What is the independent brake on a locomotive?

The independent brake is a “straight air” system that makes brake applications on the head-of-train locomotive consist independently of the automatic brake, providing for more nuanced train control. The two braking systems may interact differently as a matter of preference by the locomotive builder or the railroad.

What is dynamic braking on a locomotive?

Dynamic brakes use the kinetic energy of a train’s turning wheels to create electrical energy, which causes the train to decelerate. The dynamic brake grids consume electricity that make the traction motor less able to turn and thus slow down.

How did trains stop before air brakes?

Before the air brake, railroad engineers would stop trains by cutting power, braking their locomotives and using the whistle to signal their brakemen. The brakemen would turn the brakes in one car and jump to the next to set the brakes there, and then to the next, etc. Railroad accidents were frequent and deadly.

Do railcars have brakes?

So, do train cars have brakes? Yes, every car on a train has its own set of brakes. This is made possible by an air line that spans the entire length of the train. Each cars has a set of brakes, air lines, and cylinders, which regulate the brakes on each car by responding to the commands of the engineer.

How long does it take to air up a train?

This takes a lot of air. It takes anywhere from 15 minutes to an hour to charge a train depending on its length and how leaky the air hose couplings are. On the railroad I work for the standard brake pipe pressure is 90 psi.

How long does it take for a train to stop under full emergency braking?

The average freight train is about 1 to 1¼ miles in length (90 to 120 rail cars). When it’s moving at 55 miles an hour, it can take a mile or more to stop after the locomotive engineer fully applies the emergency brake. An 8-car passenger train moving at 80 miles an hour needs about a mile to stop.

What is the major disadvantage of dynamic braking?

The main disadvantage of this method is that regenerated power and supply power is wasted in the resistance. Therefore Plugging is most inefficient method of Braking. As shown in figure above, for Series Motor, the supply voltage is not reversed but the armature terminal is reversed.

What is the difference between dynamic and regenerative braking?

With dynamic braking, an IGBT (transistor) allows power to flow to a resistor, where it’s dissipated as heat. Regenerative braking takes the energy generated by the motor and feeds it back to the AC power source or to a common bus, where it can be used again.

What is the difference between air brake and vacuum brake?

Air brakes work off high pressure, and the air hoses at the ends of rolling stock are of a small diameter. On the other hand, vacuum brakes work off low pressure, and the hoses at the ends of rolling stock are of a larger diameter. Air brakes at the outermost vehicles of a train are turned off using a tap.

Who invented railway air brake?

George Westinghouse
Railway air brake/Inventors

The first air brake invented by George Westinghouse revolutionized the railroad industry, making braking a safer venture and thus permitting trains to travel at higher speeds.

Why can’t trains stop immediately?

The distance it takes to halt a train in an emergency is based on multiple factors: the speed when the brakes are applied, the track’s incline, the number of cars hooked behind the locomotives and the loading of those cars, the “brake delay” inherent in the train’s hydraulic system, the friction-causing metallurgy of …

What is the name of the brake pipe on a train?

The system which controls the brake pipe is called the automatic brake and provides service and emergency braking control for the entire train. The locomotive (s) at the head of the train (the “lead consist”) have a secondary system called the independent brake.

What happens when the locomotive releases the brake?

When the engine operator releases the brake, the locomotive brake valve portal to atmosphere is closed, allowing the train line to be recharged by the compressor of the locomotive.

Are there any electro pneumatic brakes in trains?

Electro-pneumatic brakes are currently in testing in North America and South Africa on captive service ore and coal trains. Passenger trains have had for a long time a 3-wire version of the electro-pneumatic brake, which gives up to seven levels of braking force.

When was the railway air brake system invented?

(July 2013) ( Learn how and when to remove this template message) A railway air brake is a railway brake power braking system with compressed air as the operating medium. Modern trains rely upon a fail-safe air brake system that is based upon a design patented by George Westinghouse on April 13, 1869.