[Serana]

 Csantucci, on 20 September 2015 - 07:23 AM, said:

Hi Serana,
some thoughts about your proposal, which surely touches a quite important point:
1) I wonder why explorer mode works in a more restrictive way than activity mode; one would expect the opposite or that they behave the same on this point;
2) What happens in reality (probably every railway system has its own rules) and how can this be emulated best without unnecessarily complicating things?
3) I would prefer linking such distance to route speed than to train speed; I think it could be a bit more prototypical;
4) As far as I am concerned, if an approach depending to train speed or route speed is chosen, I would prefer to go not only above 5000 meters, but also below 5000 meters; 5 Km can be too much for not too fast routes; I had already at least two cases where a train could not enter a route because there was another one almost 5000 meters behind, even if in reality the former would have entered the route.

Hi,

1) Don't know either. I think the SNCA value could have been used in explorer mode.
2) In France, in the modern signal box, the switch-man has a system called MISTRAL that allows him to command and control the interlocking, to monitor the trains and to protect the engineering work areas.
With the train monitoring functionality, he knows when the train is supposed to arrive, even if the train is delayed. He can set the route in advance or let the system set it automatically (with a plan he programmed the day before). The route is set several minutes before the arrival of the train.
For the simulator, I think both the SignalNumClearAhead and the distance are good solutions. Maybe the SNCA solution is a bit better because it uses data coming from the route itself. But if the value is wrong, too many or not enough signals will be opened.
3) I agree with you. When I talked about speed, I didn't precise if it was the current speed or the allowed speed. I was thinking about using the allowed speed.
4) The problem is that this minimum value depends on the type of route : fora tramway, the value will be low (maybe 500 metres) whereas, on main lines, this value should be at least 3000 metres even in low speed zones.

 vince, on 21 September 2015 - 09:39 AM, said:

Hello Serana,
If you look at the photo of the Single Heads SNCA chart I posted and assume that I use a SignalNumClearAhead value.of 6.
Now also assume the signals are all spaced at about 1500 to 1600 meters ( about a 1 mile) apart.
This will give a train traveling at 230 Km/Hr about 8 Km to stop from first encountering the first restrictive signal (Clear2 Flashing Green) before encountering the Red signal.
Is this not enough distance to have the train to slow to a stop in time? Or, if not, longer distance signal spacing would be the way. Maybe?

In France, on high speed lines, we use a system called TVM430. When the train has to stop at a signal box, there is a sequence of speed limitation : 320 kph (green) > 320 kph (green blinking = the next indication will be lower) > 300 kph (white diamond blinking = announcement) > 270 kph > 230 kph > 170 kph > 80 kph > 0 kph (red diamond = stop at the next marker). That means that the train has to stop on 7 block sections. On HSL East, the track sections are longer than those of the HSL North (1500 meters, 300 kph) due to the less important traffic. The track sections length is about 2500 meters. The train has to stop on 17,5 km (FYI, a TGV can stop on about 3,3 km from 300 kph in emergency braking :) ).
That means that, in Open Rails, the signal opening distance that has to be put in the code is at least 17,5 km for this high speed line. Of course, this is not adapted to other lines such as tramways.
The guy who modelled the TVM430 on MSTS has set a SignalNumClearAhead value of 15. That's too much. I would have set the value to 8 or 9.

[vince]

 Serana, on 21 September 2015 - 04:41 PM, said:

Hi,
1) Don't know either. I think the SNCA value could have been used in explorer mode.
2) In France, in the modern signal box, the switch-man has a system called MISTRAL that allows him to command and control the interlocking, to monitor the trains and to protect the engineering work areas.
With the train monitoring functionality, he knows when the train is supposed to arrive, even if the train is delayed. He can set the route in advance or let the system set it automatically (with a plan he programmed the day before). The route is set several minutes before the arrival of the train.
For the simulator, I think both the SignalNumClearAhead and the distance are good solutions. Maybe the SNCA solution is a bit better because it uses data coming from the route itself. But if the value is wrong, too many or not enough signals will be opened.
3) I agree with you. When I talked about speed, I didn't precise if it was the current speed or the allowed speed. I was thinking about using the allowed speed.
4) The problem is that this minimum value depends on the type of route : fora tramway, the value will be low (maybe 500 metres) whereas, on main lines, this value should be at least 3000 metres even in low speed zones.


In France, on high speed lines, we use a system called TVM430. When the train has to stop at a signal box, there is a sequence of speed limitation : 320 kph (green) > 320 kph (green blinking = the next indication will be lower) > 300 kph (white diamond blinking = announcement) > 270 kph > 230 kph > 170 kph > 80 kph > 0 kph (red diamond = stop at the next marker). That means that the train has to stop on 7 block sections. On HSL East, the track sections are longer than those of the HSL North (1500 meters, 300 kph) due to the less important traffic. The track sections length is about 2500 meters. The train has to stop on 17,5 km (FYI, a TGV can stop on about 3,3 km from 300 kph in emergency braking :) ).
That means that, in Open Rails, the signal opening distance that has to be put in the code is at least 17,5 km for this high speed line. Of course, this is not adapted to other lines such as tramways.
The guy who modelled the TVM430 on MSTS has set a SignalNumClearAhead value of 15. That's too much. I would have set the value to 8 or 9.

1. The SNCA does function in Explore mode in MSTS. I have not tried it in OR. The SNCA value was grossly wrong on some routes. Why? My guess it was early in the learning curve. Folks were writing scripts without really understanding how the system worked.

2. On this side of the pond they call that an Interlocking, Interlocking Plant, Control Point. Different RR's, different terminologies.
Most today are controlled from a central dispatcher and guarded by Absolute Signals, signals that cannot be passed except with special train orders.
Back in the day these interlockings were controlled by a local trackside tower, the signal box you mentioned. Early ones were manually operated, levers, the Armstrong kind. In 1976 in one of the photos in my LIRR Build Album there is the Nassau Tower ( filename identifies) which I believe had a 22 lever manual machine. It was in operation until 1986. Tower is now Electro Pneumatic. These interlockings were operated exactly as you describe.
Aside:
A while back there was a demo program released called MG Tower Demo (for Mid-Grade) in which you operate the interlocking machine for the MG Tower on the Pennsylvania Horse Curve grade. IDK if it's still available but I recommend it. The sound in the demo is top notch with the moan of the dynamics on a heavy down run are something to hear as is the notch 8 power going by on the upgrade.

3. Here, signal speed is absolute and over rides the Maximum Allowable Speed (MAS), sometimes referred to as 'Track Speed'

4. Well that distance must allow the train to slow to the next signal without passenger discomfort. . . .As in the example in the default NEC USA1 route . . .Ha! Less than 400 meters to slow from 70 to 30.
Re TVM430: There's the rub . . . Presently only 6 aspects (see chart) TVM430 would probably need at least 8 aspects. Make that a nice digital 16. Room for expansion, right?
I would think that additions to signal functions are cooking some already done?

So lets assume I'm running 320 kph and I encounter a Flashing Green which says that possibly there is a red stop 7 signals ahead of my train so 'knowing' the very next after Flashing Green will likely be a White Diamond blinking. And so on slower and slower until the red.
So I gotta ask, 'How much distance will the train cover from Flashing Green to the next lower speed restriction?'
THAT distance is the distance that must be between signals. Oops, didn't you already say that.
Hey I'm a computer hardware engineer not a mathematician.:pleasantry:
I'm gonna' grab a cuppa coffee and get back to pounding spikes.
regards,
vince

[Serana]

Just to show you what the driver see when the TVM430 is active, here are some videos that were taken on the korean high speed network.

TVM430 Stop Sequence

Please note that the sequence is different than the one in France. In France, the 130 kph indication is only used when the line speed limit is 200 kph. When the speed limit is 300 kph or 320 kph, we get the 80 kph instead.

TVM430 Slow Down Sequence

This sequence is shown when you have to run on a switch that is limited to 230 kph in reversed position.
As you can see, in the latest version of the TVM430 display, the diamonds have been replaced by squares. The TVM430 indications are shown on the same screen as the ETCS and they are calculated in the same on-board unit as the ETCS. That's what we call the bi-standard on-board system.

[vince]

Hi,
Thanks for the cab vids Serana. Picture worth a thousand words.
The TVM430 looks to me like a cab signal display on steroids where it is actually computing the distances required for safe operation. I didn't see any wayside signals but are they even used? The Long Island RR has been eliminating block signaling with waysides at Interlockings. US railroads assign a speed limit to each signal aspect. Those limits and with proper signal separation distance makes do here . . . most of the time

In the US the NTSB & the FRA are (rightfully) pushing for Positive Train Control (PTC) which if I guess will probably something similar.Getting a lot of flak from the RR bosses for the cost. But how much cost can you assign to a human life? Always never the $'s to do good work while paying CEO's millions of $'s a year.

I find it obscene how they can sit in their Ivory Towers and not install 4 quadrant crossing gates at grade crossings along with PTC. The US is horribly deficient in passenger operation or rather Lack of passenger operation! Forty years ago I spent two years traveling via train England, France and Germany. Even then, almost half a CENTURY ago, the system there far surpassed what we ar stuck with here today. . . . Oz can sure claim some big freight ops but we have some really great freight mountain railroading.
Here I insert a link to a Railroad Instruction video of the Saluda Mountain Grade:
How to get 11,000 tons of coal down the mountain without killing yourself. +===> https://www.youtube....h?v=9IABM8UPplY

Looking at the European systems, I've been watching some of those Engineer View videos of passenger operations in Norway and was blown away by such a slick neat operation.
One especially good one I watched over a period of several days ( it's a 3.4 HOUR video! ) was this run from Oslo to Ål
beginning with running the engine into the coach yards to couple up to the train, switch cabs and then the delightful run to Ål.
Great HD video! https://www.youtube....h?v=7o7ecadHJmU

Lots of tunnels departing Oslo but then who did you think invented the **TBM? The Norwegians! according to an episode of the How It's Made Science Channel programming.
Of course!! So THATS how the Nords overcame the Not in My Backyard protesters; Tunnel under them and build a REALLY slick rail network! Looks like it workes. Also I notice a distinct lack of rail right of way trash. I'm embarrassed the way some of our row's are maintained or is it just the folks living alongside being slobs. I sure don't know.

Back to signals and such:
I guess we'll have to wait for oncoming developments in the Signal Department. . . . which is why I'm so excited about ORTS.
A bunch of folks who love trains and are ALWAYS interested in development and some with the talent to make it happen. You'll NEVER get that in ANY corporate developed commercial Sim.
I think 'they' are running scared when thinking about what ORTS is becoming.
**Tunnel Boring Machine

Back to pounding spikes to Oyster Bay,
vince