What makes modern trains go?

Question

Someone told me that the train tracks should not be touched right before a train comes through, due to the fact that the trains are powered by the electricity running through the tracks..

Now, I know there ARE trains that are powered by high voltage, and there are some trains like that in the state, but none close to where I live (that I know of)..

Someone please help clarify.

Answer 1

A diesel train is like a car. Basically it runs on petrol and the tracks are the road. An electric train runs on electricity, which is supplied by a circuit (like a light circuit). This will be provided to the train either by overhead cables or a "live rail" on the tracks. Because the train cannot roll on the live rail (it is electrified), the live rail is additional to the two tracks the train needs to roll on.

Electricity needs to flow continuously through a circuit for it to work, so the live rail is not just electrified where the train is. However, there can be more than one circuit. Also, diesel and electric trains can use the same tracks.

The only sound advice here is to absolutely not touch train tracks unless you know exactly what you are dealing with. Why would you want to anyway? Train tracks are not a safe place to be, electrified or not.

Answer 2

The other guy is right, on a typical North American train, its a diesel engine that runs at high RPM's that spins a voltage generator with in turn, sends power to electric drive wheels. The electric drive motors also act as some of the braking power needed to stop a load train by "torquing" the motors into a lower "gear" of sorts. Its kinda like shifting a manual car down from 5th gear to 4th gear, the car will slow down without hitting the brakes. With that,m the rest of the braking is done by "air brakes". Hope this helps you out!

Tim

Answer 3

Most trains operate like this:  There is a diesel engine that drives a generator that produces electricity that powers very large electric motors.  It is these electric motors that power the train down the track.  So in most cases, the electricity is generated by and contained within the train itself.  There are trains that are powered by electricity in the track area but these are mostly subways and mass transit trains.  The large, cross-country trains operate as described above.

Answer 4

There are two systems used.One is diesel-electric which uses a large diesel engine(new ones are 4000-4400 horsepower usually) to drive a generator.That electricity is used to run traction motors on the wheels to make the train move.The other system uses straight electricity supplied by a 3rd rail or overhead wires to run the traction motors.The rails the wheels run on are not electrified to run the traction motors.They do carry a low voltage charge used to activate the signal system but it's not enough to harm you.As one poster said the traction motors also help stop the train.But they don't "shift gears".What happens is the traction motors are switched electrically to become generators.As the motor armature turns it is retarded by the electrical field surrounding the armature and varied by the amount of amperage the engineers sends to the traction motors.In any case it's a good idea to stay away from the tracks.A train can be upon you before you know it and it's easy to get killed playing around tracks.

Answer 5

People make trains go.  Thousands of dedicated men and women, true unsung heroes providing an absolutely necessary and indispensable service.

Engineers, conductors, brakemen, switchmen, machinists, carpenters, electricians, pipe-fitters, boiler makers, railroad police officers, cat skinners, laborers, clerks, truck drivers, maintenance of way people...  the list really does go on.  And all are dependent on each other.  

Take away one and the house of cards collapses.  If that happens then the way of life as we know it will change drastically, and not for the better.

Answer 6

Trains which run on external electricity pick up in two ways: 1) from an overhead wire; 2) from a third rail, placed just outside the main running rails (the London Underground has 2 live rails, one outside the running rails and one in the centre, but that is unusual). The wire or rail remains live all the time, whether a train is due or not, and carries very high voltages which can kill on contact.

The other type of power for a modern train is diesel. Many trains are powered by a system known as diesel-electric. The locomotive has one or more diesel motors which are coupled to generators. These in turn feed electric motors which are geared to the axles, thus supplying the final drive. So the locomotive is actually an electric machine with its own generator. A few locomotive types, like the class 73 used in the UK, are equipped to both to pick up power from a 3rd rail and generate their own power. The British term for such a unit is 'electro-diesel'.

Other types of diesel power are diesel-hydraulic, in which the diesel motor drives the axles through a fluid coupling  (like the fluid clutch on an automatic car, only bigger) and gears, and diesel-mechanical, in which the diesel motor transmits power through a conventional gearbox.

Answer 7

Almost all modern trains are propelled by electric motors geared to the locomotive wheels.  In the diesel electric system, the electric power for the motors is generated by a large diesel powered generator carried in each locomotive.  These generators vary from around 3,500 to 5,000 horsepower for road engines.  Switchers have smaller diesel engines.

In the pure electric system, the electric power is supplied by the electric utility companies or by special generating plants operated by the railroad.  The electric power reaches the trains by means of a "third rail" alongside the track, or by an overhead wire.  Where a third rail or overhead wire is present, it can be very hazardous.  An enormous amount of electric power is present at all times.

The third rail or overhead wire is energized at all times, and not just when a train is about to pass.  Electric railroads have an additional hazard because the trains move so quietly you may not hear one coming.

You can tell if the passing train is a diesel powered train by the sound.  The distinctive whining roar of the diesel generators is unmistakeable.  Diesel locomotives, by the way, run on diesel fuel, which is like heating oil, rather than on petrol (gasoline).

You can spot an electric railway because there is an overhead wire suspended by poles or arches over the track; this wire runs right down the center of the track and can thus be distinguished from telephone and signal cables that run alongside the track.  Alternatively, there may be a "third rail," which is at ground level beside the track, and enclosed in a box made of wood or concrete.

Here is the final point.  In most parts of the world, it is against the law to trespass on railroad tracks of any kind.  It is very hazardous, and a surprising number of people are killed each year by trains they didn't hear or see coming.  So be safe, and just stay away.

Answer 8

You have the answer above, there are some excellent answers.

The only time you would get electrocuted would be if you touch the "3rd rail" on a subway system.

However, that does not change the fact your friend gave you very very good advice, dont touch the rail anyway, it is a good way to get killed.

Answer 9

engines