06-02-2012, 02:44 PM
In general, you have to look for some kind of electric power for any sort of lighted signal, whether a block/CTC signal or a crossing flasher or wigwag. In some cases the battery is just backup, but in other cases, it's all the power that's available. Same for relays, and exactly where they go will vary, but on older style crossings the Details West two-door relay case is very, very common, as well as the large-style battery box. Some more recent installations just rely on commercial power. Here's a CTC relay case on BNSF that has a commercial electric meter:
And here's a newer-style relay case for a highway crossing (Napa Valley RR), and you can also see the electric meter for commercial power. The meter might actually be a good touch on a more modern installation, and I think you could justify both types on your layout. The newer cases are very similar to BLMA.
