Is there a way to switch between DC and DCC?

Terry has been in touch. He has a question: is there a way to switch between DC and DCC?

“Hi Al–I hope you or one of your readers may be able to help me with this question:

I currently have an old dc layout with the traditional block method where a single rail is connected throughout the layout and the other rail is insulated with plastic track connectors and used to define blocks–each with a separate on/off switch.

This way I can stop a train on a side-track-block,and run other trains around it.

I’m trying to convert to DCC where all rails are always powered and train movement is controlled through each engine not the track. I really don’t want to go through the hassle of removing all of the insulated joints.

The question is: can I just turn on all the existing switches in all the blocks without removing the insulated jointers, wire the transformer and controller for DCC and have it work properly.

I’ve asked this same question several times in other forums but have never gotten an answer. Hope your folks can help.



Idaho USA”

Is there a way to switch between dc and dcc with complex layouts?

Please do post a comment below if you can help Terry.

As always, the clever stuff is in the comments – here was one of the first replies:

“Terry – absolutely you can!

My club layout is wired up this way, having been wired for analogue 30+ years ago, it now also has DCC docking stations and a command unit which we can plug in instead of the analogue controllers.

Now we run analogue on the first Tuesday of the month and DCC on the third.

Even for home use this can be useful (a) because it allows you to temporarily switch back to analogue if you want to run unconverted locos and (b) if you get a short circuit, you can switch out sections one by one until you identify the fault.


A big thanks to Richard for helping with Terry’s Question: Is there a way to switch between dc and dcc with complex layouts?

Have a look at the comments below to see more – the comments are what I enjoy most about the blog.

That’s all this time, folks.

Please do keep ’em coming.

And if today is the day you get started on your layout, the Beginner’s Guide is here.



PS Latest ebay cheat sheet is here.

PPS More HO scale train layouts here if that’s your thing.

35 Responses to Is there a way to switch between DC and DCC?

  1. Rob says:

    For Terry
    Yes to convert to DCC (live rails all over the layout) you can just switch all the isolating switches on, but if you need the panel space or for any other reason, then just remove the switches and link the associated wires together or if possible just remove the switches and solder link wires across the rails where IRJs are fitted.

  2. Richard Standing says:

    Terry – absolutely you can! My club layout is wired up this way, having been wired for analogue 30+ years ago, it now also has DCC docking stations and a command unit which we can plug in instead of the analogue controllers. Now we run analogue on the first Tuesday of the month and DCC on the third. Even for home use this can be useful (a) because it allows you to temporarily switch back to analogue if you want to run unconverted locos and (b) if you get a short circuit, you can switch out sections one by one until you identify the fault.

  3. LOU SANTELLO says:

    The answer to the DCC layout question is it depends on which switches you are using and whether the frogs are insulated. You will not have to remove the insulators and depending on the size of your layout, you may want to add insulators along with more track feeders to keep power more consistent. Post a photo of the track plan.

  4. Henry van Wyk says:

    Hi terry, as long as there are no Wye’s or reverse loops, it should work just fine.

  5. Gary olson says:

    Regarding converting a blocked D.C. Layout to DCC, Kalmbach publishes several very good books on DCC wiring that specifically address your issue. I hate to say this but from what I’ve read converting a single wire D.C. Layout it’s easier to rip out the old wiring and do a fresh DCC install than to make all the necessary changes to the old wiring. Honestly since everything will be DCC in a few years, this might be a good time to move on to a new layout and design it for DCC operation from the start. That’s what I am doing.

  6. Richard Standing says:


    Can you post a plan of what you’re trying to do as I can’t quite visualise it. You could probably do something with 10′ between the end sections, but remember that a reversing loop on a dogbone layout requires 5-6′ depending on whether the reversing loops are symmetrical or assymetric respectively.

  7. LOU SANTELLO says:

    As a matter of fact, my layout is 16 feet x 20 feet and it’s divided into 96 blocks which both rails must be insulated 96 times for block detection and signaling. Another thing to consider is whether you have reverse loops.

  8. Ray says:

    Question 1: hide the short curves behind scenery. A building or row of trees will hide the unsightly turn radius occupied by long cars. As long as they negotiate the curve without derailing, you are fine. Keep the huge radius out in front.

    Question 2: there should be no ill effect as long as you do not under any circumstances have a reversing loop on your layout. That requires special wiring. If you try to cross over an insulated joint that has a reverse polarity to the adjacent section, you will trip your DCC controller and may even blow a fuse.

  9. Patrick says:

    For Terry in Idaho:

    Yes you can…

  10. Andrew Moult says:

    As for the wiring for all rails to be live, and not wanting to take off insulated joints etc. Only suggestion I have is to use dropper wire and link the rails using solder. Only other way is to remove insulated joints etc.

  11. Tony Dodd says:

    24″ minimum radius is recommended for those cars but remember that the ends will overhang the track as the vehicles run round the curve so you need at least 54″ and I would think you would require at least 60″ to include a little scenic background for a single track. You also need to come back from the curve to your straight track and that will need you allocating 60″ at each end BEFORE YOU GET A STRAIGHT SECTION on BOTH tracks! Good luck but this is a pretty big layout for a start – 5′ wide minimum x more than 14′ long of you want both straights to be 4′ minimum. If you want switches between tracks, you will need to add the crossover length to that so 2 pairs of crossovers increase that length by at least another 3′.
    Hope that helps and doesn’t deter you too much –

  12. Martin says:

    No problem. There is no reason not just switcj on all your section switches unless you have reverse loop. In this case you will have at least 2 switches to enable this to work. Just leave these switches off, or better still disconnect them, and install a reverse loop module. You be able to use the wkres you disconnecged from the switches.

  13. Richard Scott says:

    Absolutely yes! If you have access, run a wire under the boardwork for the second rail and just connect all the leads from each insulated section of track to it. That way you avoid the resistance involved with the extra wire distances. Use 16 or 14 gauge wire such as lamp cord, (16ga ) or 14 is better and can be purchased inexpensively at a store such as Home Depot or Lowes by the foot. Going to DCC it is important to have as little voltage drop as possible. I used 14 gauge for the mail electrical leads under the woodwork directly under each rail and ran 16 gauge to each track section. My voltage drop was less than 100 millivolts anywhere on my layout.

  14. Ed Clark says:

    Some people create era specific layouts, I mostly buy what I like but I will give you a few 85″ passenger cars I bought. Around WWII RR’s started mostly using their best tracks for most of the passenger trains. This meant they could do longer cars up to 90′. As for your question; Crests on grades, tunnel entrances and side by side 2 track operations are examples of where long cars could cause operational problems for you. Pre WWII cars were mostly shorter in the 60′ range and operate nicely on a 4×8 layout. Long cars will run on 22″ radius if you avoid long car issues as above.
    Terry, Your question has been answered nicely in the above comments.

  15. Rod Mackay says:

    Just to add that long vehicles often aren’t too happy with sharp reverse curves either, you want a car length or so of straight between the curve into your helix boards and the helix itself.

  16. JoeK says:

    IF you are willing to give up on the 85′ cars or aren’t held to a specific era, Con Cor has a ‘branchline-commuter-suburban’ 65′ cars that have superb detail, many road names, are lighted and run on dc or dcc track. They advertise they can run on 18″r.( FYI I always keep my radii one larger than the minimum the cars can handle just to be on the safe side). I have a set on my layout on 24″r and they look great. Per ad cars were used from 1920s thru 1950s. I’m not that fussy about eras so it works for me. I generally like to stay from the 50′ thru 70s but if I like the way something looks I will sacrifice accuracy for looks. but that’s just me. ps I just checked the site and they do have the ’empire builder’ paint scheme in this model. Good luck

  17. Benny says:

    For the DCC issue, you should keep the insulation and just run wires for now. You might need these insulation for later, if you should plan to run with a computer. Then you will need to have all your blocks insulated and have detectors for occupancy as feedback to the computer.

  18. Ken says:

    A good way to answer your dilemma would be to temporarily lay a couple of sheets of plywood, use some snap track or other prefab track and experiment. Lay out your end loops and connect them however, then run your train. See how it looks, then you can decide if it fits your goals. You won’t have much time or money laid out and any drawbacks will become obvious. Then decide what compromises you can make.
    Good luck, and have fun!

  19. John Reynolds says:

    I have not made the jump to DCC and would prefer not to…
    But I can see where that may limit some future modeling…

    As to the radius issue… Long cars look nice but they require lots of space.
    While 24″ radius may be a manufacturers recommended minimum, they may take a 22 inch pinch but do not count on it. Visually they need 30 inch radius or larger. That takes up a lot of real estate.

    John from California

  20. Bill Bosserman says:

    Hi, I’m new at this,and helping my grandson build a HO layout it’s 4×8 ft.
    We are using Bachmann EZ Track and EZ Command DCC Controller. We have 5 switches and one Y . All EZ Track Nickel Silver components.
    So do I use the DC transformer for the switches and lights, and the DCC power supply for the track only ? The DCC power supply doesn’t seem to have enough power to activate the switches. We can’t afford to buy DCC switches yet.
    Does anyone know where I can get an EZ Walk Around Companion # 44907 ?
    Thanks for any help , Bill

  21. Dave from Indy says:


    Relative to the 24inch Dia Curves, I suggest 30 x 30 Pieces on the Emd–Yeah it will cost you more wood. But if you like the cars you will be happy with your decesion

    Relative to the DC vs DCC Wiring, just tie the wires together on the one side it should work great. However, you should also have multiple tie points on both sides of the track, so if you have only a few points on one side it would be good to add them—Also—Be careful with Turn arounds.—-Changes may be required.


  22. paul Otway says:

    With the empire buider cars, you coud install a connection to another railroad.

    the cars could travel from a hidden storage yard to your main station and back again

    Paul Otway

  23. Ron Schultz says:

    those bleachers need safety hand rails to make them really stand out I can just see some of the little people walking off the end,or from off the top.

  24. Woody says:

    I have also purchased the 65′ cars from Con-Cor. They run well and look great on the layout I am currently building. I do have some very tight turns (close to 18″r) and they have no problem.

  25. Carl Halgren says:

    On converting DC to DCC. One place where you might want to keep your insulators and block switches active is in any yard or siding where an engine might be sitting idling for a long time. Too many idling engines might be too noisy and irritating, so if you can kill the power to their track, that is an easy way to control the noise level. My layout has block control so I can run DC at times.

    Another alternative to quieting idling engines is to turn the sound off with a DCC command to specific engines. I know some decoders have that ability – possibly all of them do.

    Still in training,
    Carl in Kansas

  26. Norton Williams says:

    To Dan,

    About your Empire Builder question. You are correct that having two helix’s with only 10′ of track between them is a bad idea. No realism whatsoever.Not to mention 24″ radius curves would eat up ALL of the 48″ end pieces you were planning. If the room dimensions you have will not allow you enough space for those curves, you will probably have to give up the cars and radii. While I do not have a passion for long passenger cars, I drew up plans for my single garage layout and found that in order to have the running distance I really “need”, I too cannot have 24″ or larger curves. So, my passenger trains will have to be with shorter cars, i.e. 36 footers of a much earlier era. But since that fits in with my overall layout plans, I’m ultimately OK with it. Of course I will run my 4-8-4 on the 18″ curves occasionally but that’s for my eyes only.


  27. Hennie says:

    My layout is also split in blocks. When I converted to DCC I replaced the switches with DIY track current sensors. When there is a loco in a section a red light indicates that. It is rather useful for my fiddle yard which I cannot always see. Each track sensor is basically 4 diodes, 3 resistors, an opto-coupler, one transistor and one LED and is very cheap to make.

    Of course, running DCC that way does not safe on wiring but these track sensor can later be incorporated with proper working signals.

    I have fitted tiny LED tail lights to a number of my wagons so that these sensor also pick up the presence of the rest of a train which might be partially stopped between two blocks.

    As my wife said – you really have a lot of fun with this.

  28. fred day says:

    as far as converting dc to dcc there is two options that do not require a rewire one is loco genie by mrc the other is blue rail both will run over dc with out modifications.
    to answer the question on 24″ curves best is to run the track in a donut with a center isle. a 24″ curve will not stay inside a 48 by 48 inch square you need about 50 inches or bigger.

  29. tom in az says:

    I do not understand what a blocked system is?

  30. Dan says:

    Thank you all for your thoughtful comments. I will abandon the long car concept and start with something less ambitious. Best to all.

  31. Paul says:

    If it was me I would leave the switches in place and just turn them all on. Down the road or the present you may have a short come up and it is a lot easier to trace down a problem if you can eliminate a percentage of your railroad with locating where the short is. Do this by turning off a block and if the short still exists it’s not in that block and proceed onto other areas.

  32. Michael Day says:

    Dan & Terry, I had my answers mentally worked out and then scrolled down and saw masses of excellent detail. Al: the response demonstrates what a fine website you run! Most of us suffer from too little room and my DCC OO-gauge British layout is no different. Sharp curves at the bottom of steep slopes: hard on Hornby-style couplings and need to constantly monitor speed of long trains; derailment of long-wheelbase 6-driving wheel locos where centre drivers are flanged, etc. My longer rolling stock such as Intercity and articulated Eurostar now consigned to a display shelf. I now run shorter pre-‘fifties rolling stock and any future layout would avoid curves under 24 inch radius, paired (opposing) crossover short-radius turnouts, platforms on curves, etc. Now considering blocks and occupancy detection to avoid rear-end collisions; I guess my Dremel is likely to have to do the opposite of what Terry is doing; put breaks in rather than taking them out. For future use, Terry may want to keep those switches wired up rather than solder across the insulated joiners. Any suggestions re blocks and occupancy detection very welcome!

    I noted above reference to wyes; it’s possible to add electronic circuitry that switches polarity automatically but a double-pole double-throw switch will do it manually for almost no cost.

  33. Terry says:

    Thanks to all for your comments and suggestions. Now that I finally have an answer, I’ll go ahead with my layout.
    Thanks again!!! Great website & member responses.


  34. Michael says:

    I just went in my control panel and bused all of the leads together. On my two reverse loops i had to add auto reversing units. I went from six cab analog control to a dcc wireless system. Changing the turnouts was just a matter of pulling back the wires from the ac bus and adding dcc controls because, mine were all wired with local control. I did find that on some longer blocks i had to add some leads. Some of the dcc decoders are sensitive to voltage drop.

  35. mike says:

    You could put a longer coupler on one end of each of the passengers cars.So you have one long and one short together. This should let them go around a smaller curve.

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