If I use two power routing switches say Kato #4s. (DC Layout). Do I leave the siding without any track feeders since the juice is coming from the main? Also with two power routing switches must both turnouts at each end need to be lined for the same route to prevent a short?
Yes, both turnouts will need to be thrown to the desired route. I suggest that you gap the rails on both the siding and the main if you plan on two trains passing at this location. Therefore you will need feeders on both the main and the siding. I only power route on industrial spurs.
