Electrical Considerations with Figure 8 Track Layout

[Gary Allen]

I am new to HO track.  It appears to me that, since the track rails are asymmetrical with respect to electrical power, a figure 8 layout might pose some restrictions.  If I call the 2 electrical conductors A and B, is it true that conductor A resides on the outboard rail on one half of the figure 8 and on the inboard rail on the other half?  If this is true, I assume I would not be able to connect the two halves of the figure 8 with two turnouts (switches), else I would create a short circuit.  I would have to create a double figure 8 using two crossing tracks and connect the two outer lobes of the dual figure 8 via turnouts?

[jonathan]

Your initial assessment is true.  You would be creating a 'reverse loop' on a figure 8, causing a short.  There are ways to electrically deal with a reverse loop.  However, if you are just starting out in HO, that may be a frustrating way to start out.

Your other description sounds like you are thinking about a 'double-track' figure 8.  This would require using 4 crossing pieces, but will remain electrically sound.  Then a 'crossover', using two turnouts, is a little easier, moving from an inner loop to an outer loop.

Another option is to keep a figure 8 on the inside, then lay an oval on the outside.  A single crossover from the inner to the outer loop will be relatively easy.  Two crossovers could create another reverse loop situation.

I hope that answers your questions. I hope I understood what information you were after.

Regards,

Jonathan

[rich1998]

Gary Allen

Post a diagram of what you would like to do.
You will need a photo hosting site to do that.
A photo is worth a thousand words.

Rich

[Ken Huck]

There is no reverse loop created in a figure eight.  The train continues to go in the
same direction.  It does not 'turn around', nor do the wheels switch 'sides'.

HTH

Ken

[Terry Toenges]

Gary - Is this like what you are talking about?

[Gary Allen]

Terry, yes, this is basically what I was considering.  But it appears to me that the turn-out paths will create short circuits.

[Terry Toenges]

Since that is the case, Jonathan is correct in that you will have reverse loops which will have to be wired different. A lot of these folks are more knowledgeable about the wiring aspects than I am.

[jonathan]

If you have your heart set on that configuration, you will have to gap the tracks in the middle, starting at the end of the divergent rails at each turnout. You will also need some sort of way to change the polarity of the oval while the locomotive is running through the middle of the figure eight. It can be done, but I wonder if you will find this troublesome or a fun challenge.

I like reverse loops just enough to use one on my layout sometimes, but it's not a regular requirement to operate my layout. It's a personal choice we have to make.

Regards,

Jonathan

[Gary Allen]

I see now, in a more general sense, any path that reverses the direction of the train will create this "short circuit" problem.  50 years ago, my Lionel Super-O train set didn't have this problem due to the symmetrical power rails.  It also had a nice feature on the electrical turn-outs (switches).  If you drove the train in to the Y end of the turnout with the turnout switched in the wrong direction, it would automatically immediately switch to accommodate the train without derailing it.  Too bad the Bachmann turnouts don't have this feature.  I read that you could simply run the train over the Bachmann turnout with it switched in the wrong direction and the train would not derail.  That has not been my experience.

[Len]

Lionel 'O' doesn't have reverse loop or wye problems because it has three rails. The center rail is 'hot' and both outside rails are tied together for the 'return'. So even with a reverse loop, no short is created. Plus it uses AC power, so there's no polarity issue. Same with Marklin HO equipment.

If you used 'live' catenary, or outside 3rd rail, electric operation it would also eliminate the problem. Except you would be limited to electric locos, e.g., GG-1, E-33, or dual mode locos like the FL-9 that could operate as an electric or diesel, that were configured to operate off catenary or 3rd rail.

Len