DCS ground wiring

I have many insulated sections running signals and gates on my 16' X 20' Fastrack layout. I have no signal problems at all, sometimes running 4 engines at the same time. You will also get the opposite advice, recommending that you keep all outside rails connected. I'm not an expert and don't play one on the forum, but it works for me.

I've seen opinions both ways, but I know a number of people that do use insulated tracks and DCS without issue.

John,

Thank you for the information. I will go ahead and use insulated rails as I hoped I could.

MTH firmly states to wire both of your outside rails together.    On smaller layouts you may get away with not doing so.  On larger layouts it is very important.   To use sections to wire a signal or anything else is old school.

Problems with isolated outside rail occur mainly with premier steam.  They have limited outside rail connection to begin with.

David,

I've found that from the perspective of the DCS signal, the "trick" is to always have a clear, straightforward return path from the engine's wheels to the Common, black post of the TIU channel. By straightforward, I mean that the path should not be dependent on going through the wheels of rolling stock or other things of that nature.

While having both outside rails tied together at all times will almost certainly provide such a path, it is absolutely not a requirement for strong DCS signal strength. There are other ways to accomplish the exact same outcome.

My DCS/Legacy/TMCC layout, while not super-huge, is fair-sized and most certainly complex. It has 5 interconnected loops on three levels with more than 100 switch tracks with automatic non-derailing operation, many of which are used as demarcation points for track blocks. I also make use of isolated rails for over a dozen track-activated accessories, many of which use DC voltage to quiet the buzzing of older postwar accessories. Al switch tracks are controlled by both control panel switches and AIUs.

I have a signal strength of 10 throughout my layout.

If using sections is "old school," what is "new school?" IR seems to have many flaws in that you may need a large number of sensors to "know" that a train is in a block. Timers for 3-color signals produce non-prototypical behavior. I'd like my layout to please me, so I'm not looking to just have "blinking lights" to entertain visitors.

Mark Wags posted:

I am in the process of building a new layout and had a question about using insulated rails to activate accessories. I plan on doing the proper star wiring for DCS operation. Will using an insulated rail to activate signals, gateman etc. cause signal degradation to the DCS signal? The operating units will be using a separate power source not track voltage.

NO. Like Barry, and many others, I have this set up in my basement. No issues at all for 7 years.

Barry Broskowitz posted:

David,

Problems with isolated outside rail occur mainly with premier steam.  They have limited outside rail connection to begin with.

I've found that from the perspective of the DCS signal, the "trick" is to always have a clear, straightforward return path from the engine's wheels to the Common, black post of the TIU channel. By straightforward, I mean that the path should not be dependent on going through the wheels of rolling stock or other things of that nature.

While having both outside rails tied together at all times will almost certainly provide such a path, it is absolutely not a requirement for strong DCS signal strength. There are other ways to accomplish the exact same outcome.

My DCS/Legacy/TMCC layout, while not super-huge, is fair-sized and most certainly complex. It has 5 interconnected loops on three levels with more than 100 switch tracks with automatic non-derailing operation, many of which are used as demarcation points for track blocks. I also make use of isolated rails for over a dozen track-activated accessories, many of which use DC voltage to quiet the buzzing of older postwar accessories. Al switch tracks are controlled by both control panel switches and AIUs.

I have a signal strength of 10 throughout my layout.

Barry,

The problem might not be so much with the signal strength but general, low speed operation.  I agree that it is best to have isolated sections on straight portions of the layout and I am not arguing that it cannot be done with good signal strength. 

My point is that MTH 2/3 rail steam engines are significantly lacking enough good contact to the outside rail.  The 44 tonner is in the same boat.  This is compounded when using non-derailing features and broken outside rail to activate accessories.  It can be corrected in steam by removing the plastic/fiber axle insulators and replacing them with metal.   It can also be improved by removing the black from the wheel surfaces.   This definitely improves performance over switches and broken outside rail sections.

Dave

I have a number of isolated rail sections to trip signals.  I always keep all isolated rails to one side of the track so that there is one rail with an uninterrupted ground.  I have had no trouble with any DCS locomotive, steam or diesel, creeping through these sections.

Dave,

My response was soley in regards to the effect on the DCS signal.

Regardless, I've dealt with several DCS engines that have difficulties on my layout, most notably due to a ladder of switches.

Solutions have been varied:

• Replacing single pickup roller assemblies with dual pickup roller assemblies.
• Adding a pickup roller to a tender.
• Tethering a lighted car to an engine. I've done this with a few Premier subway sets, among others.
• Adding a Common rail pickup to a tender and passing it though to the engine.

Dave

Question on your comment above-  "It can be corrected in steam by removing the plastic/fiber axle insulators and replacing them with metal".   When you have the engine switch in 3 rail mode, you are connecting both wheels together.  Do you obtain that much additional advantage (signal) by putting in a metal axel when in 3 rail mode?  

Bob D

rad400 posted:

Dave

Question on your comment above-  "It can be corrected in steam by removing the plastic/fiber axle insulators and replacing them with metal".   When you have the engine switch in 3 rail mode, you are connecting both wheels together.  Do you obtain that much additional advantage (signal) by putting in a metal axel when in 3 rail mode?  

Bob D

Bob,

In premier steam, only  some of the wheel sets are connected in 3 rail mode.  The DCS signal is not affected by this but general operation is. 

This does not cause problems on all layouts or switches (as some have stated above) but there are times when you have that 'perfect storm' scenario where spacing of wheel sets and track/switches can cause problems.  

In premier diesels, all wheel sets are connected in 3 rail mode.

Hope this helps,

Dave

Guys, MTH states to do it.  You can argue all day if you want.  

Mark Wags posted:

I am in the process of building a new layout and had a question about using insulated rails to activate accessories. I plan on doing the proper star wiring for DCS operation. Will using an insulated rail to activate signals, gateman etc. cause signal degradation to the DCS signal? The operating units will be using a separate power source not track voltage.

No.

Mark Wags posted:

I am in the process of building a new layout and had a question about using insulated rails to activate accessories. I plan on doing the proper star wiring for DCS operation. Will using an insulated rail to activate signals, gateman etc. cause signal degradation to the DCS signal? The operating units will be using a separate power source not track voltage.

Guy are mixing whole layout isolate, vice a section of track or two for activation of a device.  You can do it no problem.  You have connected outside rails before and after your isolated section and that will work fine. IMHO G

David Minarik posted:

rad400 posted:

Dave

Question on your comment above-  "It can be corrected in steam by removing the plastic/fiber axle insulators and replacing them with metal".   When you have the engine switch in 3 rail mode, you are connecting both wheels together.  Do you obtain that much additional advantage (signal) by putting in a metal axel when in 3 rail mode?  

Bob D

Bob,

In premier steam, only  some of the wheel sets are connected in 3 rail mode.  The DCS signal is not affected by this but general operation is. 

This does not cause problems on all layouts or switches (as some have stated above) but there are times when you have that 'perfect storm' scenario where spacing of wheel sets and track/switches can cause problems.  

In premier diesels, all wheel sets are connected in 3 rail mode.

Hope this helps,

Dave

Dave,  This is like saying all X are Y and such.  There are certainly some Premier 2R/3R especially the Scale engine that can suffer from poor ground continuity.  But if you are running 3 rail the selector switch ties the right side engine wheels to ground and connects both tender wheel sets together.  The drawbar and ground pin wire need to make a connection too.  I have seen the spring/brush used to pickup right side power be faulty and not make good connections, or the springs burn up.  You can modify engine to hardwire both wheels and same in tender if your a 3 railer only.  I have also done the same for the 2R only ground. If they only run 2R I repurpose the center pickup red wire as left wheel chassis ground.  G

David Minarik posted:

Barry Broskowitz posted:

David,

Problems with isolated outside rail occur mainly with premier steam.  They have limited outside rail connection to begin with.

I've found that from the perspective of the DCS signal, the "trick" is to always have a clear, straightforward return path from the engine's wheels to the Common, black post of the TIU channel. By straightforward, I mean that the path should not be dependent on going through the wheels of rolling stock or other things of that nature.

While having both outside rails tied together at all times will almost certainly provide such a path, it is absolutely not a requirement for strong DCS signal strength. There are other ways to accomplish the exact same outcome.

My DCS/Legacy/TMCC layout, while not super-huge, is fair-sized and most certainly complex. It has 5 interconnected loops on three levels with more than 100 switch tracks with automatic non-derailing operation, many of which are used as demarcation points for track blocks. I also make use of isolated rails for over a dozen track-activated accessories, many of which use DC voltage to quiet the buzzing of older postwar accessories. Al switch tracks are controlled by both control panel switches and AIUs.

I have a signal strength of 10 throughout my layout.

Barry,

The problem might not be so much with the signal strength but general, low speed operation.  I agree that it is best to have isolated sections on straight portions of the layout and I am not arguing that it cannot be done with good signal strength. 

My point is that MTH 2/3 rail steam engines are significantly lacking enough good contact to the outside rail.  The 44 tonner is in the same boat.  This is compounded when using non-derailing features and broken outside rail to activate accessories.  It can be corrected in steam by removing the plastic/fiber axle insulators and replacing them with metal.   It can also be improved by removing the black from the wheel surfaces.   This definitely improves performance over switches and broken outside rail sections.

Dave

Dave,

I have a Ross crossing with powered center rail over a main line entering a long straight with one insulated rail. Two truck/two axle diesels such as GP's or F units stall there when running slow because the rear truck is smack dab on the plastic crossing and front truck (which only has two wheels for common as the other axle has rubber tires) means the entire engine is relying on one wheel to complete the circuit. On either side of this are 10's.

I have several insulated blocks (including some fairly long ones) on my Super O layout.

With the caveat that my layout is smallish (5 x 13) I have no issues with DCS signal (all 10's) or very slow speed operation whatsoever.

None of the insulated sections are adjacent to switches.

I think, as long as your track and wheels are clean, you are good to go.

Marty Fitzhenry posted:

MTH firmly states to wire both of your outside rails together.    On smaller layouts you may get away with not doing so.  On larger layouts it is very important.   To use sections to wire a signal or anything else is old school.

We made sure both outside rails of our Gargraves tracked layout were connected to provide a continuous common everywhere and it has saved us from a lot of problems, or so it seems ... and the signal grounding sink wire next to the elevated tracks ending in the house ground plug.  No signal problems, unless we start messing around with "trick devices" to enhance signals, avoid dead ends, etc.

Keeping it vanilla keeps it working.

That is also why we froze the DCS at 4.3 ... it works without problems, don't have Blueteeth, etc., so that's where it stays ... 4.3.