Loop to Loop

[Anonymous]

I am new to this hobby as you can tell by my other posts. I some day want to have a 2 loop (1 outer and 1 inner ) layout (FasTrack) with 2 transformers (one for each loop). I would like to be able to run the outer loop train on the inner loop and visa-versa. I would have to make blocks on the inner loop switches correct? Would both trains be running off of one transformer for a brief time or would they stop at the blocks? I am so confused about blocks.

[thor]

Think of it like an airlock. The outer door must be closed before you open the inner one and vice versa. Your 'block' is the airlock. You have to set it up so that it can take the length of your longest train, assuming live pickup wheelsets or the length of the longest locomotive and tender or dummy (if using non conductive rolling stock). The train is driven off the inner loop using the inside transformer until its onto the block, then the rear switch goes to OFF and the front one ON so the outer loop transformer can take up the control function.

However, that won't be enough if you're using two trains, one on each loop, beause you'll have to isolate the other train or shunt it off onto a siding if you don't want to end up running two trains on the same transformer.

Sometimes I find it helps to draw out the operation on paper so you can more easily visualize which goes where.

[Anonymous]

I would need 4 switches? Two for outer to inner and two for inner to outer at opposite ends of the layout? I would have to make the track between the switches as long as the train?

[jakeoregano]

Joncoy, you might want to pick up a book called Greenberg's Wiring Your Lionel Layout by Peter H. Riddle, Ph.D. In it it describes a layout with an inner and outer loop and transitions to transfering trains to and from each. It shows what you need and how to wire it. I find it very helpful, since I'm a newbie when it comes to a layout that deviates from a circle. I don't have any online pix of the layout in the book, but perhaps someone on this forum does.

Good luck.
Dwayne.

[lionelsoni]

The popular way to do it is simply to connect one transformer to one loop, the other transformer to the other. To get from one to the other, throw the switches, set both transformers to the same voltage, and run across the crossover. I have often recommended against this. It creates a fault current at the gap between blocks unless the transformers are accurately set to the same voltage. If you use a Lionel transformer with two controls (not your situation), there is in addition no overcurrent protection at all against that fault current.

A better and safer approach is to connect the center rail of each block to the common terminal of a single-pole-double-throw electrical switch. Then connect the other terminals of each switch to the two transformer output terminals. (Connect all the outside rails together and to the common side of the transformer.) Then each switch controls which transformer powers its block. You can obviously extend this to any number of blocks and, with more complicated switches, to more than two transformer controls. A nice touch is to mount the switches on a map of the layout.