When I have done this I used it in a figure 8 set up. What you want to happen is for the train entering from one loop to change both switches at the same time and then go to the other loop. The as it comes back around tot he first switch it auto flips to be correct as it enters and switches the other to be the out bound on the other loop. Sounds like it should work. Now for how.
When wired together, as a train enters one switch it needs to turn the second as well and then as it goes over the second there should be no switching. Thus no derailment. If the outbound train on the second switch is turning the first switch under the train that is the bad result you mention. There are only two wires need to do this interconnect. these wires need to either connect the same posts on each switch or cross the posts. What you need is the second switch outbound track let's say the straight leg, to be connected to the first switch inside track, the curved leg. One post is connected to each of the insulated rails on the switch. So as a train comes into the first switch curved track it sets the second switch to straight. AS the switch goes out the 2nd switch nothing should happen to the switch and the train goes into the outside loop from the straight side. Then as the train comes around on the outside loop to the first switch it flips and also flips the second switch to the inside loop.
It should be a matter of connecting the control posts together. the ground, third post is not needed, or can be connected together. This should run automatic and not need a switch controller.
For what it is worth.
Scott
I have set up a track layout using a set of 1122 switches that are cross-wired to alternate between two loops. As the train passes over the master switch it simultaneously resets the slave switch to the alternate loop. This works great on the long outside loop and when the train length is less than the distance between the two inner loop switch points. However, in that the two switches activate simultaneously, the slave switch moves to the outside loop as the train passes over the master switch while in the inner loop, thus derailing the train which is still passing over the slave switch. Is there some way to either keep the slave switch from activating while the train is still on it? I've tried switching wires around, but it either works as it is wired, or not at all. Is there some way to jumper something?