DCS system using Gargraves track. Since outside rails are not electrically connected ... do I need to wire both?
I had the same question a couple of months ago and got some good feedback on here. You'll get two answers - yes and no. I opted for yes. I ran three drops (2 ground, 1 hot) and then tied the 2 grounds into one going to the terminal (I use home-run/star wiring, as outlined in Barry's DCS book). It has worked very well for me.
One rail will do fine if you are just running loops. If you have several switches or multiple connected loops then you may want to ground both sides. Also having some sections of outer rail isolated can be used for trackside signal activation or some other device. I have done it both ways, but normally I do ground both outer rails and tie them together.
I use TMCC and GG track. I wire the center rail to the (+) and one outside rail to the (-) and the second outside rail I use as a signal rail for track signals and road crossing signals. Using just one outside rail may not work with DCS but works great with TMCC.
CBS-- The famous layout built by Tony Lash used the method you described. It used Gargraves track with DCS on the center and one outside rail, with the other rail used in a working signal system (indications only). His longest block with working DCS signal end-to-end was 135 feet. There were actually two at 135; one was end-fed, and the other center-fed. The total blocks were 20, and the longest-- 178 feet and end-fed-- had signal loss for an unknown distance at its far end. It was in a covered level in that area.
I may post a fuller description in another thread, time permitting, as the wiring had some unique features which clearly offset the otherwise reduced traction power transmission of the track. I will post a note here if I do so. Tony was kind enough to spend a weekend afternoon explaining all this to me. Being in a commercial building, he had it wired by an electrician.
Wire both together and do not go old school and use an outside rail as a control rail for signals. One outside rail will work with TMCC. Two will work better.
Frank, MTH had several people work on the layout to get it to work correctly.
Tony is a great guy.
Marty Fitzhenry gives great TMCC/DCS advise and I applied his advise some time back to my DCS/Legacy layouts. In reality both my outside rails on my FasTrack multi level layout are Legacy wired, I split the wire coming from the Legacy Base, run a drop directly to the left FT outside rail, not used by the DCS, and because I also run DCS, I connect a Legacy wire to all the out, Black Channel DCS terminals, this sends a Legacy signal on both outside rails of my FasTrack, and my Legacy engines work really really well, with the strong Legacy signal. Because the Legacy and DCS run on a completely different engineering principle this works out real well, however I have often wondered if the ground plane, of the DCS is some how effected, because of running the legacy wire that actually connects both rails, back at the Legacy Base. So far I have seen no adverse effects from this DCS/Legacy signal join, if anything both DCS & Legacy seem to work even better connected in this manner, especially the Legacy. So far Marty's wiring technique has worked like a million bucks, on my FT DCS/Legacy layout.