10-09-2014, 10:02 AM
Railway Wagon Breaking System
[attachment=67757]
Definition
In Railway wagon as well as in passenger cars the braking system plays a very important role to stop the train, to maintain the speed of the train within specific limit. Brakes are the devices on the trains to bring it to standstill.
A moving train contains energy, known as kinetic energy, which needs to be removed from the train in order to cause it to stop. The simplest way of doing this is to convert the kinetic energy into heat energy. The conversion is usually done by applying a contact material to the rotating wheels or to discs attached to the axles. The material creates friction and converts the kinetic energy into heat energy. The wheels slow down and eventually the train stops. The material used for braking is normally in the form of a block or pad.
The vast majority of the world's trains are equipped with braking systems which uses compressed air as the force to push the blocks on to wheels or pads on to discs. These systems are known as "Air Brakes" or "Pneumatic Brakes". The compressed air is transmitted along the train through a "brake pipe". Changing the level of air pressure in the pipe causes a change in the state of the brake on each vehicle. The system is in widespread use throughout the world.
An alternative to air brake known as vacuum brake is also used in railway wagon. Like the air brake the vacuum brake system is contolled through a brake pipe conecting a brake valve in the driver’s cab with braking equipment on each vehicle. The operation of the brake equipment on each vehicle depends on the condition of vacuum created in the pipe by an ejector or exhauster.
Another braking system used by electric train is Electric Dynamic Braking System.The basic principle of operation is to convert electric motor into a braking generator dissipating the kinetic energy as heat energy. Regenerative braking is similar to Dynamic Braking. Only difference is that, it transmits generated electricity to overhead wires instead of dissipating it as heat, and is becoming more common due to it’s ability to save energy.
Operation
There is a control box on top of the driver's console. When he wants to apply the brakes, he pushes the button until the readout shows the amount of brake cylinder pressure (or percentage of braking effort) he wants. He releases the button; the control unit then codes and sends the signal to all cars. They in turn receive and interpret the message. They then begin allowing compressed air from their reservoirs to go to the brake cylinder until the desired cylinder pressure is achieved. The microprocessors on the cars will continuously monitor brake cylinder pressure against leakage and maintain the desired pressure.
Vacuum Braking System
An alternative to the air brake, known as the vacuum brake, was introduced around the early 1870s, the same time as the air brake. Like the air brake, the vacuum brake system is controlled through a brake pipe connecting a brake valve in the driver's cab with braking equipment on every vehicle. The operation of the brake equipment on each vehicle depends on the condition of a vacuum created in the pipe by an ejector or exhauster. The ejector, using steam on a steam locomotive, or an exhauster, using electric power on other types of train, removes atmospheric pressure from the brake pipe to create the vacuum. With a full vacuum, the brake is released. With no vacuum, i.e. normal atmospheric pressure in the brake pipe, the brake is fully applied.
[attachment=67757]
Definition
In Railway wagon as well as in passenger cars the braking system plays a very important role to stop the train, to maintain the speed of the train within specific limit. Brakes are the devices on the trains to bring it to standstill.
A moving train contains energy, known as kinetic energy, which needs to be removed from the train in order to cause it to stop. The simplest way of doing this is to convert the kinetic energy into heat energy. The conversion is usually done by applying a contact material to the rotating wheels or to discs attached to the axles. The material creates friction and converts the kinetic energy into heat energy. The wheels slow down and eventually the train stops. The material used for braking is normally in the form of a block or pad.
The vast majority of the world's trains are equipped with braking systems which uses compressed air as the force to push the blocks on to wheels or pads on to discs. These systems are known as "Air Brakes" or "Pneumatic Brakes". The compressed air is transmitted along the train through a "brake pipe". Changing the level of air pressure in the pipe causes a change in the state of the brake on each vehicle. The system is in widespread use throughout the world.
An alternative to air brake known as vacuum brake is also used in railway wagon. Like the air brake the vacuum brake system is contolled through a brake pipe conecting a brake valve in the driver’s cab with braking equipment on each vehicle. The operation of the brake equipment on each vehicle depends on the condition of vacuum created in the pipe by an ejector or exhauster.
Another braking system used by electric train is Electric Dynamic Braking System.The basic principle of operation is to convert electric motor into a braking generator dissipating the kinetic energy as heat energy. Regenerative braking is similar to Dynamic Braking. Only difference is that, it transmits generated electricity to overhead wires instead of dissipating it as heat, and is becoming more common due to it’s ability to save energy.
Operation
There is a control box on top of the driver's console. When he wants to apply the brakes, he pushes the button until the readout shows the amount of brake cylinder pressure (or percentage of braking effort) he wants. He releases the button; the control unit then codes and sends the signal to all cars. They in turn receive and interpret the message. They then begin allowing compressed air from their reservoirs to go to the brake cylinder until the desired cylinder pressure is achieved. The microprocessors on the cars will continuously monitor brake cylinder pressure against leakage and maintain the desired pressure.
Vacuum Braking System
An alternative to the air brake, known as the vacuum brake, was introduced around the early 1870s, the same time as the air brake. Like the air brake, the vacuum brake system is controlled through a brake pipe connecting a brake valve in the driver's cab with braking equipment on every vehicle. The operation of the brake equipment on each vehicle depends on the condition of a vacuum created in the pipe by an ejector or exhauster. The ejector, using steam on a steam locomotive, or an exhauster, using electric power on other types of train, removes atmospheric pressure from the brake pipe to create the vacuum. With a full vacuum, the brake is released. With no vacuum, i.e. normal atmospheric pressure in the brake pipe, the brake is fully applied.