Readers: The signals and signal systems that I will be reviewing and installing in my Layout How To series were provided at no cost by Azatrax LLC. However the selection, installation, operation, and opinion of these signals and systems are 100% my own.
Our example train the R-GEPB-29 (Road Switcher Gerhard to Port Belle of September 29th) led by MCIS 3833 has be issued track authority by St. Clair Sub dispatcher to proceed from mainline DTC Block Lacey (LACE) to DTC Block Upper Huron Jct (UJCT) via Upper Huron East Wye Switch (EWS).
Upon reaching the signals / block boundary at east wye switch Upper Huron, the train comes to a stop and the conductor climbs down to change the route.
Reaching the signal mast, the conductor opens the control box and pushes the button "Press to Occupy".
The operator throws the Peco switch from normal to reverse to the east leg of the wye at Upper Huron.
The operator acting as the conductor in reality pushes the "Press to Occupy" on the panel. This action shunts the signal from a "clear" to "stop" indication.
With signal indicating the east switch at Upper Huron block is now lined reverse and authority given by dispatcher to occupy the UJCT DTC block, R-GEPB-29 proceeds onto the east leg.
Train departs past the signals and operates onto the east leg of the wye which ties directly into the Port Belle Sub.
Once the train is in the clear onto the Port Belle Sub the conductor uses the north end control box where the east / west wye legs come together to line the switch back to normal and clear the signal.
With the train on the Port Belle Sub our TS2 system does not know this as it expects to either see the train reverse over the sensors at the east switch or continue over the sensors at the west switch. Since we are doing neither, we hold down the "Press to Reset" button which clears the block back to green.
At this point once the operator has verified signals display "clear"and switch is re-lined the R-GEPB-29 continues on its journey. The abs signals at the East Wye Switch stand ready for their next use.
The same process happens coming from non signal territory to signal detected territory with the exception that instead of pushing "Press to Reset" after lining the switch back to normal, the operator would simply push "Press to Occupy" again. This has to do with the train coming onto signal'd territory so the system knows there is a train occupying an actual block in signal territory versus our example above where the train left the signaled territory requiring us to manually clear the block.
This is a very simple example of using the interlocker ability, one example to automate further would be having the "Push to Occupy" button drive a tortoise motor which act as the SPST Off-On driving the TS2 to change the signal. There are plenty of other examples of ways to use this function such as a drawbridge. Take a look at the Azatrax Block Signal page for more ideas.
The best part of our hobby is the ability to make things as simple or complex as you would like based on your skills. For my setup a simple push button and using my finger to throw the switch was sufficient, and requires operators to engage "beyond the throttle and fascia".
Stay tuned in October for the last few posts of my signal install series. In these upcoming posts we will dive more into Advanced Interlocking using TS2 circuits on a passing siding, and then wrap up with a discussion on how a train would operate in DTC/ABS territory.