Speed Limits and Signals

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Valdez
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Registriert: 22.10.2020 21:02:01

Speed Limits and Signals

#1 Beitrag von Valdez »

Hello / Guten Tag

I’ve been driving Zusi 3 for a couple of days and really enjoying it - it’s nice to have a realistic driving simulation. I’m not great with German but Google Translate has been helping me out and the English manual is good too.

So far I’ve been mostly driving the 193 on Lehrte-Hamburg, and I have a couple of questions about speed limits:

First, leaving a freight yard with signals Hp2 / Vr1 (Go 40km/h, Expect Proceed), and a line speed from the Book or EBuLa of 120km/h.

When can I increase from 40 to 120? Is it when the back end of the train has passed the (Asig) or Junction (Y)? or must I wait until reaching the next Hp1 signal?

My second question is to do with braking and PZB. I was travelling at 120km/h in a freight train (70 PZB mode) approaching a signal Vr0 - the previous signal was Hp1. At the Vr0 I removed the power and applied significant braking (all of the Kn gauge on the 193 was yellow). My aim was to slow to <70 in the PZB curve and continue slowing to 30 for the 500hz. I did acknowledge the Vr0 and got the 1000hz, but a just few seconds later I got an emergency stop. Looking at the tachograph later I exceeded the curve slightly at 92km/h.

How would that situation be handled properly? Must I apply the brake before passing the Vr0? Is it normal to need a full brake application? It seems there is no margin at all on the braking curve? Would you control the speed brake with the AFB or use the train brake like I did?

Thanks for your help! Viele Grüße
Zuletzt geändert von Valdez am 22.10.2020 21:36:20, insgesamt 1-mal geändert.

F. Schn.
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Registriert: 24.10.2011 18:58:26

Re: Speed Limits and Signals

#2 Beitrag von F. Schn. »

Hi,
Valdez hat geschrieben:When can I increase from 40 to 120? Is it when the back end of the train has passed the (Asig) or Junction (Y)? or must I wait until reaching the next Hp1 signal?
The speed limit of a Asig or Bksig can be increased, when the back end of the train has passed the ¥ (end of point area).
Valdez hat geschrieben:Must I apply the brake before passing the Vr0?
Usually you should do this. 120 km/h is the upper corner of PZB mode 70 / PZB mode M and in Zusi it costs a lot of time to move the break into full apply.
Valdez hat geschrieben:It seems there is no margin at all on the braking curve?
You can set the break not only into "full apply" but also into "zero pereasure" by holding the apply key for 2 seconds. Maybe this is a kind of "margin".
Valdez hat geschrieben:Would you control the speed brake with the AFB or use the train brake like I did?
train break

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Thomas R.
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Re: Speed Limits and Signals

#3 Beitrag von Thomas R. »

Hi Valdez,
welcome to Zusi! :schaffner
Valdez hat geschrieben:[...] When can I increase from 40 to 120? Is it when the back end of the train has passed the (Asig) or Junction (Y)? or must I wait until reaching the next Hp1 signal? [...]
To make a long story short:
When you pass an exit signal, you can increase speed when the last car reached the location of the Yen-sign in Ebula.
Within an station - in other words when you passed an entry or intermediate signal - you can increase speed when the last car reached the following signal.

There are more special rules to it and the key word is "anschließender Weichenbereich", see for example here (in German): http://www.tf-ausbildung.de/BahnInfo/weichenbereich.htm
Maybe Google translator can help you getting an idea of the concept.
Valdez hat geschrieben:[...] How would that situation be handled properly? Must I apply the brake before passing the Vr0? Is it normal to need a full brake application? It seems there is no margin at all on the braking curve? Would you control the speed brake with the AFB or use the train brake like I did? [...]
Yes, with a freight train it is advisable to apply the brakes as early as possible. I'm no engine driver but as far as I understand, it is also advisable to use full brake application with freight trains.

I hope this is of help.

Regards,
Thomas
Zuletzt geändert von Thomas R. am 22.10.2020 22:01:42, insgesamt 2-mal geändert.

jonathanp
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Re: Speed Limits and Signals

#4 Beitrag von jonathanp »

When can I increase from 40 to 120? Is it when the back end of the train has passed the (Asig) or Junction (Y)? or must I wait until reaching the next Hp1 signal?
It's at the Y point. If you want to be sure whilst learning, you can use the cheat display, which shows the current permitted speed.
How would that situation be handled properly? Must I apply the brake before passing the Vr0? Is it normal to need a full brake application? It seems there is no margin at all on the braking curve? Would you control the speed brake with the AFB or use the train brake like I did?
The "yellow display" is the state of the electrical braking on the locomotive. On a heavy freight train this will have limited affect. Did you apply the air brakes as well?
It is up to your judgement when you apply the brakes, but I imagine freight drivers would almost always apply the brakes at the earliest possible opportunity. On a long train it takes quite some time for the air brakes to take full effect, and it is indeed tough to beat the PZB safety curve.
You should never use the AFB to do your braking for you*, it will brake harshly and could break the couplings.

*obviously this is a just a game, and you can do whatever you like, but imaging this is real life...
Autor - Zusi 3 C++ Client, zusidatenbank.de - Das Zusi3 Addon-Datenbank

Valdez
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Re: Speed Limits and Signals

#5 Beitrag von Valdez »

Thanks everybody for your input so far. I’ve just got a 91.1% which is my best effort yet thanks to your help!

Yes the Yen sign is easy to understand. I assume that if I’m in a larger junction and I pass an Hp1 before the Yen sign I can accelerate after the whole train has passed the Hp1?

Similarly if I get a Hp2+Zs3 for 60km/h, then next a “plain” Hp2 without Zs3 I should then slow to 40km/h?

Thomas - I’ll have a look at that link thanks, I’ve switched out my Learning French audiobook for German so maybe that will help a little bit too ;-)

Jonathan - yes I used the train brake I think. I had a pressure drop in the train pipe and the locomotive brake cylinders showed pressure, although thinking about it I could have accidentally used the AFB instead so maybe that’s part of the problem for me.

Also - I should brake manually rather than AFB even when under LZB or ETCS?
Zuletzt geändert von Valdez am 22.10.2020 22:44:42, insgesamt 1-mal geändert.

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Thomas R.
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Re: Speed Limits and Signals

#6 Beitrag von Thomas R. »

Hi again,
Valdez hat geschrieben:[...] I assume that if I’m in a larger junction and I pass an Hp1 before the Yen sign I can accelerate after the whole train has passed the Hp1? [...]
Yes, that is the second possibility I mentioned:
"Within an station - in other words when you passed an entry or intermediate signal - you can increase speed when the last car reached the following signal." In this case, there is no meaning to the following Yen-sign.
Valdez hat geschrieben:[...] Similarly if I get a Hp2+Zs3 for 60km/h, then next a “plain” Hp2 without Zs3 I should then slow to 40km/h? [...]
Yes.

Regards,
Thomas

Valdez
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Re: Speed Limits and Signals

#7 Beitrag von Valdez »

Thanks Thomas, I’m fact I’ve just been reading that web page you linked and it looks to answer every question I have on signalling at the moment - really useful TVM!

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Zimmer
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Re: Speed Limits and Signals

#8 Beitrag von Zimmer »

Just throwing in a hint / tidbit of advice for decelerating freight trains, especially but not limited to Zusi:

- Before you have to apply the brakes for the frist time, take a quick look at the "composition sheet" (the train data displayed in the 2nd tab of the timetable). Check the value "Bremshundertstel" (= vulgo: brake-percentage, a value indicating how efficient your train might brake). Compare it to the Value "Mbr" (minimum brake percentage) in the time table. The greater the (positive) gap, the more relaxed you may handle the situation.
- A distant signal in warning being passed at maximum speed requires immediate and drastic action: apply a full break instantly. This should be reserved for "surprising" distant signals only though.
Regular deceleration procedure:
- Well before the distant signal, gently remove the traction force and let the whole train calm down and "push" the engine. (During acceleration, the buffers usually don't touch each other, esp. in the front thrid of your train. Removing power will make the tail part press forward and make the buffers connect.)
- If you decide to take the distant signal at warning (a couple hundred yards short of the signal, you ought to decide), decrease the pressure in the main pipe by at least 0.5 bar and wait for this decrease to reach the tail car. This may take a while!
- The train should now lose speed slightly. If judged the distant to the distant signal correctly, you should pass it with the brakes effectively applied and the speed reduced by approx. 10 km/h.
- Most important - even if the distant signal changes its aspect between you applying the brakes and the brakes having started braking, do not immediately release them. (Especially valuable if carrying liquid cargo!). Absolutely you must not, under any circumstance, turn back on traction power.
- Let you eyes wander rapidly from the main signal in the distance (if already visible) to the speed meter and back. Is the train slowing down fast enough for your guts feeling? If not, lower the pressure further. If yes, hands off the brake lever!
- Keep in mind that you need to get the whole bloody thing slower than 65 in PZB-M and under 50 in PZB-U within the respective time (24s/36s). This also applies if the main signal in the mean time changed its aspect from Stop to Proceed!
- Try to get this done with the least fumbling with the brake leaver. It's a leaver not a joystick. Changing your mind multiple times of what you want from your train's brakes will get them confused - and confused brakes cause a multitude of problems.
- Once you came to a standstill (or a tiny bit before that), release the brakes, secure the train with the loco break and wait for the train to release completely. (For a 700m train which you forced to stop by a full break this may take up to 7 minutes, depending on the brakes of the indiviual waggons.) In real life you'll feel the train either pull on or push the loco a tiny bit.

i hope this was to some extent useful - and will help you to close the gap of those missing 8.9% sucessfully.

Regards

Johannes

LCYCowboy
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Re: Speed Limits and Signals

#9 Beitrag von LCYCowboy »

Thanks Johannes,

This is fantastic information. I am also keen to learn as much as possible (I am new to train driving after decades of flying, and it is great fun to learn something new).

Another quick question on braking. A lot of the trains have separate Air brake and Dynamic brake levers. Do you normally use the Dynamic brake first (especially in passenger trains) when reducing say for a change of speed limit, or do you always apply both together?

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Zimmer
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Re: Speed Limits and Signals

#10 Beitrag von Zimmer »

Hi Cowboy,

you're welcome. The matter you raise now is bound to lead into a semi-religious war. There have been times, when clearly all guides told one to former and a few years later all was reversed and it was said to use the latter. Of course, the more and more sophisticated equipment of the coaches (ep-Bremse, an electro-penumatic brake system, triggering all brakes in the train simultaneously without any noticable delay) has made it a lot easier for any engineer to bring the train to a halt smoothly and comfortably. But... from my experience as a passenger, travelling long distance twice a week for half a decade, today nobody's keen on doing so anymore: bangs, clangs, as the dynamic brake is levered out all the way in one brisk motion, the entire IC-train of 400 tons tries desperately to remain its momentum and crashing into the buffers of the engine which up to just now has steadily pulled the waggons with almost the same force as its now, seconds later, tries to slow them down --> this is disrespectful to passengers, laws of physic and one own's pride.

An old instructor once told me that it's all well to fumble around with girls in any fashion one or them like and use as many hands on them as necessary to achieve the objective in question—but a railway brake is *not* a girl. One hand only, and no fumbling around. One lever forwards, one backwards, then a bit of this, more of that now, less of the former, a tiny bit more of the latter, oh, ooops, you forgot "Wachsam" - no wonder, with no free hand and both eyes glued to the molested brakes. While it's okay, if one is quite certain to be able to perform it, to operate small speed reductions (+NOT+ to zero) with the dynamic brake alone, one should follow a simple rule: away with the traction, wait, is the train running faster than the engine now? (You notice by a slight 'bump', a soft pad, nothing that will get the attention of even the keenest passenger.) Then, apply the first step of dynamic brake, WAIT again, until the entire train now is 'leaning' against the enginge, nudging against the gentle braking force. And now, increase as much as necessary, when done, release in reverse order. Thus rules followed, the waiter in the dining coach can fill a glass at table hands-free without spilling, and the chef chop onions without bleeding.

As cargo is in general less sensitive than passengers are, it's very useful (if foreseen early enough!) to use the dynamic brake (obviously not on hydraulic diesel engines or old/standard electric ones, these are not re-using the energy) early and as long as possible alone, in order to save energy. (Never though when approaching a halt-signal and/or a buffer-stop. Once did so in practise years, instructor killed the main and suddenly nothing slowed us down any more. Horrible memory, never forgotten ever since.)

Hope that helped you, though it got a bit narrativly styled...

J

LCYCowboy
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Re: Speed Limits and Signals

#11 Beitrag von LCYCowboy »

Thanks Johannes,

this is really great information. It all makes sense thanks to your description!

Does this mean that on an old Diesel like the 218 you do not touch the dynamic brakes? I had though that they might be used to save on brake wear (on the brake blocks etc). Looks like I have been doing it completely wrong when driving the Sylt shuttle.

I have noticed that the brakes release very quickly on a 600m+ train. Is this realistic?

Thanks again,

Neil

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Re: Speed Limits and Signals

#12 Beitrag von KlausMueller »

The statement from Johannes is mainly regarding energy saving. Obviously diesel engines and old electric engines using braking resistors are not able to recuperate energy to the overhead line so their dynamic brake has no effect on energy saving.

I dont see why not to use their dynamic brake for small speed reduction or holding speed on downward grades as it at least reduces wear of the mechanic brakes. As Johannes wrote you should not put it into action directly with full power as this has negative effect on the driving dynamics of the train and on passenger comfort. Just apply and release it slowly step by step (unfortunately you can't feel the effect in the simulation, when the train pushes the loco from the back, as you would on a real loco).

Regarding your question about release speed of the brakes I unfortunately don't have experience from real trains. Im working in the railway business but not on the trains. I plan and build power supply substations to bring the electricity into the contact line.

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Zimmer
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Re: Speed Limits and Signals

#13 Beitrag von Zimmer »

Dear Neal,

Klaus is quite right about the effect of recuperative breaks in the modern engines.

Regarding your questions concerning class 218 (and her sisters of class 215 of course), the dynamic break (H-break, H derivated from hydraulic as the energy is destroyed in the hydraulic gears by boiling up the oil) lever needn't to be touched - it's coupled with the regular brake handle, unless it's being unhinged by a push to its foremost position.

So, upon regular application without unhingingen the H-break lever, the following happens:

HL-pressure decreases -> pneumatic brake of enginge enganges whilst
simultaneously the tranmission unit fills the brake converter with oil, hydraulic retarding force is built up—and according to its increase, the pneumatic brake (of the engine only of course) is released. (This is important to avoid the wheelsets to be exposed to exuberant brakeforce as this might easily lead to a loss of wheelspin. The pressure being released from the pneumatic system is stored and immediately reapplied in case the H-break should falter or fail for any reason, including:
at around 40 km/h the H-break is automatically disenganged.

If you want to save wear and tear on the coach brakes as well, small changes of speed can also be done by the H-break alone. In this case be careful not to apply it brutally, as Klaus explained.

How did you deduce the brakes on the 600+ to be releasing very quickly? Since cargo is the majority of what I do get to drive IRL these days, I'm usually confiding myself to passenger services in Zusi and therefore have no experience from Zusi trains.

Calling from a (drastic) brake excercise with complete emptying the HL, we've been taught to consider a minimum time of 1 minute per 100 m before the brake maybe considered fully released. Various (mostly eastern) international brakes require even more time to release; after a full stop a waiting period of up to ten minutes can be indicated. On the other hand, modern (intermodal) waggons are rather likely to operate in a quick and reliable fashion. After a moderate manoeuvre (not exceeding a loss of 0,8 bar) one should be fine to continue fairly soon.

Unfortunately, the 'behind'-meter of the real world cannot be used in Zusi: the slight nudge/pull of the train once it's fully/almost released itself.

Glad to have been of service,

Johannes

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Re: Speed Limits and Signals

#14 Beitrag von LCYCowboy »

Thank you so much for all your answers (I am trying to take it all on board).

The freight train brakes I am used to are from Train Simulator (virtual railroads Loks) where you need to plan so far ahead and if you brake too hard you will end up waiting a long time for the brakes to release (nudging the brake lever into release dissipates the air, but if you're not careful you could end up with too much air and a stuck train). This was all from Train Simulator (which isn't the most realistic). I was a bit surprised when driving the Sylt shuttle that I could brake and the brakes would release very quickly for such a long train).

Now, my next question. I have just driven a 146 between Köln and Düsseldorf (I lived in Köln for a bit, so love this route). When driving the 146 (or any other train like the 401, 101, 120 etc) with LZB using the AFB, do you let the automatics get on with all the speed changes? Say the LZB has a speed reduction from 160 to 120 km/h, do you just leave all the levers alone and let the train automatically slow down to the next speed? Or for comfort, do you put the power lever to 0 and use the Dynamic brakes gently to slow down by applying it manually (and any additional pneumatic brakes to keep in the curve)?

Do the more modern trains when slowing down automatically using AFB keep it smooth, or do the drivers take over to make sure it is comfortable for the passengers?

Thanks so much for all the info!!!!

Neil

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