Monk Subdivision: Lazy Signals for Dumb People

I wanted signals on the Monk Subdivision because they always appears on 1960s and 1970s pictures, but the truth is that adding the detectors to get a true railway logic according to Canadian standards is both a costly endeavour and a descent into madness. If you aren’t an electronic wiz, a programming enthusiast or haven’t that level of very specific autistic obsession with such intricate intellectual challenges, let’s just say it’s not for you.

Add to that the Monk Subdivision slice I depict is just one station, so not enough place to really implement full signalling over many blocks. It wouldn’t add that much of a layer of entertainment. Thus, I thought I should just wire the signals to be coupled with turnout positions. Simple, vaguely prototypical, and at least useful when operating trains because you get an obvious visual indication about what’s going on with the siding.

My approach to my dumb signals is to wire them all on a tortoise switch machine. They have two built-in switches, one will control the turnout frog polarity and the other one the signals. And here is the catch. I need to wire up to 4 signals to that single switch. Sounds crazy, but it is in fact relatively simple and very different to how I wired some on my stuff on the late Vince Valley layout (now demolished to provide free building materials to finish Monk.

I've read a little bit about Canadian signals and decided to replicate a few of their aspects that suits my needs the best. My objective are simple, I won't model occupation but route. It means that a diverging turnout or one aligned on the main line will change aspects. Not prototypical, but not completely nonsense either. As long as signals help you understand where you are moving, I'm fine. Anyway, Monk still used some TT & TO with their signals, and it wasn't a full CTC or ABS system. Just some hybrid thing to automate sidings a little bit.

Dumb signals schematics

Let's say a train is travelling from West to East (Staging to Armagh), if the route is aligned on the mainline, the restricted signal 2 will show green on red meaning to go full speed ahead and continue on the mainline... At the turnout, the signal will also show green on red. In the opposite direction, signal 4 will be also green on red. If occupation and direction of travel was taken into account, it wouldn't be necessary the case. Dwarf signal 5 is red since any train in that siding should wait the turnout is properly aligned to proceed.

Let's say we move in the same direction, but the turnout is set on the diverging route to take the siding. The staggered signal 2 show us red on yellow, meaning the main line is not accessible, but the siding is. Since yellow means to slow down the speed since we take the diverging route, we also get, in advance, an indication of things to come and to start reducing speed. Signal 3 is also red on yellow for the same logical reasons. Signal 4 is red on red because a train on the mainline can't move and must stop there.

If you travel from East to West, things are rather simple. Signals 4 and 5 will display green or red depending if the turnout is properly aligned with your respective track. Signal one is the less prototypical, but it serves a purpose of telling you if you are continuing on the mainline at full speed or if you are entering the staging area an must slow down. Occupancy will probably be done through optic sensors and a track diagram with LEDs... or simply a small camera in the staging room with a screen in the layout room.

I won't stress enough my system is dumb and really simple to implement. Better, it animates the signals, giving them an realistic aesthetic while providing useful information for an operator. Most derailments on model railroads are caused by misaligned turnouts. Looking at LEDs on a fascia isn't always practical, intuitive or interesting because it breaks the suspension of disbelief. Having the signals giving you that precious information is both more realistic, but also visually compelling to the point the route ahead is clear to understand at a glance. As long as the signals have a "real" purpose, they are "prototypical" in my eyes. I can understand if purists will be horrified at these shortcuts, but they make it possible to have working signals on a realistic budget and with bulletproof logic to it. It's simple and at the level I can do myself with some wire, a DPDT and my trusty soldering iron.

Also, it must be noted that with a DPDT on each specific signals, it could be possible to give them a different aspect, but that would need some little thinkering.