TILTING TRAINS

(TECHINICAL SEMINAR)Submitted By

SURESHA.C (1GV01ME063)

In partial fulfillment of the requirementsFor the successful completion of VIII semester of

Bachelor of EngineeringIn

Mechanical Engineering

Under the Guidance of:

C.N.SURESHA

DEPARTMENT OF MECHANICALENGINEERING

GOLDEN VALLEY INSTITUTE OF TECHNOLOGY KOLAR GOLD FIELDS - 563120.

GOLDEN VALLEY INSTITUTE OFTECHNOLOGY

Kolar Gold Fields-563120 DEPARTMENT OF MECHANICAL ENGINEERING

CERTIFICATECertified that the technical seminar

TILTING TRAINS Is a bonafied work carried out by

SURESHA.C (1GV01ME063)In partial fulfillments of the requirements for the successful completion of 8TH semester of Bachelor of Engineering (Mechanical) of Visveswaraiah Technological University, Belgaum during the Academic Year 2004-2005.It is certified that all corrections /suggestions indicated for internal Assessment have been incorporated in the Report deposited in the Department Library.This seminar report has been approved as it satisfies the academic requirements in respect of seminar work prescribed in the syllabus.

Signature of committee1.2.

Signature of the Guide Signature of the H.O.D

(C.N.SURESHA) (Prof.D.SRINIVAS RAO)

SYNOPSIS

With the invention of new technologies in various features of the railway transportation

the human beings are more benefited.

One of the technology that the railway engineers thinking is about the “THE TILTING

TRAINS”, which provide the passengers and the goods to reach the destination with a

minimum time.

The technology involved in TILTING TRAIN is that when ever the trains pass over the

curves and turnings of the railway tracks the compartments of the train is tilted to a

certain angle by which the trains can travel with no reduction in speed.

By adopting this technology of TILTING TRAINS the fuel consumed by the trains can

be saved ,the passengers can feel comfort and also time can be saved.

CONTENTS

1. Introduction

2. Problem with corners

3. What is tilting train?

4. Why tilting helps?

5. How do trains tilt?

6. Problems associated in tilting the track

7. Passenger comfort ness

8. Countries who developed the tilting technology

9. Advantages and Disadvantages of tilting trains

10. Summary

11. Bibliography

INTRODUCTION

Train is a mass transporter, which transports humans and goods from one place to another

place. We have trains, which run by diesel and electricity. Among goods and passenger

trains the most concerned one is passenger trains.

The passenger train should move quickly with high speeds. The rail road will not be

always straight it should pass through curves and turns. We all know that if you are

driving in your car and you take a turning at speed you feel centrifugal forces. Well it is

no different from trains, if a train takes a turning at speeds centrifugal forces will be

experienced.

The major problem for any trains is to pass over the curves and turns of the railroads. If

the train moves with the same speed at the curves and turns the train may slip from the

track, so the speed of the train will be slowdown drastically to avoid slip.

This results in wastage of fuel and in turn reduces the speed of the train, which is main

consideration for the passenger trains. One of the solution found to avoid this situation is

the tilting trains.

PROBLEMS WITH CORNERS

We all know that if your driving in your car and you take a corner at speed you feel

centrifugal forces. Well it is no different from trains; if a train takes a corner at speed then

centrifugal forces come in. Often train operating companies face a decision for building a

high speed railway transport system... they can either invest money in the train to make it

tilt but use existing railway lines, or they invest money in a new railway but don't need to

spend money on expensive tilting mechanisms. This is why TGV, and ICE and bullet

trains do not tilt, because they have their own dedicated high speed railway lines where

curves are built with very high radii.

It is worth pointing out that the centrifugal force is a function of v2/r where v is the

velocity and r is the radius. This means if you double the velocity, you quadruple the

centrifugal force. Similarly, if you want to triple the velocity but keep the centrifugal

force the same, you must increase the radius by a factor of nine! Something not always

possible. This is why even apparently gentle curves can be much more of a problem with

high speeds than one might thing, because the force rises with the square of velocity.

WHAT IS TILTING TRAIN ?

Tilting train consists of a tilting mechanism that enables increased speed on regular

tracks.

In the upper part of the tilting trains that is in which the passengers are seated can be

tilted sideways. During the motion of the train if the train has to steer to left in a left

turning the coaches of the train will be tilted to the left in order to compensate the

centrifugal push to the right and conversely during the right turn.

These trains are constructed such that inertial forces which cause the tilting can be

controlled by a computer.

If the trains travel at speeds more than the specified speeds at the turnings of the railway

tracks their will be centrifugal forces acting on the train. Due to these centrifugal forces

the train may slip and push out of the tracks. But in case of tilting trains which will not

happen, because of the reason that centrifugal forces will be compensated by tilting

mechanism.

WHY TILTING HELPS?

When sitting on a corner going at speed there are two forces acting on you, gravitational

force and the centrifugal force which is accelerating you into the corner. In physics when

two forces act, then this causes a resultant force. The resultant force will push you into

your seat and to the side. However if the train is tilting, then the normal contact force of

you on your seat will be the same as the resultant force you are experiencing. This means

as far as the passenger is concerned he or she is just being pulled into his or her seat, and

he or she is used to that so no discomfort is felt.

This is true also of aero planes, commercial planes tilt a large amount, up to 30 degrees

when going around corners in some cases to cater for passenger comfort. As the tilting of

the aero plane is to get rid of the problem of centrifugal forces, or more accurately to

disguised the centrifugal forces as a part of gravity as far as the passengers are concerned.

The only way you know if the aero plane is tilting is to look out of the window.

Trains that tilt can go up to 25% to 40% faster around curves than conventional trains

without upsetting the passengers, and as mentioned before this can significantly increase

average speeds and cut journey times.

HOW DO TRAINS TILT?

Carriages have tilting mechanisms. Obviously the bogies cannot tilt because they ride on

the track and must follow the path of the track. So the coaches have to tilt on the bogies.

The way they do this is simple, the bogie acts a fulcrum in the center and it is free to tilt

either side. Then pistons control how much the coach tilts. The pistons are controlled by a

small computer, which uses a spirit level. The spirit level is used to check if things are

horizontal remember, i.e. at right angles to the resultant force acting. Normally this force

is gravity, but when going round a corner the resultant is a combination of gravity and

centrifugal forces. This means the spirit level indicates it is no longer horizontal, so the

computer adjusts the pistons until horizontal is read. Again this will not be horizontal to

the ground, but as far as anyone on the train is concerned it will be horizontal, keeping

the passengers happy.

In the early days they tried to use inertial force to let the trains tilt… i.e. they would have

no mechanism to make them tilt but the carriages would have a low center of gravity so

centrifugal forces on the carriage would cause them to tilt. This proved unsuccessful.

PROBLEMS ASSOCIATED IN TILTING THE TRACK

Well on high speed lines the track in the UK is heavily banked up on corners, although

going in a high speed train you don't notice it at all. Occasionally when a high speed train

in the UK comes to a stop because of a red signal or something on a curve you can really

notice how much its slanted, on a stop on a curve put a bottle on the floor and will slide

across to the other side.

However there are limitations with tilting tracks, first of all the banking has to be

designed with a specific speed in mind. A banked up track meant for 125mph trains is

going to cause discomfort to passengers in a local 75mph train, as when a slower train

goes round a banked corner it will make passengers feel like they are falling to a side. Of

course you could build dedicated high speed lines, but then you would engineer them

without tight curves. This limits the extent to which tracks can be banked up. If the track

is banked too much for really fast trains, then if any train comes to a stop on the curve

due to a red signal the slant will cause discomfort to passengers. Also arranging for the

overhead pantrograph to make proper contact with a wire above a banked curve is a little

tricky.

Clearly trains themselves need to tilt, then you get the double benefit of tilted track and

tilting train, and the train can tilt to exactly suit the speed it is going at.

PASSENGER COMFORTNESS

One might think it is not safe to push a train round a corner at high speed. Indeed that is

true. However the crucial thing is that the speed at which it becomes unsafe, i.e. the speed

at which there is enough force to push the train off the track is incredibly high. In fact the

force needed would be enough so that all passengers on the train couldn't move and

would be stuck to the sides of the train. This implies that there is scope for increasing the

speed of a train round corners a great deal without it becoming unsafe, however

passengers will object.

There are two reasons why it is bad for passengers. I have been on a late running Inter

City 125 and it took a corner at some speed although only about 90mph and the corner

wasn't tight enough to say see the train at the other end by looking out of the window.

The corner wasn't tight enough to notice turning either. However you could feel the

forces definitely, and empty cups rolled across tables, bags creaked and I felt pushed

against the wall.

Any faster and it would be extremely uncomfortable for passengers and they would rather

the train slowed down and take a little longer. Also companies don't like to run trains at

speed round corners because it upsets passengers, as when exposed to turning forces they

may become worried the train is going to fly off the tracks (which incidentally has never

happened). This might make people nervous about traveling on high speed trains. The

reason no one is ever nervous about traveling at nearly 200mph on a train is because it is

smooth and constant. If it was doing corners at these speeds people wouldn't like it.

People get freaked out doing 50mph on a roller coaster which involves tight curves,

imagine how they feel when serious speed is involved! Its all down to the forces a

passenger feels, if a passenger feels a lot of strong forces then he or she is going to be

nervous, and may avoid traveling on the train, or just choose a slow train.

COUNTRIES WHO DEVELOPED THE TILTING TECHNOLOGY

Britain

The UK was interested in developing the advanced passenger train for quite a while

France

The development of the tilting train in France began in 1956 when eng. Mauzin built and

experimented a single car unit that used inertial (non-assisted) tilting. This experiment

were suspended because a natural tilting proved too difficult to accomplish. France

preferred to built a vast network of high speed lines and the development of TGV started

in the early seventies with a two-car modified turbo train. Today GEC-Alsthom has

decided to start the development of a tilting TGV that has been delivered few weeks ago

for testing and trials.

Spain

With the ETR-401 Fiat delivered in 1976 a wide-gauge version to Spain that was

designated Tren Basculante (RENFE Type 443). However like its Italian sibling it

remained a single vehicle. Later Spain developed a tilting version of its own Talgo train

(talgo pendular) that so far has proved itself the only successful example of natural tilting

and has met with a huge success.

USA/Canada

The first experiments were carried over in the thirties with non-powered cars (called

pendulum), but the first successful tilting train in the USA was the Sikorsky Turbo Train

which incorporated an inertial tilting mechanism. Later, in 1973 Amtrak tested an active

tilting train called LRC (Light - Rapid - Comfortable) made of ten cars, that unfortunately

had no success. Today Amtrak is trying again with the American Flyer built by

Bombardier using some TGV-derived technologies.

Sweden

ABB developed in the early seventies an active tilting mechanism that was alternative to

the Italian and British ones. This was tested in the X15 vehicle and implemented in the

X2000 series train that so far has had a good success. One curious feature of this trains is

that the tilting mechanism is applied only to the passengers cars and not to the driving

motor units.

Switzerland

As a part of the IC-2000 project the Swiss railways are developing a tilting train that has

the provisional designation ICN-2000 and will be built by SIG.

Germany

Germany has adopted tilting technology on its 610 and 611 class series EMU and will

built the ICT for long-range intercity services

ADVANTAGES

1. Fuel consumed by the trains can be minimized.

2. Speed of the trains can be maintained constant and hence time to reach the destination is minimized

3. Their will be Comfort ness for the passengers.

DISADVANTAGES

1. Very costly to manufacture these kind of trains.

2. If the coaches do not tilt then it is dangerous.

SUMMARY

While the Very high speed trains like the TGV could be regarded as the Rolls Royce of

trains, tilting trains could be thought of as the cheep and cheerful mini metro. The price

differential is fairly similar too, it costs about 20 times more per unit distance to build a

dedicated high speed line than it does to upgrade existing lines for tilting trains. This is

what makes tilting trains extremely attractive. However there are disadvantages. 140mph

or 230km/h is about as fast as trains go when not on dedicated lines. And then they have

to be fitted in with slower moving traffic.

With rail travel growing all over Europe, the problems of railways reaching saturation

point has forced new lines to be build. This is why despite the success of the Italian

Pendolini a new high speed line with 300 km/h trains is being built, because existing lines

are at saturation.

BIBILOGRAPHY

Theory of machines KHURMI . R. S

Railway Engineering PROFILLDIS . V. A

www.goggle search.com TILTING TRAINS

TILTING OF TRAINS WHILE TAKING RIGHT TURN IN

THE TRACKS

TILTING OF TRAINS WHILE TAKING RIGHT TURN

IN THE TRACKS