Insulated Railjoiners

I have a simple ovel with a branch to the outside. It runs around my christmas tree. Looks pretty sweet. Any ways i have a string of cars on the oval with two locomotives on it. On the branch i have a 4-8-4 steamer, but now its a2-8-4 thanks to some 4-6 year-old kids i didn’t even know. ANY WAYS when i swithed the locomotives around i’d make the two desiels go the steamer would move too. I experimented with the switch a bit but that wasn’t it. So i’m wondering, do i need insulated joiners on the on the no frog rails on each side. The mainline rails.

Thanks PJK

Yes, the branch needs to be insulated from the oval. An on off switch can be wired to the branch to cut the power to it.