Methods of wiring

I am in the beginning stages of fair large O Gauge Hi-Rail layout. The problem I have how to wire the layout. I a lot of traditional equipment, A lot of MTH DCS and traditional equipment, and quite of few Lionel TMCC engines. Lionel suggests doing a common rail type wiring following the tracks around the layout with drops. MTH wants star or homerun type wiring. I have the original MTH DCS TIU and AIU. I also have the original TMCC base unit and remote. I used this stuff several other layouts years ago before getting the TMCC equipment. I only had the MTH system and used their suggested homerun wiring scheme. It work fine and I could operate all my traditional engines by varying  the voltage. Next I added the TMCC stuff with that special serial cable and seemed to work OK. Those some what uncomplicated layouts compared to my current plan. The plan I am about to start building has of parallel trackage and tracks going top of hidden tracks a layer below. This layout will be fairly large covering 3/4's of the basement 30' x 22'5". I know how both systems operate. Lionel uses the outside rail as an antenna. MTH sends the coded information directly through the center rail. Should I wire the Lionel wants or MTH's way? I watched many YouTube video about wiring and all the problems they encountered. Also I read countless books on wiring plus the ones about this subject from MTH and Lionel. I would really like some ideas on the correct way to go about wiring this layout. Wiring the layout seems to me the most part of building a smooth running railroad.   

Alan D Bauder

Original Post

For optimal control when running conventional, my experience is that the best approach is to use is to have many relatively short blocks, each controlled by a toggle switch.  This permits operation of several locos on the same "power district"/handle.  This is how my final layout was butilt in the early 90s, and it worked great.  Then, after the turn of the century, my son gave me a complete DCS system.  No way was I going to rewire that behemoth, and I still had many conventional locos.  So I just dropped in the DCS system, did a few tweaks with light bulbs, and have been running DCS ever since, with no problems.  I have a common buss for all track and accessory and light common (ground), and from each of the 6 TIU channels, power goes to a section of the control panel, feeds through 10-20 toggle switches, and then goes out to each block thru 14-gauge wire.

There are many of us who do not use the so-called star wiring system.  It certainly is not friendly to conventional operation if you want to run many trains at once.

Thanks! That was the most helpful article I read yet. It sounds like you have a really large layout. Do you run any Lionel TMCC or Legacy engines on your railroad? I never had any problems running my few TMCC engines with last layout many years ago. Lionel system seems so **** complicated compared to MTH. I have heard running Lionel stuff on a large layout can be troublesome because of their use of the ground rail for an antenna. I saw that on Eric's Trains You Tube channel.

Alan D Bauder

Wire it for DCS and then connect the Lionel command base wire to the common .

MTH requires star wiring and blocks for the most reliable operation.

Tmcc/Legacy has no "preferred wiring style".

" No matter how far we travel, the memories will follow in the baggage car."

 I was in the same situation as RJR. An already functioning conventional layout with common ground buss wiring trying to incorporate DCS. Once I got into command with TMCC and DCS I wasn’t going to run conventional. I had no need for toggles except in the passenger yard sidings and engine facilities. The rest were removed. The ones that remained. The track power is done with relays. Eliminating long runs back and forth through toggles. All done with common ground. The more recent area does incorporate some star wiring. I use Gargraves track and Ross turnouts. Pretty much every rail has an attached wire. I think relying on track pins or joiners to power up a long block with star wiring may give you problems down the road. Unless the rails are joined by jumper wires.  I believe the biggest key wiring your layout.  Is to use quality wire and secure connections. Not so much how it’s done as far as star wiring or common ground. I use fourteen gauge feeders soldered to twelve gauge buss wiring. I’ve seen both methods yield great results. Keep your switch motors on a separate power source.

 What you do need to keep in mind when running TMCC.  Is the ground plane issue when tracks pass over one another. I had one area in a hidden tunnel that had a loss of signal with some engines. Easily fixed with a wire over the problem area run to a wall outlet. 


RJR posted:


There are many of us who do not use the so-called star wiring system.  It certainly is not friendly to conventional operation if you want to run many trains at once.

I guess this addresses an issue about track connections and power dips? Otherwise I can't see why you'd state this? I believe you're pointing out the type of track and it's weakness?

 I believe that many cure power loss by adding extra connections via buss wiring. That is not the only cure. Good track joints would also solve it on many brands of track. I'd agree not all brands or types.

When I test my outside layout, I drop the TIU out of the chain and run a couple of engines to see how they react around the backyard. They'll point out any area where there's a bad track joint real fast. Running 2 or 3 engines at once, helps by having a larger power draw where one engine might not show an issue.

That said, I am running star wiring on all my layouts. May not work for everyone. I just think it's unfair to post against trying it. If you can't have good track joints, or the type of track won't conduct power well, the DCS signal probably won't be well either. Where I've had good power flow, the signal came with it.

" on Sour mash and cheap wine " ??

Why go back to DCC when I have DCS!

Dave C, I do not have long runs back & forth.  Power goes from TIU directly to control panel, and then out to blocks.  I agree completely with your choice of wire gauge.  When I built 8x4 layouts with centralized control panels for young grandkids, I used 16 gauge. For anything larger, 14 gauge with a 12 gauge common buss.

When I built my layout about 1992, relays were expensive.  The cheap Chinese relays hadn't arrived.  But when I rebuilt my postwar Lionel gantry crane to move, I used relays and cheap power supplies for those relays, so I have 22 gauge wire running from panel to crane.

Electrically, I can see no difference between running power to the center of a layout and then running feeds from there to blocks, or running it to a control panel and running feeds from there to blocks.

Just to condense my (and other's) feelings on the matter: wire it with DCS in mind.

TMCC is more robust and flexible, and can overcome most things - in fact, it seldom has issues per the layout and signal. (The "ground plane" issue does exist, but seldom happens; typically it comes up with stacked metal bridges and the like.)

I agree with those that said to wire it for DCS (star pattern), then run on wire from the TMCC/Legacy Command Base to the common ground.  This has worked on my small Super O layout as well as the large floor layout that we used to set up at meets (25' x 25').  Both systems work very well and compliment each other on any layout.  You MUST have a well grounded outlet in order for TMCC to work (we had a bad one at a train meet once and could not run TMCC until we ran a separate ground from another outlet.  This will not happen in a modern home with proper ground and is a separate issue from the "Ground Plane" issue that D500 described (above).

RAK TCA 94-3880 TTOS C45 Southern California DCS Demonstration Team Angels Gate High Railers LCCA

Alan D

MTH still sells Barry's Books, DCS Companion and DCS Wireless Companion in digital format. Trust me they are what you want to use. Barry was the MOST knowledgeable person when it came to DCS. MTH even paid tribute to him in the beginning of their 2019 Volume 2 catalog.

The DCS Companion book is everything for the remote with some wireless added. The DCS Wireless Companion deals with the Wireless side and the MTH App.

I run remotely via handheld remote, Wireless with MTH app ( top version ), TMMC and Legacy along with some conventional. ALL DONE VIA MTH DCS WIRING and MTH app or remote with NO PROBLEMS!


D500 posted:

Just to condense my (and other's) feelings on the matter: wire it with DCS in mind.

TMCC is more robust and flexible, and can overcome most things - in fact, it seldom has issues per the layout and signal. (The "ground plane" issue does exist, but seldom happens; typically it comes up with stacked metal bridges and the like.)

Nailed it pretty tightly 🤔

Make even sized isolated blocks out of each power drop around a line; each drop centered on about every 6pc of track per block.


RJR, data signals can sort of perform a looping and cause echoing and mabe the loco sees it twice. No telling what the loco "brain" might be looking for numerically already, exactly when the data comes around turnout #2 for it's second pass in a micro-second later, hitting its own data tail end like a long train on a small reverse loop...except merging, and the data string is now "random numbers" but still read, the chip isn't smart enough to see that merge and stop reading.

 Maybe a new command used fixes it, maybe a reset, et.. but the wiring runs suggested really should help keep that issue at bay.   I've had data jump 3ft airborne into a similar but unrelated machines data lines too.


 MTH DCS is a little more sensitive to this and tmcc gr.plane issues are a case by case; Lay it; test it, move any plane/signal around near the issue as needed until it's gone.


"Still trying to not shoot my eye out"


"Nursing insomnia one railcar at a time"

My aroma therapy? Smoke Pellets.


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