Power failures?

Question

Always we face power failures but the railways are never affected by the power failures. Why is it?

What will happen if some day power failure happens and a train is at maximum speed on a track?

Answer 1

Power failures do effect electrified rail operations, both underground and above.

A moving train that loses power still has the brake system in tact for the simple reason the systems operate on air pressure.  Enough residual air is available to get the train stopped before any air leaks can deplete the system.  Keep in mind it takes an air supply source to release the brakes, not apply them.

Answer 2

I suspect that the railroads you ask about have separate power substations and it takes a different set of faults to disrupt power to them.

Above answer is absolutely correct, the tains affected will (and have in the past) be able to make a safe stop and wait til power is restored.

Answer 3

In the UK we use air brakes rather than vacuum brakes, so air is needed to apply them. However, if the main air pressure drops below a certain level because there is no power to run the compressor, the emergency brake will automatically cut in and stop the train while there is still sufficient pressure to do so.

I drive electric trains here in the UK and can confirm that the power for the railway is from a seperate supply. More than once I've driven through a blacked-out station because there is a local outage. However, if the power trips to the overhead line equipment then you are banjaxed. You can coast a certain distance, but it's always better to try and stop in a platform if at all possible before you run out of air and become a passenger yourself. After all, you could be there a very long time and being in a platform would make de-training the passengers a whole heap easier than evacuating them onto the track.

Things get a bit more serious if the power failure affects the signalling equipment though, as every signal will either go off or revert to danger. When that happens, every driver will drop the brake (and probably the contents of their bowels as well) and stop the train as quickly as possible and remain there until either the power is restored or some means of degraded working can be implemented.