Power routing turnouts

[kvp]

As most of us already know, there are power routing turnouts and power everywhere ones. Older european turnouts route power everywhere and require isolated sections for stopping trains. Some european, many american and most japanese turnouts are power routing, so they only power those tracks that are selected. Classic examples for this type are Peco electrofrogs, Kato, Tomix, Rokuhan and even 2 rail Lego. However there is a big difference between power routing turnouts. There are three types:

a ) the classic electro frog, where there is no isolation and both inner rails get the same polarity as the frog (example: Peco)

b ) the isolated electro frog, where only the frog is polarised and one of the inner rails get power (examples: Kato, Lego and Rokuhan)

c ) the fully isolated, where the stock rails are isolated and they receive power together with the inner rails only when the direction is selected (example: Tomix)

 

With the a ) type, it's possible to set the turnouts in a way at a bypass station to cause a short, by routing both polarities into the same rail.

 

The type b ) is better, but you can still leave a track powered when you power one rail from one side through the stock rail of the turnout, while power the other rail from the other side through the stock rail of the other turnout. This means there are routes, where you can't power off certain tracks, even though they don't have valid routes on either end.

 

Type c ) is easy, since the power only goes where it should, so this type of turnout even allows single track reversing loops and deltas to be built without extra circuits or isolation.

 

I ran into this problem with the following track layout:

 

The power is connected at the green triangle and when the turnouts are set to the two stub tracks all tracks receive power with type b ) turnouts and the layout shorts at 4 points with type a ) turnouts. With type c ) tracks 2 and 3 would be unpowered and movement is allowed between track 1 and 4.

 

I'm looking for suggestions on what to do. It's possible to change the turnouts to power everywhere and use isolated blocks for tracks 1 to 4, but i would like to avoid this complexity. It would be possible to isolate the stock rails and switch their power with relays, but that would need extra circuits that follow the turnouts and make manual throwing impossible. The third option is to isolate some of the stock rails, but that would mean each track could be powered only from one direction. I would like to achive something similar to what the Tomix fully power routing turnouts provide, without too many extra circuits and hacks.

 

Any suggestions on what would be the best solution? (the track system in question is Rokuhan Z, but the same applies to Kato N)

[Dani]

Hello,

 

In my case, I'm using Peco code 55 electro frog (case A) and my layout is digital (DCC + Loconet). Using isolating joiners in the two inner rails, there is no way of provoking a sort circuit. And feeding the frog with the right polarity, even the shortest locomotives can pass at extremely low speeds with no problems. I'm using servos to move them and a Loconet module that manages both the servo and the frog polarization. This kind of modules I'm using turn off the frog current when the movement starts, and feed it again with the correct polarity when servo ends the movement (http://wiki.rocrail.net/doku.php?id=mgv136-en).

 

It's realistic, reliable, secure and I like it much more than the traditional coil switches (difficult to hide and making a lot of noise).

 

But I know nothing about that Rokuhan system... I don't know if switches have the same behavior than Peco....

 

Cheers,

Dani

Edited June 8, 2015 by Dani

[kvp]

 

But I know nothing about that Rokuhan system... I don't know if switches have the same behavior than Peco....

Yes, except they handle the frog polarity themselves and have the frog isolators built in, just like Kato-s /they are type b ) /. The problem is that when you run in analog, you want to turn off the power on those tracks that are not selected, so you can park trains on them. However the route setting above still provides power to all tracks, even though track 2 and 3 are not selected by any of the turnouts. The reason is that the rails are powered through the continous stock (outside) rails of the two turnouts. (one from each side) I'm looking for a simple solution to be able to set the routes as above and still isolate the two passing tracks.

[katoftw]

You just need two isolators added. Left end of line 2 and right end of line 3.  That way you use the 2 left side points to control lines 3 and 4.  And the right side points control lines 1 and 2.  The outer 2 points can be shared still by the same switch.

Edited June 8, 2015 by katoftw

[kvp]

This could work, but then i couldn't power track 2 from the left and track 3 from the right, so a route of track 1 - loop - track 2 would only be possible if i throw the topmost switch after the train left track 1 and before it arrives at track 2. Thinking about it, this sounds acceptable...

 

Now i only have to find out a way to add isolation to the Rokuhan tracks without using the isolating insert, since that extra tie would put the track geometry completly out of whack (cutting the rails is also not an option, since they are only fixed at the middle and any cut piece would just fall out) and there are no isolating joiners i know of. I probably have to mod the normal joiners some way.