Apologies for the long time since the last post, but I have been busy with work on the layout.
The main task lately has been to complete the wiring for the staging yards and to install all the components that will control and monitor trains in the staging yards.
From the beginning, one of the main reasons for me building the layout was to not only be able to run trains, but also to hopefully recreate a number of prototype scenes from books and magazines in model form for photography purposes. I have always had a fascination for the Liverpool Range area since I first started in the hobby in the late 80’s and got to chase trains in the area. The era I am modelling though is a about eight years prior to this, circa 1980. I always knew I wanted to run trains rather than shunting them around a yard, and since the three locations I am modelling are essentially only crossing loops, I needed a storage area for trains to be marshalled in.
Over time, the decision was made to select a number of trains from printed publications, in both UP and DOWN consists that I particularly liked and wanted to model. The plan is to have complete trains marshalled in the staging yards and using small touchscreens incorporated into the fascia at Ardglen, select a train and it’s required route out of the yard. The idea is to use the touchscreens as the ‘eyes’ of the staging yards and by using detectors, an operator should not have to physically look in the yard to see what is going on.
But first, a bit of background as to how the staging yards will work. Refer to the schematic below. Clicking the image below will open up a larger version in a new window.
- There are two separate yards, an UP yard and a DOWN yard, each containing nine roads.
- Each yard has the capacity to store eight complete trains, which will remain in fixed consists facing the appropriate direction.
- The ‘through’ road will never store a train. It is bi-directional.
- Yards will be controlled via RR-Cirkits equipment and interfaced to JMRI PanelPro running on a computer.
- Interlocking will be programmed within PanelPro.
- Train/route selection will be via a PanelPro schematic using the touchscreens.
- Power to each road will be via relays and selected via the touchscreens.
- Each road is a detection section. It is there to detect a train in the road. If a train is fouling the ‘clearance point’ of the road, ie either end of the train, this will be picked up by detection in the turnout yard ladders at each end which are separate detection sections. ‘End of train’ detection will be achieved with resistive (10k) wheelsets in the guards van. If a train has reached the limit of the road and therefore fouling the clearance point, it will show as a detection in the exit turnout yard ladder.
The above is only a brief description on how trains will operate on the layout. The plan is to make running trains as foolproof as possible and to incorporate safeworking and possible interlocking with the lever frames at Kankool and Pangela, ie only one train is allowed in a section at a time as per single line safeworking rules. I will expand more on this later when I come to program how the yards work.
Now to the hardware that runs it all.
When I was thinking on how I wanted to manage train operations, I started looking around on the internet for suitable hardware that would do the job.
I had known about JMRI and DecoderPro for programming DCC decoders, but I didn’t know much about another application within JMRI, called PanelPro. After some investigation, I decided that I could use PanelPro to control the yards. Now I just had to find the appropriate hardware to use.
I had originally planned to control the Cobalt motors using their own DCC accessory decoders, which would have been wired to the DCC bus and controlled via the throttle. This would have been OK, but I couldn’t see an easy way to also control the power to each road. I didn’t really want to build traditional control panels with switches or pushbuttons.
After some internet searching, I found a range of reasonably priced electronic control boards that would allow point motor control, train detection and yard power control, all via a Digitrax type interface to a computer. Check out RR-Cirkits.
Initially I wasn’t convinced about the Digitrax part of the system, because I’d had some exposure to Digitrax DCC many years ago when a mate bought a system to convert his then DC layout to DCC. At the time, DCC systems were in their infancy, and I really wasn’t a fan of the Digitrax stuff.
Having said that, upon further investigation, I discovered that the RR-Cirkits range of devices only used the Digitrax LocoNet® protocol and that JMRI handled it all easily. It wasn’t a Digitrax system as such.
My system comprises the following RR-Cirkits hardware which I purchased from BNM Hobbies in the US. The owner, James Koretsky has been very helpful. Thanks must also go out to Dick Bronson from RR-Cirkits for technical assistance and for allowing me to use images from his website.
The BOD-8 is a DCC block occupancy detector board that has inputs for eight blocks using remote current transformers (CT’s). Three of these boards were required.
These 100:1 toroid coils sense the track current on leads passing through the hole in the middle of the coil. They connect to the BOD-8 with twisted pair cable such as CAT-3 or CAT-5 network cable. Twenty four of these CT’s were required.
The SMD-8 is an eight output, optically isolated driver board for stall motor switch machines (eg Tortoises and Cobalts). Four of these boards were required.
This board (FOB-C) is designed to allow easy termination of the point motor wiring to a single SMD-8 board. It connects to the SMD-8 via ribbon cable. Four of these boards were required.
The power to each yard road is controlled via this relay board (RB-4). It contains four 10 amp single pole, single throw (SPST), optically isolated relays. Four of these boards were required.
The TC-64 Tower Controller is the ‘heart’ of the system. It is a 64 line (8 port) I/O controller designed to run on LocoNet based DCC systems. All the above boards connect to the unit via 10 way flat ribbon cable. I required two of these units as I had eleven boards that required connecting. The interface between the TC-64 and the computer is the LocoBuffer-USB which connects via USB. One of these was required.
Well, that’s pretty much all of the hardware I obtained for the control of the staging yards. In the next post I will go more into the wiring that was required and how it all connects together.