Distance between railroad signals

[enginewhistle]

Does anybody know how far apart railroad signals are placed? I want to get an accurate distance between signals and blocks on a route i'm currently working on.

 

[RRSignal]

It's based on safe braking distance for the type of train involved, factoring in speed, gradient, size of trains, etc. generally under wet or lousy conditions.

http://www.railway-technical.com/sigtxt2.shtml

This is more oriented towards passenger stuff but the same principles apply. Where blocks need to be shortened, a 3- or 4-block system is employed.

 

[cascaderailroad]

Alot of industrial and yard tracks are unsgnaled, and Invisible signals are great for those locations.

Usually there is a distant signal, much farther backwards on the track, that warns of the home signals aspect.

 

[ctclark1]

Are you trying to do a prototypical route (ie, one that exists in real life) and be fairly accurate with it? You may be able to find a track chart that shows signals, turnouts, and other information about the route. Based on your signature I'd assume its somewhere in the Northwest US, so presumably BNSF or UP... I'm not sure how much info is on the site for either of those roads (or sometimes its predecessor companies), but you can try http://www.multimodalways.org/archives/rrs/rrs.html and see if its under any of the companies involved (You're better off looking under the individual "Carrier" section rather than the first Maps link on the page...) Like I said not sure how much detail they have for BNSF/UP/ATSF/etc... I do know that there is a ton of info for Conrail, CSX, and NS in the northeast (Conrail "Track Charts" are immensely helpful for a lot of North East lines once you determine where the line was "divided" within Conrail's system, if anyone else is looking for assistance with prototyping.)

That being said, it is going to vary from railroad to railroad, but I can tell you that the old New York Central mainline through New York (Conrail called it the "Chicago Line", CSX has a variety of subdivisions within the "Albany" Division on it now) are roughly two miles apart, varying slightly depending on where the control points (ie, "interlockings" despite not being true interlockings anymore) are located. (ie, if there are two control points within two miles, there are no intermediates or "Autos" between them, if control points are, say, 3 miles apart, there may be an auto in between).

Depending on the era you're aiming for they may be closer together even (when NYC originally put up the signals through here they were only about a mile apart due to shorter/slower running trains)

 

[JohnnyC1]

Depending on the type of track and location, on a long I use a signal every 2 miles, as the track enters multiple junctions I shorten to 1 mile, and at the junctions themselves, they are signaled entering & leaving. The more traffic on the route the shorter the distance between signals. And you have to consider the behavior of AI.

John

 

[ctclark1]

Right, I did fail to mention that one of the things that can be done to attempt to get the AI to run at least a little more as expected (Nothing that I've found can make it foolproof but lots of things can help) is to place invisible signals in between the visible signals if trying to look prototypical.