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Staging yards control Part II …

Hi all,

Quickly following on from Part One, I will attempt to describe the wiring that I have done.

Probably the first bit of wiring I did was when I was installing the Cobalt motors.  The turnout vee crossings will be ‘live’ and polarity switched when the turnout is thrown.  This is done using the auxiliary contacts within the motor.  So, positive and negative droppers were connected to the turnout at an appropriate spot and along with the dropper from the crossing, were terminated at the motor.

turnout motor wiring

Wire size is 7/0.16mm, Altronics Light Duty Hook Up Wire, Cat No. W2250 (Red), W2251 (Black) and W2255 (Green).  I bought 100 metre rolls of ten different colours years ago.  The grey wires are figure 8 type that supply power to the motor.

As mentioned above, the red and black droppers are connected to a convenient spot on the turnout.dropper connections for vee crossing polarity

With the requirement for each road to be a detection section, I had to run a positive bus wire for each road, including the turnout ladders at each end of the yards.  There a total of twenty two detection sections, eleven per yard.  Once these bus wires (1.5mm2) were run, smaller gauge dropper wires were attached to every piece of rail and then connected to their respective bus wires.  The negatives from each road were bonded together and connected to a negative bus for each yard.  The photo below shows a section underneath the UP yard showing the bus runs, the positive rail connections and the common negative connections.

detector section bus wiring

dropper connection to positive rail

The wiring for each turnout motors was run using figure 8 type wire back to a central terminal block, one for each bank of eight motors.  To connect these back to the control boards (SMD-8’s), four core alarm cable was used.  This was obtained from my local electrical wholesaler.  I got one hundred metres for only thirty five cents per metre.  I needed four runs of this cable for each bank of turnouts.  The conductor size of this cable was 14/0.2mm.

turnout motor wiring

Due to the small conductor size of the alarm cable and figure 8, and the large terminal block connections, small ferrules were used to make it easier to terminate these wires.  The ferrules were obtained from the local Jaycar store, part number PT4433.

All this wiring had to be terminated at the control boards.  I chose a location under one end of the UP yard and screwed some timber to the wall to make a mounting board.  The image below shows the finished product.

staging yard control

The following images show close-up views of the individual components.

SMD-8 and FOB-C boards for turnout control

There a four SMD-8 boards that control the thirty two point motors.  The alarm cable wiring from each bank of eight is terminated at the fan-out board (FOB-C).

BOD-8 boards for train detection

There are three BOD-8 boards for the detector sections.  The Cat5 wiring comes from the current transformers.

CT's for current detection of trains

There is a total of twenty four detection sections, twenty two for the yards and another two for the sections between the UP yard and Kankool and the Down yard and Pangela.  At the moment, I haven’t installed the last two CT’s, but the Cat5 wiring is terminated already.

Relays for road power control

The wiring to control the power to each road was probably the most complex.  The original plan was to just use the RB-4’s, but I found it was too difficult to terminate the larger wires (brown & grey) into the small terminal blocks on the RB-4.  So I purchased another lot of relays that would control the main DCC power and used the RB-4’s to control these new relays.  I was then able to use much smaller hook-up wire in the RB-4 terminals.  The new relays were from Altronics, part number S4197 for the relay and S4320 for the base.  They are mounted on DIN rail which was also obtained from Altronics.

TC-64 Tower Controllers

All the boards are connected to the two TC-64 Tower Controllers by 10-way ribbon cable.  The TC-64’s are connected together via 6-way flat data cable with RJ-12 type connectors.  These are then connected to the Locobuffer USB interface, which will then be connected to a laptop that will sit just to the right hand side of the control board on a shelf.

I am yet to test the system as it will involve a lot of time to carry out the programming and addressing of the hardware in JMRI and PanelPro.

For those interested, I have included some wiring and schematic diagrams that I drew up to not only assist in the actual wiring installation but to help with future fault finding.





Staging yards control Part I …

Hi all,

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.


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