Linking DCC and DC layouts

[Simon-376330]

Hello

First time posting having kicked off my midlife crisis in earnest with a starter set for Christmas.

i have a lot of old locos/ rolling stock from my youth (predominantly OO GWR steam) that is DC but wanting to create a new DCC layout with a bit more freedom of locos/ themes etc.

My ideal solution is a DCC layout, with a separate “heritage” line that meet at a station platform off the main DCC layout.

Clearly directly linking the two is a no-no, I was wondering about having a section of track along a platform (or siding) that joined the two layouts with isolation points at each end. The purpose of this link being to allow me to transfer rolling stock between the two layouts (and possibly the odd DCC loco onto the DC layout for special occasions if that is workable).

With no practical experience of DCC, whilst theoretically this should work I am hoping people more knowledgable of DCC than I will be able to point out any flaws.

any thoughts very welcome.

thanks

[Brew Man]

If you are going DCC there is no need to isolate track. With DCC ALL the track is live and connected together, unless of course there are different gauges of track in play. I suggest you read the getting started tutorial at the top of the General Forum.

EDIT: Sorry, I've just re-read your post. You are wanting to mix DC with DCC. Why would you want to do that? If it's because your old locos are Analogue then it might be worth considering converting them to DCC. Most can be.

[derekr1707821591]

If you can be 101% certain that the two systems will never electrically connect together then go ahead.

But if they connect, could be a locomotive or coach derailing, then the Magic Smoke will be let out.

Derekr.

[P-Henny]

All forms of physical isolation, whether they be insulated rail joiners OR isolating points will still allow an electrical connection between tracks that are powered by the DC Analogue and DCC Digital controllers. This is because the metal wheels will bridge across the isolating gaps and even more so if rolling stock has wheel pickups. For example locos with motors & carriages with track powered lighting.

This will severely damage the DCC Controller and possibly the DC Analogue one as well.

By all means have two separate tracks (one per platform) to run DC & DCC separately, but do not physically connect them together by any method, particularly isolating points. I recommend that you lift off rolling stock and place back on, if you want to transfer carriages and wagons between DC & DCC tracks. A plastic "Re-railer" will make that task easier.

https://www.ebay.co.uk/sch/i.html?_nkw=oo+gauge+rerailer&_trksid=p4432023.m4084.l1311&_sacat=0

[ellocoloco]

An isolated - dead - section for shunting wagons from one to the other sounds fine. I would suggest an isolated track section rather than relying on points which can be left in the wrong position.

Enjoy your midlife crisis. sunglasses

[Fishmanoz]

Short answer - don’t do it.

Longer answer - refer to Paul’s two above.

[Yelrow]

Simon, i had/have similar quandry with 100 DC locos and existing layout. When i was unable to go upstairs, my wife bought me the Majestic DCC set, which we set up downstairs. Upon recovery, i was faced with putting 2 layouts into one. Fortunately, space, is not a problem, so i built a new layout, upstairs. There are 2 DC designated tracks, with sidings, and next to them, 2 DCC tracks, sidings, turntable etc. They are Clearly labelled DC, and DCC, and only one or the other, is powered at any one time. Power switches, clearly labelled. In the unlikely case of a derailement, it matters not as only tracks i am running are powered at that time. Its not ideal, but neither was converting/selling 100 DC locos, or selling my DCC locos. I consider this is a workaround, and i wont bore you with double helix, TT, N gauge and Hornby Dublo 3 rail tracks, that comprise the whole thing. Thats the problem with starting collecting in your teens , and then going into DCC, at 75.

[96RAF]

If thinking of power switching remember that any DCC accessories connected to the track will have to be included in that isolation switching arrangement, else they will expire as well.

Completely separate tracks as suggested is the way to go.

[Simon-376330]

Thanks for the comments all. In answer to a couple of bits

1. looking at both DCC and dc and not sure I’m confident enough to convert the dc locos. Maybe will do over time
2. for the isolation I was planning on using some wires passing through isolator switches at each end of the piece of track, rather than using sets of points (or ive misunderstood something somewhere)
3. hadnt considered the fact a wheel could complete the circuit as it passes over; good point, need to think that one through a bit

i may resort to the human error proof suggestion of lifting wagons between two sidings to simplify things as sure I will cock up any isolation activity at some point.

Sounds like it is doable, but there are risks around inadvertent connections. Plenty to think about; thanks for the input, very helpful.

Need to have a go at converting a dc loco i think and see how that goes!

[Yelrow]

Simon, taint as simple as that, regarding conversion. In order to convert an old DC loco, firstly, it must be a perfect runner. If not, conversion is a waste of time, as it will perform badly. Thats why, i run both. Secondly, DCC, is not the be all and end all, its cracked up to be. Many, many people still prefer DC. One reason for DCC, is sound, which used not to be possible on DC, but Bachmann, MTH, and several others, now have sound on their DC locos. Tis also, expensive, to convert, and the older locos, need to be hard wired, and many, are very difficult to do. I have not added to my DCC locos, for several years, preferring to use my existing DC ones, as they just dont need the same care, and are very forgiving.

[Barry-350851]

Simon, I can understand not wanting to have to separate and lift everything over, its a pain.

If you were to make a piece of plastic track that is longer than your longest loco or electrically conductive stock (bear in mind some modern DMUs might be interconnected). It has been done before on a straight by someone who used plastic extrusion to make the rails.

You have to be accurate with where you glue your track so it isn't out of gauge. Curving the track would be very difficult. The hardest bit would probably be getting the metal to plastic railhead transitions smooth so the stock doesn't derail. The plastic can be painted so it looks OK but it'll never look as good as proper track. Stock would have to be pushed in on one side to be hauled out on the other.

[ModelerXYZ]

Its possible to do that. The DC locos cannot run on DCC, however what I would do if I was going to put both on my tracks would be to put a pair of insulated rail joiners each end of a switched section and then connect the track on the joining section only, via a Double pole Double throw switch. The middle goes to the track, the top and bottom ones go to the controllers. The dc and dcc controllers are connected to their respective tracks as normal and one either side of the dpdt switch. Remember that a DC loco must NEVER go on a DCC track, and this includes the linking track. It might be worth putting a light on it so that you know which one is controlling it at any time. Thus the linking section should be set to the control that you are using to put the rolling stock on the track. It must also be propelled onto the track at low speed so that the loco doesn't end up at the wrong end. DCC acessories must be connected to the DCC layout. Logically anything is possible. Enjoy building your railway and remember that dc and dcc should never meet.

XYZ.

[Fishmanoz]

If I’m interpreting you correctly XYZ, the only thing separating the two controllers is the IRJs (at one end of the switched section or the other depending on switch position). Then you only drive into the switched section from DC if it’s switched to DC or from DCC if it is switched to DCC?

If I have that correctly, one mistake would blow the DCC controller: either have the switch wrong driving in or overshoot the other end. In either case, wheels can bridge the IRJs.

[RDS]

It does concern me that someone like Simon-376330 asks a perfectly valid question only to be met by an assortment of different answers, some of which sometimes could cause irreparable damage to their layout or Loco's.

Simon obviously has previous DC experience and that would be why he knew to ask the question in the first place.

However, answers should really be worded in a way that does not, or could not, in any way cause damage.

The obvious answer in this case is: Don't physically connect DC and DCC tracks together under any circumstances.

[Flashbang]

I have to agree RDS.

Best safe practice says.... Do Not allow any connection to occur between a DCC and a DC powered rail. You severely risk destroying the DCC system controller if DC is allowed to connect to the DCC system.

END.

[ModelerXYZ]

I suggested putting them on oppsite sides of a switch so that switching one onto the rail disconnected the other. The idea of a transfer of wagons can't be overlooked, but the two systems cannot be connected together electrically. That was why i suggested what I did. I'm not sure if you could make a small section either end go dead when the wrong power source is connected, its probably not impossible. XYZ

[Barry-350851]

I'm not sure if you could make a small section either end go dead when the wrong power source is connected, its probably not impossible. XYZ

 

 

Your "dead" section at either end couldn't have metal rail though, otherwise it would be possible for wheels to bridge the two IRJs at the same time as they pass.

 

 

Simon, do you have any area that will be non-scenic? If so and you have space for two sidings alongside each other, you could create a cassette system where one siding runs on to a moveable cassette that you can then slide across to line up with the other siding. If you go to exhibitions, have a look at some of the fiddle yards, especially on the shorter end-to-end layouts.

 

 

 

 

[dBerriff]

It also possible for DCC to damage an analogue controller. We were lucky - it only blew an internal fuse - and this was when the analogue device was switched off.

As said above the only safe solution is complete electrical separation, however achieved.

[96RAF]

The clue is labelled on the back of each controller - it says 'output'. If you use another controller's output to push back into those terminals you will cause damage.

[dBerriff]

Absolutely. I merely report the accident waiting to happen - and it did. It was not my wiring plan and never would be. Just keep DCC and Analogue apart and that includes making it impossible for a locomotive, stuck relay or point/turnout blade to bridge the gap.

[Yelrow]

Simon, like you i have about 90 DC locos. So i built a layout with 4 separate tracks. First 2 DC only, clearly labelled. Inner 2 with points Turntable, etc DCC, again, Clearly labelled. So i can run 4 locos at once, should i wish, but totally, separate. I usually have a DC day, or a DCC day, meaning, only controllers turned on, are for that system. I have made DC controllers, have a light, so i know when they are on. I have the best of both worlds, as cannot afford to convert DC locos, even if i wanted to.