Weak Brakes (Independent & Train Brakes)

[GoGoran]

FYI, trains don't stop on a dime.

If trains could not break fast enough, they would be running over red signals all the time ...

[derekmorton]

I am afraid that that statement does not make sense.
If trains could not brake fast enough for what?

Drivers spend a long time learning about how long trains take to stop, and they remember these things, that is why they DON"T go through red lights.

[GoGoran]

I am afraid that that statement does not make sense.
If trains could not brake fast enough for what?

Drivers spend a long time learning about how long trains take to stop, and they remember these things, that is why they DON"T go through red lights.

My statement makes a lot of sense. It means that a train has to stop in vision distance of a red light, plain and simple. And that distance is often small, depending on the line, its turns and the greenery along the tracks.

In Germany, pre-signals are employed, which are erected 1,000 meters before the main signal and inform the driver about possible stops at the main signal. Which means that he must be prepared to stop in front of the main signal.

The maximum permissible braking distance on German rail lines is 1,000m -- i.e. any train must be able to come to a stop within 1,000m, even when travelling at its maximum permitted speed. On mainlines, that is. On many mid-sized and regional lines, that maximum braking distance is reduced to 700m or less, depending on the signal distances. 400m on branch lines with 80kmh maximum speed, e.g., and that's also why within station and yard areas you got a very low maximum speed of 60 or 40kmh, and maximum braking distances of down to 200m.

[baldwin]

Just to put that braking distance into perspective, http://en.wikipedia.org/wiki/Linienzugbeeinflussung is a good read on a German train control system. Without it the 1000m distance would not be possible for high speed trains.

[GoGoran]

Just to put that braking distance into perspective, http://en.wikipedia.org/wiki/Linienzugbeeinflussung is a good read on a German train control system. Without it the 1000m distance would not be possible for high speed trains.

You mean without LZB train speeds above 160kmh (i.e. 200kmh and more) would not be possible. 1,000m is the braking distance of a train travelling at 160kmh. LZB is basically a look-ahead signal monitor and train positioning system, which tells the driver e.g. that the next red signal is 8,000m ahead and that he's got to start braking in 5,000m distance.

[PRR4435]

Ok, so wait, do I go to the ENG file or WAG file to change the brake physics?

[baldwin]

That braking distance does seem to be attainable using ordinary train brakes according to the article. Trains running at that speed have to use much stronger braking systems, including electromagnetic track brakes, not something your everyday ordinary train uses. Indeed, the LZB system seems to be designed to allow trains to run at a speed consistent with prevailing traffic levels so avoiding where possible the need to come to a complete stop. In fact it also seems that LZB will ensure that a train is in fact below posted track speed should the need to stop within 1000m arise.

[baldwin]

Ok, so wait, do I go to the ENG file or WAG file to change the brake physics?

You go to the ENG file, but remember it has two sections, the first is the wagon part where lines I posted should be and the first NumWheels. The second part is the Engine which contains all of the power items, plus some extra brake parameters along with the cabview and controls. This is also where the second NumWheels resides.

[GoGoran]

That braking distance does seem to be attainable using ordinary train brakes according to the article. Trains running at that speed have to use much stronger braking systems, including electromagnetic track brakes, not something your everyday ordinary train uses.

I am German, and I know the German rolling stock quite well. Trains travelling up to 200kmh used to have only conventional brakes, though they differ from the simple and outdated US system in that they are graduated release brakes instead of single release. The system is called the Knorr Brake and was introduced in 1913 for the first time.

Starting with the late 1970s, the first passenger coaches with disk brakes were introduced, don't nail me on the exact date, and by now they have largely replaced the old brake shoe system on passenger coaches, though a few remain with the old system. Both systems are fully compatible, however.

Indeed, the LZB system seems to be designed to allow trains to run at a speed consistent with prevailing traffic levels so avoiding where possible the need to come to a complete stop. In fact it also seems that LZB will ensure that a train is in fact below posted track speed should the need to stop within 1000m arise.

Yes, and to ensure smooth traffic and passing of trains we got another system, PZB (Punktuelle Zugbeeinflussung - punctual train interaction).
http://en.wikipedia.org/wiki/Punktf%...gbeeinflussung

[derekmorton]

And again you have taken another thread off topic.