I have a double dog bone set up and its fairly large. All my siding etc are on the inside track. I was big into scenery and the running of trains was minor. As I devekloped more indudtries etc I realise it would be great to be able to go from the insode track to the outside etc. I have tried very unsucessfully to utilize two sets of switches to perform this cross over with no luck. I am wondering is=f I use a walters 8812 which is a fancy cross over with insulators etc will that work or is there someother secret thing I need to add to make this work. Your comments will be appreciated. thank you
By connecting the legs of the dogbone you are creating a reverse loop. Are you using DC or DCC? If you are using DC look up the wiring for a reverse loop. You will need insulated rail joiners to isolate the loop and a second reversing switch (besides the one in your power pack). If you are using DCC, you can use a device called an autoreverser to automatically flip the poalrity as your traisn enter and exit the reversing section. The loop still needs to be isolated with insualting rail joiners in DCC.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I'm a little confused by the question and Randy's reply. If by a double dogbone you mean two seperate circular tracks, then you should have no problem. I have a double main line that runs about 120 feet and while it looks like a dogbone, in reality it's just a twisted and elongated circle. I cross over from east to west and from west to east with no problem. My layout is DCC so direction is not a problem. If you are DC, you are shorting out as you cross over. I don't think it's a reversing question but I could be wrong.
Keep working on it and let us now your outcome.
Ron K
If it wasn;t creating a reverse loop somewhere, there would be absolutely no issues connecting what is essentially two concentric ovals. I've never had any issues, DC or DCC, connecting a simple crossover between two mains. You do need insulated joiners in the middle of the two turnouts forming the crossover unless it's all powered by a single power supply. The train will have to run the same direction - ie if it's running east on the eastbound main, it will have to continue running east when it crossed to the westbound main, at least until it gets over the crossover, then you can back it up. But so long as all you are doing is connecting two independent ovals of track, there should be no problems. If it shorts out everything when the connection is made, it has to be a reverse loop, accidently.
A dogbone is nothing but an oval which is squeezed in the center, not re-connected. Any crossover that mechanically fits should work.
If by "double dogbone" you mean you have an oval within an oval, but squeezed together like a dogbone, you can set up a crossover from one 'oval' to the other but you may need to add some insulated joiners between the turnouts. I assume if you have two separate 'ovals' each one has it's own throttle so you can run trains independently, one on each 'oval' ?? If so, you could cause a short circuit if the tracks of the two ovals aren't set up to be going in the same direction when you switch a train from one to the other...like if a train on the outside loop is going clockwise and the train on the inside is going counter-clockwise for example; if you try to run the outside train into the inner track, there will be a short circuit because the polarity of the inside is the opposite of the outside. That's why the two trains were running in different directions!! If you don't have the turnout connections insulated, the short will show up as soon as you throw the switches (assuming your're using power-routing switches). If you have the connection insulated, it won't show until the train goes thru the crossover.
BTW a track plan - even a scan of a simple hand-drawn sketch - would be very helpful !!
In rethinking your problem, my guess is the track wirnig. With DC double track going from front to rear, you would wire opposite directions (e.g. red-white on inner track and white-red on outer track) since the trains run opposite. With DCC you should wire the same direction, red-white on inner track and red-white on outer track. This way when you go from east to west you won't short-circuit since all rails would have the same feed from the booseter. Remember that with DCC, the Loco can go either direction on the same track even if both are set for forward.
Many of us going fromm DC to DCC forget to do this. I was one of them.
Ron K.
I think that all of us are confused as to whether "double dogbone" means an oval within an oval, or two single tracks with reverse loops at the end of each. Might I suggest that you get a double-slip switch,(which requires only two solenoids or motors to operate , which sells for about $40. The $60 Walthers 8812 is basically four switches, which require 4 solenoid motors to operate. The rails of the 8812 may be insulated from each other, but that does not mean that the polarity is adjusted. Either way, these are reverse loops, which require reverse loop modules to change the polarity automatically. Make a double track + - drawing of your layout polarity, to see where you will have to install plastic joiners, and where the wires of the reverse loop modules must be attached. Get the "DCC Projects" book, and get help from an electrical engineer.
With DCC you should have no issues so long as you have all the feeders wired the same way (inside rail is always the Rail A connection, outside rail is always Rail B). You'll probably want TWO crossovers, so you can get back from the inside to outside loop. Look at the plan for my old 8x12, it's all DCC, I did put insulated joiners where the two turnouts of the crossovers touch, and that's it.