Reworking Block Detection for Signals

The Richmond Terminal is a signaled railroad. The end goal is to have a functional CTC system in place like version 1 did. Version 1 used a virtual CTC panel based on the Union Switch and Signal components inside JMRI.

As we are still working on the operating scheme, I decided that an Automatic Block System (ABS) would make the most sense to implement at the start and once the operating scheme was solidified, I would pivot to setting up the CTC system.

ABS is currently running based on the LogixNG inside JMRI. As I have worked through the configuration, I realized that when I connected the track blocks, I erred.

The Richmond Terminal is a 2 track mainline railroad, which means there are crossover from one track to another. These crossovers are frequent. The railroad is just shy of 10 scale miles; there are 14 crossovers total.

I setup 1 detection section per crossover. This meant a couple of things - detection of the crossover section would prevent a dispatcher from throwing one under a train, but the detection state would not help me drop to red until a train moved through the crossover and hit the next block, and I could not test the crossover occupancy to set a signal aspect, either. 

Consider this example - a train is southbound on track 3, approaching a crossover. On track 2, a northbound train is moving through a crossover section, on a straight route. The crossover shows occupied, which is true for track 2, but NOT track 3.

This meant that I needed to go back and break apart the detection for each crossover and connect my blocks so that each component turnout of the crossover was detected separately.

I took advantage of this and did some rationalization of my DCC bus as well.

That's wire I pulled out from a part of 1 peninsula...

Here is a shot where I shortened bus wire and soldered new ends on. Had to clamp up a piece of plywood to give myself a working surface.

More pictures are in the gallery at richmond-terminal.org