Challenges in making the Bullet Train

Submitted byAppalla Aditya Shiva

12881A0306

CONTENTS: • Bullet Train systems currently used.• Challenges in making the Bullet Train.• Hunting Oscillation.• Power Transmission.• Power to Speed conversion.• Cornering.• Earthquake management.• Conclusion.• References.

Bullet Train systems currently used:

Japanese: ShinkansenFrench: Train á Grande Vitesse Maglev

Challenges in making the Bullet Train: Hunting Oscillation. Power Transmission. Power – to – Speed conversion. Cornering. Earthquake management.

Hunting Oscillation:Self oscillation about an equilibrium. Causes:High speed resulting in higher interactions between adhesion & inertial forces.Effects:1. Violent movement in yawing manner.2. Derailment.3. Severe rail damage.

Solution:1. Wheel design. Speed (N)

Make the train wheel nearly flat.

2. Use heavy springs to dampen yawing.

Power Transmission:High voltage of 25kV – 30kV created by stepping up the voltage instead of current.Pantograph is used for transmission. Problem:Improper contact between line and pantograph – causing a plasma arc of 10000C.Effect:Power loss/power overload.

Solution: Lever principle of a CROWBAR.

Spring attached to the pantograph to make a compensatory mechanism.

Power – to – Speed Conversion: Key point is to increase the traction to run at high speeds. Problem:Weight constraint and engine pull.Effects:• More power required to run the train.• Slip of bogie wheels.• Pulling force at high speeds rather than pushing force, thereby creating less traction.

Solution:All – axle drive except for the engines – creating more traction and more control. Also called ELECTRIC MULTIPLE DRIVE UNIT. Provides for REGENERATIVE BRAKING.

Cornering:Centrifugal force is experienced, which can derail the train – causing accidents.

Solution:Banking the track to create a centripetal force that will balance the centrifugal force.Limitations:• Train cannot be run at high speeds.• Passengers and other luggage in the compartment will oscillate.

This limitation can be overcome with the Airbag Tilting System.

Airbag Tilting System (Courtesy: Eastern Japan Railway Corporation)

Earthquake Management: Japan – plagued by 900 earthquakes a year of magnitude 5 and above. Bullet Trains are equipped with Urgent Earthquake Detection & Alarm System (UrEDAS).

Comprehensive system to detect the

p – waves using electromagnetic

seismometer, relay the information to

the alarms which brake the train in 2

seconds.

Support rails are used to hold the train

if it is too close to the epicenter.

Conclusion:• Extreme engineering depends on simple physical principles.• Bullet Trains in India to become a reality in 2025 and these challenges are

the first step to build on the project.• Transport system can be improved and the necessity of domestic flight

travel can be highly reduced with bullet trains.• With the bullet train use, there is less pollution due to CFC and CO than by

regular diesel locos and flights.

References: • https://en.wikipedia.org/wiki/Hunting_oscillation• https://www.youtube.com/watch?v=ulDhklLJxZc (Nat Geo

Engineering)• https://en.wikipedia.org/wiki/Pantograph_(transport)• https://www.quora.com/How-can-a-pantograph-in-electric-

trains-move-up-and-down-according-to-the-height-of-an-overhead-electric-line

• http://www.irfca.org/faq/faq-elec2.html • http://www.geo.mtu.edu/UPSeis/waves.html• http://web-japan.org/trends/09_sci-tech/sci101209.html

Thank You!