Once the layout was largely wired the lessons of how to wire a layout reliably and for continuous operation in a show environment started coming home to roost. Before continuing with the building of the layout I have to detail a bit more about how the control system for the layout has ended up.  A lot of this blog entry happened once the layout was largely finished but since all of these decisions flow from making the layout control better it is better to put them all in one place.

The first problem is running the track, the points (and later the signals as well) from a single DCC supply. Sooner or later something will short the track. It cannot be avoided. Whether its changing some stock in the fiddle yard or a wagon derailing or, more often than not, running over a point that is set against the train then the track will be shorted. Most DCC command stations deal with this really well. They turn off the track voltage and either wait for the driver to clear the fault and reset on the controller like the Lenz system or just turn the track power back on the moment the short has gone like the NCE Powercab. The problem is while the track is shorted then any other systems attached to the track like the points controllers will also not be working. That means that a point set against the train cannot be changed while the train is shorting the frog.

The first change I did quite quickly was to put a pair of track current trips onto the front and back of the layout. This meant that a short in the back of the layout did not affect anything running on the front of the layout and vice versa. It also meant that I could run the DCC Command station output all the way around the layout on a separate pair of wires to power the point controllers so that they carried on working when part of the layout was shorted. What actually happened was that every now and again the DCC Command station would still trip out faster than the track current trips.

Since the point control was still going to need a big control panel I looked at JMRI (Java Model Railroad Interface) to run the points on the layout. This also meant that signals could be controlled and linked to the point positions using the JMRI software. Initially I used the USB interface to interface the laptop to the NCE Powercab and send the DCC point signals to the track but soon realised that the Powercab was not going to be powerful enough to power the number of trains (and points) I was going to end up with.  I then bought the 5 Amp NCE Powerhouse Pro. I already had two NCE Controllers including the Powercab. The PC running JMRI connected to the command station over RS232 which required a USB to RS232 convertor for my laptop.

This worked very well for some time. However there still ended up being moments where a track fault caused by a derailment or train running onto a wrong way set point would take down the whole command station output. Also since my signals would end up powered from the DCC signal that controlled them they would also go dark. For a few years now I have had a SPROG DCC Command station running the points and signals over the separate bus so that those systems, controlled by JMRI, would never be able to affected by the track voltage.

The NCE system ended up not so good for running large numbers of trains on my layout. The layout had two main controllers - up and down - and each of these controllers had a stack of six trains. While you used trains on the stack it would preserve the direction, lights on and off and later on, sound on and off of each of those trains. However the moment you needed to access another train you would need to set its direction and lights on and off. Given that I was fitting two trains or more in some of the sidings I had far more than six trains on each controller so regularly trains had to be swopped onto the stack and the direction and lights be reset each time. Some of my older stock like the Farish 158 didnt have lights so if it was sitting in the bay platform of the station and you couldn't see which way it was facing it often took two attempts to go in the right direction.

The rest of our Preston club layouts were all running on Lenz systems at this point. The Lenz system was a lot better for the sort of layouts we had. Mainly large fiddle yards full of trains which needed to be sent round the front of the layout in quick succession. Good examples were Bee Lane and now Euxton Junction. Both could end up with 50 or 60 locos on the fiddle yard. The Lenz system has a stack of something like 255 trains which are all kept up to date in terms of lights, sound and direction. We had also started buying Lenz radio controllers between us for the OO show layouts so they could be borrowed for my layout. Coketown now has a Lenz system running the tracks and trains and the SPROG controlled by JMRI still running the points and signals.

And now back to building the actual layout from where we left off......