Problem with speed limits

[213 001-1]

Dear railway friends!

I'm sure one or two of you have already noticed this. If not, I would like to draw your attention to it.

I noticed that if a signal reduces the maximum speed permitted on the route, the speed reduction applies from the moment the front of the train has passed the signal.

However, if a signal indicates that a higher maximum speed is permitted, the higher maximum speed only applies when the rear of the train has passed the signal.

This is obviously a mistake, because normally the higher maximum speed applies in the same way as the reduced maximum speed from the moment the front of the train has passed the signal.

Can this error be eliminated using the adjustable options in the OR or is it due to the programming of the OR?

[oper190]

If I am wrong, I stand corrected, but I do believe what you describe is proper for US based railroads.
Simple logic - a train enters a reduce speed zone, it must comply when entering the zone. Only after the last car has left that zone can speed be increased. - Say a train enters a reduced speed zone and when the engine reaches the next speed post for higher speed, the cars behind are still in the zone that required lower speed, and with a long train the last cars might not yet have entered the low speed zone. There's a reason for the low speed, whatever it may be, so all cars must comply while in the zone.

[R. Steele]

For a specific case that fits within the general rule posted by "oper190" -- Paul Charland's answer ( given to the same question at ET ) is particularly appropriate:

Let's say that you are coming up on a sharp curve. There is a speed reduction and the front of the train needs to slow down before hitting the curve. At the end of the curve the speed gets increased back to the normal track speed. The higher speed applies after the rear of the train passes it, if the speed were to increase when the front of the train passed the higher speed limit, all the cars behind the engine would still be in the curve and be in danger of derailing.
Paul :-)

Apologies to Paul for cribbing his answer.

Now my question is....Is this rule different in other regions --- India? Europe? South America? --- and so forth?

[213 001-1]

That sounds logical at first, but how is the driver supposed to know when the end of the train has passed the signal that allows a higher speed? He cannot see the end of the train from the driver's cab and in the original there is no track monitor like OR. So if you want to drive without a track monitor, you will always run the risk of having to experience an emergency stop.

In Germany you can accelerate immediately after the front of the train has passed the signal that allows a higher speed. Even if the train is quite long, although it should be noted that in Germany trains can have a maximum length of 700m (765yd).

[derekmorton]

Trains in America can be 2KM or more in length, German trains much shorter.
Driver has a distance counter in the cab to calculate the end of the train.
American drivers always know the tonnage and length of their train

[R. Steele]

Driver has a distance counter in the cab to calculate the end of the train.

That's what I use the counter for in OR.

[PerryPlatypus]

Seems there is some misunderstanding here. In the real world, on lines that use "route signaling", the moment a signal upgrades to a less restrictive indication, the speed can increase - even before the *front* of the train has reached the signal. In that case, you can't compare it to standard speed restrictions, which are usually a limitation of the track geometry.

Think of this example:
A train is on a long, flat tangent track and passes an approach indication at the start of a siding, which by a particular railroad's rules enforces a 35 MPH maximum speed (and tells the crew to expect a stop indication at the next signal). The next signal is already visible over a mile ahead with a red aspect / stop indication, and all of a sudden the signal ahead at the far end of the siding turns green, indicating a full proceed indication (likely a train has just cleared into the siding). In the real world, the train can now accelerate all the way to full track speed (if they have enough horsepower / favorable grade to do so), whether that's 60 MPH or something higher - even before the front of the train has passed the signal ahead.

What complicates matters is that some railroads use "speed signaling" where the indications have a track geometry-related speed limit aspect which is really a helpful reminder to the engineer about a restricted track speed through a turnout, for example. Technically speaking, a route builder should enforce a speed limit through turnouts or crossovers rather than relying on the signal script speeds, but I'm sure many route builders rely entirely on the speeds set by signals to do this. In the case of "speed signaling", the speed limit for a train doesn't rise until the *rear* of the train has cleared the signal (or really, whatever track geometry the signal was advising about, i.e. a turnout or interlocking). So I'm not sure we can easily arrive at a universal solution, since route builders have likely not been at all consistent on this.

[R. Steele]

Seems there is some misunderstanding here

Are you ignoring the reduced speed for a curve? That sure seemed logical to me. Waiting until all the train cleared the curve before increasing speed.

[PerryPlatypus]

Are you ignoring the reduced speed for a curve? That sure seemed logical to me. Waiting until all the train cleared the curve before increasing speed.

OP only mentioned *signals* which I am taking to mean signal-enforced speed restrictions, not regular trackside sign type speed restrictions (which are independent of signal indications).

For "regular" speed restrictions, we are in agreement, Gerry

[R. Steele]

OP only mentioned *signals* which I am taking to mean signal-enforced speed restrictions,

&

Seems there is some misunderstanding here.

Yes!! the misunderstanding was mine, as one who prides himself on reading posts, I flubbed that one --- big time. All Clear now. Thanks.

[213 001-1]

There are no such distance monitors here.

On the railways in Germany, there are speed signs, among other things, that show the maximum speed permitted from the signal.

Here is a screenshot from the signal book that is valid in Germany. This is specifically about the paragraph below the signal shown. I have translated this text into English.

Original text:
Die gezeigte Kennziffer bedeutet, dass der 10-fache Wert in km/h als Fahrgeschwindigkeit vom Signal »Lf 7« ab zugelassen ist.

Translation:
The code number shown means that 10 times the value in km/h is permitted as the driving speed from the signal »Lf 7«.


Signal Lf7.jpg

[l.k.]

Higher speeds always apply from the rear of the train. That's the case in Germany as well (and most of Europe as far as I know): The driver must know the length of his/her train and is only allowed to start accelerating when the end of the train has passed the signal (or speed sign). The behaviour of Open Rails is correct (and MSTS was wrong). There are some special cases where a train is allowed to accelerate earlier (e. g. speed limits for level crossings only apply until the front of the train has passed the crossing, and in some cases it's allowed to start accelerating earlier when leaving a station). But those few cases are not really worth modeling in my opinion. Open Rails handles most speed limits correctly.

Modern german (=european) locomotives have distance monitors as well (eg. Siemens Taurus, Vectron, Bombardier Traxx etc.). But the traditional (for over 100 years) method of knowing where the end of your train is, is to look at the so called "Hektometertafeln" (hectometer boards): German railway lines have signs every 200 meters showing the milage (or better kilometrage if that's a word...) of the line. These boards enable the driver to always exactly know where the rear of his/her train is in relation to any signals, speed signs etc. (when driving trains you are constantly doing maths, adding the length of your train to the position of signals, speed signs etc.). Sadly most commercial german add-ons for MSTS do not model the hectometer boards correctly. In ProTrain add-ons for example there are hectometer boards only every kilometer, making them mostly useless for their intended purpose (knowing exactly where your train and it's rear are on any given stretch of railway).

Hope that's all comprehensible - I'm a bit out of training with my English...

[motormaster532]

Higher speeds always apply from the rear of the train. That's the case in Germany as well (and most of Europe as far as I know): The driver must know the length of his/her train and is only allowed to start accelerating when the end of the train has passed the signal (or speed sign). The behaviour of Open Rails is correct (and MSTS was wrong). There are some special cases where a train is allowed to accelerate earlier (e. g. speed limits for level crossings only apply until the front of the train has passed the crossing, and in some cases it's allowed to start accelerating earlier when leaving a station). But those few cases are not really worth modeling in my opinion. Open Rails handles most speed limits correctly.

Modern german (=european) locomotives have distance monitors as well (eg. Siemens Taurus, Vectron, Bombardier Traxx etc.). But the traditional (for over 100 years) method of knowing where the end of your train is, is to look at the so called "Hektometertafeln" (hectometer boards): German railway lines have signs every 200 meters showing the milage (or better kilometrage if that's a word...) of the line. These boards enable the driver to always exactly know where the rear of his/her train is in relation to any signals, speed signs etc. (when driving trains you are constantly doing maths, adding the length of your train to the position of signals, speed signs etc.). Sadly most commercial german add-ons for MSTS do not model the hectometer boards correctly. In ProTrain add-ons for example there are hectometer boards only every kilometer, making them mostly useless for their intended purpose (knowing exactly where your train and it's rear are on any given stretch of railway).

Hope that's all comprehensible - I'm a bit out of training with my English...

If you think that you are out of training with your English,then I would love to see you when you think that you are "back in training". You are more comprehensible than 95 percent of Native speakers!! All the Best! Brian

[CSRX]

Speed signals were always fun... Looking at you NORAC book.....

I think Sean pretty well has it covered on the proper explanation here.

However, let's throw some confusion in this some more.
Canadians under CROR, call trackside signs "signals". Which is bizarre to me, and most of the time, I ignore it and call a sign a sign and a signal a signal even though we no longer run on signal territory. So in a sense, I get the confusion when it came to the OP's post on signal versus sign. Or maybe I'm just looking too much into the differences of rules with CROR, GCOR, and NORAC. Shrugs.

[eric]

Here's what I wrote at Elvas earlier today....

Even without technology, the crew needs to know the length of their train with regard to sidings and speed restrictions.

If you don't have a counter, you would count line poles, landmarks or intermediate milepost markers, or ultimately the next milepost greater than your length.

Or break out your watch. At a constant speed, you can easily calculate the number of seconds or minutes it will take for your rear end to clear the restriction. Those math test questions many of us grew up with came from actual use and practices.