This is probably slightly oddball but here goes: Would a prototype railroad have crossing "sensors" placed in different positions in a multiple track situations if said tracks have different priorities? e.g. triple track where two are yard tracks (one east, one west) vs the mainline track. Where I'm running into the problem is an eastbound train into the yard would clear the crossing but wouldn't clear the eastmost "sensor" on its track and a westbound waiting to depart would block the eastmost "sensor" on its track but not block the crossing. As usual any assistance that can be provided would be most welcomed.
I have sometimes witnessed crews on a slow moving train or a yard job that might trip the gates but the engine is not going to occupy the crossing. One of the crew would walk ahead and manually disable the circuit with a switch key.
Some circuitry can detect the speed of the approaching train and determine what delay to use to start the flashers. I use the LogicRail setup which determines train direction and stops the flashers when the last car clears the sensor (IR or PC) closest to the roadway. It is a very prototypical system.
Why not use a toggle switch to manually overide the automatic circuit for those times when a slow moving train is entering the yard?
Some discussion of the LogicRail system regarding complex trackage is here:
https://www.logicrailtech.com/gcp_appnote_complex_crossings.pdf
Even if you are not using the GCP you might get some ideas from the examples.
Good Luck, Ed
I also use LogicRail controllers and I second Ed’s post.Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
I'm setting up a Circuitron crossing crossing system. Sounds like what I should do is set the end sensors a bit closer than one would for a standard mainline crossing.
Mainline tracks have the crossing detection circuits (but we can call it a "sensor" for now - real railroads use electrical circuits in the track; if you're using optical or I/R sensors on a model, these would be located at the boundaries of the equivalent track circuits) out far enough that a train at speed trips the signals with enough time to safely cross the road.
It is certainly plausible that a parallel yard track or siding would have a shorter approach circuit * - perhaps one where the train would have to stop short of the crossing and then proceed once the protection is activated and traffic stopped. (i.e. no "approach" circuits at all, just the crossing circuit) Add little STOP signs ** before the crossing and cover this procedure in your "special instructions" or timetable footnotes to stop before crossing or "not exceed (x) MPH over (street name) crossing on yard lead" if you actually publish written documentation for operators.
*If you watch a train cross a grade crossing (on a main track) you'll note the signals start well in advance of them crossing, and then stop almost immediately once they're clear, not keep going until they clear half a mile down. There's usually 3 circuits - an approach on either side and the crossing itself. Thus the system can detect direction and terminate the signals once the train is out of the crossing. However for minor industrial spurs crossing roads that have signal protection because the road traffic is busy enough, there's usually no approach. The train stops short of the crossing to trigger the protection (and a crew member may or may not also manually protect the crossing) and the train crosses at slow speed.
**Additional detail note - often the RR may also have small little "Circuit End" signs showing the limit of the crossing circuit or other track block.
Chris van der Heide
My Algoma Central Railway Modeling Blog
I've seen the industrial crossing idea as we have a company that repairs cars that uses the old Milwaukee yard here in town. They turn the lights on if their engine needs to cross either of the two streets that their tracks cross.
I have the crossing set up where one set of lights will cover all three tracks. Mentioning the lights turning off when the train passes will probably prompt me to change the location of a sensor or two as the travel on the yard tracks is in one direction. (One west one east)