Hey, OP!
What did you think of our responses? Did they help?
Ed
My version:
For a SINGLE crossover, there should be a two-head signal at the point end of each switch. The other two can be single head. Four total. Since this is a model railroad, I assume the tracks are bi-directional. If they were single opposing directions, I think they would still have the same signal layout, because a train COULD physically enter the "wrong way" by order of the dispatcher.
This is true whether or not there are any other signals "out there".
The crossover, IF SIGNALED, is an interlocking. There are four tracks into the interlocking. Each track will have a signal. The signal(s) at the point end of the track indicates the condition of the main track (upper) and the condition of the diverging track (lower). Thus, two heads. The other location can get a single head because there is only one choice of route through the interlocking.
Since this is an interlocking, the switches would be either controlled from a tower via mechanical linkage or electically, or via CTC, and be electic only. The switches would be thrown together (as Randy says), because there is NEVER a reason for differing positions.
The signal display (from each end, as it is symmetrical):
Switches set for mainline: two head--green over red, one head--green
Switches set for crossover: two head--red over yellow, one head--red
For wiring the above, my second (deleted the first) is to use two of the snap-relays. I expect wiring logic would be a slice of cake. If the OP goes this route, I'd be happy to do "personal advising" on the matter.
You answered it yourself. With no distant signals, each track would only need ONE head. Not two. Unless he just want to make up some random aspects to change both heads where it wouldn;t really happen, or just light a color on the upper head permanently. Otherwise, only 1 head per track.
And he says a PAIR of Atlas turnouts - so it's only a single crossover, not a double. So even if the main is bi-directional, on one track you either have a clear route through, or are approaching a turnout with the points lined against you. Green or red. On the other main, you either are going straight, or are crossing over. There's zero reason to oeprate the two turnouts independently, so you have green for straight or yellow for crossing. Repeat for the opposite side.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
rrinker Unless you have other signals down the line and can tie into them, there's no need for 2 heads in each direction at the crossover, ....
Not sure I understand that. Assuming the OP has two parallel tracks going (say: East to West) and both tracks are bidirectional, each track will need one head on either side of the cross over. That’s four heads.
Assuming the signals are turnout position indicators only, one snap relay will suffice.
At crossover closed: all green
At crossover thrown: tracks leading to crossover Yellow. Others Red.
Now if he didn’t have a yellow aspect, then he would only need two heads to stop movement into the plant against a switch alignment.
NP
Here's a couple pic's of the Atlas Snap Relay instructions so You can see how they work. I use them on My own layout to power the frogs and signals. I Do Not use any other Atlas controls.other than under-table machines. I use normally open push-buttons instead on a control panel. I got My relays back when they were 7.50 apiece though...early 80's....have not had a bit of trouble with them since. I only use one 2-color signal for each direction on a double track mainline. I use two relays for that even though they are both thrown at the same time simply because of the powered frogs. I have eight crossovers......the good part is.....there is no need for passing sidings on a double track mainline.
You may click on them for a larger view:
Take Care!
Frank
Unless you have other signals down the line and can tie into them, there's no need for 2 heads in each direction at the crossover, only one head will ever change, unless you just want to randomly make up an aspect not part of the standards.
With no other distant signals to interact, on the point side of each turnout, you would have the signal show green if the points are lines for straight, not crossing over. Yellow if crossing over and both sets of points are lines, red if one is lines for crossing over and the one on the other track is not. This will require more than just 2 snap relays to get all working. For the signal on the frog side of each turnout, it's only going to show either green when the points are lined straight, or red when the points are lines to cross over. That's easy enough to do with one contact set on the snap relays.
Hi guys
I'm going to install 2 pairs of signals to govern my crossover, two in each direction, can anyone post a diagram of a signal crossover system, on your railroad? mine is going to be with two Atlas turnouts, and operated DC by a Atlas snap relay,
And, thanks guys n gals, and have a SAFE and happy holiday season,,