1. INTRODUCTION

1.1 WHAT ARE MAGLEV TRAINS?

Have you heard of maglev trains? Well these are going to be the trains of the 21st century. They are high-speed trains running in Japan and Germany. The speed of a normal Indian trains is much less than 60 km/hour, where as a maglev train is expected to go as fast as 400 km/hour! This will revolutionize the way people travel, in the near future. Maglev stands for magnetic levitation. Maglev trains function on the principles of magnets. 

A substance that attracts another substance is known as a magnet. Mankind has known permanent magnets like loadstones, since thousands of years. These days magnets can be made from alloys of elements like iron, nickel, samarium, cobalt, tin, niobium, etc. All of us are familiar with a magnetic compass needle. This instrument has a small magnet, which deflects and shows the north-south directions. 

Any magnet has two poles : the north pole and the south pole. Two like poles attract each other and two unlike poles repel each other. This means that when two magnets are brought close together, and if their N poles face each other, the magnets will be repelled. On the other hand if the N pole of one magnet is brought close to the S pole of the second magnet, the two magnets will get attracted together.

When a magnet is kept at one place, it influences its surrounding. If you take a bar magnet on a piece of paper and sprinkle some iron filings, you will notice that the iron filings form a particular pattern around the magnet. The pattern is called the magnetic lines of force. The effect the magnet has around its surrounding is called the magnetic field.   

These days electromagnets are used everywhere. When electric current is passed through a circular coil, a magnetic field is produced. Take a wire and connect it to a battery and a key. Keep a compass needle in the centre. Note its initial position. As soon as you pass a current through the wire, the compass needle will show a deflection. As long as the current is passing through the wire, the compass needle will stay deflected. This clearly demonstrates that an electric current induces magnetic field around itself.  Reverse the current, the deflection of the needle will be in the opposite direction. Thus electromagnets can be constructed easily. Also its magnetic poles can be reversed by reversing the direction of flow of the current. 

In a maglev train, a series of electromagnets are placed at the bottom of the train and sides of the tracks. The maglev trains are pushed and speeded up by the fact that like poles attract and unlike poles repel. The strength of attraction and repulsion depends on the current. The speed of the train is determined by how fast the currents can be reversed.  The train is virtually levitating from the tracks or the ground. The levitation arises due to repulsion of like poles. The train glides frictionless along the tracks, as there is no physical contact with the track. The trains are generally levitating a few inches above the ground.  

In ordinary trains, the friction of the wheels with the tracks puts a restriction on the amount of speed the train can reach. Since there is no physical contact between the tracks and the train, the ride in this train is smooth, without any noise and fast. The speed is obtained due to attraction of unlike poles. The magnets are positioned in such a precise well aligned way, that one pair of electromagnets is in an attractive mode and the immediate pair is in the repulsive mode. The switching or reversing the current in the electromagnets propels the train forward. The rate of this switching determined the speed of the train. 

When the train has to halt, the current through the electromagnets is switched off (this makes the magnetic fields zero) and a set of wheels is lowered so that the friction between the tracks and the wheels brings the train to a halt.  

1.2 FROM STEAM  TO  MAGLEV:

Today, new technology has resulted in faster, more efficient trains that consume less energy than ever before. For almost 150 years, locomotives burned wood, coal, or oil to create steam. The steam was then injected into cylinders to create pressure to drive the pistons; the spent steam was exhausted upwards through the stack and also created a draft to bring oxygen into the firebox. Steam-powered locomotives required massive amounts of water and fuel -- either coal or wood -- consuming four times as much water as fuel. As the railroads began searching for an alternative to the steam locomotive at the turn of the century, they turned to electrical power. Electric locomotives were clean (important because of new air pollution ordinances) and powerful. These trains could convert electrical energy from an outside power source directly into mechanical energy, resulting in smooth torque, almost instantaneous, unlimited power (important for climbing hills), and eliminating the need to carry fuel on board

This view of railroad logging in Oregon illustrates the melding of steam and railroad technologies in providing development of forest products in the late nineteenth and early twentieth-century. Douglas County Museum Photograph

In Montana and Washington, cheap hydroelectric power made it possible for railroads such as the Chicago, Milwaukee, St. Paul and Pacific -- also known as the Milwaukee Road -- to electrify close to 950 kilometers of track by 1916. Eventually, however, the high start-up construction and maintenance costs made early long distance electric trains impractical.

In 1892, German engineer Rudolph Diesel patented a new type of engine that could be used to power a locomotive. Instead of relying on coal or wood to produce steam, the diesel engine relies on petroleum-based fuel ignited under compression. The vaporized fuel is injected into compressed, high-temperature air and ignited in a combustion chamber to drive pistons in the cylinders. Energy is then transmitted to generators that make electricity to power the motors that turn the wheels. Compared to steam locomotives, diesel-electric trains consume less fuel, produce less pollution, require less maintenance, and can stay in service longer each day. Several diesel locomotives linked together can be operated by a single engineer, unlike the steam engine, which requires at least two men to a unit. The first successful diesel locomotive was introduced in 1925 by the Central Railroad of New Jersey. Today, nearly all trains operating in the United States are powered by diesel engines.

One of the most exiting recent innovations in railroad technology is magnetic levitation, or Maglev, which relies on the principals of magnetism -- attraction and repulsion. This new technology, still under development, will result in trains that are faster, more efficient, more comfortable, and more environmentally sound. No longer will trains rumble heavily along steel rails; rather, they will float along a magnetic cushion without any direct contact with the ground.

A steam engine on the Florence and Cripple Creek Railroad in Colorado. Today, this area is part of the Gold Belt Loop, a back country byway on public land that allows visitors to drive on parts of old rail bed Colorado Historical Society

From cumbersome coal-and-wood-powered steam engines to the emerging technologies of Maglev, the railroads have become faster and more energy efficient. But at the same time, the world's demand for energy continues to grow. Just as railroad technology helped shape the development of the United States one hundred years ago, the development of new transportation technologies will influence the way we wrestle with environmental challenges in the future. Studying the evolution of railroad technology not only gives students a feel for how a vast landscape was settled and developed, but also illustrates the important relationship between technology, society, and our environment.

2. PRINCIPLE OF MAGLEV

Maglev is a system in which the vehicle runs levitated from the guideway (corresponding to the rail tracks of conventional railways) by using electromagnetic forces between superconducting magnets on board the vehicle and coils on the ground. The following is a general explanation of the principle of Maglev.

2.1 Principle of magnetic levitation:

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The  figured levitation coils are installed on the sidewalls of the guideway. When the on-board superconducting magnets pass at a high speed about several centimeters below the center of these coils, an electric current is induced within the coils, which then act as electromagnets temporarily. As a result, there are forces which push the superconducting magnet upwards and ones which pull them upwards simultaneously, thereby levitating the Maglev vehicle

2.2 Principle of lateral guidance:

The levitation coils facing each other are connected under the guideway, constituting a loop. When a running Maglev vehicle, that is a superconducting magnet, displaces laterally, an electric current is induced in the loop, resulting in a repulsive force acting on the levitation coils of the side near the car and an attractive force acting on the levitation coils of the side farther apart from the car. Thus, a running car is always located at the center of the guideway.

2.3 Principle of propulsion:

A repulsive force and an attractive force induced between the magnets are used to propel the vehicle (superconducting magnet). The propulsion coils located on the sidewalls on both sides of the guideway are energized by a three-phase alternating current from a substation, creating a shifting magnetic field on the guideway. The on-board superconducting magnets are attracted and pushed by the shifting field, propelling the Maglev vehicle.

3. HOW MAGLEV TRAINS WILL WORK

3.1.IN-DEVELOPMENT:

While maglev transportation was first proposed more than a century ago, the first publicly used maglev trains will not debut until at least 2003, and it looks like this debut will take place in Shanghai, China, using the train developed by German company Transrapid International. Germany and Japan are both developing maglev train technology, and both are currently testing prototypes of their trains. Although based on similar concepts, the German and Japanese trains have distinct differences.

In Germany, engineers are building an electromagnetic suspension (EMS) system, called Transrapid. In this system, the bottom of the train wraps around a steel guideway. Electromagnets attached to the train's undercarriage are directed up toward the guideway, which levitates the train about one-third of an inch (1 cm) above the guideway and keeps the train levitated even when it's not moving. Other guidance magnets embedded in the train's body keep it stable during travel. Germany has demonstrated that the Transrapid maglev train can reach 300 mph with people onboard.

Japanese engineers are developing a competing version of maglev trains that use an electrodynamic suspension (EDS) system, which is based on the repelling force of magnets.

The key difference between Japanese and German maglev trains is that the Japanese trains use super-cooled, superconducting electromagnets. This kind of electromagnet can conduct electricity even after the power supply has been shut off. In the EMS system, which uses standard electromagnets, the coils only conduct electricity when a power supply is present. By chilling the coils at frigid temperatures, Japan's system saves energy.

Another difference between the systems is that the Japanese trains levitate nearly 4 inches (10 cm) above the guideway. One potential drawback in using the EDS system is that maglev trains must roll on rubber tires until they reach a liftoff speed of about 62 mph (100 kph). Japanese engineers say the wheels are an advantage if a power failure caused a shutdown of the system. Germany's Transrapid train is equipped with an emergency battery power supply.

Despite U.S. interest in maglev trains over the past few decades, the expense of building a maglev transportation system has been prohibitive. Estimated costs for building a maglev train system in the United States range from $10 million to $30 million per mile. However, the development of room temperature superconducting supermagnets could lower the costs of such a system. Room temperature superconductors would be able to generate equally fast speeds with less energy.

If you've been to an airport lately, you've probably noticed that air travel is becoming more and more congested. Despite frequent delays, airplanes still provide the fastest way to travel hundreds or thousands of miles. Passenger air travel revolutionized the transportation industry in the last century, letting people traverse great distances in a matter of hours instead of days or weeks. The only alternatives to airplanes -- feet, cars, buses, boats and conventional trains -- are just too slow for today's fast-paced society. However, there is a new form of transportation on the horizon that will revolutionize transportation of the 21st century the way airplanes did in the 20th century.

At least two countries are using powerful electromagnets to develop high-speed trains, called maglev trains. Maglev is short for magnetic levitation, which means that these trains will float over a guideway using the basic principles of magnets to replace the old steel wheel and track trains.

3.2 ELECTROMAGNETIC-PROPULSION:

If you've ever played with magnets, you know that opposite poles attract and like poles repel each other. This is the basic principle behind electromagnetic propulsion. Electromagnets are similar to other magnets in that they attract metal objects, but the magnetic pull is temporary. As you can read about in How Electromagnets Work, you can easily create a small electromagnet yourself by connecting the ends of a copper wire to the positive and negative ends of an AA, C or D cell battery. This creates a small magnetic field. If you disconnect either end of the wire from the battery, the magnetic field is taken away. The magnetic field created in this wire-and-battery experiment is the simple idea behind a maglev train rail system. There are three components to this system:

• A large electrical power source
• Metal coils lining a guideway or track
• Large guidance magnets attached to the underside of the train

The big difference between a maglev train and a conventional train is that maglev trains do not have an engine -- at least not the kind of engine used to pull typical train cars along steel tracks. The engine for maglev trains will be rather inconspicuous. Instead of using fossil fuels, the magnetic field created by the electrified coils in the guideway walls and the track will combine to propel the train.

Above is an image of the guideway for the Yamanashi maglev test line in Japan. Below is an illustration that shows how the guideway works.

The magnetized coil running along the track, called a guideway, will repel the large magnets on the train's undercarriage, allowing the train to levitate between 0.39 and 3.93 inches (1 to 10 cm) above the guideway. Once the train is levitated, power is supplied to the coils within the guideway walls to create a unique system of magnetic fields that pull and push the train along the guideway. The electric current supplied to the coils in the guideway walls are constantly alternating to change the polarity of the magnetized coils. This change in polarity causes the magnetic field in front of the train to pull the vehicle forward, while the magnetic field behind the train adds more forward thrust.

Maglev trains float on a cushion of air, eliminating friction. This lack of friction and the trains' aerodynamic designs allow these trains to reach unprecedented ground transportation speeds of more than 310 mph (500 kph), or twice as fast as Amtrak's fastest commuter train. In comparison, a Boeing-777 commercial airplane used for long-range flights can reach a top speed of about 490 mph (789 kph). Once manufacturers can prove that maglev trains can transport passengers safely at such high speeds, maglev trains could become an ideal alternative to airplanes. Developers say that they will likely link cities that are up to 1,000 miles (1,609 km) apart. At 310 mph, you could travel from Paris to Rome in just over two hours.

4. TYPES OF  MAGLEV

1. LEVITATION BY ATTRACTION
2. LEVITATION BY REPULSION

4.1 LEVITATION BY ATTRACTION:

Common knowledge of magnetism shows that opposite magnetic poles repel each other. This basic principle is how this type of Maglev train appears to float closely to the track. In order for the train to float, there must be two coils. The top coil is installed in the train and the bottom coil is placed in the track. Attraction is caused by having the currents within each of the circuits traveling in the same direction. It is important to note that with attractive forces created between the train and the track, that there are coils    located under the car and on an extension that wraps under the track.

In contrast to traditional means of transport, the propulsion system is not in the vehicle but in the guideway. Below and on both sides of the guideway are iron table stator packages in which there is a three-phase cable. The vehicle glides when the support magnets attract it from below the guideway. Lateral guidance magnets hold the vehicle in the guidway.

There are two types of propulsion systems:

• Linear Synchronous Motor (LSM)
• Linear Induction Motor (LIM)

4.2 LEVITATION BY REPULSION:

The creation of a magnetic field is shown in the middle illustration. Common knowledge of magnetism shows that similar poles of a magnet repel each other. This basic principle is how this type of Maglev train appears to float on a cushion of air. In order for the train to float, there must be two coils. The top coil is placed within the train and the bottom coil is place on the track. The current in the top circuit travels in the opposite direction of the current in the bottom; resulting in an repulsion between the two coils. Smaller resistances allow for more current to be generated using less power, making the magnetic field stronger.

                                              Cross Section of Train & Track

5. HOW MAGLEV FLOAT ON COURSE:

• Drift between the rail and levitation magnets caused by wind or when the train rounds a curve

• The gap widens between the train and the track because of a shortage of magnetic force
• .The enhanced current input into the leviation magnets increases the magnetic force.
• Lateral shift is corrected with the assistance of gap sensors and the train is assured to stay directly above the guiderails

PRINCIPLE  OF PROPULSION:

The propulsion of the train is based on two types of motors:

• Linear Synchronus Motor (LSM)
• Linear Induction Motor (LIM)

         Basically these two types of motors generate a force that will directly propel the train car. The primary coil (stator) of the motor is mounted on the car, and the secondary rotor is in the form of an aluminum reaction plate installed along the rail surface. The combination of these two elements results in a force strong enough to propel the train.

6. MEGARAIL TRANSPORTATION SYSTEMS

The patented maglev system uses strong permanent magnets located on vehicles and uses passive levitation rails in the guideway. The combination of (1) permanent magnets instead of expensive electromagnets (2) passive guideway and (3) full-speed, car-based switching will allow the company to develop a high-speed inter-city transportation system that is about 85% lower in cost than current maglev train systems. The system employs enclosed levitation rails that fully shield the suspension magnets, levitation rails, electrical power supply rails and control and communication elements both from the effects of weather and possible damage from foreign objects. The enclosed rail design will allow the system to operate at full speed in any type of weather, including heavy snow and ice.

Unlike other maglev systems that operate trains that must to stop at stations along the line to pick up and let off passengers, the individual car switching system makes it practical to dispatch small and light-weight individual cars carrying only a few passengers non-stop between stations along the line. The individually dispatched cars offer the advantage of shorter trip times possible by eliminating intermediate stops. (Intermediate stops for train operations can easily reduce the effective trip speed to onehalf or less than the top speed of the train.) The small car approach has the further advantage of making it practical to have cars leave whenever passengers want to travel to a particular station rather than having to wait for scheduled trains to depart. With automated car operation, service can be provided on a 24-hour day basis. Use of small cars rather than large train cars also allows use of a much lighter weight and less expensive guideway. Both the magnetic levitation and directional control are achieved by use of rare-earth permanent magnets on the vehicles that interact with passive electrical coils in the guideway. These coils are imbedded in both the levitation rails and in separate directional control rails of the guideway. Electrical currents induced in the guideway coils by movement of the magnets near the coils produces opposing magnetic forces that lift and steer the vehicles.

The patented transportation system locates both the levitation and directional control rail coils inside enclosed rail boxes where they are shielded from weather elements. The Figure 1 drawing illustrates a crosssectional view of the rail box, the two rails, the magnets and other elements inside the rail box. The magnets, low-speed support wheels and electrical power collection contact shoes are mounted to support arms that extend from the vehicles into the enclosed rail box through inverted slots in the rail boxes.

Figure1. Guideway rail cross section

The inventor says that the enclosed rail boxes provide complete protection of the levitation, propulsion, braking, steering, and power elements from weather elements such as rail, ice, hail, sleet and snow that can stop conventional maglev trains in their tracks. Henderson also notes that the unique rail structure design enables very low cost fabrication of the rail boxes from flat steel with a minimum amount of material. He says that this low-cost fabrication and use of small cars allows construction of twoway guideway with only about 260 pounds of steel per foot of guideway at significantly less cost than guideway for current maglev train systems that use about 2,000 pounds per foot of guideway. The low weight and low-cost fabrication concept was recently validated by testing a similar guideway section for another MegaRail system guideway.

Unlike current heavy maglev train systems that generally require dedicated rights of way, the small and lightweight guideways of the maglev system to be developed by MegaRail will be designed for installation over existent interstate and other highway rights of way. Such an approach allows lower cost and avoids the often long times required for obtaining right of way.

Lateral directional control and switching of cars between guideways is accomplished by use of a combination of a steering rail mounted inside the top of the rail box and steering magnets mounted on both sides of the car as shown in the Figure 1 cross-sectional drawing. The magnets on one side are lowered as shown in the Figure 2 drawing to allow the car to follow a side steering rail in guideway section that leaves the main guideway in a similar manner as railroad tracks leave main lines at switches. The rail covers are removed at switches and the entire guideway is covered by roof and sidewalls to protect the system from weather elements.

Figure 2. Guideway rail cross-section view with lowered switching magnets

The cross-sectional drawing of Figure 3 depicts the arrangement of the two rail boxes of a guideway and shows a passenger car cross-section on the guideway.

Figure 3. Guideway & car cross-section viewMegaRail Transportation Systems

It is a Texas based company currently engaged in developing a family of patented all-weather elevated automated transportation systems that employ enclosed rail designs. The first of these systems is in the prototype stage. All of the systems are designed for installation over existent road and street rights of way. These systems use lightweight and low-cost elevated guideway designs and will provide superior service to conventional light rail and monorail systems. The MegaRail system is designed for cross-country use along interstate highways and major roads.

7. A NEW  APPROACH FOR MAGLEV TRAINS

FOR the past two decades, prototype magnetically levitated (maglev) trains cruising at up to 400 kilometers per hour have pointed the way to the future in rail transport. Their compelling advantages include high speeds, little friction except aerodynamic drag, low energy consumption, and negligible air and noise pollution.
However, maglev trains also pose significant drawbacks in maintenance costs, mechanical and electronic complexity, and operational stability. Some maglev train cars, for example, employ superconducting coils to generate their magnetic field. These coils require expensive, cryogenic cooling systems. These maglev systems also require complicated feedback circuits to prevent disastrous instabilities in their high-speed operation. Lawrence Livermore scientists have recently developed a new approach to magnetically levitating high-speed trains that is fundamentally much simpler in design and operation (requiring no superconducting coils or stability control circuits), potentially much less expensive, and more widely adaptable than other maglev systems. The new technology, called Inductrack, employs special arrays of permanent magnets that induce strong repulsive currents in a "track" made up of coils, pushing up on the cars and levitating them.

7.1 TOTALLY PASSIVE TECHNOLOGY:

During the past two years, a Livermore team, headed by physicist Richard Post, has successfully demonstrated the Inductrack concept in test trials. The test runs demonstrated the system's totally passive nature, meaning that achieving levitation requires no control currents to maintain stability, and no externally supplied currents flowing in the tracks. Instead, only the motion of train cars above the track is needed to achieve stable levitation. The results have been so promising that NASA has awarded a three-year contract to the team to explore the concept as a way to more efficiently launch satellites into orbit.

7.2 INDUCTRACK INVOLVES TWO MAIN COMPONENTS:

A special array of permanent, room-temperature magnets mounted on the vehicle and a track embedded with close-packed coils of insulated copper wire. The permanent magnets are arranged in configurations called Halbach arrays, named after Klaus Halbach, retired Lawrence Berkeley National Laboratory physicist. Originally conceived for particle accelerators, Halbach arrays concentrate the magnetic field on one side, while canceling it on the opposite side. When mounted on the bottom of a rail car, the arrays generate a magnetic field that induces currents in the track coils below the moving car, lifting the car by several centimeters and stably centering it.
When the train car is at rest (in a station), no levitation occurs, and the car is supported by auxiliary wheels. However, as soon as the train exceeds a transitional speed of 1 to 2 kilometers an hour (a slow walking speed), which is achieved by means of a low-energy auxiliary power source, the arrays induce sufficient currents in the track's inductive coils to levitate the train. To test the Inductrack concept, Post, project engineer J. Ray Smith, and mechanical technician Bill Kent assembled a one-twentieth-scale model of linear track 20 meters long (Figure 1). The track contained some 1,000 rectangular inductive wire coils, each about 15 centimeters wide. Each coil was shorted at its ends to form a closed circuit but not otherwise connected to any electrical source. Along the sides of the track, they attached aluminum rails on which a 22-kilogram test cart could ride until the levitation transition velocity was exceeded (Figure 2). Finally, the team secured Halbach arrays of permanent magnet bars to the test cart's underside for levitation and on the cart's sides for lateral stability. The cart was then launched mechanically at the beginning of the track at speeds exceeding 10 meters per second. High-speed still and video cameras revealed that the cart was consistently stable while levitated, flying over nearly the entire track length before settling to rest on its wheels near the end of the track.
Post says the test results are consistent with a complete theoretical analysis of the Inductrack concept he performed with Livermore physicist Dmitri Ryutov. The theory predicts levitation forces of up to 50 metric tons per square meter of magnet array using modern permanent magnet materials such as neodymium-iron-boron. The theory also shows levitation of loads approaching 50 times the weight of the magnets, important for reducing the cost relative to maglev vehicles.

7.3 EXTERNAL POWER NEEDED:

Post notes that a power source is needed to accelerate the cart to its operating speed of 10 to 12 meters per second. The first section of the test track uses a set of electrically energized track coils--aided by a stretched bungee cord--to reach this speed. A full-scale train might use an electronic drive system, as found on experimental German trains, or even a jet turbine, as proposed by Inductrack engineer Smith. "Inductrack allows you the possibility of carrying all the power with you," emphasizes Post.
Even though the electromagnetic drag associated with Inductrack becomes small at high speeds, an auxiliary power source would also be needed to maintain the train's high speed against aerodynamic drag. The amount of power needed depends on the weight of the vehicle and its maximum speed. If the external drive power ever fails, or when the train arrives at a station, the train cars would simply coast to a stop, easing down on their auxiliary wheels.

8. APPLICATION

Bullet train shoots from Washington to New York and Boston

The high-speed trains are being built by a manufacturing consortium of Canada's Bombardier Transportation and France's Alstom  Ltd.

WASHINGTON -- As the new bullet train shot between the nation's capital and New York City, America entered a new era of rail transportation aboard Amtrak's Acela Express.

"The train was unbelievable. It was the best ride I ever had," said one young woman lucky enough to be aboard during Thursday's invitation-only inaugural trip.

"It was great. Goose bumps," said train engineer Bill Dotterer as he described how he felt seeing the speedometer hit 135 mph (216 km/h)

The electrically powered Acela Express pulled out of Washington's Union Station at 9:54 a.m., precisely as scheduled after a champagne christening, fireworks, light shows and a send-off by business leaders, members of Congress and other dignitaries.

"Today's inaugural run symbolizes the beginning of a new era of American transportation, not only in the Northeast, but eventually across the entire country," U.S. Transportation Secretary Rodney Slater said.

TIME, MONEY AND AMTRAK'S FUTURE:

Acela Express will cut about a half-hour off the current Metroliner train service between Washington and New York and about 45 minutes off the trip from New York to Boston.

A one-way coach ticket between Washington and New York will be $143, up from $122 on the Metroliner. Travel between New York and Boston will cost $120, compared to $57 on conventional Amtrak trains, which will continue to run in the Northeast corridor.

The railroad company has also added comfortable seating, better food, video entertainment and plug-ins for laptop computers on the express cars.

The train got a rave review from sex therapist Dr. Ruth Westheimer, who hopped aboard briefly in New York. "I think it's a very sexy train," she said.

Amtrak's board of directors hopes that the increased traveling speed and comfort offered by the high-speed trains will draw more passengers and more funding from taxpayers.

"Our highways aren't working, and our airports are a mess," said Amtrak vice-chairman and former presidential candidate Michael Dukakis. "People are finally waking up to the fact you have to invest in rails."

Amtrak and high-speed rail advocates have a lot riding on Acela Express. If it's a success, it will boost Amtrak's revenues and could lead to other high-speed trains elsewhere in the country.

If it fails, however, Acela Express could be the swan song for Amtrak, the federally subsidized railway that is under orders from Congress to become financially self-sufficient by 2003. Amtrak is relying on the service to earn $180 million a year

JAPAN’S TEST  MAGLEV TRAINS

1. ML100

ML100 (side view, dimension in mm)

ML100 is propelled by LIM (Linear Induction Motor). Built as a show-case experimental vehicle, it was intended for celebrating Japan's railway centennial in 1972. It runs astride the inverted-T guideway looking like a vertical wall.
"ML" stands for "Magnetic Levitation" and "100" implies the 100th anniversary of Japan's railway.

2. MLU001

MLU001 (3-car train)

MLU001 to serve for long-distance mass transport in the future was designed as a coach accommodating passengers. To carry passengers, the passenger room had to be located above the bogie to get clear of the inverted-T guideway, which resulted in an enlarged carbody. For this reason, instead of the inverted-T guideway a U-shaped guideway was adopted, yielding a box-like carbody. "U" in the designation MLU implies that the design was changed to a U-shape. Three cars including a middle car were built.
Using MLU001, its moving characteristics have been investigated in test runs with the three cars coupled and with the guideway intentionally provided with irregularities

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9. ADVANTAGES/ DISADVANTAGES  OF MAGLEV

ADVANTAGES:

The advantages of magnetically elevated trains are numerous.  They are fast, quiet, safe, cost effective, and most importantly environmentally efficient.  Maglev is truly the train of the future.

Because there is no friction with the ground, maglev is extremely quiet.  Since there is hardly any air friction, maglev trains speed by with no sound at all.  Also, they are extremely fast.  The trains produce noise at about 60 decibels while normal inner city traffic produces 80 decibels.  On test runs maglev trains have been able to exceed 300mph.  In Germany the top speed of a maglev train was 312mph and Japan's maglev trains reached 323mph in 1979 shattering the record books. With advances on maglev trains, people say it will be able to go 600mph to 1000mph in the future. If maglev trains succeed they will revolutionize the way we get around and dramatically reduce travel time.  More speed will eventually equal more passengers!

However, the most important advantages of maglev are its safety and cost effective measures.  Because the train uses the repulsion and attraction of magnets, no natural resources are used.  We can save large amounts of coal, natural gases, and oil.  They carry no fuel to reduce fire hazards and to increase safety as well.  Collisions are impossible because only sections of track are activated as needed.  All trains will be traveling in synchronization and at the same speed reducing the likelihood of crashes.  Not only are maglev trains faster and more efficient, they can be cheaper and safer to the environment as well.  Maglev uses 30% less energy than a high-speed train traveling at the same speed (1/3 more power for the same amount of energy).

Maglev trains will also be easily maintained.  There is almost no wear on the trains.  Most mechanical wear is due to friction.  Since maglev trains do not touch the ground mechanical wear is almost reduced to nothing.  Additionally, electrical components almost suffer no wear.  The faster turnaround time means fewer vehicles and cheaper costs!

DISADVANTAGES:

Maglev is a relatively new technology.  Must testing still needs to be done before that trains can actually be put into service.  One problem is the actual construction of lightweight trains and magnetic tracks.  The preliminary costs of building trains as well as tracks may be quite large.  Much tax money may have to be put into a maglev project, but the overall rewards will be quite large.

10. ARE MAGLEVS REALLY MORE ENVIROMENTALLY FRIENDLY?

In terms of energy consumption maglev trains are slightly better off than conventional trains. This is because there is no wheel-on-rail friction. That said the vast majority of resistive force at high speed is air resistance (often amounting to several tons), which means the energy efficiency of a maglev is only slightly better than a conventional train.German engineers claim also that a maglev guideway takes up less room and because greater gradients are acceptable there is not so much cuttings and embankments meaning a new guideway would be less disruptive to the countryside than a new high speed conventional railway. Will Maglevs replace conventional trains?

Provided maglev can be proved to be commerciably viable (which has not yet been done) it should be a success. Most people have their eyes on Germany, where the first maglevs will run in commercial service. This may decide whether or not maglevs will be used across the world. Maglev may become the preferred path for new high speed railway lines although it would depend whether or not services were needed to stretch beyond a high speed line. For example, if you have 300km of conventional track between two cities cleared for over 200km/h but there was a 60km long section only cleared for 80km/h then it would make sense to build a new high speed (300km/h) line for the 60km distance. If a maglev train were to be used a track 300km long would have to be built. However if there is no existing rail network (only the case in the USA) then it makes sense to build a maglev line. Whether or not new railway lines stopped being built in favour of maglevs, one thing is certain, there is 31932km of track in the UK, 34449km in France and 40726km Germany, no one is going to convert all of this into maglev track, conventional trains are here to stay for a long time.

11. THE FUTURE OF MAGLEV

America transportation volume is rapidly growing every year.  An incredible number of cars, planes, and trains are being utilized for business and leisure everyday.  This in turns implies more traffic, more delays, and more gridlock.  With this increase in the use of transportation, there is an equal increase in the demand for a cheaper, faster, and more efficient mode of travel.  What’s the solution you ask?  The answer is Maglev.  The term Maglev means super-conducting magnetically levitated vehicle.  The future of transportation can  Maglev stands for magnetic levitation. A normal train has wheels that run along a rail, whereas a maglev train glides a fraction of a centimeter above the rail, held up my magnetic repulsion. By eliminating the need for mechanical rotation of a wheel, much greater speeds can in principle be achieved. Maglev technology is not yet mature, but maglev trains have already set speed records. We can expect that maglev trains can eventually rival jet aircraft in speed, perhaps going beyond the speed of sound in the twenty-first century. But even though there are no rotating parts and no friction on rails, air friction puts a practical limit on the speed of these trains at no more than about 3000 kilometers per hour. At that rate, it would still take almost two hours to go from New York to Los Angeles.

Let’s now imagine a maglev train running in an evacuated tube. If the vacuum is sufficiently hard inside the tube, air friction will be negligible and insignificant. Through a vacuum, there is no practical limit to a train's speed. With a sufficiently advanced maglev technology, you could travel across a continent while eating breakfast. And since the train is not in physical contact with anything at all, not even air, the ride will be one of unprecedented quiet and steadiness. Indeed, even space flight has its noisy rocket engine to disturb the peace of space. But on a maglev train, the thrust is provided by magnets fixed to the ground, and the train's only job is to maintain its internal magnets.

We can even imagine that in the next hundred years, a web of maglev tubes will dive beneath the oceans and over the Bering Strait, connecting the world. You could then travel to any point on earth in no more than an hour, in supreme quiet and comfort. Saving space will be less of an issue on maglev trains than on aircraft, so we can expect that cars will be roomy, and in fact private cars might even be available.

With well developed maglev-in-vacuum technology, there is in fact only one reasonable barrier to speed, and that is human fraility under acceleration. When your automobile quickly speeds up, you are pressed back in your seat, and your weight increases. This effect would be magnified on a maglev train that was really in a hurry, since the acceleration would be for the entire trip, at magnitudes much higher than an automobile can achieve. So although these trains would be quintessentially quiet and steady, they might also represent a new level of discomfort to those who need as much speed as possible. The passengers would be protected from the weight of acceleration by heavily cushioned seats like those currently used in the space shuttle. But still, the average passenger, who is content to spend as much as an hour travelling, would find the maglev train an enjoyable experience.

CONCLUSIONS

Even though three maglev train designs have been developed to commercial readiness, we have

yet to see any maglev systems in continuous commercial operation. Obstacles to commercial use

of the maglev trains include

• Expense, especially in guideway construction
• Existence of conventional high-speed rail systems, such as the French TGV
• Health concerns regarding exposure to electromagnetic fields
• Absence of a commercially successful example to reassure investors
• Possibility of selecting a guideway design that will be incompatible with future systems

It appears that maglev transportation will not become popular without further government funding and additional advances in technology. The Japanese and German systems were developed at considerable government expense, but still lack a clear commercial advantage over conventional high-speed rail. The Inductrac technology shows promise but will require a long and expensive development period before it can be evaluated as a candidate for commercial use. With the recent $1 billion commitment to maglev research and development by the U.S. Government, there is renewed hope for magnetic levitation transportation.

REFERENCES

1. National Maglev Initiative. Final Report on the National Maglev Initiative. www.bts.gov/nt/DOCS/TNM/html.

2. Thornton, Richard. Why the US needs a Maglev System. Technology Review.

3. Railway Technical Research Institute. Maglev Systems Development

Home Page. http://www.rtri.or.jp/rd/maglev/html.

4. Magnetic Levitation: Jonathan Jacobs

5. http://bhs.csd3.k12.ny.us/~ppicard/maglev.html

6. Magnetic levitation for transportation: by S.S. Verma.