How do train compression brakes work?

Question

I'm doing an assignment, and I was wondering if I could get an answer on compression brakes. I've done most of it, i just need some confirmation. Any history of these brakes and the materials they are made of and hav been made of would be great. thanks

Answer 1

Locomotives have three types of brakes .

1. Air brakes

2. Dynamic Brakes .. there not really brakes.. the engines power is cut from the traction motors that are attached to the wheels ... when you do this the wheels wanna turn backwards.. slowing the train down .. is a very strong force ..

3. Hand brakes ..

a trains brake system works by air ... if there is any disruption in the train ( i.e. separation, derailment, or going to fast ) the train goes into "Emergency".. all the air is dumped and all brakes automatically apply,on all cars..

Answer 2

Thumbnail quick facts:

Brakes were at one time operated by hand.

George Westinghouse designed the first "automatic air brake" for application on freight and passenger cars in 1868.  This design is still used today, with improvements, produced by WABCO  (Westinghouse Air Brake Co.)

The brakes are applied by letting the air out a a portion of the system.  Air is put into the system to initially charge the system and to release an application of the brakes.  That way, if a train looses its air, it will stop.

The earliest brake was the "steam jam brake."  It was found on the locomotives of aways back.  It put steam into a cylinder that put wrought iron brake shoes against the drivers of the locomotive.  The term "jam" is still used today, when speaking of the engine brakes, which can be operated  independently of the automatic air brakes, giving rise to its more common name, "independent" brake.

Though not a part of your assignment, there are two other braking systems other than these two above.  That is the dynamic brake and the hand brake.

One propulsion system, four braking systems.  What does that say?  Hard to stop.  So, even with the automatic air brakes of today, it takes a freight train a very long distance to stop.  If I can see you, it is too late to stop for you.

That ought to get ya goin'.

Here's your safety star.

Answer 3

Trains dont use compression brakes, not the kind of compression brakes that deisel semi trucks use anyway.

There is a similar system in use, one that does not require the air brakes on each indivudual car to be applied, I guess you could say it is similar to downshifting in your car or truck.

Basically it turns the electric motors on each locomotive axle into a large generator, requiring a huge amount of energy to keep the locomotive moving, thus slowing the train down.

This electricity generated in deisel locomotives is more or less "wasted" by being routed into huge heating grids that dissipate the electricity generated as heat.

In locomotives on electrified lines the electricity generated is passed back into the overhead wires and is used to provide energy to a train elsewhwere in the system that is needing power.

In effect a train going downhill on one of these typse of systems is "pulling" another train miles away.

Added later: oops, got to wondering if you were referring to air brakes using compressed air not the compression brakes used on deisel trucks.

Hoghead had air brakes pretty covered, air is pumped into a system, when the air pressure is lowered either by the engineer or an accidental separation of the train it causes the brakes on each car to apply individually. The same basic system with small modifications has been in use for over a hundred years, simple, cheap, quite reliable.

There are much better alternatives but the are costly and you know how industry hates squandering money that could better be used in pay bonuses and stock options for ineffective business executives.