedom to manage curved trajectories. Coach modules of 12.5 m in length are defined (see Fig. 14). The concept of the Cobra (as presented on Fig. 18) use the same concept, but with a further reduction of the coach module length to achieve a lower radius for tighter turns.

13 13 Figure 9: Support and guidance of Maglev Transrapid (10 N/cm 2 ) and high-speed railway system ICE3 (50 to 100 kn/cm 2 ); source: Thyssen Krupp. 4. Maglev Technologies 4.1 Basic Concepts Two basically different concepts of magnetic suspension and guidance are considered: The electromagnetic suspension (EMS) uses electromagnets on the vehicle body, which are attracted to the iron reactive rails. It is a variable reluctance effect. The vehicle magnets wrap around the iron guide ways and the attractive upward forces lift the vehicle. The resulting attractive electromagnetic forces are independent of the speed. Consequently, there are lift forces at zero speed (at standstill of the vehicle). Furthermore, these forces are unstable requiring an electronic control which one generates damping forces. In order to limit the usually involved Joule losses, the electromagnetic suspension requires small magnetic air gap ( 25 mm). Such a technology is usually defined as classical. the German and Chinese Transrapid are based on this technology as most of the urban maglev (Japan HSST and Korean Incheon); The electrodynamic suspension (EDS) levitates the train by repulsive forces from the induced currents in the conductive guide ways. The origin of these forces is due to the temporal variation of a magnetic field in a conductor. The system is stable: there is equilibrium of the repulsive forces and the weight of the vehicle. As a result, the magnetic air gap is function of the mass of the vehicle. The considered magnetic air gap can be large ( 80 mm). However, there is no damping forces and no repulsive forces at zero speed. Such a system requires bogies at low speed ( 100 km/h). In order to match large air gap, actual technology is based on superconductivity. The Japan JR-Maglev (MLX) is based on such a technology.

14 Superconductivity Observation of the used technologies for Maglev shows three main technologies, classical ones and superconducting magnets are considered for some Maglev systems or projects: Classical technologies working at ambient temperature (propulsion, levitation, guidance); Low temperature superconductive coils, operating below liquid helium temperature (4,2 K); High temperature superconducting (HTS) magnets, at liquid nitrogen temperatures (77 K) Low Temperature Superconductive Coils Low temperature superconducting coils are used only in the Japan JR-Maglev (MLX). The superconducting coils see a DC magnet motrice force (MMF) of about 700 ka using cryocooler at 4.2 K. These coils are the DC excitation of the synchronous propulsion motor, the flux sources for the levitation, the guidance and the energy transfer to the vehicle. The magnetic air gap is about 50 mm and the commercial speed up to 505 km/h. The levitation and guidance forces are repulsive forces High Temperature Superconducting (HTS) Magnets The use of high-temperature superconducting wires (HTS wires) as superconducting magnets for maglev has several advantages such as improvement in the stability of the superconducting magnet, improvement in reliability through simplification of the magnet structure, and decrease in the mass of the superconducting magnet and energy consumed by the on-board cryocooler. Industrial developments of bismuth strontium calcium copper oxide wires (BSCCO wires) and rare-earth barium copper-oxide wires (REBCO wires), with a critical temperature higher than the liquidnitrogen temperature of 77 K, can be found on the market (Fig. 10). At 77 K, (RE)BCO operates at several Tesla. The world's first prototypes of cables and rotating machines have been successfully constructed and tested using SuperPower (subsidiary of Royal Philips Electronics N.V.) 2G HTS wire. A high field 2G HTS coil of SuperPower built in 2007 achieved world-record results: 9.81 Tesla achieved at 4.2 K central field (self-field); 26.8 Tesla achieved at 4.2 K central field (19 Tesla background axial field). SuperPower is manufacturing long lengths (kilometer-class) of robust 2G HTS wire. HTS superconducting magnets are currently tested on the JR-Maglev (MLX), figure 11 shows such a magnets. Figure 10: SuperPower 2G HTS wire; source: SuperPower. Figure 11.a: JR-Maglev HTS Magnet for running test Yamanashi; source: Central Japan Railway Company.

15 15 MMF 700 ka; number of wire strands 4, A; number of turns 1380, wire width <4.4mm, wire thickness 0.21 mm 4.3 Vehicle Figure 11.b: JR-Maglev HTS Magnet for running test Yamanashi; source: Central Japan Railway Company Introduction Maglev vehicles distinguish themselves per their light vehicle structure closer to airplane structure than high speed wheel rail trains even compared to the latest French AGV or Japan latest railway developments. Furthermore, a high level of aerodynamic is achieved, clearly apparent for the JR-Japan Maglev. None Maglev has a double deck approach for passengers, which could be considered in the future as a handicap in relation with capacity and station length German and China Transrapid Transrapid latest levels are the TR08 (1999, city-airport connector and long distance network), the China TR SHA (2002) and the TR09 (2007, city-airport connector). Transrapid vehicle is divided in sections. The total length or the number of sections can be adapted to the required capacity. Transrapid 09 (2007, Fig. 12) is the latest development of the German consortium. Transrapid 09 has the following main characteristics: Speed airport connector 402 km/h; Long distance 500 km/h; acceleration from 0 to 300 km/h within 120 s and 5 km; Capacity 449 passengers in a 3 section vehicle of 76 m length; 800 passengers in a 8-section vehicle of 200 m length.

16 JR-Maglev (MLX) Figure 12: Transraapid 09; source: Thyssen Krupp. JR-Maglev vehicle (Fig. 13) has an end, trail sections and intermediate sections connected by magnet bogies including wheels. Deep investigation of the aerodynamics leads to nose from 15 m up to 23 m length. These modifications have great effects on improving aerodynamics and reducing air vibration when entering tunnels. Its rectangular cross section is also a major difference from the round shape of the original vehicles. The top speed of 581 km/h was reached. The mass is 22 ton for the middle section of 24.3 m length and 33 ton for a front section of 28 m length. Initial round shape New rectangular cross section Speed profile of two vehicles crossing each other. Figure 13: JR-Maglev (MLX)- vehicle; source: JR-Railway Technical Research Institute Swissmetro Project Swissmetro project is a high speed Maglev ( km/h). For Swissmetro, travelling in a partial vacuum environment has a major impact on the concept of the vehicle. A partial vacuum below Pa is needed when a blockage ratio of 0.4 to 0.5 is imposed in order to decrease the aerodynamic drag forces. The Swissmetro tunnel structure naturally imposes to have horizontal vehicle arms supporting the levitation, the guidance inductors and the motor on board parts (Fig. 14). Simultaneously, the active forces (levitation, guidance, propulsion) act very close to the gravity horizontal centerline. The mechanical vehicle structure leads to a frame similar to an airplane frame, light and flexible, of 3 m inside diameter, with a nose, a trail and intermediate cells of 12.5 m length. Furthermore, the small tunnel inside diameter of 5 m and the total vehicle length of 80 m for 200 passengers, request a deformation in the axial direction in

17 17 order to guarantee the guiding air gap of 20 mm in the curves and a minimum curve radius of m. Flexible joints on the vehicle (Fig. 14) assure this function. The total mass is 80 ton Italian UAQ 4 Project Rayon de courbure min m Fig. 14: Swissmetro Maglev - vehicle; source Swissmetro, EPFL. The Italian UAQ4 is actually a project. The vehicle is a guided train using superconductors and HTS super-magnets for lifting and guiding. Figure 15 gives the expected vehicle dimension. It is described as a high-speed maglev Inductrack Project Figure 15: UAQ 4 Maglev - vehicle; source Engineering Faculty, University of Aquila, Italy. The USA project Inductrack (Fig. 16) is an urban maglev from General Atomics, Based on EDS using Halbach spatial distribution of permanent magnets for the levitation. It uses only permanent magnets and does not require cryogenically cooled superconducting coils. The maximum considered speed is 100 km/h. Figure 16: Inductrack Urban Maglev - vehicle; source General Atomics.

18 Cobra Project The Maglev-Cobra project (Fig. 17, 18) developed at the Federal University of Rio de Janeiro is an urban maglev of maximum speed is <100 km/h. The Brazilian Cobra proposes a maglev with HTS superconducting magnets for the levitation and guidance. A vehicle is made of short modules, one meter long each one. Once the modules are connected, the vehicle resembles a snake, or cobra in Portuguese, and can follow curves with just 30 m of radius. Each module offers space for eight passengers and maximal loaded weight of 800 kg. Figure 17: The Maglev-Cobra Urban maglev; source: Federal University Rio-Janeiro. Figure 18: The Maglev-Cobra at the Federal University Rio-Janeiro island Cobra operational line (200 m lenght in 2014) Japan HSST The Japan HSST is a EMS urban maglev (Fig. 19). Different vehicles are considered the HSST-100L (long), HSST100S (short) and the LINIMO which maximum speed is 100 km/h and a gradient of 7%. Small curve radius of 50 m is possible. HSST-100L: 14.4x2.6x3.2 m, 17ton/car to 25 ton/car, 110 pas/car; HSST-100S: 8.5.x2.6x3.2 m, 17ton/car to 25 ton/car, 67 pas/car;

19 19 HSST-LINIMO Korean Incheaon Maglev Figure 19: The Japan HSST: Different types of vehicles; source: HSST. The Korean Incheon maglev (Fig. 20) is an urban maglev which technology is closed to the HSST technology. Vehicle size: 12x2.7x3.45 m, no load: 12 ton, 115 passengers, 110 km/h, 4 LIM motors/car, gradient 7%, curve: 50 m, air gap 8 mm 4.4 Infrastructure Track Transrapid Figure 20: The Korean Incheon Maglev; source: Hyundai-Rotem. For the Transrapid (Fig. 21, 22, 23), a concrete V block allowing a rotation on its bottom summit defines the vehicle spatial position. This permits considering curves with an inclined guide way without changing the concrete columns supporting the V block. This optimization leads to vehicle arms going under knee the concrete V block. As a result, the total vehicle height increases to 4.16 m. The V block structure limits advantageously the overall cross section of the complete concrete structure thus permitting to consider the Transrapid at different ground level heights (0 to 17.7 m height). On the other hand specific concrete structure was developed to decrease costs, as presented in Fig. X. Experiences showed that optimization of the hybrid girders would be possible. The aim was to optimize all stages of design and construction of the guide way system for the Maglev. In 2004, the compact guide way girder was created, and by 2009 it was a completely equipped, developed, modular holistic guide way system for the Maglev. Table 1 gives the cross section of tunnels versus the speed.

20 < 3,5 m 2,5 10 m 20 At grade guideway Typ III Elevated guideway Typ II 6,19 m 2,75 m 0,4 m Cross area - tunnel length >150 m Speed [km/h] Double track tunnel [m2] Simle track tunnel [m2] ,76 m Table 1 : Transrapid tunnel cross section. 1 m 12 m Elevated guideway Typ I 49,536 m 2 m 25 m V-Block concrete shape Elevated girder with integrate stator and guidance reactive rail Length: m. Holistic hybrid- fully equipped, at-grade girder length: 9.14 m Figure 21: Transrapid infrastructure; source: Dornier Consulting and Max Bögl Bauunternehmung. Figure 22: Transrapid infrastructure - Holistic hybrid- fully equipped, tt-grade girder; source: Max Bögl Bauunternehmung.

21 21 Correction: 13.9: inside diameter; 14.5: outside diameter Shangai - On-bridge girder structure Figure 23: Tunnel, source: Jianwei Wang, Xianlong Jin, Yuan Cao, Shanghai Jiao Tong University and Shanghai Maglev Transportation Engineering R&D Center JR-Maglev (MLX) Japan Maglev MLX is based on a U concrete shape (Fig. 24, 25), which supports the lateral levitation plus guidance coils and the propulsion stator windings, offers a compromise for both uses: essentially at ground level and underground compatibility. New free-standing reinforced concrete (RC) sidewalls are investigated. Further improved sidewalls were developed, made of reinforced powder concrete (RPC), so that the thickness is 7 cm thus 40% lighter than conventional sidewalls. This lightness contributes not only to the cost reduction of the infrastructure but also to simplicity of substructure of viaduct. Double track tunnel is side width of 12.6 m and 7.7 m height. Figure 24: JR-Maglev bridge and track; source: JR-Railway Technical Research Institute. Conventional sidewalls Reinforced concrete (RC) sidewalls Powder concrete sidewall (RPC) Panel model Direct attachment model New method Figure 25: JR-Maglev - New free-standing RC sidewalls and sidewalls with powder concrete (RPC); source: JR-Railway Technical Research Institute.

22 Swissmetro Project Swissmetro (Fig. 26) is developed around two tunnels, one per direction, environment. The tunnel has an inside diameter of 5.0 m and an outside diameter of 7.7 m. Swissmetro-under ground station Revolver: changing tuve Air lock passenger embarquement Variant A Variant B A1: transfer of energy to the vehicle, linear transformer B1: transfer of energy to the vehicle, linear transformer A2: fixed stators with the tunnel, rotor poles on board B2: rotor poles fixed with the tunnel, stators on board A3: magnetic guidance per attraction B2: magnetic guidance per attraction following the stators A4: magnetic levitation per attraction B3: inductors, urgency brake B4: magnetic levitation per attraction Inductrack Project Fig.ure 26: Swissmetro: Vehicle and tunnel cross Section: source: Swissmetro. For the USA Urban Maglev Inductrack project (speed 100 km/h), the infrastructure is a simple rectangular shape of girder, as shown in Fig. 27. Work has been performed to date related to the use of a steel fiber-reinforced hybrid girder system. It supports both the long stator windings of the synchronous motor and the reactive conductive ladder track or laminated conductive track for the levitation. Long stator: fixed with the track Double sided PM array, on board Halbach PM array, on board Shorted wires: fixed with the track

23 23 Figure 27: Inductrack Maglev Reverse rectangular shape of concrete: source: Lawrence Livermore National Laboratory Urban Maglev Urban maglev infrastructure is usually a concrete platform at ground level or at high levels (Fig. 28, 29). It supports the different elements and the contact line (usually DC voltage) along the track. Figure 28: Korean Incheon Maglev - Infrastructure of urban transports; source Hyundai Rotem. Figure 29: Impact of infrastructure of urban transports; source Korean Institute of Machinery and Materials. 4.5 Propulsion High Speed Maglev For high speed (>400 km/h), all worldwide Maglev have synchronous linear motors with long or short stators (Fig. 30). Short stator (Swissmetro) implies that the lateral guidance, the levitation and the transfer of energy to the vehicle must be independent electromechanical systems. Short stator implies the use of homopolar linear synchronous motor where the reactive part is iron only and on board of the vehicle. Both the DC excitation and the stator winding are at the level of the fixed stator with the track. Short stator has the main advantages that the winding configuration (number of poles

24 24 and number of slots) can be optimized. With long stator (Transrapid, JR-Maglev), propulsion and levitation are combined functions and systems. This permits decreasing the Joule losses of the levitation systems and consequently to decrease heat dissipation at the level of the vehicle. Long stator implies, when iron part (teeth and yoke) is used, a one coil per slot and consequently, high voltage cable as wire. The magnetic (mechanical) air gap and the pole pitch define the chosen technology for the propulsion. The choice of the air gap is compared with the technical and qualitative aspects. For the passenger comfort, Transrapid 10 mm air gap requires a complementary mechanical suspension in parallel with the magnetic levitation; Air gap up to 20 mm should permit lower suspension rigidity; For air gaps 10<δ<20 mm, the local heat of the components is a key issue. Cooling systems for the guidance and the levitation inductors are considered; Air gaps of >80 mm refer mainly to satisfy earthquake specifications and very high speed (>400 km/h). This large air gap usually requires superconductivity to still obtain acceptable efficiency; The values of the air gap and the top speed have a direct effect on the vibrations, the resonance frequencies, of both the vehicle and the track Low Speed Maglev Figure 39: Long stator fixed with the track and short stator; source: Swissmetro. Low speed Maglev use synchronous or asynchronous linear motors. Linear asynchronous motors permit a simple conductive reactive rail, usually of aluminum Transrapid As shown in Fig. 31, Transrapid combines the propulsion the levitation and the transfer of energy to the vehicle in the same electromechanical system. The length of the Transrapid vehicle is variable between two sections with a total of 150 places to ten sections for 1060 passengers. The long stator is composed of lamination with teeth and yoke. The stator is energized by sectors up to 4 km length. The winding configuration is one coil per slot, the coil opening is three slots, the coil being a high voltage cable (Fig. 32). On board of the vehicle, the poles of the motor are laminated. Each pole is surrounding by the DC coils of the excitation. The DC excitation assures the control (motor direct axis) of the levitation. Furthermore, each pole has four slots containing the wires of the linear generator. The choice of classical linear motors implies a short pole pitch of 258 mm, corresponding to more than 25 times the air gap (10 mm). This pole pitch dimension is necessary in order to decrease the motor end winding lengths. The maximum synchronous frequency is 300 Hz. such a limit frequency corresponds to a synchronous speed of about 500 to 550 km/h. Depending on the length of the vehicle, the mechanical power has a minimum of 8 MW.

25 25 Figure 31: Transrapid Propulsion - guidance - levitation linear generator; Source: Thyssen-Krupp. Figure 32: Transrapid - High voltage cable; Source: Thyssen-Krupp and Max Bögl Bauunternehmung JR-Maglev (MLX) The JR-Maglev superconductivity technology permits a higher pole pitch of 1350 mm and a corresponding lower synchronous frequency, typically 72 Hz for 700 km/h, which is the speed goal of the Japanese engineers. The stator is energized per sector. The low synchronous frequency permits to have relative long stator sectors. The DC excitation is

26 26 produced by superconducting coils (Fig. 33). The equivalent MMF is about 700 ka. Such high MMF permits to have large magnetic air gap of about 50 to 70 mm. The mechanical power is above 8 MW, for a power greater than 13 kva. In order to simplify the original double-layered propulsion coils, two types of single-layered propulsion coils were developed and installed at the Yamanashi Maglev Test Line. One is an integrated type of coil, which has a propulsion coil and a levitation coil in it. This coil can reduce the number of coils to one third of the conventional types. The other consists of cable. It is aimed to reduce production cost using power cable whose producing method is already highly established. Super conductive coils on board of the vehicle. Original double-layered propulsion coils. beam model Single-layered propulsion coils. Figure 33: JR-Maglev (MLX) New free-standing RC sidewalls and sidewalls with reinforced powder concrete (RPC); source: JR-Railway Technical Research Institute Swissmetro Project Swissmetro first propulsion variant is a linear homopolar synchronous motor (Fig. 34). The pole pitch is 231 mm, corresponding to more than 10 times the air gap of 20 mm. The maximum synchronous frequency is 300 Hz, Such a limit frequency corresponds to a synchronous speed of about 500 to 550 km/h. The mechanical power is only 6 MW, due to the positive effect of the vacuum on the aerodynamic drag force. Short stator fixed with the track are disposed only, where an acceleration or re-acceleration and braking are necessary along the track, as the speed profile is imposed.

27 27 Figure 34: Long rotor poles and linear homopolar synchronous motor; stator on board of the vehicle; source Swissmetro Italian UAQ 4 Project The propulsion is a linear synchronous motor which excitation is permanent magnets fixed on both sides of a iron U shape, all along the track (Fig. 35). The short ironless stator is on board of the vehicle. The characteristics of the propulsion are not published, only schematic is given Inductrack Project Figure 35: UAQ 4 Maglev - propulsion; source Engineering Faculty, University of Aquila, Italy. For the Urban Maglev Inductrack, the motor is a synchronous linear motor which long stator is fixed with the track (Fig. 27). On board of the vehicle, the permanent magnets create the necessary excitation. The characteristics of the propulsion are not published, only schematic is given. Testing with chassis weight up to 10,000 kg, to a speed of 10 m/s, air gaps up to ~30 mm, and acceleration up to 2.8 m/s2 has been achieved (nominal acceleration is 1.6 m/s2) Cobra Project The propulsion is a linear synchronous motor with short stator on board of the vehicle (Fig. 36). The excitation is PM fixed along the track. A consumption power of 90 kw is given for a speed of 70 km/h and 10 MW for 450 km/h.

28 28 Figure 36: The Maglev-Cobra- Propulsion; source: Federal University of Rio, Brazil, Japan HSST and Korean Incheon Maglev For Urban Maglev (<250 km/h), linear asynchronous motors (LIM) can be found for the Japanese HSST (100 km/h) (Fig. 37, 38) and the Korean Hyundai Rotem (110 km/h). Usually the reactive rail is in aluminum. Both technologies are very similar. For the Japanese HSST, the module of the linear motor (one side of the vehicle) has a nominal thrust of 3000 N for a three-phase motor having 8 poles. The maximum current is 380 A and the reactive rail is a 4 mm plate of aluminum. Each vehicle has 10 LIM ea/car. The no load vehicle is 17.3 ton/car for a length of 43.3 m. Figure 37: Japan HSST Propulsion bogie linear induction motor and levitation inductors; source: HSST. Figure 38: Japan HSST - Propulsion; source: HSST 4.6 Levitation and lateral guidance Transrapid Korean Incheon Maglev; source: Hyundai Rotem. For Transrapid, the attractive force between the single sided motor stator and the rotor poles creates the levitation forces (Fig. 39, 40). These forces are distributed all along the vehicle. The levitation control has to satisfy two values: the necessary levitation forces and a high motor power factor (>0.8). The air gap is 10 mm. The no load vehicle linear mass is about 2.13 ton/m. For Transrapid, inductors, placed along each side of the vehicle, assure the lateral guidance per attraction. The corresponding air gap is 8-10 mm.

29 29 Figure 39: Transrapid levitation and lateral guidance; source: Dornier Consulting and Thyssen-Krupp, JR-Maglev (MLX) Figure 40: Transrapid levitation control; source: Thyssen-Krupp, For the JR-Maglev (MLX) the magnetic levitation and guidance are obtained by the same on board, two per half-cell, supra conducting coils. The on board superconducting coils (700 ka) induced a reactive current in the fixed levitation and guidance coils forming an "8 shaped figure" (Fig. 41, 42). The interaction of the inductor currents and the induced currents create both vertical and lateral forces. Electrical connections of the fixed coils, on both side of the concrete U shape, creates a current balance effect, which decreases current on the fixed coils seeing the smallest air gap and increases the current on the opposite side, thus the lateral and vertical motion is better damped and stable. This technology permits to have large air gap about mm. As a result, magnetic levitation and lateral guidance appear only at a relative high speed of 100 km/h., below this speed, bogies with wheels are necessary. Furthermore a magnetic drag force appears which usually is not negligible. Figure 41: levitation and lateral guidance; source: JR-Railway Technical Research Institute and Prof. Gieras and Piech.

30 30 Figure 42: JR-Maglev (MLX) Levitation and guidance principle; source: JR-Railway Technical Research Institute Swissmetro The levitation and the lateral guidance, per attraction, involves inductors (Fig. 43), on board of the vehicle, which are positioned all along the vehicle, on the different cells. The air gap is 20 mm and the corresponding dimensions are given in Fig. 44, 45. A reactive rail laminated is fixed with the track. Figure 43: Swissmetro - Levitation and guidance principle; source: Swissmetro, EPFL. The reference solution for the levitation corresponds to the following parameters: Number of levitation inductors, per vehicle: 28 [-] Rated force per inductor: 30 [kn] Total power per vehicle, nominal behavior, copper wire: 125 [kw] Total power per vehicle, nominal behavior, copper aluminum: 200 [kw] Inductor mass, copper wire: 130 [kg] Inductor mass, copper aluminum: 101 [kg] Linear mass of the reactive rail: 60 [kg/m] Converter efficiency: 0.97 [-] Figure 44:Swissmetro - Levitation; source: Swissmetro, EPFL. The reference solution for the guidance, without deformation of the vehicle, corresponds to the following parameters: number of levitation inductors, per vehicle: 30 [-] rated force per inductor: 13 [kn]

31 31 total power per vehicle, nominal behavior, copper aluminum: 60 [kw] inductor mass, copper aluminum: 46 [kg] lineic mass of the reactive rail: 60 [kg/m] converter efficiency: 0.97 [-] Italian UAQ 4 Project Figure 45: Swissmetro Lateral guidance; source: Swissmetro, EPFL. Levitation and guidance are created by the same high temperature superconducting system. Permanent magnets (NdFeB) are placed all along the both sides of the track. Superconducting high temperature runners on board of the vehicle refuses the flux created by the fixed permanent magnets, thus repulsive forces are created (Fig. 46, Meissner effect). The V shape of the PM system creates both lateral and levitation forces, even at no speed. It can be demonstrated that for small air gap the levitation force is repulsive and attractive for large air gap. Thus the system is fully stable by itself. Furthermore it does not produce a magnetic drag force. Superconducting runner Fixed PM on one side of the track Flux without superconducting runner Flux with superconducting runner Figure 46: UAQ 4 Maglev Superconducting levitation; source: University of l Aquila, Enginnering Transportation Department Inductrack Project For Inductrack, the levitation, the guidance forces are obtained by the same fixed reactive short-circuited coils on the track (Fig. 47, 48). The on board excitation magnets are arranged in a Halbach single or double sided array(s) to increase the field in the active air gap and to decrease the field on the outside surface The levitation force per meter length is 500 N/m. Double sided Halbach permits to minimize the magnetic drag force. Schematic Drawing of Inductrack Model Track Coil Wood Ferrite "Tile"

32 32 Figure 47: Inductrack Maglev Levitation based on single sided Halbach spatial PM distribution; source: Lawrence Livermore National Laboratory. Weak Field Strong Field Permanent Magnets Figure 48: Inductrack Maglev Levitation based on double sided Halbach spatial PM distribution; source: Lawrence Livermore National Laboratory Cobra Project Coils The Maglev-Cobra levitation method is based on the flux pinning properties of high temperature superconductors (HTS) in the presence of magnetic fields provided by Nd-Fe-B permanent magnets. The magnetic rail (Fig. 49) uses Nd-Fe-B permanent magnets arranged in a flux shaper scheme, with iron parts properly located. The magnetic rail contains 5x5x10 cm 3 Nd-Fe-B magnets arranged in a flux shaper scheme. The size of the iron between the two permanent magnets is 1.2 cm. As for the Italian UAQ 4, repulsive forces are created, the levitation and the guidance are assures in a stable state, even at no speed. Figure 49: The Maglev-Cobra- Levitation lateral guidance; source: Federal University of Rio, Brazil, Japan HSST and Korean Incheon Maglev For the urban maglev magnetic inductors working by attraction with a small air gap of 8 to 10 mm are placed on each side of the vehicle (Fig. 38). The reactive rail is non-laminated iron. As the inductor and the reactive rail have a U shape, lateral reluctance effect appears. This passive effect is used to guide laterally the vehicle. Of course this guidance is possible only for low speed urban maglev ( km/h). For the Korean Incheon maglev, the levitation assures a force corresponding to 265 kn, for two vehicles of 12 m length each and 93 persons per vehicle. 4.7 Transfer of Energy to the Vehicle Introduction Maglev requires a transfer of energy to the vehicle. For high speed maglev contactless transfer is considered. For low speed maglev, catenary is usually the chosen technology with a DC voltage of 1500 VDC. Possibilities of contactless technologies are seen or a combination of them: linear generator; transformer action; inductive power transfer; gas turbine generator Transrapid At low velocities and standstill, e.g. in and near stations, the Transrapid needs additional energy supply. The Transrapid 08 uses a conventional system composed of current collectors (catenary) and power rails attached to the guide way. Transrapid 09 is equipped with a linear transformer (Fig. 50, 51, Inductive Power Supply or IPS ), was

33 33 developed), only at start part of the motion, near and in the stations. This linear transformer furnishes an active power of 6kW/m. The primary has a mono phase supply at 400 V and 20 khz. The coaxial feeder cable has Litz wires. To compensate for the inductivity of the induction loop, capacitors are connected in series at regular intervals. The capacity is chosen so that the series resonant circuit, primary cable and compensation capacitors, is tuned to the system operating frequency of 20 khz. Thus, it represents a pure resistance load for the supply. At high speed, it uses the linear generator created by the flux harmonics induced in the wires inserted in each motor pole (Fig. 31, 4 slots per pole). Figure 50: Transrapid 09 - Linear transformer Inductive power supply (IPS) Cable of the primary; source: Thyssen- Krupp JR-Maglev (MLX) Figure 51: Transrapid 09 linear transformer (IPS); source: Thyssen-Krupp. At low and no speed, JR-Maglev uses a gas turbine. At speed, a linear generator is used (Fig. 52). Superconducting coil (1) for the linear generator, on the magnetic bogie, creates a flux. This flux create a variation of the flux due to the speed in the upper coil of the levitation (2), thus creating a reactive variable current and consequently a variable flux in the upper and lower coils of the levitation (2, 3). This variable flux induced a variable flux in the generator coils (4),

34 34 thus a variable flux. Consequently, active power is transferred to the vehicle. Of course, a magnetic drag force appears too "Magnetic Bogie on board of the vehicle" concentrate type linear generator 1 Super conducting coils for linear generator; 2, 3. Levitation coils fixed with the track; 4 Generator coils Concentration type Distribution-type Figure 52: JR-Maglev (MlX) Two types of the linear generators used in MLX. Concentration type.and distribution-type; source: JR-Railway Technical Research Institute Swissmetro The average power to transfer is about 500 kw, for the functions such as the levitation, the guidance, the air conditioner, the lightning, communications and controls. The solution consists in a linear transformer (Fig. 53), without iron. The air gap is 20 mm. The efficiency is greater than 80%. The primary winding has Litz wire, the primary length is 1 km and the secondary, on board of the vehicle, a length of 50 m. The inverter frequency is 2kHz. 1. primary; 2. Secondary and Litz wire; 3 secondary

35 35 Figure 53: Swissmetro Principle of linear transformer; source: Swissmetro, EPFL Italian UAQ 4 Project No specific information data is given at that time Inductrack Project No specific information data is given at that time Cobra Project No specific information data is given at that time Japan HSST and Korean Incheon Maglev Both systems use V DC catenary on the side of the vehicle. 4.8 Power Supply Transrapid For Transrapid (Fig. 54, 55), at the outputs of the substation (high voltage switching equipment with step-down transformers), the inverters energize the stator sectors of the motor. The corresponding AC bus, which sees the same frequency (0-215 Hz, for 400 km/h) than the motor synchronous frequency, assures the transfer of energy along the track. Sectors with switches permit to decrease the energized motor section length. There are only inverters at the substation, none along the track. A disadvantage is the line effect of the AC high voltage cable bus, which limits the distance between two consecutive substations. Figure 54: Transrapid principle of the power supply; source: Prof. A. Stephan, J. Lieske.

36 Figure 55: Transrapid Shanghai power supply; source: Prof. A. Stephan, J. Lieske. 36

37 JR-Maglev (MLX) JR-Maglev presents a very similar strategy to Transrapid power supply approach. Figure 56 represents the chosen topology Swissmetro Figure 56: JR-Maglev Yamanashi test line - power supply; source: Prof. Gieras and Piech. The power supply of the Swissmetro is shown in Fig. 57. The 125 kv, 50 Hz corresponds to the surface grid. The substation (125 kv/6 kv) is in an underground substation.. After the three level rectifier, a DC bus (-5, 0, 5 kv) supplies the different motor stators. The DC bus permits to transfer energy on long distance with low Joule losses. Figure 57: Swissmetro - power supply; source: Swissmetro, EPFL Italian UAQ 4 Project No specific information data is given at that time Inductrack Project No specific information data is given at that time Cobra Project No specific information data is given at that time.

38 Japan HSST and Korean Incheon Maglev Both systems are supplied by a DC catenary of 1500 V. The DC bus is usually put on one side of the track. 4.9 Operational control All maglev are based on an automatic operation, even at high speed (Transrapid, JR-Maglev). The basic principle of control is shown in Fig. 58. Figure 58: Transrapid control system; source: Thyssen-Krupp. 5. Comparison between high-speed rail and maglev 5.1 Resistance to motion Aerodynamic resistance represents the major part of the train resistance to motion at high-speed. This resistance is essentially dependant on the geometry of the coaches. It grows with approximately the square of the speed. There are no fundamental differences between railway and maglev systems. The maglev systems offer a better streamlining because of the absence of pantograph and less complex bogies. The combined contribution to aerodynamic resistance of

39 39 pantograph and bogie is approx. 25%. The leading parameter remains the cross-sectional area and the length (more than 65% of the drag is associated to this pair of parameters). The resistance associated with the vehicle-track interaction comes in a second place and has a typical shape as described in the following figure where the resistance of Transrapid and JR-Maglev are compared for different train length. This resistance is significantly higher at low speed. Figure 59: train resistance; source: Stephan et al ref. 18 Train resistance due to wheel-rail interaction shows a linear increase and therefore, the maglev systems exhibit a significant advantage compared to railway systems as the speed is increased: the power consumption is less. The higher the speed, the bigger the gain for the maglev. 5.2 Infrastructure Tunnel infrastructure and tunnel passing The use of tunnels is more and more necessary on railway mainlines. The capability of the Transrapid to have lower radius of turn and steeper gradient (about 10% compared to about 4% for trains, see Fig. 61) reduces the length of tunnels required on a line compared to railway system. Tunnels cannot be avoided though. The behaviour of Transrapid in tunnels has been extensively described by Tielkes (ref. 32) and Ravn & Reinke (ref. 33). With high-speed, a large frontal area (which gives a very confortable internal volume to the coaches) and relatively squared section, Transrapid experience some difficulties travelling into tunnels: 1) The infrastructure has been designed for operation on a viaduct and the geometrical constraints have been optimized to ground forces through pillars. The geometry of the viaduct is difficult to integrate in a tunnel and is not optimal for underground operation. 2) The particular aerodynamic effects associated to tunnel, such a crossing, sonic boom or tunnel passing, have a strong impact on vehicle design. Tunnel operation requires larger tunnel diameter or decreased speeds. The Transrapid system was not optimized for these aerodynamic effects. The JR-maglev is fully optimized for these effects, which have been intensively studied on the Yamanashi test line, which has a large proportion of tunnels (more than 80%) Integration aspects Figure 60 illustrates the cross section of an ICE3 slab-track track (without ballast), the typical track sizes are given. For a total lateral cross width of 12 m, the visual impact of Maglev is similar to high-speed train.

40 40 Figure 60: Cross section of Maglev Transrapid and high-speed railway system ICE3; source: Thyssen-Krupp. Figure 61: Transrapid gradient 10% slope rate ICE gradient 4% slope rate; source: Thyssen-Krupp. The integration of the Transrapid guideway can be easier when considering the viaduct structure. Nevertheless, the integration problems of new lines are huge, particularly in urban area. These difficulties have been shown by the Munich project, where a link between city center and airport was planned using Transrapid. The straight line, which could only be considered if a fully underground solution could be proposed, is 28 km. The length of the acceptable line that was proposed for Transrapid had a length of 37 km and the additional constructions required for environmental protection, noise reduction contributed to increase the cost of the project. 5.3 Audible Noise The noise of a high-speed transport vehicle is essentially coming from aerodynamic sources. The noise level grows with approx. the power 6 of the speed. With the possibility to have a better streamlining of the bogie and the absence of catenaries, the maglev has a slightly lower noise emission compared to railway systems as shown in Fig Energy consumption The energy consumption of railway has been continuously improved, for example in Japan. Modern trainset uses 51% of the energy required by the first generation of Shinkansen at the same speed. For the reasons exposed above (see 5.1), the energy consumption of a maglev is less than the one of a train and the difference is increasing with the speed. The consumption can be further reduced by the use of tunnels under reduced pressure. A summary of the energy consumption of various systems is presented in Fig. 63.

41 41 Figure 62: Comparison of audible noise; source: Swissmetro (left), Masada (right). 5.5 Emissions Figure 63: Comparison of energy consumption; source: Swissmetro. Emissions are following the same trends as energy consumption, essentially for the same reasons. 5.6 Costs Figure 64: Comparison of emissions compared also with other transport means; source: Swissmetro. Cost comparison between Transrapid and railway system has been thoroughly studied by Witt et al (ref. 20). The results can be summarized in Fig. 65, which shows that the initial higher cost of the Transrapid can be amortized thanks to the reduction of operational and maintenance costs over the years. It can also be seen that further optimization of the system would decrease life-cycle cost to reach break-even point at 15 years only.

42 42 Figure 65: Total and cumulated cost curve of the Maglev and the Rail/Wheel (R/W) systems; source: Witt et al (ref. 20). Naumann et al (ref. 22) have also analyzed the risk on investment for Transrapid and a railway system and has summarized his analysis by the following figure. Figure 66: Investment for a new line, comparison between railway system (left) and maglev (right); source: Naumann et al (ref. 22). It can be seen that the risks are lower for the Transrapid with a bigger investment. An essential point is the difference in maintenance and operational cost between a maglev and a railway system, which increases as the speed increases. 5.7 Performance It has been shown that the maglev system exhibits some advantages, particularly at higher speed than commercial speeds of railway systems. Another advantage is the higher acceleration which allows not only to decrease journey duration, but also to densify the train operation and therefore the usage of the line. Figure 67: Acceleration characteristics; source: Masada (ref. 1).

43 43 6. Maglev World Wide Projects 6.1 Europa Germany System At the end of 2011, there is no more active market or foreseen pilot track, corridor or network in Germany, for Transrapid. Only the Emsland test line is still active. But there is no formal information on the future of this test line. Transrapid 09 completed successfully all its dynamic tests. New girders were also implemented and tested. German safety certification was completed in May Figure 68: Transrapid 09 - Speed Airport Connector mph; Long Distance mph; Acceleration from 0 to 185 mph within 120 sec and 3 miles; Capacity 449 Passengers in a 3 section vehicle (76 m); 800 Passengers in a 8 section vehicle (200m); Source: Thyssen-Krupp. Figure 69: Emsland tranrapid test line 31.5 km, Source: Thyssen-Krupp.

44 Italy Project The UAQ4 was presented as the train of the future during the G20 political meeting in Atila. However, there is no known planning at the end of Spain Project In autumn 2010, the island s President arranged for the Maglev Tenerife Planning Consortium, consisting of Consulting Engineers Dipl.-Ing. H. Vössing Ltd. (IBV) and the Institute of Railway Engineering Ltd. (IFB), to examine the highspeed magnetic levitation railway as an alternative for a North-South link on Tenerife in a feasibility study. The operational Transrapid concept (Fig. 69) assumes a constant length of the high-speed maglev trains for the entire service period of 17 hours. The frequency of services is defined differently for the peak and off-peak service periods. In peak traffic time (2 hours) frequency is 15 min. A 30- or 60-minute frequency will be provided for the off-peak period (15 hours). Within the service period stated and the frequency of services defined, a total of 60 journeys (in both directions) are operated every day. An operational top speed of 270 km/h is achieved on the Southern route, and 230 km/h on the Northern route. Since the guide way distance between stops on the Southern route is roughly 40 km. Higher speeds do not result in any operational advantage on the other route sections but cause significantly higher traction energy costs. A total of 16 trains are required. These include three trains as an operational reserve or as a maintenance reserve. In the context of the feasibility study, 6 route variants, the total investment is between 3 and 3.55 billion EUR. Figure 70: Transrapid on the island of Tenerife, Source: Institute of Railway Enginerring, Berlin, Germany Switzerland Swissmetro Maglev Project Swissmetro, a high-speed and high frequency passenger transport system independent of built-up areas and surface obstructions such as topography, working as a super underground railway, meets the new needs that are arising at the dawn of the third millennium. It fits in with existing or projected railway networks, provides a credible response to the foreseeable increase in mobility and contributes actively to the transfer of private/road traffic to public/rail traffic. Swissmetro is a fully underground network with the following main objectives: an entirely underground infrastructure, comprising two tunnels of 5 m interior diameter, driven through the bedrock at a depth varying between 60 and 300 m according to the topography, as well as stations in the center of towns connected to the public urban and regional surface transport networks, a reduction of the pressure in the tunnels (partial vacuum corresponding to the pressure at about Pa in order to save the energy necessary for the propulsion of the pressurized vehicles, a propulsion system of the vehicle made of linear electric motors, allowing speeds in the order of 500 km/h. Estimated costs, full system including: stations, tunnels, and vehicles. Genève Lausanne 58.5 km 3'524 MCHF Lausanne Berne 81.0 km 4'614 MCHF Berne Lucerne 69.2 km 3'930 MCHF Lucerne Zurich 48.2 km 3'225 MCHF Bâle Zurich 75.0 km 5'383 MCHF Total km 20'676 MCHF (costs determined in 1997)

45 Switzerland SwissRapide Express Project Figure 71: Swissmetro network, Source: Swissmetro, EPFL. The SwissRapide Express project was launched in Based on the Transrapid Maglev on ground transport system technology, SwissRapide AG has expanded the scope of the SwissRapide Express and has three initial lines in Switzerland in the planning phase and will offer service every 5 minutes in peak hours: SwissRapide Central from Berne to Zurich, 115km in 20 min; SwissRapide West from Lausanne to Geneva; SwissRapide East from Zurich to Winterthur; According to the detailed project financial plan, the planning and building costs for the line Berne - Zurich are estimated at CHF 9.7 billion ( 7.8 billion). 6.2 South Korea Incheon International Airport System The demonstration line, at the Incheon international airport is 6.1 km length, for a cost of 300 MUSD. Six stations are set along the line and one depot. Four maglev train set (2 cars/set) will be in service. The construction started in 2010, the test evaluations are planned for Twenty-six organizations are participating to its development. On the other hand, a 2.1 km test line is actually active at the Korea Institute of Machinery and Materials.

46 China Figure 72: Line map, Source: Korea Institute of Machinery and Materials and Hyundai Rotem. Shanghai Maglev demonstration line from Pudong airport to downtown Shanghai started its trial operation on a single track at the beginning of 2003, began shuttle running on the double track in September of 2003 and completed the test and acceptance at the end of The year of 2004 witnessed its beginning of commercial operation. The train runs at the highest speed of 430km/h in the day and 300km/h in the morning and evening. Up to June 2011, the maglev train has covered a mileage of about 9 million kilometer and carried passengers of about 29 million person times. In the past years, the maglev system has undergone bad weather such as hurricane, heavy snow, and typhoon. No accidents that injured people have happened, nor has the operation been interrupted by bad weather. Statistical results of the past years since 2004 show that average operation punctuality rate reaches 99.72% and 99.88% of the operation schedule is fulfilled,

47 47 Figure 73: Shanghai city Pudong airoport Transrapid-08(license); 3 train sets with 5 sections; Track length 33km; Operational velocity: 430km/h; Maximum speed 501km/h; Commercial operation since 2004; source: Thyssen Krupp 6.4 Japan MLX JR-Maglev Central Japan Railway Co. has announced to operate the superconducting maglev (JR-Maglev) link between Tokyo and Nagoya in Figures 74 & 75 described the extension and foreseen network. Figure 74: Extension the existing 18.4 km test line to 42.8 km; Introducing 14 new test vehicles; Upgrade the ground coils and electrical facilities; Start running tests in the end of FY 2013; Project Cost: JPY 355 billion by JR Central; source: JR Central.

48 48 Figure 75: The Tokaido Shinkansen Bypass Project (515 km): 1 st step: Start commercial operation between Tokyo area and Nagoya area by 2025; Travel Time: minutes (100 minutes by the actual rail Shinkansen); Project Cost: JPY 5.1 trillion by JR Central; source: JR Central HSST At the Nagoya Tobu Kyuryo line, HSST LINIMO is in use. The double-track elevated route connects Fujigaoka station of Nagoya city subway and Yakusa station of Aichi Loop Line with 9 stations and 8.9 km service length including 1.3 km tunnel, a minimum curve radius of 75m and maximum slope is 6%. A train consists of 3 cars with total length of 43.3 m, a width of 2.6 m and a height of m. The empty weight is 17 tons per car and the maximum design weight of 28 tons per car. The HSST system has a maximum speed is 100 km/h. The total trip time is approximately 15 minutes, with an average speed of 35.6 km/h. The nominal capacity is 255 passengers per train. The system carries passengers per day. Construction started in the spring of The total construction cost is 100 billion Japanese Yen (90 MUSD/km). Normal operation started in March 2005, with the start of the World Expo 2005 in Nagoya (Fig. 76). The system has carried over 30 M passengers with quite good safety and reliability. During the Expo period, it carried about 20 M passengers, (from to per day). 6.5 USA Maglev 2000 Figure 76: HSST - World Expo 2005 in Nagoya; source: HSST. Maglev 2000 is a large USA project seen as a national maglev network. It is an active project MagneMotion MagneMotion is a urban (160 km/h) and high speed (430 km/h) maglev based on EMS suspension. End of 2001, should begin test on 75 m track at Old Dominion University, Norfolk, Virginia.

49 American Maglev Technology It is a EMS suspension, which propulsion is linear induction motor. A test line is undergoing at full scale on 600 m track, near Atlanta, Georgia Transrapid Technology Several corridors were proposed and studied based on the Transrapid technology. Most of them are in waiting status General Atomics Indutrack II Figure 77: Maglev Main USA corridors; source: HSST. The test track is full-scale, 120 meters in length, with a 50-meter radius curve. The track was completed in November 2004 by General Atomics, in San Diago, California. Technical feasibility and initial EIS and federal objectives were completed. It is actually ready for deployment. Technical feasibility and initial EIS and federal objectives were completed. It is actually ready for deployment. A line is foreseen at the University of California of Pennsylvania of 7.2 km. 6.6 South America - Brazil Cobra The next step will be the connection of two blocks of the Center of Technology inside the university campus (CT1- CT2), as shown in Fig. 78. They are just 200 meters apart but this short line will allow the daily operation and test of the proposed technology. The service is expected to start in 2014.

50 50 7. Conclusions Figure 78: Cobra test line and vehicle view; source: Federal University of Rio de Janeiro, Brazil High Speed - Industrial Achievement Transrapid is well established for practical applications. Airport connection in Shanghai has been successfully operated with Transrapid up to 430km/h. JR-Maglev has proven reliability and high level feasibility. JR maglev will be put into practical operation between Tokyo and Nagoya until 2025, at a commercial speed of 500 km/h Urban Maglev- Low Speed - Industrial Achievement Markets Many industrial solutions exist and have proven their attractiveness in Japan, Korea, China and USA. Main market seems to be in Asia, due to the Asian capacities to develop maglev and high mobility demands. Europa market could be extremely tough to penetrate due to the well-developed network of high speed railways and future European developments of new lines. USA has several corridors under studies since more than 20 years, but no real realization is foreseen Sustainable development All maglev operate in a fully automatic control, thus decreasing operational costs and increasing reliability and safety. Maglev has proven clear advantages regarding emissions, audible noise and power consumption. Maglev allows decreasing the total cost of ownership for high-speed operations below railway values. Associated to the shortening of the journey time, the high-speed perspectives offered by Maglev allow the constitution of a decentralized metropolis. All present high-speed maglev and railway systems try to avoid construction of tunnels on their lines. The combination of maglev technologies into depressurized tunnels offer attractive high speed solutions with lower total cost of ownership, as demonstrated by Swissmetro. The use of linear motors in fully underground low-speed metros leads to solutions less expensive than classical approaches and easier to integrate Maglev Accidents On August 11, 2006, a maglev train compartment on the Transrapid Shanghai airport line caught fire.

51 51 On September 22, 2006, a Transrapid test train in Emsland, Germany, had 29 people aboard during a test run when it crashed into a repair car that had been accidentally left on the track. Most passengers were killed in the first fatal accident involving a maglev train.

52 52 8. APPENDIX I - Transports without Wheel and Rail - Brief Historic 1852 L.O. Girard Levitation using water pressure John Thornycraft Aircushion principle J. S. Ward Levitation and propulsion with blowers. Other concepts based on the airship were also proposed A model train levitated with the water pressure based on Girard s idea was demonstrated in Paris Exposition of Robert Goddar Maglev train was first conceived Emile Bachelet Electro-dynamic levitation: USA Patent, for levitating transmitting apparatus Herman Kemper German Patent of the levitated railways with train without wheels. Jean Bertin s Aerotrain was studied and tested in France. Development were ended in 70 s as the TGV (train à grande vitesse) was chosen as the technical solution by the French government. Similar developments were carried out in USA and Brazil J. Powell, G. Danby First practical system for magnetically levitated transport using superconducting magnets. 1970s mid-1990 s Today The Japanese and the Germens started their researchs on maglev transportation. General Atomics Corporation developed a permanent magnet maglev system. The root of the system design stems from General Atomics' work for the military on the Electro-magnetic launching System (EMALS). EMALS will be part of the newest aircraft carriers, where a lbs. fighter jet will be launched, accelerating from 0 to 200 mph in under two seconds. Today, only the Otis People Mover is in used with air cushion. Figure AI.3 : Aérotrain I80-250:Orléans - 80 places Figure AI.4 : Otis People Mover Los Angeles Otis People Mover Detroit airport