Railroad Forums 

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  • General discussion of computer gaming and railroad simulations. Topics include MS Train Simulator (MSTS), Auran Trainz, Railroad Tycoon, Railroad Dispatcher and more...
General discussion of computer gaming and railroad simulations. Topics include MS Train Simulator (MSTS), Auran Trainz, Railroad Tycoon, Railroad Dispatcher and more...

Moderators: LIRRMEDFORD, 8th Notch

 #1420688  by TheDefiantPirate
 
Hi all Names Kirt and i joined to farther my knowledge of how railroads work and so my first question is on line speed limits

see for a while i was playing Train SImulator 20XX(insert whichever year is in place of XX and the way Speed limits worked in the game or at least for changes in speed limit was that when the speed limit was increasing it only came into effect once the last car of the train passed the sign while if it was Decreasing it took effect the moment the nose of the locomotive past the sign Is this how it works in real life and if so Why?
 #1420736  by LIRRMEDFORD
 
Welcome to the forums! While this is how speed limits are enforced in train simulator that is not the case IRL. Here in America while all Railroads must adhere to speed rules and restrictions put in place by the FRA, they have their own rules and restrictions for the rest of their territories. Train Simulator has a New York-New Haven Route which runs the MTA Metro North Line and uses the train simulator speed limit. While a different game World Of Subways 4 uses the MTA Subway 7 Line. In that game you have to decelerate before you reach the sign but can accelerate as soon as the front of the cab has passed the sign. Every game is different, every railroad is different!
 #1420765  by NaugyRR
 
I know with NORAC rules, with the temporary speeds anyways, you're not to increase speed until the train has cleared the sign. I think it's Rule 296?

Train Simulator's pretty strict with their speed regulation, where in real life, different railroads have different rules as far as how many MPH over is considered overspeed. Many railroads use an advanced warning board to let crews know of an impending restriction (usually a V-shaped sign with the upcoming speed), and railroads that use cab signalling have the advantage of a heads up there.

Of course in the real world, train crews are conditioned to know every inch of their territory, where as you and I are thrown into a virtual cab somewhere we may have never even heard of before, and expected to perform as if we've run that line our whole lives. That's where the HUD comes in handy, haha.
 #1422750  by JayBee
 
There are two different types of reduced speed limits, temporary speed limits(normally caused by track problems) and permanent speed restrictions(for curves, switches, bridges, and some other reasons). In either case the speed limit sign will be put at the point where the speed needs to be at the lower speed. If the sign is for a sharper curve then if you are traveling faster you could go flying off the track, on a bridge it likely will increase vibrations possibly damaging the bridge or causing it to collapse. As to why when you pass the end of a speed limit, while the locomotive is now outside the speed limited area, the rest of the train is not. The whole train will start accelerating very quickly, with the trailing cars going faster than they should. Remember that the opposite side of the end of speed limit sign is also the sign that says the beginning of speed limit for trains moving in the opposite direction. Speed limits do not apply just to locomotives, they apply to the whole train.
 #1423275  by rovetherr
 
MERailFanJay wrote:How do they know when the last car has passed a speed limit increase sign in the real world with a mile long consist?
There are several methods. One is to go off of mile posts. So if your train is one mile long, and the slow order runs from MP 58.1 to MP 59.3, the engineer would go past the resume speed flag at 59.3, pass MP 60, and then continue on at the reduced speed until he passed MP 61 to ensure the rear of the train had passed the resume speed flag. This method can lead to running slower than you need to for longer than you need to, but is a safe method if there is no counter or working EOT. However, if the lead unit is equipped with some sort of footage counter(most EOT boxes have them, as do most of the digital speedometers I have seen), and the footage of the train is known, then the engineer runs the footage of the train after passing the resume speed flag, and can then resume speed. Equally safe if done properly, and can allow the train to resume speed sooner.